Ref: SEL letter No. SEUSPV/CNINH-16/IFJTech/2016/62/2338 dated

Transcription

1 Si.- hapuri exp :;ssw&.y _:~.~SC Ltr No: SEIJSPV, C:-Jt:\1-I-16/IEIT ech/2016/62' 1248 Date: 2gth June 2016 To The Team Leader, JCT& SNC-Lavalin N, SarojiniNilayam, 151 Lane Annavarappadu, Ongole Sob: Six Laning of Chilakaluripet - Nellore Section of NH-16 from Km to (Length ) in the State of And.bra Pradesh under NHDP Phase V to be executed as BOT (Toll) Project on DBFOT Pattern-General arrangement drawing, foundation and substructure Design Drawings for RSR Minor bridge at Ch U as a part COS ID-Reg Ref: SEL letter No. SEUSPV/CNINH-16/IFJTech/2016/62/2338 dated Dear Sir, In continuation to our letter cited above, we herewith submitting the design & drawings for your review without prejudice to our rights under the Concession Agreement and in order to avoid delays in design review. SI No DrgNo Rev Drg Description Remarks 01 DDG 149 RA General arrangement of minor bridge for No of Girders right service road at ch Modified 02 DDB 170 RO Num.& RC of abutment Al & A2 of First Submission minor bridge for right service road at ch (sh 1 of2) 03 DDB 171 RO Num.& RC of abutment Al & A2 of First Submission minor bridge for right service road at ch (sh 2 of2) 04 DN 113 RO Design of Sub str for MIB@ First Submission (RSR) The detailed cost estimate will be submitted on approval of the drawings. Thanking you and assuring our best services at all times. Yours faithfully, lmcrcentinental Consultants & Tecpocr~ PnLuL \ Received On..?./1./.~./1.6.. WP~ Project Director Simbapuri Expressway Limited Encl: As above Cc. The Prnjecl Director; NHA:I Pill Ndlme. _ Project Office: Door No {4A), find Lane, Bhagya Nagar. Ongole, Prakasam "'-. KMC Tele: Fax: , E:simhapuriexpressway@gmail.com r ~ Register Office: D.No. 1-80/40/. SP/ Shilpa Homes Layout. Gachibowli, Hyderabad Ph: Fax: E:info@kmcgroup.co.in. BSCPL

2 L&T Infra Engineering

3 L&T Infra Engineering

4 L&T Infra Engineering

5 Client: L&T Infrastructure Engineering Ltd. Simhapuri Expressway Limited KMC BSCPL (Consortium), Banjara Hills, Hyderabad. Project: Six Laning of Chilkaluripet Nellore Section of NH 5 Title: Design of Abutment for Minor Ch: (Right Service road) This document is the property of L&T Infrastructure Engineering Ltd. (formerly known as L&T-Rambøll Consulting Engineers Limited) and must not be passed on to any person or body not authorised by us to receive it nor be copied or otherwise made use of either in full or in part by such person or body without our prior permission in writing. Notes: Project No.: Document No.: DN 113 Rev.: 0 File path: l:\roads\2010\c chilkaluripet-nellore project\inputs\calculations\structures\04. detailed design\minor bridges\r0- ara-minb at for right service road\docs\sub\dn 113-r0-ara.docx Revision Details: First submission ARA ARA SSM Init. Sign. Init. Sign. Init. Sign. Rev. Date Details Prepared Checked Approved

6 DN 113 rev. 0 TABLE OF CONTENTS Introduction Structural Arrangement Design Methodology Design basis Reference Code of Practice Materials Concrete Reinforcement Wearing coat Exposure Condition Loads Dead Loads Superimposed Dead Load (SIDL) Live loads Vehicle Collision Load Wind Loads (WL) Braking Force Bearing deformation force Earth pressure Seismic Forces Load Combinations Analysis and Design...5 LIST OF FIGURES Figure 1-1: Cross-sectional arrangement...1 Figure 1-2: Longitudinal sectional arrangement...2 Figure 1-3: Plan view of pile and pile cap...2 Figure 2-1: Girder Arrangement...4 Annexure-1 Scour Depth calculation LIST OF ENCLOSURES For Staad Files, refer DN 112-R0-ARA-Design of Superstructure Ch (RSR) L & T Infrasturestructure Engineering Ltd. Table of Contents Page i

7 DN 113 rev. 0 Introduction The Government of India through Ministry of Shipping, Road Transportation and Road Highway is augmenting the existing road to six-lane road in Chilkaluripet Nellore section of NH5 from km to km in the state of Andhra Pradesh, to enhance the capacity and safety for efficient transhipment of goods and passengers. This design note pertains to the analysis and design of abutments of minor bridge at km for Right service road. In this note, structural design has been presented. 1.1 Structural Arrangement The general arrangement of the structure is as shown in drawings DDG-149. The superstructure consists of 6 numbers of PSC I-girders, with cast-in-situ slab. This Design note pertains to Abutment A1 & A2. The abutment is a wall type supported on 9 numbers of 1m diameter piles. The bearings are placed over the abutment cap. The dimensions of different segment of substructures are shown in figure. Figure 0-1: Cross-sectional arrangement L & T Infrasturestructure Engineering Ltd. 0 Introduction Page 1

