EUROCODES. Background and Applications. EN 1997 Eurocode 7: Geotechnical design. Dissemination of information for training workshop

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1 Dissemination of information for training workshop February 2008 Brussels EN 1997 Eurocode 7: Geotechnical design Organised by European Commission: DG Enterprise and Industry, Joint Research Centre with the support of CEN/TC250, CEN Management Centre and Member States

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3 Wednesday, February 20 Palais des Académies EN Eurocode 7: Geotechnical design Bordet room 9:00-10:00 General presentation of EC 7 Geotechnical design part 1 General rules R. Frank Ecole Nationale des Ponts et Chaussées 10:00-11:00 Section 2: Basis of geotechnical design B. Schuppener Bundesanstalt für Wasserbau 11:00-11:15 Coffee 11:15-12:15 Section 3 Geotechnical data and 6 Spread foundations 12:15-14:00 Lunch T. Orr Trinity College Dublin 14:00-15:00 Section 7 Pile foundations R. Frank Ecole Nationale des Ponts et Chaussées 15:00-16:00 Section 8 Anchorages and Section 9 Retaining structures 16:00-16:15 Coffee 16:15-17:15 Section 10 Hydraulic failure, Section 11 Overall stability and Section 12 Embankments 17:15-18:15 Eurocode 7 part 2: Ground investigation and testing B. Simpson Arup T. Orr Trinity College Dublin B. Schuppener Bundesanstalt für Wasserbau All workshop material will be available at

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5 GEOTECHNICAL DESIGN PART 1 GENERAL RULES R. Frank Ecole Nationale des Ponts et Chaussées

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7 Brussels, February 2008 Dissemination of information workshop 1 Brussels, February 2008 Dissemination of information workshop 2 Workshop Eurocodes: background and applications Brussels, February 2008 General presentation of EUROCODE 7 Geotechnical design 1. Introduction 2. Contents of Eurocode 7 - Parts 1 & 2 3. Some aspects of Eurocode 7-1 Characteristic values ULS Design Approaches SLS Serviceability limit states Roger FRANK, Professor Ecole nationale des ponts et chaussées, Paris STRUCTURAL Brussels, February 2008 Dissemination of information workshop 3 Brussels, February 2008 Dissemination of information workshop 4 EN 1990 EN 1991 EN 1992 EN 1993 EN 1994 EN 1995 EN 1996 EN 1999 Basis of Structural design Actions on structures «Material» resistance Eurocode 7 Geotechnical design EN (2004) : Part 1 - General rules EN (2007) : Part 2 - Ground investigation and testing EN 1997 EN 1998 Geotechnical and seismic design Contents of Part 1 (EN ) Brussels, February 2008 Dissemination of information workshop 5 Brussels, February 2008 Dissemination of information workshop 6 2. Contents of Eurocode 7 Parts 1 & 2 Section 1 General Section 2 Basis of geotechnical design Section 3 Geotechnical data Section 4 Supervision of construction, monitoring and maintenance Section 5 Fill, dewatering, ground improvement and reinforcement

8 Brussels, February 2008 Dissemination of information workshop 7 Contents of Part 1 (cntd) Informative annexes Brussels, February 2008 Dissemination of information workshop 8 Section 6 Spread foundations Section 7 Pile foundations Section 8 Anchorages Section 9 Retaining structures Section 10 Hydraulic failure Section 11 Site stability Section 12 Embankments Annex C Active earth pressure Annexes D & E : Bearing capacity of foundations R/A' = c' N c b c s c i c + q' N q b q s q i q + 0,5 γ' B ' N γ b γ s γ i γ R /A' = σ v0 + k p le Annex C Passive earth pressure Annex F : Settlement of foundations s = p b f / E m Contents of Part 2 (EN ) Brussels, February 2008 Dissemination of information workshop 9 Part 2 (EN ): Geotechnical design - Ground investigation and testing Laboratory and field tests : essential requirements for the equipment and tests procedures essential requirements for the reporting and the presentation of results interpretation of test results and derived values They are NOT test standards see TC 341 Brussels, February 2008 Dissemination of information workshop 10 Section 1 General Section 2 Planning and reporting of ground investigations Section 3 Drilling, sampling and gw measurements Section 4 Field tests in soils and rocks Section 5 Laboratory tests on soils and rocks Section 6 Ground investigation report > Also a number of Informative annexes Brussels, February 2008 Dissemination of information workshop Some aspects of Eurocode 7-1 Characteristic values and design values ULS Design Approaches SLS and deformations of structures Brussels, February 2008 Dissemination of information workshop 12 Type of test F= field L= laboratory Correlations Test results and derived values EN EN Geotechnical properties F 1 F 2 L 1 L 2 C1 C Cautious selection Geotechnical model and characteristic value of geotechnical properties Application of partial factors Information from other sources on the site, the soils and rocks and the project Design values of geotechnical properties

9 Brussels, February 2008 Dissemination of information workshop 13 Characteristic value of geotechnical parameters P The characteristic value of a geotechnical parameter shall be selected as a cautious estimate of the value affecting the occurrence of the limit state. If statistical methods are used, the characteristic value should be derived such that the calculated probability of a worse value governing the occurrence of the limit state under consideration is not greater than 5%. Brussels, February 2008 Dissemination of information workshop 14 Design values of geotechnical parameters Design value of a parameter : X d = X k / γ M Design values of actions and resistances fulfilling for STR/GEO ULS : E d R d E d = E {γ F.F k } and R d = R { X k / γ M } (= at the source, MFA) or E d = γ E.E { F k } and R d = R { X k } / γ R (RFA) Brussels, February 2008 Dissemination of information workshop 15 Ultimate limit states Eurocode 7-17 Brussels, February 2008 Dissemination of information workshop 16 EN Ultimate limit states EQU and STR/GEO EQU : loss of equilibrium of the structure STR : internal failure or excessive deformation of the structure or structural elements GEO : failure or excessive deformation of the ground UPL : loss of equilibrium due to uplift by water pressure (buoyancy) or other vertical actions HYD : hydraulic heave, internal erosion and piping caused by hydraulic gradients E d < R d J.A Calgaro STR/GEO : persistent and transient situations Brussels, February 2008 Dissemination of information workshop 17 Approach Combinations Action (γ F ) Symbol Set A1 Set A2 A1 + M1 + R1 1 Permanent & Unfavourable γ 1,35 1,00 G A2 + M2 + R1 Favourable γ G 1,00 1,00 2 Or A2 + M1 or M2 + R4 A1 + M1 + R2 Variable Unfavourable γ Q 1,50 1,30 3 A1 or A2 + M2 + R3 Favourable γ Q 0 0 Soil parameter (γ M ) Symbol Set M1 Set M2 Angle of shearing resistance γ ϕ 1,00 1,25 Effective cohesion γ c 1,00 1,25 Undrained shear strength γ cu 1,00 1,40 Unconfined strength γ qu 1,00 1,40 Weight density γ γ 1,00 1,00 Resistance (γ R ) Symbol Set R1 Set R2 Set R3 Bearing Portance γ Rv 1,00 1,4 1,00 γ R for Spread Sliding γ Rh 1,00 1,1 1,00 foundations Brussels, February 2008 Dissemination of information workshop 18 STR/GEO : accidental situations Actions : all values of γ F (and γ M ) = 1.0 Resistances : all values of γ R (and γ M ) depend on the particular accident Seismic situations: see Eurocode 8-5

10 Brussels, February 2008 Dissemination of information workshop 19 Ultimate limit states (UPL) Ultimate limit states (HYD) Brussels, February 2008 Dissemination of information workshop 20 buried hollow structure Water tight surface T b u W T T Anchored structure W P T Anchorage Sand Water tight surface slab below water level Sand Injected sand u Sand Heave due to seepage of water Water low permeability soil Permeable subsoil piezometric level in the permeable subsoil Piping Examples of situations where uplift might be critical σ v G dst;d + Q dst;d G stb;d + R d Sand Former ground surface b Sand Sand u dst;d σ stb;d Watertight surface u lightweight embankment during flood bottom Clay of an excavation Gravel W u Clay Clay Gravel Δu dst;d σ stb;d Example of situation where heave or piping might be critical Verifications of ULS Brussels, February 2008 Dissemination of information workshop 21 Ultimate limit states of static equilibrium (EQU) : E d,dst E d,stb Ultimate limit states of resistance (STR/GEO) : E d R d Ultimate limit state of uplift (UPL) : G dst;d + Q dst;d G stb;d + R d Ultimate limit state of hydraulic failure (HYD) : u dst;d σ stb;d or S dst;d G stb;d Brussels, February 2008 Dissemination of information workshop 22 EN Serviceability limit states SLS Verifications : E d C d C d = limiting design value of the relevant serviceability criterion E d = design value of the effects of actions specified in the serviceability criterion, determined on the basis of the relevant combination all γ F and γ M = 1.0 Conclusions Brussels, February 2008 Dissemination of information workshop 23 Movements and deformations of structures smax δ s max settlement s, differential settlement δs, rotation θ and angular strain α relative deflection Δ and deflection ratio Δ/L ω and relative rotation (angular distortion) β (after Burland and Wroth, 1975) Brussels, February 2008 Dissemination of information workshop 24 Eurocode 7 : - a tool to help European geotechnical engineers speak the same language - a necessary tool for the dialogue between geotechnical engineers and structural engineers Eurocode 7 helps promoting research - it stimulates questions on present geotechnical practice from ground investigation to design models

11 Brussels, February 2008 Dissemination of information workshop 25 Brussels, February 2008 Dissemination of information workshop 26 and to really conclude : It should be considered that knowledge of the ground conditions depends on the extent and quality of the geotechnical investigations. Such knowledge and the control of workmanship are usually more significant to fulfilling the fundamental requirements than is precision in the calculation models and partial factors. Thank you for your attention!