8 DN 113 rev. 0 Figure 0-2: Longitudinal sectional arrangement Figure 0-3: Plan view of pile and pile cap L & T Infrasturestructure Engineering Ltd. 0 Introduction Page 2

9 DN 113 rev Design Methodology The following design methodology has been considered in the analysis and design of various structural elements. Dead loads, SIDL & Live load reactions are obtained from grillage model of the super structure. Earth pressure upto bottom of the pile cap is considered along with the live load surcharge. The Braking force & bearing deformation force due to the elastomeric bearings are also considered in the design. 2 Design basis 2.1 Reference Code of Practice 1. IRC: IRC: IRC: IRC: 83 (Part-II) IS Materials Concrete The grade of concrete (f ck ) considered for various elements is as below. Pedestal Pier & Pile cap Pile Modulus of Elasticity of Concrete M45 M35 M x f ck The unit weight of Reinforced Conc. 25 kn/m Reinforcement The grade of reinforcement considered is Fe 500 and its density assumed as 78.5 kn/m Wearing coat Wearing coat shall be 65 mm-thick comprising 25mm-mastic asphalt layer overlaid by 40mm bituminous concrete. Unit weight of the wearing coat material is taken as 22 kn/m Exposure Condition The condition of exposure has been considered as Moderate for the purpose of design. L & T Infrasturestructure Engineering Ltd. 2 Design basis Page 3

10 DN 113 rev Loads Dead Loads Dead loads are calculated according to their dimensions and unit weights as mentioned in section Superimposed Dead Load (SIDL) The super-imposed dead load consists of 65mm thick wearing coat, crash barrier and foot path handrail. Unit weight of the wearing coat material is taken as 22 kn/m Live loads As per Table 2 of IRC: , the superstructure has 2 lanes for movement of live loads for the given width of carriageway. For the Analysis and design of superstructure the following Load cases have been considered Table 2-1: Live Loads Considered for the analysis and design of substructure Live Load LL Case- 1 LL Case- 2 LL Case- 3 LL Case- 4 Details of the Load 70 R Eccentric to girder G6 70 R over Girder G3 1 Class A Eccentric to girder g6 2 Class A Eccentric to girder g Vehicle Collision Load Figure 2-1: Girder Arrangement Since the bridge piers are located in a riverbed, no carriageway is there in the vicinity. Hence, vehicle collision loads need not be considered. L & T Infrasturestructure Engineering Ltd. 2 Design basis Page 4

11 DN 113 rev Wind Loads (WL) Wind forces computed as per Clause 209 of IRC: have not been considered due to very low height of structure above the existing ground/water level Braking Force Braking force is considered as per the Clause 211of IRC: The calculation is shown in the calculation sheet Bearing deformation force Bearing friction force is calculated as per Clause of IRC: Earth pressure Earth pressure upto bottom of the pile cap is considered along with the live load surcharge Seismic Forces The project stretch lies in Zone III as per the seismic map. The Zone factor for the same has been taken as Longitudinal and transverse seismic coefficients are calculated as per Clause of IRC 6: Load Combinations The loads and load combinations are considered as per IRC 6:2014. The load cases and the combinations that are used in the analysis and design are shown in Section Analysis and Design The abutment is designed for the different type of loads coming from the superstructure, and the self-weight of soil and pile cap with suitable combination with seismic condition. The description of superstructure and STAAD model can be referred from superstructure design note no. DN 112. Since the abutment A1 is of greater height than abutment A2, the design is done for A1 and the same is adopted for A2. L & T Infrasturestructure Engineering Ltd. 3 Analysis and Design Page 5

12 3 Analysis & Design of Wall Abutment A1 (Applicable to Wall abutment A2) Input Data Length of Pile Cap (Along traffic - X direction) = 8.40 m Width of Pile Cap (Across traffic - Z direction) = 10 m Diameter of the pile = 1 m Depth of Pile Cap = 1.5 m Road reference FRL inner edge = 8.03 m Finished Road Level at the outer edge = m Thickness of wearing coat = m Thickness of deck slab = 0.2 m Depth of the Girder = 0.95 m CG of the Superstructure from top of the deck slab = m No of bearings = 6 m Thickness of the bearing = m Minimum Depth of the pedestal = m Height of Crash Barrier = 1.1 m C/C distance Between Bearings = 1.7 m C/C distance Between EJ & EJ = 23.8 m C/c span of Bearings- Effective span of the bridge = 21.4 m Width of the deck = 10 m Average Depth of Bearing pedestal = m Bed level = 2.67 m High Flood Level (HFL) = m Average Bearing top level = m Abutment cap top level = m Thickness of Abutment cap = m Length of Abutment = 10 m Length of Abutment considered for design = 1 m Level at the Bottom of Abutment cap = Level at the bottom of Pile cap = 1.17 Level at the Top of Pile cap = 2.67 Effective Size of the Abutment = 1.00 x 0.80 m Size of the bearing pedestal = 0.70 x 0.55 m Size of the Abutment cap = x m Safe capacity of piles = 305 T Velocity of the vehicle in KMPH V = 100 kmph Radius of curvature in meters R = m Bearing Arrangement: Wall Abutment A1 1.2 B1 B2 B3 B4 B5 B6 CL of EJ CL of Bearing L & T Infrastructure Engineering Ltd. Page 6

13 Transverse Section of Deck: CG of vehicle CG of super str % Gradient FRL CL of Abutment CG of Abutment cap CL of Pile Cap G.L 2.67 Transverse Section of the Structure : rtl = m Road Top Level = m Abt Cap Top Level = m Abt Cap Bottom Lvl = m High flood level = m CG of the Abutment gl = m Ground Level = m Pile Cap Top Lvl fdl = m Pile Cap Bottom Lvl L & T Infrastructure Engineering Ltd. Page 7

14 3.1.2 Material Properties Granular Backfill Unit weight of soil overburden above pilecap γ fill = 18.0 kn /m 3 Concrete Unit weight of Concrete for Design γ con = 25 kn /m 3 Grade of concrete in Pile & Pile Cap f ck = 35 N/mm 2 Grade of concrete for Abutment = 35 N/mm 2 Grade of steel reinforcement f y = 500 N/mm 2 Clear Cover to reinforcement = 75 mm Youngs modulus of concrete E = 3.15E+07 KN/m 2 modular ratio = Slenderness effect Slenderness of the Abutment is checked as per the clause of IRC: page 58. Slenderness in dirn Long. Trans. C/S area of the Abutment 8 8 m 2 Moment of Inertia of the Cross section m 4 Radius of gyration m 3 Maximum height of the Abutment (measured from top of pilecap to top of Abutment cap) m Effective Length Condition 1 Only Abt condition (Without Superstructure) 2L 2L 2 Superstructure on one side condition 1.75L 1.75L Abutment is checked for slenderness during service condition, hence effective len = L Effective length of the Abutment = m Slenderness ratio = < 50 < 50 Short column Short column Factor for reducing permissible stresses due to slenderness β = Permissible stresses Normal Wind Seismic Unit Permissible compressive stress in concrete N/mm 2 Permissible tensile stress in steel N/mm 2 Neutral axis depth factor Lever arm factor (j) Moment resistance factor (Q) As Per Table-1 of IRC 6:2014 Permissible stresses are increased by 33% in wind case and by 50% in seismic case. 3.2 Forces Calculation Reactions from Superstructure Sr. No. Load Case Bearing Reaction (kn) Brg 1 Brg 2 Brg 3 Brg 4 Brg 5 Brg 6 1 Dead Load SIDL Live load Reaction Without Impact i P max (LL) ii P min (LL) iii Max M T (LL) iv Max M L (LL) L & T Infrastructure Engineering Ltd. Page 8

15 Refer Staad Files: File 1-01-LL 70R Ecc G6 File 2-02-LL 70R on G3 File 3-03-LL 1 Class A Ecc File 4-04-LL 2 Class A Ecc Notation: P max (LL) - Maximum load case P min (LL) - Minimum load case Max M T (LL) - Maximum Transverse moment case Max M L (LL) - Maximum Longitudinal moment case Summary of Loads & Longitudinal Moments due to Superstructure V Longitudinal Moment M L at Sr. No. Load Case (kn) (kn/m) Lever arm (m) Pile Cap Top (knm/m) Lever arm (m) Pile Cap Bottom (knm/m) 1 Dead Load -Superstructure SIDL Live load Reaction Without Impact i P max (LL) ii P min (LL) iii Max M T (LL) iv Max M L (LL) Summary of Transverse Moment due to Superstructure Sr. No. Load Case (knm) (knm/m) (knm) (knm/m) 1 Dead Load -Superstructure SIDL Live load Reaction Without Impact M T (Top of Pile Cap) M T (Bottom of Pile Cap) i P max (LL) ii P min (LL) iii Max M T (LL) iv Max M L (LL) L & T Infrastructure Engineering Ltd. Page 9

16 3.2.2 Loads from Substructure Bearing pedestals = 17.7 kn Abutment cap =(( )-( ( ))) 25 = 45 kn/m Abutment stem = = 63 kn/m Abutment (Rectangular portion) for seismic =0.8 1 ( ) 25 = 63 kn/m Volume of Pile Cap Toe portion = = m 3 /m Volume of Pile Cap heel portion = = 7.5 m 3 /m Volume of pilecap below abutment portion = = m 3 /m Total Volume of Pile Cap = = m 3 /m Volume of soil above Toe portion = 0.0 m 3 Volume of soil above Heel portion up to GL = 0.0 m 3 Volume of soil behind the abutment =5.000 ( ) 1 = m 3 /m Total Volume of Soil above Footing = = m 3 /m C/S Area of Dirt Wall = = m 2 Weight of Dirt wall for per m length of Abutment = = kn/m Weight of Approach slab for per m length of Abt = /2 = kn/m Summary of Loads & Longitudinal Moments due to Substructure self weight Force Longitudinal Moment M L at Pilecap Pilecap Load Description Lever Arm Lever (kn/m) Top Bottom (m) Arm (m) (knm/m) (knm/m) Abutment Bearing pedestals Abutment cap Abutment stem Dirt wall Approach slab Abt (Rectangular port) for seismic Total for Abt bottom Pile Cap & Soil above Pile Cap Soil above pile cap Total Pile cap & Soil above Total Abt + Pilecap + Soil above Summary of Transverse Moment due to Substructure Load Description M T (Top of Pile Cap) (knm) M T (Bottom of Pile Cap) (knm) Bearing pedestals Abutment cap 0 0 Abutment 0 0 Dirt wall 0 0 Approach slab 0 0 Abt (Rectangular portion) curtailment - - Total for Abt bottom Total for curtailment level L & T Infrastructure Engineering Ltd. Page 10