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13 SECTION 2: BASIS OF GEOTECHNICAL DESIGN B. Schuppener Bundesanstalt für Wasserbau

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15 Brussels, February 2008 Dissemination of information workshop 1 Brussels, February 2008 Dissemination of information workshop 2 EN 1997 Eurocode: Geotechnical design Section 2: Basis of geotechnical design Dr.-Ing. Bernd Schuppener, Federal Waterways Engineering and Research Institute, Karlsruhe, Germany 2 Basis of geotechnical design 2.1 Design requirements 2.2 Design situations 2.3 Durability 2.4 Geotechnical design by calculation 2.5 Design by prescriptive methods 2.6 Load tests 2.7 The Observational Method 2.8 The Geotechnical Design Report Annex A + B Brussels, February 2008 Dissemination of information workshop 3 Brussels, February 2008 Dissemination of information workshop Design requirements limit states (1)P For each geotechnical design situation it shall be verified that no relevant limit state, as defined in EN 1990:2002, is exceeded. (4) Limit states should be verified by one or a combination of the following: use of calculations as described in 2.4; adoption of prescriptive measures, as described in 2.5; experimental models and load tests, as described in 2.6; an observational method, as described in Design requirements Geotechnical Categories (8)P In order to establish minimum requirements for the extent and content of geotechnical investigations, calculations and construction control checks, the complexity of each geotechnical design shall be identified together with the associated risks. (10) To establish geotechnical design requirements, three Geotechnical Categories, 1, 2 and 3, may be introduced. Brussels, February 2008 Dissemination of information workshop 5 Brussels, February 2008 Dissemination of information workshop Design requirements Geotechnical Categories (14) Geotechnical Category 1 should only include small and relatively simple structures: for which it is possible to ensure that the fundamental requirements will be satisfied on the basis of experience and qualitative geotechnical investigations; with negligible risk. (9) For structures and earthworks of low geotechnical complexity and risk, such as defined above, simplified design procedures may be applied. 2.1 Design requirements Geotechnical Categories (17) Geotechnical Category 2 should include conventional types of structure and foundation with no exceptional risk or difficult soil or loading conditions. (18) Designs for structures in Geotechnical Category 2 should normally include quantitative geotechnical data and analysis to ensure that the fundamental requirements are satisfied. (19) Routine procedures for field and laboratory testing and for design and execution may be used for Geotechnical Category 2 designs.

16 Brussels, February 2008 Dissemination of information workshop 7 Brussels, February 2008 Dissemination of information workshop Design requirements Geotechnical Categories (20) Geotechnical Category 3 should include structures or parts of structures, which fall outside the limits of Geotechnical Categories 1 and 2. (21) Geotechnical Category 3 should normally include alternative provisions and rules to those in this standard. NOTE Geotechnical Category 3 includes the following examples: very large or unusual structures; structures involving abnormal risks, or unusual or exceptionally difficult ground or loading conditions; structures in highly seismic areas; structures in areas of probable site instability or persistent ground movements that require separate investigation or special measures. 2.2 Design Situations (EN ) (1)P Both short-term and long-term design situations shall be considered. Brussels, February 2008 Dissemination of information workshop 9 Brussels, February 2008 Dissemination of information workshop Durability (1)P At the geotechnical design stage, the significance of environmental conditions shall be assessed in relation to durability and to enable provisions to be made for the protection or adequate resistance of the materials. 2.4 Geotechnical design by calculation Characteristic values of geotechnical parameters (1)P The selection of characteristic values for geotechnical parameters shall be based on results and derived values from laboratory and field tests, complemented by well-established experience. (2)P The characteristic value of a geotechnical parameter shall be selected as a cautious estimate of the value affecting the occurrence of the limit state. Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters 4)P The selection of characteristic values for geotechnical parameters shall take account of the following:... the type and number of samples; the extent of the zone of ground governing the behaviour of the geotechnical structure at the limit state being considered; the ability of the geotechnical structure to transfer loads from weak to strong zones in the ground... Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters (10) If statistical methods are employed in the selection of characteristic values for ground properties, such methods should differentiate between local and regional sampling and should allow the use of a priori knowledge of comparable ground properties. (11) If statistical methods are used, the characteristic value should be derived such that the calculated probability of a worse value governing the occurrence of the limit state under consideration is not greater than 5%. NOTE In this respect, a cautious estimate of the mean value is a selection of the mean value of the limited set of geotechnical parameter values, with a confidence level of 95%; where local failure is concerned, a cautious estimate of the low value is a 5% fractile.

17 Brussels, February 2008 Dissemination of information workshop 13 Selection of characteristic values: Slope failure in a cut Brussels, February 2008 Dissemination of information workshop 14 Selection of characteristic values: c u = 76 MN/m² c u = 62 MN/m² c u = 65 MN/m² c u = 71 MN/m² c u = 68 MN/m² c u = 73 MN/m² c u = 76 MN/m² c u = 62 MN/m² c u = 65 MN/m² c u = 71 MN/m² c u = 68 MN/m² c u = 73 MN/m² c u = 50 MN/m² c u = 60 MN/m² c u = 64 MN/m² c u = 50 MN/m² c u = 60 MN/m² c u = 64 MN/m² c u = 55 MN/m² c u = 75 MN/m² c u = 55 MN/m² c u = 75 MN/m² Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters Determination of the characteristic value X k by statistical methods: X k = X mean (1 - k n V x ) Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters Number n of test results s x Mean of test results X mean s x Normal distribution through tests results where X mean arithmetical mean value of the parameter values; V x the coefficient of variation k n statistical coefficient which depends on the number n of test results, the level of confidence and a priori knowledge about the coefficient of variation (case V x unknown or V x known ). X k (local) X k (mean) X mean X mean k n,fractile V x X mean k n,mean V x Value of parameter Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters Determination of characteristic values proposed by Schneider (1999): X k = X mean -0.5 s x Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters Example: results of triaxial tests used for the selection of the characteristic values using statistical methods (V x unknown) Borehole / test Statistical result c [kpa] [ ] tan [-] BH 1/ ,601 BH 1/ ,577 BH 2/ ,700 BH 2/ ,532 Mean value c mean = 3.75 (tan )mean = Standard deviation sc = 2.50 s = Coefficient of variation Vc = Vtan = 0.118

18 Brussels, February 2008 Dissemination of information workshop 19 Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Characteristic values of geotechnical parameters Table: summary of the statistical evaluation of the example Basis and method of statistical evaluation and c of 4 tests for the case V x unknown and c of 4 tests for the case V x known Characteristic values of shear parameter k [ ] c k [kpa] Schneider (1999) Geotechnical design by calculation Actions (1)P The definition of actions shall be taken from EN 1990:2002. The values of actions shall be taken from EN 1991, where relevant. Section 1 of EN : Geotechnical action Action transmitted to the structure by the ground, fill standing water or groundwater. Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Actions NOTE (to (9)P) Unfavourable (or destabilising) and favourable (or stabilising) permanent actions may in some situations be considered as coming from a single source. If they are considered so, a single partial factor may be applied to the sum of these actions or to the sum of their effects. Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation Actions W top W bottom W d= W bottom dst -W top stb W d,dst = (W bottom -W top ) dst Brussels, February 2008 Dissemination of information workshop Geotechnical design by calculation characteristic values geotechnical parameter actions design values geotechnical ultimate limit states design approaches DA1, DA2 and DA 3 serviceability limit states Brussels, February 2008 Dissemination of information workshop Design values of actions (2)P The design value of an action (F d ) shall either be assessed directly or shall be derived from representative values F rep using the following equation: F d = F F rep (2.1a) with F rep = F k (2.1b) where F is the partial factor on geotechnical actions or effects of geotechnical actions and is a combination factor. (3)P Appropriate values of shall be taken from EN 1990:2002.

19 Brussels, February 2008 Dissemination of information workshop Design values of actions (2)P The design value of an action (F d ) shall either be assessed directly or shall be derived from representative values F rep using the following equation: F d = F F rep (2.1a) with F rep = F k (2.1b) where F is the partial factor on geotechnical actions or effects of geotechnical actions and is a combination factor. (4)P The partial factor F for persistent and transient situations defined in Annex A shall be used in equation (2.1a). Brussels, February 2008 Dissemination of information workshop Design values of actions NOTE The values to be ascribed to G and Q for use in a country may be found in its National annex to EN The recommended values for buildings in EN 1990:2002 for the two sets A1 and A2 are given in Table A.3. Table A.3: Partial factors on actions ( F ) or the effects of actions ( E ) Permanent Variable Action Unfavourable Favourable Unfavourable Favourable Symbol G Q A1 1,35 1,0 1,5 0 Set A2 1,0 1,0 1,3 0 Brussels, February 2008 Dissemination of information workshop Design values of geotechnical parameters (1)P Design values of geotechnical parameters (X d ) shall either be derived from characteristic values using the following equation: X d = X k / M (2.2) or shall be assessed directly. (2)P The partial factor M for persistent and transient situations defined in Annex A shall be used in equation (2.2). Brussels, February 2008 Dissemination of information workshop Design values of geotechnical parameters Table A.4 - Partial factors for soil parameters ( M ) Set Soil parameter Symbol M1 M2 Shearing resistance 1 1,0 1,25 Effective cohesion c 1,0 1,25 Undrained strength cu 1,0 1,4 Unconfined strength qu 1,0 1,4 Unit weight density 1,0 1,0 Brussels, February 2008 Dissemination of information workshop General Ultimate limit states (1)P Where relevant, it shall be verified that the following limit states are not exceeded:.. failure or excessive deformation of the ground, in which the strength of soil or rock is significant in providing resistance (GEO); loss of equilibrium of the structure or the ground due to uplift by water pressure (buoyancy) or other vertical actions (UPL); hydraulic heave, internal erosion and piping in the ground caused by hydraulic gradients (HYD). Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR (1)P When considering a limit state of rupture or excessive deformation of a structural element or section of the ground (STR and GEO), it shall be verified that: E d R d (2.5) E d : the design value of the effects of all the actions; R d : the design value of the corresponding resistance of the ground and/or structure.

20 Brussels, February 2008 Dissemination of information workshop 31 Load and Resistance Factor Approach R d E d R k ( k, c k) / R E k ( k, c k) E R k : characteristic values of ground resistance R : partial factor for the ground resistance E k : characteristic value of the effect of action E : partial factor for the effect of action or the action k,c k: characteristic values of the shear parameter Brussels, February 2008 Dissemination of information workshop 32 Design values of shear parameter k, c k characteristic value of shear parameter d, c d design values of the shear parameter c tan d = (tan k) / c d = c k / c partial factor for the angle of shearing resistance partial factor for the cohesion intercept Brussels, February 2008 Dissemination of information workshop 33 Material Factor Approach R d ( d, c d) E d ( d, c d) Brussels, February 2008 Dissemination of information workshop 34 Example for the three Design Approaches of EN Q k G k q k R d : E d d c d design value of the ground resistance design value of the effects of actions of the ground design value of the angle of shearing resistance design value of the cohesion intercept E G E Q V, H, M R v = (V, H, M,, c ) R v,d V d Brussels, February 2008 Dissemination of information workshop 35 Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR Verification of resistance for GEO and STR Design Approach 1 Design Action or effects of actions Approach structure ground 1 Resistance ground Design Action or effects of actions Resistance Approach Structure Ground ground Comb. 1 G = 1.35; G,inf = 1.00; Q = 1.50 = c = Comb. 2 G = 1.00; Q = 1.30 = c = G = 1.35; G,inf = 1.00; Q = 1.50 R;e = R;v = 1.40 R;h = G = 1.35; G,inf =1.00 Q = 1.50 = c = G = 1.35; G,inf = 1.00; Q = 1.50 R;e = R;v = 1.40 R;h = G = 1.35; G,inf =1.00 Q = 1.50 = c = 1.25

21 Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR Design Approach 1 Combination 1 Combination 2 Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR Design Approach 2 Q d = Q Q k = 1.50 Q k G d = G G k = 1.35 G k R v,d q d = Q q k = 1.50 q k = c = 1.0 d = k, c d = c k E Q,d = E Q ( k, c k, q d ) E G,d = G E G ( d,c d)=1.35e G ( k,c k) V d,h d,h d, d, M d d = R v (V d, H d,m d, d, c d) R v,d V d R v,d Q d = Q Q k = 1.30 Q k G d = G G k = 1.00 G k q d = Q q k = 1.30 q k tan d = tan k/ = tan k/1.25 c d = c k / c = c k / 1.25 E Q,d = E Q ( d, c d, q d ) E G,d = G E G ( d, c d) = 1.00 E G ( d, c d) V Vd d,h,h d, d, M d d = R v (V d, H d,m d, d, c d) Design Action or effects of actions Approach Structure Ground 1 Resistance ground Comb. 1 G = 1.35; G,inf = 1.00; Q = 1.50 = c = 1.0 Comb. 2 G = 1.0; Q = 1.30 = c = G = 1.35; G,inf = 1.00; Q = 1.50 R;e = R;v = 1.40 R;h = G = 1.35; G,inf =1.00 Q = 1.50 = c = 1.25 Brussels, February 2008 Dissemination of information workshop 39 Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR Design Approach 2 DA 2 Q d = Q Q k = 1.50 Q k G d = G G k = 1.35 G k q d = Q q k = 1.50 q k = c = 1.00 d = k, c d = c k E Q,d = E Q ( d, c d, q d ) E G,d = G E G ( d, c d)=1.35e G ( k,c k) Q k G k DA 2 q k = c = 1.0 d = k, c d = c k E Q,k = E Q ( k, c k, q k ) E G,k = E G ( k, c k) Verification of resistance for GEO and STR Design Approach 3 Design Action or effects of actions Resistance Approach Structure Ground ground Comb. 1 G = 1.35; G,inf = 1.00; Q = 1.50 = c = Comb. 2 G = 1.0; Q = 1.30 = c = 1.25 V d,h d,h d, d, M d d R v,k = F(M d, V d, H d, d, c d) R v,d = R v,k / Rv = R v,k /1.40 R v,d V d V k,h k,h k, k, M k k V d = G V G,k + Q V Q,k V d = 1.35 V G,k V Q,k R v,k= (M k, V k, H k, k, c k) R v,d = R v,k= / Rv = R v,k / G = 1.35; G,inf = 1.00; Q = 1.50 R;e = R;v = 1.40 R;h = G = 1.35; G,inf =1.00 Q = 1.50 = c = 1.25 Brussels, February 2008 Dissemination of information workshop Verification of resistance for GEO and STR Design Approach 3 Q d = Q Q k = 1.50 Q k G d = G G k = 1.35 G k q d = Q q k = 1.30 q k tan d = tan k/ = tan k/1.25 c d= c k/ E Q,d = E Q ( d, c d, q d ) c = c k / 1.25 E G,d = G E G ( d,c d) = 1.00 E G ( d,c d) V d = V G,d +V Q,d R v,d = (V d, H d, d, c d) R v,d V d Brussels, February 2008 Dissemination of information workshop Serviceability limit states (1)P Verification for serviceability limit states in the ground or in a structural section, element or connection, shall either require that: E d C d, (2.10) or be done through the method given in (4). E d : effects of the actions e.g. deformations, differential settlements, vibrations etc. C d : limiting values (2) Values of partial factors for serviceability limit states should normally be taken equal to 1,0. (5)P This limiting value shall be agreed during the design of the supported structure

22 Brussels, February 2008 Dissemination of information workshop 43 Brussels, February 2008 Dissemination of information workshop 44 Annex H (informative) Limiting values of structural deformation and foundation movement (2) The maximum acceptable relative rotations for open framed structures, infilled frames and load bearing or continuous brick walls are unlikely to be the same but are likely to range from about 1/2000 to about 1/300, to prevent the occurrence of a serviceability limit state in the structure. A maximum relative rotation of 1/500 is acceptable for many structures. The relative rotation likely to cause an ultimate limit state is about 1/ Observational method (1) When prediction of geotechnical behaviour is difficult, it can be appropriate to apply the approach known as "the observational method", in which the design is reviewed during construction. (2)P The following requirements shall be met before construction is started: acceptable limits of behaviour shall be established; the range of possible behaviour shall be assessed and it shall be shown that there is an acceptable probability that the actual behaviour will be within the acceptable limits; Brussels, February 2008 Dissemination of information workshop 45 Brussels, February 2008 Dissemination of information workshop Observational method a plan of monitoring shall be devised, which will reveal whether the actual behaviour lies within the acceptable limits. The monitoring shall make this clear at a sufficiently early stage, and with sufficiently short intervals to allow contingency actions to be undertaken successfully; the response time of the instruments and the procedures for analysing the results shall be sufficiently rapid in relation to the possible evolution of the system; a plan of contingency actions shall be devised, which may be adopted if the monitoring reveals behaviour outside acceptable limits. 2.8 Geotechnical Design Report (1)P The assumptions, data, methods of calculation and results of the verification of safety and serviceability shall be recorded in the Geotechnical Design Report. (2) The level of detail of the Geotechnical Design Reports will vary greatly, depending on the type of design. For simple designs, a single sheet may be sufficient. Brussels, February 2008 Dissemination of information workshop Geotechnical Design Report Brussels, February 2008 Dissemination of information workshop 48 Summary Job Title New start housing development Structure Reference: Strip foundations Report used: Ground Investigation report (give ref. date) Factual: Bloggs Investigations Ltd report ABC/123 dated 21 Feb 95 Interpretation: Ditto Codes and standards used (level of acceptable risk) Eurocode 7 Local building regs Description of site surroundings: Formerly agricultural land. Gently sloping (4 ) Calculations (or index calculations) Characteristic load 60 kn/m. Local experience plus Local Building Regulations (ref..) indicates working bearing pressure of 100 kpa acceptable. Therefore adopt footings 0.6 m wide, minimum depth 0.5 m (Building Regs) but depth varies to reach c u 60 kpa test on site. Job No. Sheet no of Made by: Date Checked by: Date Approved by: Date Section through structure showing actions: Assumed stratigraphy used in design with properties: Topsoil and very weathered glacial till up to 1 m thick, overlying firm to stiff glacial till (c u 60 kpa on pocket penetrometer). Information to be verified during construction. Notes on maintenance and monitoring. Concrete cas on un-softened glacial till with c u 60 kpa (pocket penetrometer) Section 2: Basis of geotechnical design: introduces Geotechnical Categories as options, describes geotechnical design situations defines characteristic values of geotechnical actions and the selection of ground parameter defines geotechnical ultimate limit states defines three Design Approaches as options and introduces the Observational Method as an equivalent geotechnical design method