17 Pile cap & Soil above Pile cap & Soil above 0 0 Soil above footing 0 0 Total Pile cap & Soil above 0 0 Total Abt + Pile cap + Soil above ANALYSIS OF ABUTMENT = Liveload Surcharge AEP = = = ( ) Earth Pressure Calculation : The following Earth pressure calculations are considered for the stability of Abutment Back Fill : Angle of slope of the embankment or backfill β = 0 deg Angle of internal friction φ = 35 deg Angle of friction with wall to soil δ = 0 deg Inclination of wall with respect to vertical α = 0.00 deg Cohesion c = 0 kn/m 2 Density of water γ W = 10 kn/m 3 Coefficient of active earth pressure in horizontal direction Normal case Ka = Cos 2 (f-a) * 1 '2 = Cos 2 a * Cos (d+a) 1+ Sin(f+d)*Sin(f-b) 1/2 Cos (a-b) * Cos(d+a) Active Earth Pressure Calculation on Seismic Case: As per clause of IS , The Active Earth Pressure exerted against the wall shall be P a = 0.5*w*h 2 *K a w = Unit Weight of Soil in kn/m 3 P a = Active Earth Pressure in kn/m length of wall h = Height of wall in m K a = (1+a v ) * Cos 2 (f-l-a) * 1 a v - Vertical Seismic Coefficient - its direction being taken consistently Cos l * Cos 2 a * Cos (d+a+l 1+Sin(f+d)*Sin(f-i-l) 1/2 Cos (a-i) * Cos(d+a+l) throughout the stability analysis of the wall and equal to 1/2*a h = l - tan -1 (a h /(1+a v ) = deg i - Slope of earth fill = 0 deg a h - Horizontal Seismic Coefficient = Coefficient of active earth pressure Ka = L & T Infrastructure Engineering Ltd. Page 11

18 Live load surcharge height = 1.2 m Summary of Active Earth presssure & Live Load Surcharge Description Normal Case Seismic Case Active Earth Pressure kn/m 2 kn/m 2 Pile Cap Bottom = ( ) = ( ) Live Load Surcharge = = Description Vertical Horizontal Load Lever Arm B.M Vertical (seismic) Horizontal Load (Seismic case) kn/m kn/m m knm/m kn/m kn/m knm/m B.M Active Earth Pressure Pile Cap Bottom Live Load Surcharge Pile Cap Bottom The following Earth pressure calculations are considered for the Stem. Back Fill : Angle of slope of the embankment or backfill β = 0 deg Angle of internal friction φ = 35 deg Angle of friction with wall to soil δ = deg Inclination of wall with respect to vertical α = deg Cohesion c = 0 kn/m 2 Density of water γ W = 10 kn/m 3 Coefficient of active earth pressure in horizontal direction Normal case Ka = Cos 2 (f-a) * 1 '2 = Cos 2 a * Cos (d+a) 1+ Sin(f+d)*Sin(f-b) 1/2 Cos (a-b) * Cos(d+a) Active Earth Pressure Calculation on Seismic Case: As per clause of IS , The Active Earth Pressure exerted against the wall shall be P a = 0.5*w*h 2 *K a w = Unit Weight of Soil in kn/m 3 P a = Active Earth Pressure in kn/m length of wall h = Height of wall in m K a = (1+a v ) * Cos 2 (f-l-a) * 1 a v - Vertical Seismic Coefficient - its direction being taken consistently Cos l * Cos 2 a * Cos (d+a+l 1+Sin(f+d)*Sin(f-i-l) 1/2 Cos (a-i) * Cos(d+a+l) throughout the stability analysis of the wall and equal to 1/2*a h = l - tan -1 (a h /(1+a v ) = deg i - Slope of earth fill = 0 deg a h - Horizontal Seismic Coefficient = Coefficient of active earth pressure Ka = Live load surcharge height = 1.2 m Summary of Active Earth presssure & Live Load Surcharge Description Normal Case Seismic Case Active Earth Pressure kn/m 2 kn/m 2 Pile Cap Top = = Live Load Surcharge = = L & T Infrastructure Engineering Ltd. Page 12