23 Brussels, February 2008 Dissemination of information workshop 49 Thank you

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25 SECTION 3 GEOTECHNICAL DATA AND 6 SPREAD FOUNDATIONS T. Orr Trinity College Dublin

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33 SECTION 7 PILE FOUNDATIONS R. Frank Ecole Nationale des Ponts et Chaussées

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35 Brussels, February 2008 Dissemination of information workshop 1 Workshop Eurocodes: background and applications Brussels, Februray 2008 Design of pile foundations following Eurocode 7-Section 7 Roger FRANK, Professor Ecole nationale des ponts et chaussées, Paris Contents of Part 1 (EN ) Brussels, February 2008 Dissemination of information workshop 2 Section 1 General Section 2 Basis of geotechnical design Section 3 Geotechnical data Section 4 Supervision of construction, monitoring and maintenance Section 5 Fill, dewatering, ground improvement and reinforcement Section 6 Spread foundations Section 7 Pile foundations Section 8 Anchorages Section 9 Retaining structures Section 10 Hydraulic failure Section 11 Site stability Section 12 Embankments Informative annexes Brussels, February 2008 Dissemination of information workshop 3 Section 7 of EN Brussels, February 2008 Dissemination of information workshop 4 EN : E A sample semi-empirical method for bearing resistance estimation H Limiting foundation movements and structural deformation EN : D.7 Example of a method to determine the compressive resistance of a single pile (CPT) D.6 Example of a correlation between compressive resistance of a single pile and cone penetration resistance E.3 Example of a method to calculate the compressive resistance of a single pile (PMT) Pile load tests Axially loaded piles - ULS compressive or tensile resistance ( bearing capacity ) - Vertical displacements of pile foundations: serviceability of the supported structure Transversely loaded piles Structural design of piles Specificity of pile foundations Brussels, February 2008 Dissemination of information workshop 5 Need to take into account the actions due to ground displacement : - downdrag (negative skin friction) - heave - transverse loading the design values of the strength and stiffness of the moving ground should usually be upper values the ground displacement is treated as an action and an interaction analysis is carried out, or an upper bound of the force transmited by the ground is introduced as the design action. General Brussels, February 2008 Dissemination of information workshop 6

36 Brussels, February 2008 Dissemination of information workshop 7 Pile load tests Brussels, February 2008 Dissemination of information workshop 8 Axially loaded piles Brussels, February 2008 Dissemination of information workshop 9 Brussels, February 2008 Dissemination of information workshop 10 ULS Compressive or tensile resistance of piles (bearing capacity) Brussels, February 2008 Dissemination of information workshop 11 Brussels, February 2008 Dissemination of information workshop 12 ULS - From static load test results Ultimate compressive resistance from static load tests (8)P For structures, which do not exhibit capacity to transfer loads from "weak" piles to "strong" piles, as a minimum, the following equation shall be satisfied: ( R ) ( R ) c;m mean c;m min R c; k = Min ; (7.2) ξ1 ξ2 where ξ1 and ξ2 are correlation factors related to the number of piles tested and are applied to the mean (Rc;m) mean and the lowest (Rc;m )min of Rc;m respectively. Characteristic resistance from measured resistances Table A.9 - Correlation factors ξ to derive characteristic values from static pile load tests (n - number of tested piles) ξ for n = ξ1 1,40 1,30 1,20 1,10 1,00 ξ2 1,40 1,20 1,05 1,00 1,00 NOTE The values of the correlation factors may be set by the National annex. The recommended values are given in Table A.9.

37 Brussels, February 2008 Dissemination of information workshop 13 ULS From ground test results : Model pile method Ultimate compressive resistance from ground test results (5)P The characteristic values Rb;k and Rs;k shall either be determined by: ( R ) ( R ) Rb;cal + Rs;cal Rc;cal c;cal mean c;cal min R c; k = ( Rb;k + Rs;k ) = = = Min ; (7.8) ξ ξ ξ3 ξ4 where ξ3 and ξ4 are correlation factors that depend on the number of profiles of tests, n, and are applied respectively: to the mean values (Rc;cal )mean = (Rb;cal + Rs;cal)mean = (Rb;cal)mean + (Rs;cal)meanand to the lowest values (Rc;cal )min = (Rb;cal + Rs;cal)min, Brussels, February 2008 Dissemination of information workshop 14 Characteristic resistance from calculated resistances Table A.10 - Correlation factors ξ to derive characteristic values from ground test results (n - the number of profiles of tests) ξ for n = ξ3 1,40 1,35 1,33 1,31 1,29 1,27 1,25 ξ4 1,40 1,27 1,23 1,20 1,15 1,12 1,08 NOTE The values of the correlation factors may be set by the National annex. The recommended values are given in Table A.10. Brussels, February 2008 Dissemination of information workshop 15 ULS From ground test results : Alternative method Brussels, February 2008 Dissemination of information workshop 16 ULS - Permanent and transient design situations - Load factors Ultimate compressive resistance from ground test results (8) The characteristic values may be obtained by calculating: Rb;k = Ab qb;k and Rs;k = As; i qs; i ; k (7.9) i where qb;k and qs;i;k are characteristic values of base resistance and shaft friction in the various strata, obtained from values of ground parameters. NOTE If this alternative procedure is applied, the values of the partial factors γb and γs recommended in Annex A may need to be corrected by a model factor larger than 1,0. The value of the model factor may be set by the National annex. Brussels, February 2008 Dissemination of information workshop 17 ULS - Permanent and transient design situations - Resistance factors Design resistance Brussels, February 2008 Dissemination of information workshop 18 Characteristic value : R k = R / ξ where R = γ Rd R cal or R = R m (1) Design value : R d = R k /γ t or R d = R bk /γ b + R sk /γ s (2) Applied compression/tension load : F d = γ F F k (3) General condition for ULS being : F d R d (4) equations (1) to (4) lead to : F k R / γ F.γ t.ξ = R / FS (5)

38 Brussels, February 2008 Dissemination of information workshop 19 Piles in compression : Piles in group Brussels, February 2008 Dissemination of information workshop 20 Piles in tension : Brussels, February 2008 Dissemination of information workshop 21 Vertical displacements of pile foundations (serviceability of supported structure) Vertical displacements under SLS conditions must be assessed and checked against limiting value : Piles in compression - downdrag must be taken into account - settlement due to group action must be taken into account Piles in tension - check upward displacements in the same manner Brussels, February 2008 Dissemination of information workshop 22 Example from pile load test results (Orr, 2005) Settlement (mm) Pile Load (MN) Load Test 2 Load Test 1 Pile Load Test Results Load Settlement Settlement (MN) Pile 1(mm) Pile 2 (mm) driven piles B = 0.40 m D = 15.0 m allowable settlement is 10 mm loads : G k = 20,000 kn and Q k = 5,000 kn Results Brussels, February 2008 Dissemination of information workshop 23 SLS Serviceability check Brussels, February 2008 Dissemination of information workshop 24 From Table, for n = 2 pile load tests : for n = 2 pile load tests : ξ 1 = 1.30 and ξ 2 = 1.20 R k = Min{5.3/1.30; 5.0/1.20} = Min{4.08; 4.17} = 4.08 DA : F d = 26.5 MN and R d = 3.14 MN. 9 piles are needed (neglecting group effects) & DA1-1 1 : F d = 34.5 MN and R d = piles are also needed (neglecting group effects) DA 2 : F d = 34.5 MN and R d = 3.71 MN 10 piles are needed (neglecting group effects). G k + Q k = 25 MN load per pile : through analysis of the 2 load curves for s < 10 mm Same analysis as for ULS (ξ 1 = 1.30 and ξ 2 = 1.20) leads to R k = Min{3.25/1.30; 3.0/1.20} = 2.5 MN thus, 10 piles are needed (neglecting group effects)

39 Brussels, February 2008 Dissemination of information workshop 25 Transversely loaded piles Adequate safety against failure (ULS) F tr R tr One of the following failure mechanisms should be considered : - short piles : rotation or translation as a rigid body - for long slender piles : bending failure of the pile with local yielding and displacement of the soil near the top of the pile Brussels, February 2008 Dissemination of information workshop 26 Transverse resistance R tr : from head transverse displacement pile load test from ground tests results and pile strength parameters The theory of beams with subgrade reaction moduli can be used Transverse displacement Brussels, February 2008 Dissemination of information workshop 27 Conclusions Brussels, February 2008 Dissemination of information workshop 28 The following must be taken into account: - non linear soil : E(ε) - flexural stiffness of the piles : EI - fixity conditions (connections) - group effect - load reversals and cyclic loading Designing pile foundations with Eurocode 7 : importance of static pile load tests an innovative approach to pile capacity taking account of number of load tests or number of soil profiles need of assessing serviceability of structures through displacement calculations Brussels, February 2008 Dissemination of information workshop 29 Thank you for your attention!

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41 SECTION 8 ANCHORAGES SECTION 9 RETAINING STRUCTURES B. Simpson Arup

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43 BP106.9 EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 1 EN Eurocode 7 Section 8 Anchorages Section 9 Retaining structures Brian Simpson Arup Geotechnics EN Geotechnical design General Rules BP111.5 BP112.6 BP124-T General 2 Basis of geotechnical design 3 Geotechnical data 4 Supervision of construction, monitoring and maintenance 5 Fill, dewatering, ground improvement and reinforcement 6 Spread foundations 7 Pile foundations 8 Anchorages 9 Retaining structures 10 Hydraulic failure 11 Overall stability 12 Embankments Appendices A to J 2 8 Anchorages BP124-F General 8.2 Limit states 8.3 Design situations and actions 8.4 Design and construction considerations 8.5 Ultimate limit state design 8.6 Serviceability limit state design 8.7 Suitability tests 8.8 Acceptance tests 8.9 Supervision and monitoring

44 7 8 8 Anchorages Section depends on EN Execution of special geotechnical work - Ground anchors Not fully compatible with EN1537. Further work on this is underway. BS8081 being retained for the time being EN1537:1999 Execution of special geotechnical work - Ground anchors EN1537:

45 EN1537:1999 Execution of special geotechnical work - Ground anchors - provides details of test procedures (creep load etc) Partial factors in anchor design Partial factors in anchor design EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 16 EN Eurocode 7 Section 8 Anchorages Section 9 Retaining structures Brian Simpson Arup Geotechnics 15 EN1997-1: Anchorages and Retaining structures EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 17 Brussels, February 2008 Dissemination of information workshop 18 EN Eurocode 7 Section 9 Retaining structures Fundamentals Design Approaches Main points in the code text Examples: Comparisons with previous (UK) practice Comparison between Design Approaches Lessons from the Dublin Workshop EN Eurocode 7 Section 9 Retaining structures Fundamentals Design Approaches Main points in the code text Examples: Comparisons with previous (UK) practice Comparison between Design Approaches Lessons from the Dublin Workshop 3

46 Genting Highlands BP87.59 BP BP BP BP BP124-F3.9 BP BP145a.8 Genting Highlands BP87.60 BP BP BP BP BP124-F3.10 BP BP145a.9 BP87.61 BP BP BP BP BP124- F3.11 BP BP145a.10 BP BP BP FOS > 1 for characteristic soil strengths - but not big enough The slope and retaining wall are all part of the same problem. BP87.62 BP BP124-F3.12 BP BP145a.11 Structure and soil must be designed together - consistently ISGSR First International Symposium on Geotechnical Safety and Risk Approaches to ULS design The merits of Design Approach 1 in Eurocode 7 Brian Simpson Arup Geotechnics BP145a.1 EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 24 EN Eurocode 7 Section 9 Retaining structures Fundamentals Design Approaches Main points in the code text Examples: Comparisons with previous (UK) practice Comparison between Design Approaches Lessons from the Dublin Workshop 23 4

47 BP111.5 BP112.6 BP124-T1.31 EN Geotechnical design General Rules BP Retaining structures 1 General 2 Basis of geotechnical design 3 Geotechnical data 4 Supervision of construction, monitoring and maintenance 5 Fill, dewatering, ground improvement and reinforcement 6 Spread foundations 7 Pile foundations 8 Anchorages 9 Retaining structures 10 Hydraulic failure 11 Overall stability 12 Embankments 9.1 General 9.2 Limit states 9.3 Actions, geometrical data and design situations 9.4 Design and construction considerations 9.5 Determination of earth pressures 9.6 Water pressures 9.7 Ultimate limit state design 9.8 Serviceability limit state design Appendices A to J Limit states 9.2 Limit states Geometrical data Geometrical data 100% 100% 10% 10%

48 9.4 Design and construction considerations 9.4 Design and construction considerations Drainage systems 9.5 Determination of earth pressures Determination of earth pressures Limiting values of earth pressure Annex C also provides charts and formulae for the active and passive limit values of earth pressure

49 Annex C Sample procedures to determine limit values of earth pressures on vertical walls Wall friction Based on Caquot and Kerisel (and Absi?). No values for adverse wall friction, which can lead to larger K a and much smaller K p. Adverse wall friction may be caused by loads on the wall from structures above, inclined ground anchors, etc C.2 Numerical procedure for obtaining passive pressures Ka, Kp charts in Simpson & Driscoll Also provides Ka Programmable formulae (though not simple) Incorporated in some software (eg Oasys FREW, STAWAL) Precise source not known (to me), but same values as Lancellotta, R (2002) Analytical solution of passive earth pressure. Géotechnique 52, Covers range of adverse wall friction. Slightly more conservative than Caquot & Kerisel when φ and δ/φ large but more correct? Comparison with Caquot & Kerisel 9.7 Ultimate limit state design Ka(C&K) / Ka(EC7) % Kp(C&K) / Kp(EC7) %

50 9.7.2 Overall stability Foundation failure of gravity walls Rotational failure of embedded walls Vertical failure of embedded walls Structural design of retaining structures Structural design of retaining structures

51 BP BP BP BP BP124-F3.15 BP Failure by pull-out of anchorages 9.8 Serviceability limit state design Displacements EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 52 EN Eurocode 7 Section 9 Retaining structures Fundamentals Design Approaches Main points in the code text Examples: Comparisons with previous (UK) practice Comparison between Design Approaches Lessons from the Dublin Workshop 51 8m propped wall BP m propped wall - data BP CASE: DA1 DA1 EC SLS Unplanned overdig (m) Dig level: Stage Stage Characteristic φ' ( ) γ (or M) on tan φ' Design φ' δ'/φ' active δ'/φ' passive Ka Factor on Ka Design Ka Kp Factor on Kp Design Kp Excd. side Retd. side 1.0 γq

52 BP BP BP BP124-F3.16 BP BP BP BP124-F BP BP124- F3.17 BP BP BP BP124-F3.19 BP BP m propped wall - length and BM BP78.28 Redistribution of earth pressure BP87.75 CASE: DA1 DA1 EC SLS Unplanned overdig (m) Design φ' Design Ka Design Kp Excd. side Retd. side γq Computer program STW STW F Data file PROP11 PROP1 BCAP3A Wall length (m) Max bending moment (knm/m) Factor on bending moment ULS design bending moment (knm/m) Computed Assumed Compare CIRIA 104 BP kPa (13kPa) 0-8m (-8.5m) φ = 24 (19.6 ) kN/m xbcap5-feb07c Event 3 Run 3 Increment 1 11: : Bending moment Bending moment [knm/m] Scale x 1:101 y 1:13681 y coordinate (x = m) 8m propped wall - length and BM BP78.32 CASE: BS DA1 DA1 EC7 DA1 DA1 DA1 DA1 CIRIA Fs CIRIA Fs SLS Unplanned overdig (m) Design φ' Design Ka Design Kp Excd. side Retd. side γq Computer program STW STW STW STW STW FREW FREW FREW FREW SAFE Data file PROP4 PROP5 PR1B-03 PROP11 PROP1 BCAP3A BCAPBA BCAP1A BCAP4A XBCAP5 Wall length (m) Max bending moment (knm/m) ## Factor on bending moment ? ULS design bending moment (knm/m) ? Computed Assumed ## Not used in design 59 10

53 BP BP124- F3.22 BP BP BP BP124- F3.20 BP BP124-F3.24 BP78.34 BP BP BP BP124- F3.21 BP124-F3.25 BP BP m excavation - comparison of methods Redistribution of earth pressure BP Length (m) BM/50 Prop F/ CIRIA 104 BS8002 EC7-STW EC7- FREW EC7- SAFE German practice for sheet pile design - EAB (1996) BP87.39 Weissenbach, A, Hettler, A and Simpson, B (2003). Stability of excavations. In Geotechnical Engineering Handbook, Vol 3: Elements and Structures (Ed U Smoltczyk). Ernst & Sohn / Wiley m SAFE Grundbau2 BP q=80kpa Grundbau in STAWAL BP Bending Mom ent [knm /m ] φ k =35 γ= 17 kn/m 3 δ/φ = 2/3 (active) K a = γ = 20 kn/m Weissenbach, A, Hettler, A and Simpson, B (2003) Stability of excavations. In Geotechnical Engineering Handbook, Vol 3: Elements and Structures (Ed U Smoltczyk). Ernst & Sohn / Wiley.? 3.32m 8m Reduced Level [m] kN/m [1] [2] [2] Toe m Sh ear Moment Water Pressure Actual Pressures Scale x 1:128 y 1:128 Pressure [kpa] Shear Force [kn/m ]

54 BP130.3 BP124- F3.26 BP130.1 BP130.4 BP130.2 Grundbau: DA1 and DA2 XBP EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop EN Eurocode L=10.7 L=10.6 Section 9 Retaining structures 200 Penetration cm BM knm/m Strut force kn/m Fundamentals Design Approaches Main points in the code text 50 0 Char DA1-1 DA1-2 DA2 Examples: Comparisons with previous (UK) practice Comparison between Design Approaches C:\bx\Grundbau\Prague\[grundbau.xls] Lessons from the Dublin Workshop 67 Eurocode 7 Workshop Dublin, 31 March to 1 April 2005 Organised by European Technical Committee 10 Technical Committee 23 of ISSMGE GeoTechNet Working Party 2 Retaining Wall Examples 5 to 7 Example 5 Cantilever Gravity Retaining Wall 6m 0.75m Sand 0.4m Surcharge 15kPa Fill B =? 20 o Design situation - 6m high cantilever gravity retaining wall, - Wall and base thicknesses 0.40m. - Groundwater level is at depth below the base of the wall. - The wall is embedded 0.75m below ground level in front of the wall. - The ground behind the wall slopes upwards at 20 o Soil conditions - Sand beneath wall: c'k = 0, φ'k = 34 o, γ = 19kN/m 3 - Fill behind wall: c'k = 0, φ'k = 38 o, γ = 20kN/m 3 Actions - Characteristic surcharge behind wall 15kPa Require - Width of wall foundation, B - Design shear force, S and bending moment, M in the wall Example 5 Example 5 Surcharge 15kPa Surcharge 15kPa 20 o 20 o 6m 0.4m Fill 20 o 6m 0.4m Fill 20 o 0.75m K a γz 0.75m K a γz Sand B =? Sand B =?