19 Description Vertical Horizontal Load Lever Arm B.M Vertical (seismic) Horizontal Load (Seismic case) kn/m kn/m m knm/m kn/m kn/m knm/m B.M Active Earth Pressure Pile Cap Top Live Load Surcharge Pile Cap Top Loads Due to Centrifugal Forces (F cf ) Centrifugal forces are calculated as per Clause:212.2 of IRC: Centrifugal Force = W V 2 127R W = Total Live load R = Radius of curvature in meters = m V = Velocity of the vehicle in KMPH = 100 kmph Lever arm to the CG of vehicle from pile cap top = = m Lever arm to the CG of vehicle from pile cap bottom = = m Summary of Transverse Forces due to Curvature Load Case Transverse Moment at Vertical Calculation H T Lever Arm Pilecap Lever Pilecap Load Top Arm Bottom kn/m kn/m m knm/m m knm/m P max (LL) 82 =82 100^2/ ( ) P min (LL) 23 Max M T (LL) 82 Max M L (LL) 82 =23 100^2/( ) =82 100^2/ ( ) =82 100^2/ ( ) Braking Force Braking force is estimated in accordance with Cl of IRC: Horizontal force due to braking and traction in 70R vehicle = 100 kn Horizontal force due to braking and traction in 1 Class A vehicle = 56 kn Horizontal force due to braking and traction in 2 Class A vehicles = 83 kn Lever arm for Pile Cap Top = m Lever arm for Pile Cap bottom = m Summary of Longitudinal Forces due to Braking force Longitudinal Moment at Load H L Lever Arm Pile Cap Top Lever Arm Pile Cap Bottom kn kn/m m knm m knm Braking force Forces due to Bearing deformation: Calculation of shear rating of bearings Overall breadth (longitudinal Direction b 0 = 225 mm Overall length (trans. Direction) l 0 = 400 mm Thickness of each layer of elastomer h i = 8 mm Number of internal elastomer layer n = 4 Nos. L & T Infrastructure Engineering Ltd. Page 13

20 Thickness of outer elastomer layer h e (=h i /2 <=6mm) = 4 mm Thickness of outer steel plate h s = 3/4/6 FOR h i <=8,10/12/16 3 mm Side elastomer cover h c = 6 mm Total elastomer thickness h =nh i +2h e = 40 mm Outer dimension (overall thickness) h 0 =h+(n+1)h s = 55 mm Eff. width of brg.(excluding cover) b =b 0-2h c = 213 mm Eff. length of brg.(excluding cover) l =l 0-2h c = 388 mm Eff.plan area of brg.(excluding cover) A =l * b = mm 2 Shear rating of elastomeric bearing Vr =GA/h = 2068 kn/m Total length of deck = m Total Strain = 5.00E-04 Translation in Longitudinal Direction = m Horizontal Force on the Abutment = V r x L c x No of Bearings = kn Increased to 10% as per Cl of IRC6:2014 Lever arm from bearing top to pilecap top = m Lever arm from bearing top to pilecap bottom = m Summary of Longitudinal Forces due to Bearing deformation Longitudinal Moment at Load H L Lever Arm Pile cap Top Lever Arm Pile cap Bottom kn kn/m m knm/m m knm/m Bearing Deformation force Wind Loads (W) I Wind without live load Total Length of the superstructure considered (Half span) = 11.9 m (a)wind Load on Superstructure Height of the crash Barrier = m Total depth of superstructure exposed of wind = m Height of structure above ground level = m From Table 4 of IRC: Hourly Mean Wind Speed - Plain terrain - upto 10m height = m/sec Hourly Mean Wind Pressure = N/mm 2 Basic Wind Speed Considered = 33 m/sec Actual wind speed at the location of the structure From appendix A of IS:875 part-3 = 50 m/sec Hourly Mean wind Pressure =464 50^2/33^2 P Z = 1065 N/m 2 Hourly Mean wind Speed = /33 V Z = 42 m/sec 1 Transverse Wind Force F T = P Z.A 1. G.C D Where A 1 = Solid area (Exposed area in transverse direction) = = = m 2 G = Gust factor = 2 C D = Drag Coefficient b/d = 10/2.25 = 4.44 = 1.38 For Bridge with single Girder = 2.07 Increased by 50% for Bridge with more than one girder L & T Infrastructure Engineering Ltd. Page 14