55 BP130.5 BP124.A6.12 BP130.5 BP124.A6.11 BP130.5 BP124.A6.12 Example 5 Cantilever Gravity Retaining Wall BASE WIDTH m b 1=3 2 N Example 5 - Gravity wall 1 3 N 2 1 N 1 N N N N 2 2=N G C C C C C C C C:\BX\BX-C\EC7\Dublin\[Dublin-results.xls] N 1, 2 or 3 EC7 DA1, DA2 or DA3 b EC7 DA1 Comb 1 only N national method b b Contributor Example 5 Cantilever Gravity Retaining Wall BP m 0.75m Sand 0.4m Surcharge 15kPa Fill B =? 20 o Design situation - 6m high cantilever gravity retaining wall, - Wall and base thicknesses 0.40m. - Groundwater level is at depth below the base of the wall. - The wall is embedded 0.75m below ground level in front of the wall. - The ground behind the wall slopes upwards at 20 o Soil conditions - Sand beneath wall: c'k = 0, φ'k = 34 o, γ = 19kN/m 3 - Fill behind wall: c'k = 0, φ'k = 38 o, γ = 20kN/m 3 Actions - Characteristic surcharge behind wall 15kPa Require - Width of wall foundation, B - Design shear force, S and bending moment, M in the wall Additional specifications provided after the workshop: 1 The characteristic value of the angle of sliding resistance on the interface between wall and concrete under the base should be taken as 30º. 2 The weight density of concrete should be taken as 25 kn/m3. 3 The bearing capacity should be evaluated using to the EC7 Annex D approach. 4 The surcharge is a variable load. 5 It should be assumed that the surcharge might extend up to the wall (ie for calculating bending moments in the wall), or might stop behind the heel of the wall, not surcharging the heel (ie for calculating stability) Example 5 Cantilever Gravity Retaining Wall Example 5 Cantilever Gravity Retaining Wall Example 5 - Gravity wall 6.0 BASE WIDTH m b 1=3 2 N 1 3 N 2 1 N 1 N N N N 2 N 2=N 1 2 b b E C C C C C C C γ E E{γ F F rep ; X k /γ M ; a d } = E d R d = R{γ F F rep ; X k /γ M ; a d }/γ R C:\BX\BX-C\EC7\Dublin\[Dublin-results (version 1).xls] 23-Jun-05 00: Example 5 Cantilever Gravity Retaining Wall Example 5 Cantilever Gravity Retaining Wall Example 5 - Gravity wall Column no Base width Column no. 1 Characteristic values of all parameters Eccentricity (m) Effective width B' (m) Vertical force kn/m Horizontal force kn/m Inclination H/V R (kn/m) γ(r) Rd (kn/m) Rd/Vd See note Column no. 2 Column no. 3 Column no. 4 Column no. 5 Characteristic eccentricity and inclination; forces and resistance factored. Characteristic eccentricity; unfavourable (horizontal) force and resistance factored. Favourable (vertical) force not factored in deriving inclination or for comparison with resistance. Unfavourable (horizontal) force and resistance factored. Favourable (vertical) force not factored in deriving inclination or eccentricity, but factored for comparison with resistance. Unfavourable (horizontal) force and resistance factored. Favourable (vertical) force not factored in deriving inclination or eccentricity, or for comparison with resistance. BENDING MOMENT knm/m =3 1 b 2 1 N 1 N N G C C C C C C C N N 2=N b b C:\BX\BX-C\EC7\Dublin\[Dublin-results.xls] 27-Jun-05 21:

56 BP124.A6.14 BP130.8 BP Example 5 Cantilever Gravity Retaining Wall Example 5 - Gravity wall SHEAR FORCE kn/m =N N 200 b b b 1 N N N 150 N E C C C C C C C Example 5 Cantilever Gravity Retaining Wall Serviceability: No criteria in the instructions Mainly ignored ½(K a + K 0 )? Middle third? Very large range of results Importance of sequence of calculation and factoring this is the main difference between the design approaches for this problem Factors of safety must allow for errors and misunderstanding C:\BX\BX-C\EC7\Dublin\[Dublin-results (version 1).xls] 23-Jun-05 00: Example 6 Embedded sheet pile retaining wall BP130.9 Example 6 Embedded sheet pile retaining wall BP130.9 Sand 10kPa 1.5m 3.0m D=? Design situation - Embedded sheet pile retaining wall for a 3m deep excavation with a 10kPa surcharge on the surface behind the wall Soil conditions - Sand: c'k = 0, φ'k = 37 o, γ = 20kN/m 3 Actions - Characteristic surcharge behind wall 10kPa - Groundwater level at depth of 1.5m below ground surface behind wall and at the ground surface in front of wall Require - Depth of wall embedment, D - Design bending moment in the wall, M Sand 10kPa 1.5m 3.0m D=? Design situation - Embedded sheet pile retaining wall for a 3m deep excavation with a 10kPa surcharge on the surface behind the wall Soil conditions - Sand: c'k = 0, φ'k = 37 o, γ = 20kN/m 3 Actions - Characteristic surcharge behind wall 10kPa - Groundwater level at depth of 1.5m below ground surface behind wall and at the ground surface in front of wall Require - Depth of wall embedment, D - Design bending moment in the wall, M Additional specifications provided after the workshop: 1 The surcharge is a variable load. 2 The wall is a permanent structure Example 6 Embedded sheet pile retaining wall BP Example 7 Anchored sheet pile quay wall Huge range of results Values of Kp? C&K / EC7 / Coulomb?? What about overdig? (5) Less severe values than those recommended in Annex A may be used for temporary structures or transient design situations, where the likely consequences justify it. Kp(C&K) / Kp(EC7) % 10kPa 1.5m Tie bar anchor GWL 3.3m Sand 8,0m Water 3.0m D =? Design situation - Anchored sheet pile retaining wall for an 8m high quay using a horizontal tie bar anchor. Soil conditions - Gravelly sand - φ'k = 35 o, γ = 18kN/m 3 (above water table) and 20kN/m 3 (below water table) Actions - Characteristic surcharge behind wall 10kPa - 3m depth of water in front of the wall and a tidal lag of 0.3m between the water in front of the wall and the water in the ground behind the wall. Require - Depth of wall embedment, D

57 BP87.78 BP BP BP BP99.90 BP BP BP BP Example 7 Anchored sheet pile quay wall 10kPa 1.5m Tie bar anchor GWL Sand 3.3m 8,0m D =? 3.0m Water Design situation - Anchored sheet pile retaining wall for an 8m high quay using a horizontal tie bar anchor. Soil conditions - Gravelly sand - φ'k = 35 o, γ = 18kN/m 3 (above water table) and 20kN/m 3 (below water table) Actions - Characteristic surcharge behind wall 10kPa - 3m depth of water in front of the wall and a tidal lag of 0.3m between the water in front of the wall and the water in the ground behind the wall. Require - Depth of wall embedment, D Additional specifications provided after the workshop: 1 The surcharge is a variable load. 2 The wall is a permanent structure. 3 The length of the wall is to be the minimum allowable. Example 7 Anchored sheet pile quay wall Example 7 - Bending moments BENDING MOMENT knm/m not the end of the design b b b b N N b 1 1 N N b 1 N N N N b b N b 2 N N N c 1 N N N b A A D B C C C C C C:\BX\BX-C\EC7\Dublin\[Dublin-results (version 1).xls] 23-Jun-05 00: Eurocode 3, Part 5 The significance of yield in structural elements BP Economies of up to 30% due to plastic design Example 7 Anchored sheet pile quay wall Large range of results SSI important Optimise: length, BM, anchor force? Design doesn t end at the bending moment Nobody considered SLS The wall must be 12m long. What tie force is required? BP

58 BP BP BP BP99.92 BP BP As a cantilever, length would be about 14m. BP BP99.91 DA1 Comb 2 gives a tie force of 75kN But characteristic calculation gives zero tie force, for 12m length. BP99.93 EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 94 EN Eurocode 7 Section 9 Retaining structures Fundamentals Design Approaches Slopes and walls all one problem Design Approaches matter! Main points in the code text Good basic check lists Values of K a and K p Overdig Not enough attention to SLS (by users, at least) Examples: Results broadly similar to existing practice DAs: big effect on gravity walls; small effect on embedded Lessons from the Dublin Workshop Very wide range of results Effect of DAs for gravity walls and K p for embedded Human error important partly offset by safety factors Need to work with EC EN1997-1: Anchorages and Retaining structures Brussels, February 2008 Dissemination of information workshop 95 EN Eurocode 7 Section 8 Anchorages Section 9 Retaining structures Brian Simpson Arup Geotechnics 16