21 Transverse wind force = /1000 = kn 2 Longitudinal Wind Force F L = 25% of Transverse wind force 3 Vertical Wind Load F V = P z. A 3. G. C L = = 29.5 kn A 3 = Plan area = = = 119 m 2 C L = Lift Coefficient = 0.75 Total vertical Wind load = /1000 = 190 kn (b) Wind force on Substructure i. Abutment cap Depth of the Abutment cap = 0.90 m t/b = 4.55 m H/b = 0.41 m Exposed area = 1.98 m 2 Drag coefficent = 0.80 Transverse wind force on Abutment cap = 3.37 kn Longitudinal wind force on Abutment cap =25% of Transverse wind force =25/ = 0.84 kn ii.abutment 1.Transverse wind force Height of the abutment above GL = 3.13 m t/b =10/0.8 = m H/b =3.13/0.8 = 3.91 m Exposed area = 2.50 m 2 Drag coefficent = 0.80 Transverse wind force = /1000 = 4.26 kn 2. Longitudinal wind force Longitudinal wind force on Abutment =25% of Transverse wind force = 1.07 kn II Wind with live load - wind velocity to be considered is 36m/sec Total Length of the superstructure considered = m (a) Wind Load on Superstructure Height of the crash Barrier = m Total depth of superstructure exposed of wind = m Height of structure above bed level = 6.3 m From Table 4 of IRC6:2014 Hourly Mean wind Speed = m/sec Hourly Mean wind Pressure = N/mm 2 Basic Wind Speed Considered = 33 m/sec Actual wind speed at the location of the structure From appendix A of IS 875 part-3 = 36 m/sec Hourly Mean wind Pressure =464 36^2/33^2 P Z = 552 N/m 2 Hourly Mean wind Speed =28 36/33 V Z = 30 m/sec 1 Transverse Wind Force F T = P Z.A 1. G.C D Where A 1 = Solid area (Exposed area in transverse direction) = = m 2 G = Gust factor = 2 C D = Drag Coefficient b/d = 10/2.25 = 4.44 L & T Infrastructure Engineering Ltd. Page 15

22 (From Table:2 of IRC 6 Notification No:33 ) = 1.38 For Bridge with single Girder = 2.07 Increased by 50% for Bridge with more than one girder Transverse wind force = /1000 = 61.1 kn 2 Longitudinal Wind Force F L = 25% of Transverse wind force 3 Vertical Wind Load F V = P z. A 3. G. C L = = 15.3 kn A 3 = Plan area = = = 119 m 2 C L = Lift Coefficient = 0.75 Total vertical Wind load = /1000 = 99 kn (b) Wind force on Live Load Transverse wind force F T = P Z.A 1. G.C D A 1 = exposed area = =11.90 ( ) = m 2 G = Gust factor = 2 C D = Drag Coefficient = 1.2 Transverse wind force F T = /1000 = 29.9 kn Longitudinal wind force F L = = 7.5 kn (c) Wind force on Substructure i. Abutment cap Depth of the Abutment cap = 0.90 m t/b = m H/b = 3.91 m Exposed area = 2.50 m 2 Drag coefficent = 0.80 Transverse wind force on Abutment cap = 2.21 kn Longitudinal wind force on Abutment cap =25% of Transverse wind force =25/ = 0.55 kn ii.abutment 1. Transverse wind force Height of the abutment above GL = 3.13 m t/b =10/0.8 = m H/b =3.13/0.8 = 3.91 m Exposed area = = 2.50 m 2 Drag coefficent = 0.80 Transverse wind force = /1000 = 2.21 kn 2. Longitudinal wind force Longitudinal wind force on Abutment =25% of Transverse wind force =25/ = 0.55 kn Lever Arm Calculations: Lever arm of Superstructure from Pile cap top lvl =( ) = m Lever arm of Superstructure from Pile Cap bot. lvl =( ) = m Lever arm of C.G of vehicle from Pile cap top level =( ) = m Lever arm of C.G of vehicle from Pile cap bottom level =( ) = m Lever arm of C.G of Abutment cap from pilecap top level Lever arm of C.G of Abutment cap from pilecap bottom lvl = = m = = m L & T Infrastructure Engineering Ltd. Page 16

23 Lever arm of C.G of Abutment from pilecap top level Lever arm of C.G of Abutment from pilecap bottom lvl = = m = = m Summary of Wind Forces (Without Live Load) Velocity of Wind = 50 m/sec Moment at Direction Vertical Comp, F V Horizontal Comp, H Lever arm pilecap Top Lever arm pilecap Bottom kn kn/m kn kn/m m knm/m m knm/m Transverse Super structure Substructur Abt e Abt Cap Total Longitudinal Super structure Substructur e Abt Abt Cap Total Summary of Wind Forces (With Live Load) Velocity of Wind = 36 m/sec Moment at Direction Vertical Comp, F V Horizontal Comp, H Lever arm Pile cap Top Lever arm Pile cap Bottom kn kn/m kn kn/m m knm/m m knm/m Transverse Super structure Substructur Abt e Abt Cap Live load Total Longitudinal Super structure Substructur Abt e Abt Cap Live load Total Seismic force calculation (F eq ) Total Load from Superstructure (DL+SIDL) = = kn/m Total Load from Superstructure (DL+SIDL+0.2*LL) = kn/m Size of Abutment = 0.8 x 1 m Youngs Modulus ( E) As per IRC:21 = N/mm 2 Load required for unit deflection at the top of the Abt(stiffness of Abt) = 3EI/L 3 MI of section - Transeverse = Ixx = 0.04 m 4 MI of section - Longitudinal = Izz = 0.07 m 4 Height of the Abutment = 4.03 m Average Response Acceleration Coefficient = Sa/g Importance factor = I = 1.2 Zone factor for Zone III = Z = 0.16 Response reduction Factor = R = 2.5 for Column - As per IRC 6:2010 Cl Seismic Coefficient = Ah = (z / 2) x (Sa / g) x (I / R) Fundamental time Period T = 2 D/1000F L & T Infrastructure Engineering Ltd. Page 17