59 SECTION 10 HYDRAULIC FAILURE SECTION 11 OVERALL STABILITY SECTION 12 EMBANKMENTS T. Orr Trinity College Dublin

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61

62 Δ σ γ γ Δ γ Δ γ γ Δ γ Δ σ Δ σ γ γ γ γ γ γ φ γ γ γ γ Δ γ γ σ γ γ γ γ γ γ γ γ γ γ γ γ γγ γ γ σ γ γ γ γ Δγ γγ γ γ γ γγ γ Δγ γ φ γ

63 τσ φσ δ δφ γ φ δ φ δφ φδ δφ σ δ σ γ φ δ φ δ δ δφδ φφ φ δφ δ φ σ δ σ σ σ = σ δ γ φ δ κ γ γ φ δ φ δ δ φ σ δ σ κ γ γ σ δ δ φφ γ Δ

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65 EUROCODE 7 PART 2: GROUND INVESTIGATION AND TESTING B. Schuppener Bundesanstalt für Wasserbau

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67 Brussels, February 2008 Dissemination of information workshop 1 Brussels, February 2008 Dissemination of information workshop 2 Eurocode 7 - Geotechnical design - Part 2 Ground investigation and testing Dr.-Ing. Bernd Schuppener, Federal Waterways Engineering and Research Institute, Karlsruhe, Germany Eurocode 7: Geotechnical design Part 1: General rules 2.4 Geotechnical design by calculation General (2) It should be considered that knowledge of the ground conditions depends on the extent and quality of the geotechnical investigations. Such knowledge and the control of workmanship are usually more significant to fulfilling the fundamental requirements than is precision in the calculation models and partial factors. Brussels, February 2008 Dissemination of information workshop 3 Brussels, February 2008 Dissemination of information workshop Scope of Eurocode 7-2 (1) EN is intended to be used in conjunction with EN and provides rules supplementary to EN related to: planning and reporting of ground investigations; general requirements for a number of commonly used laboratory and field tests; interpretation and evaluation of test results; derivation of values of geotechnical parameters and coefficients. Note: Establishment of characteristic values is covered in EN Hierarchy of standards EC 7 Geotechnical design - part 2 Ground investigation and testing EN ISO EN ISO EN ISO Field testing EN ISO Sampling and Part 1 to to Identification groundwater and measure- CEN classification of of ments ISO/TS Laboratory soil and rock tests Part 1-12 Brussels, February 2008 Dissemination of information workshop 5 Brussels, February 2008 Dissemination of information workshop 6 Content of Eurocode General 2. Planning of ground investigations 3. Soil and rock sampling and groundwater measurements 4. Field tests in soil and rock 5. Laboratory tests on soil and rock 6. Ground investigation report 1.5 Definitions Specific definitions used in EN derived value value of a geotechnical parameter obtained from test results by theory, correlation or empiricism (see 1.6) 23 Annexes

68 Brussels, February 2008 Dissemination of information workshop Test results and derived values Brussels, February 2008 Dissemination of information workshop 8 2 Planning of ground investigations 2.1 Objectives General Ground Construction materials Groundwater 2.2 Sequence of ground investigations 2.3 Preliminary investigations 2.4 Design investigations Field investigations Laboratory tests (dealt with later) 2.5 Controlling and monitoring Brussels, February 2008 Dissemination of information workshop Objectives General (1)P Geotechnical investigations shall be planned in such a way as to ensure that relevant geotechnical information and data are available at the various stages of the project. Geotechnical information... (6) Before designing the investigation programme, the available information and documents should be evaluated in a desk study. (7) Examples of information and documents that can be used are: geological maps and descriptions; previous investigations at the site and in the surroundings; aerial photos and previous photo interpretations; topographical maps; Brussels, February 2008 Dissemination of information workshop Objectives Ground (1)P Ground investigations shall provide a description of ground conditions relevant to the proposed works and establish a basis for the assessment of the geotechnical parameters relevant for all construction stages. (2) The information obtained should enable assessment of the following aspects, if possible: the suitability of the site with respect to the proposed construction and the level of acceptable risks; the deformation of the ground caused by the structure or resulting from construction works, its spatial distribution and behaviour over time; Brussels, February 2008 Dissemination of information workshop Objectives (2) The information obtained should enable assessment of the following aspects, if possible (continued): the safety with respect to limit states (e.g. subsidence, ground heave, uplift, slippage of soil and rock masses, buckling of piles, etc.); the loads transmitted from the ground to the structure (e.g. lateral pressures on piles) and the extent to which they depend on its design and construction; the foundation methods (e.g. ground improvement, whether it is possible to excavate, driveability of piles, drainage); the sequence of foundation works; the effects of the structure and its use on the surroundings; Brussels, February 2008 Dissemination of information workshop Objectives (2) The information obtained should enable assessment of the following aspects, if possible (continued): any additional structural measures required (e.g. support of excavation, anchorage, sleeving of bored piles, removal of obstructions); the effects of construction work on the surroundings; the type and extent of ground contamination on, and in the vicinity of, the site; the effectiveness of measures taken to contain or remedy contamination.

69 Brussels, February 2008 Dissemination of information workshop Objectives Ground water (3) The information obtained should be sufficient to assess the following aspects, where relevant: the scope for and nature of groundwater-lowering work; possible harmful effects of the groundwater on excavations or on slopes any measures necessary to protect the structure; the effects of groundwater lowering, desiccation, impounding etc. on the surroundings; the capacity of the ground to absorb water injected during construction work; whether it is possible to use local groundwater, given its chemical constitution, for construction purposes. Brussels, February 2008 Dissemination of information workshop Sequence of ground investigations Desk studies Preliminary investigations Design investigations Supervision of construction (EC 7-1) Controlling and monitoring Brussels, February 2008 Dissemination of information workshop Design investigations Locations and depths of the investigation points (2) When selecting the locations of investigation points, the following should be observed: the investigation points should be arranged in such a pattern that the stratification can be assessed across the site; the investigation points for a building or structure should be placed at critical points relative to the shape, structural behaviour and expected load distribution (e.g. at the corners of the foundation area); for linear structures, investigation points should be arranged at adequate offsets to the centre line, depending on the overall width of the structure, such as an embankment footprint or a cutting; Brussels, February 2008 Dissemination of information workshop Design investigations Locations and depths of the investigation points (2) When selecting the locations of investigation points, the following should be observed (continued): - for structures on or near slopes and steps in the terrain (including excavations), investigation points should also be arranged outside the project area, these being located so that the stability of the slope or cut can be assessed. - Where anchorages are installed, due consideration should be given to the likely stresses in their load transfer zone; the investigation points should be arranged so that they do not present a hazard to the structure, the construction work, or the surroundings (e.g. they may cause changes to the ground and groundwater conditions); Brussels, February 2008 Dissemination of information workshop Design investigations Locations and depths of the investigation points (2) When selecting the locations of investigation points, the following should be observed (continued): the area considered in the design investigations should extend into the neighbouring area to a distance where no harmful influence on the neighbouring area is expected; for groundwater measuring points, the possibility of using the equipment installed during the ground investigation for continued monitoring during and after the construction period should be considered. Brussels, February 2008 Dissemination of information workshop Design investigations (6)P The depth of investigations shall be extended to all strata that will affect the project or are affected by the construction. For dams, weirs and excavations below groundwater level, and where dewatering work is involved, the depth of investigation shall also be selected as a function of the hydro-geological conditions. For slopes and steps in the terrain shall be explored to depths below any potential slip surface. NOTE For the spacing of investigation points and investigation depths, the values given in Annex B.3 can be used as guidance.

70 Brussels, February 2008 Dissemination of information workshop 19 Annex B.3 Examples of recommendations for the spacing and depth of investigations (1) The following spacing of investigation points should be used as guidance: for high-rise and industrial structures, a grid pattern with points at 15 m to 40 m distance; for large-area structures, a grid pattern with points at not more than 60 m distance; for linear structures (roads, railways, channels, pipelines, dikes, tunnels, retaining walls), a spacing of 20 m to 200 m; for special structures (e.g. bridges, stacks, machinery foundations), two to six investigation points per foundation; for dams and weirs, 25 m to 75 m distance, along vertical sections. Brussels, February 2008 Dissemination of information workshop 20 Annex B.3 Examples of recommendations for the spacing and depth of investigations (2) For the investigation depth z a the following values should be used as guidance. (The reference level for z a is the lowest point of the foundation of the structure or structural element, or the excavation base.) Where more than one alternative is specified for establishing z a, the one which yields the largest value should be applied. NOTE For very large or highly complex projects, some of the investigation points should extend to greater depths than those specified under Annex B.3 (5) to B.3 (13). Brussels, February 2008 Dissemination of information workshop 21 Brussels, February 2008 Dissemination of information workshop 22 Annex B.3: Spacing and depth of investigations (5) For high-rise structures and civil engineering projects, the larger value of the following conditions should be applied: z a 6 m; z a 3,0 b F. where b F is the smaller side length of the foundation. Annex B.3: Spacing and depth of investigations (6) For raft foundations and structures with several foundation elements whose effects in deeper strata are superimposed on each other: z a 1,5 b B where b B is the smaller side of the structure, Brussels, February 2008 Dissemination of information workshop 23 Annex B.3: Spacing and depth of investigations Brussels, February 2008 Dissemination of information workshop 24 Annex B.3: Spacing and depth of investigations Road Trench (7) Embankments and cuttings, the larger value of the following conditions should be met: a) For dams: 0,8h < z a < 1,2h z a 6 m where h is the embankment height. b) For cuttings: z a 2,0 m z a 0,4h where h is the dam height or depth of cutting. For roads and airfields: z a 2 m below the proposed formation level. For trenches and pipelines, the larger value of: z a 2 m below the invert level; z a 1,5b Ah where b Ah is the width of excavation.

71 Brussels, February 2008 Dissemination of information workshop 25 Brussels, February 2008 Dissemination of information workshop 26 Annex B.3: Spacing and depth of investigations (9) For small tunnels and caverns: b Ab < z a < 2,0b Ab where b Ab is the width of excavation. The groundwater conditions described in (10) b) should also be taken into account. Annex B.3: Spacing and depth of investigations (10) Excavations a) Where the piezometric surface and the groundwater tables are below the excavation base, the larger value of the following conditions should be met: z a 0,4h z a (t + 2,0) m where: t is the embedded length of the support; and h is the excavation depth. Brussels, February 2008 Dissemination of information workshop 27 Annex B.3: Spacing and depth of investigations b) Where the piezometric surface and the groundwater tables are above the excavation base, the larger value of the following conditions should be met: z a (1,0H + 2,0) m z a (t + 2,0) m where H is the height of the groundwater level above the excavation base; and t is the embedded length of the support. Brussels, February 2008 Dissemination of information workshop 28 Annex B.3: Spacing and depth of investigations (12) For cut-off walls: z a 2 m below the surface of the stratum impermeable to groundwater. Brussels, February 2008 Dissemination of information workshop 29 Annex B.3: Spacing and depth of investigations (13) For piles the following three conditions should be met: z a 1,0b g z a 5,0 m z a 3D F where D F is the pile base diameter; and b g is the smaller side of the rectangle circumscribing the group of piles forming the foundation at the level of the pile base. Brussels, February 2008 Dissemination of information workshop Sampling (2)P For identification and classification of the ground, at least one borehole or trial pit with sampling shall be available. Samples shall be obtained from every separate ground layer influencing the behaviour of the structure. (3) Sampling may be replaced by field tests if there is enough local experience to correlate the field tests with the ground conditions to ensure unambiguous interpretation of the results. 2 Planning of ground investigations (7) Samples should be taken at any change of stratum and at a specified spacing, usually not larger than 3 m. In inhomogeneous soil, or if a detailed definition of the ground conditions is required, continuous sampling by drilling should be carried out or samples recovered at very short intervals.

72 Brussels, February 2008 Dissemination of information workshop 31 2 Planning of ground investigations 2.5 Controlling and monitoring (1)P A number of checks and additional tests shall be made during the construction and execution of the project, when relevant, in order to check that the ground conditions agree with those determined in the design investigations and that the properties of the delivered construction materials and the construction works correspond to those presumed or specified. (2)P The following control measures shall be applied: check of ground profile when excavating; inspection of the bottom of the excavation. Brussels, February 2008 Dissemination of information workshop Soil sampling (1)P Samples shall contain all the mineral constituents of the strata from which they have been taken. They shall not be contaminated by any material from other strata or from additives used during the sampling procedure. (2)P Three sampling method categories shall be considered (EN ISO ), depending on the desired sample quality as follows: category A sampling methods: samples of quality class 1 to 5 can be obtained; category B sampling methods: samples of quality class 3 to 5 can be obtained; category C sampling methods: only samples of quality class 5 can be obtained. Brussels, February 2008 Dissemination of information workshop Soil sampling (6)P Soil samples for laboratory tests are divided in five quality classes with respect to the soil properties that are assumed to remain unchanged during sampling and handling, transport and storage. Brussels, February 2008 Dissemination of information workshop Soil sampling Table Quality classes of soil samples for laboratory testing and sampling categories to be used Soil properties / quality class Unchanged soil properties particle size water content density, density index, permeability compressibility, shear strength Properties that can be determined: sequence of layers boundaries of strata broad boundaries of strata fine Atterberg limits, particle density, organic content water content density, density index, porosity, permeability compressibility, shear strength Sampling category according to EN ISO A B C Brussels, February 2008 Dissemination of information workshop 35 4 Field tests in soil and rock 4.1 General 4.2 General requirements 4.3 Cone penetration and piezocone penetration tests (CPT, CPTU) 4.4 Pressuremeter tests (PMT) 4.5 Flexible dilatometer test (FDT) 4.6 Standard penetration test SPT 4.7 Dynamic probing tests (DP) 4.8 Weight sounding test (WST) 4.9 Field vane test (FVT) 4.10 Flat dilatometer test (DMT) 4.11 Plate loading test (PLT) Brussels, February 2008 Dissemination of information workshop Cone penetration tests (1) The objective of the cone penetration test (CPT) is to determine the resistance of soil and soft rock to the penetration of a cone and the local friction on a sleeve. (2)P The CPT consists of pushing a cone penetrometer vertically into the soil using a series of push rods. The cone penetrometer shall be pushed into the soil at a constant rate of penetration. The cone penetrometer comprises the cone and if appropriate a cylindrical shaft or friction sleeve. The penetration resistance of the cone q c as well as, if appropriate, the local friction on the friction sleeve shall be measured.

73 Brussels, February 2008 Dissemination of information workshop Cone penetration and piezocone penetration tests (CPT, CPTU) Brussels, February 2008 Dissemination of information workshop Cone penetration and piezocone penetration tests (CPT, CPTU) q c cone resistance (bar) f s sleeve friction (bar) friction ratio R ft =100 F s /q c Sandy fill Porewater pressure measurement: u 1 : on the cone face u 2 : at the cylindrical extension of the cone u 3 : directly behind the friction sleeve fine and medium sand Glacial till Brussels, February 2008 Dissemination of information workshop Cone penetration and piezocone penetration tests (CPT, CPTU) q c cone penetration resistance friction ratio R ft = f S /q c 100 friction ratio R ft = f S /q c 100 Brussels, February 2008 Dissemination of information workshop Cone penetration tests - Annex D D.1 Example for deriving values of the effective angle of shearing resistance and drained Young s modulus D.2 Example of a correlation between the cone penetration resistance and the effective angle of shearing resistance D.3 Example of a method to determine the settlement for spread foundations D.4 Example of a correlation between the oedometer modulus and the cone penetration resistance D.5 Examples of establishing the stress-dependent oedometer modulus from CPT results D.6 Example of a correlation between compressive resistance of a single pile and cone penetration resistance D.7 Example of a method to determine the compressive resistance of a single pile. Brussels, February 2008 Dissemination of information workshop 41 Annex D Cone penetration tests Table D.1: Effective angle of shearing resistance ( ) and drained Young s modulus of elasticity (E ) from cone penetration resistance (q c ) a Values given are valid for sands. For silty soil a reduction of 3 should be made. For gravels 2 should be added. b E' is an approximation to the stress and time dependent secant modulus. Values given for the drained modulus correspond to settlements for 10 years. They are obtained assuming that the vertical stress distribution follows the 2:1 approximation. Brussels, February 2008 Dissemination of information workshop 42 5 Laboratory tests 5.1 General 5.2 General requirements for laboratory tests 5.3 Preparation of soil specimens for testing 5.4 Preparation of rock specimens for testing 5.5 Tests for classification, identification and description of soil 5.6 Chemical testing of soil and groundwater 5.7 Strength index testing of soil 5.8 Strength testing of soil 5.9 Compressibility and deformation testing of soil 5.10 Compaction testing of soil 5.11 Permeability testing of soil 5.12 Tests for classification of rocks 5.13 Swelling testing of rock material 5.14 Strength testing of rock material

74 Brussels, February 2008 Dissemination of information workshop Strength testing of soil - Annex P Table P.1 Triaxial compression tests. Recommended minimum number of tests for one soil stratum Brussels, February 2008 Dissemination of information workshop Compressibility and deformation testing of soil - Annex Q Table Q.1 Incremental oedometer test. Recommended minimum number of tests for one soil stratum Variability in Comparable experience oedometer modulus E oed (in the relevant stress range) None Medium Extensive Range of values of E oed 50 % % < Range of values of E oed < 50 % Range of values of E oed 20 % a a One oedometer test and classification tests to verify compatibility with comparable knowledge (see Q.1 (2)). Brussels, February 2008 Dissemination of information workshop 45 Brussels, February 2008 Dissemination of information workshop Permeability testing of soil Annex S Table S.1 - Permeability tests. Recommended minimum number of soil specimens to be tested for one soil stratum. Variability in measured coefficient of permeability (k) k max /k min > < k max /k min 100 k max /k min 10 Comparable experience None a A single test and classification tests to verify compatibility with existing knowledge Medium Extensive a 6 Ground investigation report 6.1 General requirements 6.2 Presentation of geotechnical information 6.3 Evaluation of geotechnical information 6.4 Establishment of derived values Brussels, February 2008 Dissemination of information workshop 47 Brussels, February 2008 Dissemination of information workshop 48 6 Ground investigation report 6.1 General requirements (1)P The results of a geotechnical investigation shall be compiled in the Ground Investigation Report which shall form a part of the Geotechnical Design Report. (2)P The Ground Investigation Report shall consist of, if appropriate a presentation of all available geotechnical information including geological features and relevant data; a geotechnical evaluation of the information, stating the assumptions made in the interpretation of the test results. 6 Ground investigation report 6.2 Presentation of geotechnical information (1)P The presentation of geotechnical information shall include a factual account of all field and laboratory investigations. (2) The factual account should include the following information, as relevant:......