24 Seismic Coefficient (Considering Fixed Pier base) Direction Transverse direction Longitudinal direction Load Stiffness Time Period (kn/m) (T) Sa/g Ah Lever arm of C.G of vehicle from Pile Cap top level = = m Lever arm of C.G of vehicle from Pile Cap bottom level = = m Lever arm of Superstructure C.G from Pile Cap top level = = m Lever arm of Superstructure C.G from Pile Cap bottom lvl = = m Lever arm of SIDL from Pile Cap top level = = m Lever arm of SIDL from Pile Cap bottom level = = m Lever arm of C.G of Abt cap from Pile Cap top level = = m Lever arm of C.G of Abt cap from Pile Cap top level = = m Lever arm of C.G of Abt from Pile Cap top level = = m Lever arm of C.G of Abt from Pile Cap top level = = m Lever arm of C.G of Dirt wall from Pile Cap top level =1.205/2+( ) = m Lever arm of C.G of Dirt wall from Pile Cap top level =1.205/2+( ) = m Lever arm of C.G of Approach slab from Pile Cap top level =( )-0.3/2 = m Lever arm of C.G of Approach slab from Pile Cap top level =( )-0.3/2 = m Seismic Forces in Transverse Direction: Description Transverse Moment at Vertical Horizontal Calculation Pile cap Lever Pile cap Load, P Comp, H Lever arm Top arm Bottom kn/m kn/m m knm/m m knm/m Superstructure 151 = SIDL 36 = Total Substructure Abtcap 47 = Abt 63 = Dirt wall 18 = Approach slab Total Live Load Pmax(LL) = = Pmin(LL) = = Max MT(LL) = = Max ML(LL) = = Seismic Forces in Longitudinal Direction: Description Vertical Load, P Calculation Horizontal Comp, H Longitudinal Moment at Pile cap Lever Pile cap Lever arm Top arm Bottom kn/m kn/m m knm/m m knm/m Superstructure 151 = SIDL 36 = Total Substructure Abtcap 47 = Abt 63 = Dirt wall 18 = Approach slab 13 = Total Longitudinal and transeverse moments at bottom of Pilecap are increased by 25% as per IRC clause L & T Infrastructure Engineering Ltd. Page 18

25 3.3 Summary of Forces and Load Combinations Forces at Base of the Abutment (Top of Pile Cap) Summary of Forces at Base of the Abutment (Top of Pile Cap) (10m width of abutment considered) Load Case Notation P H L H T M L M T kn kn kn knm knm Dead Load Super structure Substructure SIDL Total G Live Load P max (LL) Q P min (LL) Q Max M T (LL) Q Max M L (LL) Q Active Earth Pressure F ep Active Earth Pressure (Seismic case) Live Load Surcharge Live Load Surcharge (seismic case) Centrifugal Force F cf Due to P max (LL) Due to P min (LL) Due to Max M T (LL) Due to Max M L (LL) Braking force F b Bearing deformation force F f Wind Force W Without Live Load With Live Load Seismic Forces - lateral and longitudinal F eq Superstructure DL+SIDL Substructure Total Vertical seismic force - for lateral case 210 Vertical seismic force - for longitudinal case 210 Live Load P max (LL) P min (LL) Max M T (LL) Max M L (LL) Load Combinations at Base of the Abutment (Top of Pile cap) Load P H L H T M L M Description T Case kn kn kn knm knm Normal Case I G + Q 1 + F cf + F b + F f + F ep I G + Q 2 + F cf + F b + F f + F ep I G + Q 3 + F cf + F b + F f + F ep I G + Q 4 + F cf + F b + F f + F ep Normal Case with wind up IIIA G + F f +F ep + W(Up) IIIA G + Q 1 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 2 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 3 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 4 + F cf + F b + F f + W(Up) + F ep L & T Infrastructure Engineering Ltd. Page 19

26 Normal Case with wind down IIIA G + F f + F ep + W(Dn) IIIA G + Q 1 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 2 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 3 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 4 + F cf + F b + F f + W(Down) + F ep VI Seismic Load Combinations r3 r1 r2 r1 r2 r r r3 Seismic Components VIa G + 0.2(Q 1 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 2 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 3 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 4 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep r r2-0.3r3 Seismic Components VIb G + 0.2(Q 1 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 2 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 3 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 4 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep r1 + r r3 Seismic Components VIc G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep r1 + r2-0.3r3 Seismic Components VId G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep r r2 + r3 Seismic Components VIe G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep r r2 - r3 Seismic Components VIf G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep Design of Wall Abutment M X Y end spacing L Y M Y X L X Grade of concrete used = 35 Mpa Grade of steel used = 500 Mpa Length of section along X direction: = 0.8 m Length of section along Y direction: = 10 m Effective Cover = m End Spacing = 0.13 m L & T Infrastructure Engineering Ltd. Page 20

27 No of bars along X direction (one side) = 3 Nos. Diameter of bar = m Details of bars in Y- direction Bar dia spacing Ast Prov No of bars mm mm mm 2 Earth face Other Face Total No of bars along Y direction (one side) = 112 Nos. Diameter of bar = m Code of Practise = IRC Modular Ratio m = 10 Normal (N/mm2) Seismic (N/mm2) Wind (N/mm2) Permissible Stresses in Concrete for bending Compression Permissible Stresses in Steel for Compression Permissible Stresses in Steel for Tension Area of Concrete = m 2 Area of Steel =2 3.14/4 (0.012^ ^ ) 1e mm 2 Percentage of Steel =61076/8.000/ % Area of concrete to resist axial load only = / mm 2 Area of Steel = 0.8% of above =0.8/ mm 2 Steel Prov > Min reqd Area of Steel = 0.3% of gross Area =0.3/ mm 2 P MX MY ex ey σ CONCRETE σ ST COMP σ ST TENSION Load case t tm tm m m N/mm 2 N/mm 2 N/mm 2 Normal Case I I I I Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 L & T Infrastructure Engineering Ltd. Page 21

28 VIa VIa VIa VIa r r2-0.3r3 VIb VIb VIb VIb r1 + r r3 VIc VIc VIc VIc r1 + r2-0.3r3 VId VId VId VId r r2 + r3 VIe VIe VIe VIe r r2 - r3 VIf VIf VIf VIf Distribution Reinforcement: 0.12% bd = mm 2 /m Provide Y 150 mm at tension face + Y 150 mm at comp. face = mm 2 /m Safe Check for Shear: Normal case: Shear force at the bottom of the stem (V) = kn Breadth B = mm Effective depth d = 741 mm τ max for M35 = 2.3 MPa Shear stress τ v = V/bd = N/mm 2 Percentage of steel 100 A st /bd = % Permissible shear stress τ c = N/mm 2 τc > τv; No shear reinforcement required L & T Infrastructure Engineering Ltd. Page 22

29 Wind Load case: Shear force at the bottom of the stem (V) = kn Breadth B = mm Effective depth d = 741 mm τ max for M35 = 2.3 MPa Shear stress τ v = V/bd = N/mm 2 Percentage of steel 100 A st /bd = % Permissible shear stress τ c = N/mm 2 τc > τv; No shear reinforcement required Seismic case: Shear force at the bottom of the stem (V) = kn Breadth B = mm Effective depth d = 741 mm τ max for M35 = 2.3 MPa Shear stress τ v = V/bd = N/mm 2 Percentage of steel 100 A st /bd = % Permissible shear stress τ c = N/mm 2 τc > τv; No shear reinforcement required 3.5 Forces at Pile Cap Bottom Summary of Forces at Pile Cap Bottom (10 m width of abutment considered) Load Case Notation P H L H T M L M T kn kn kn knm knm Dead Load Super structure Substructure SIDL Total G Live Load P max (LL) Q P min (LL) Q Max M T (LL) Q Max M L (LL) Q Active Earth Pressure F ep Active Earth Pressure (Seismic case) Live Load Surcharge Live Load Surcharge (Seismic case) Centrifugal Force F cf Due to P max (LL) Due to P min (LL) Due to Max M T (LL) Due to Max M L (LL) Braking force F b Bearing deformation force F f Wind Force W Without Live Load With Live Load Seismic Forces - lateral and longitudinal F eq Superstructure DL+SIDL Substructure Total Vertical seismic force - for lateral case 262 Vertical seismic force - for longitudinal case 262 L & T Infrastructure Engineering Ltd. Page 23

30 Live Load P max (LL) P min (LL) Max M T (LL) Max M L (LL) Load Combinations at Pile Cap bottom Load P H L H T M L M Description T Case kn kn kn knm knm Normal Case I G + Q 1 + F cf + F b + F f + F ep I G + Q 2 + F cf + F b + F f + F ep I G + Q 3 + F cf + F b + F f + F ep I G + Q 4 + F cf + F b + F f + F ep Normal Case with wind up IIIA G + F f +F ep + W(Up) IIIA G + Q 1 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 2 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 3 + F cf + F b + F f + W(Up) + F ep IIIA G + Q 4 + F cf + F b + F f + W(Up) + F ep Normal Case with wind down IIIA G + F f + F ep + W(Dn) IIIA G + Q 1 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 2 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 3 + F cf + F b + F f + W(Down) + F ep IIIA G + Q 4 + F cf + F b + F f + W(Down) + F ep VI Seismic Load Combinations r3 r1 r2 r1 r2 r r r3 Seismic Components VIa G + 0.2(Q 1 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 2 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 3 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep VIa G + 0.2(Q 4 +F cf +F b ) + F f + F eql + 0.3*F eqt + 0.3*F eqv + F ep r r2-0.3r3 Seismic Components VIb G + 0.2(Q 1 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 2 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 3 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep VIb G + 0.2(Q 4 +F cf +F b ) + F f + F eql + 0.3*F eqt - 0.3*F eqv + F ep r1 + r r3 Seismic Components VIc G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep VIc G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + F eqt + 0.3*F eqv + F ep r1 + r2-0.3r3 Seismic Components VId G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep VId G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + F eqt - 0.3*F eqv + F ep L & T Infrastructure Engineering Ltd. Page 24

31 0.3r r2 + r3 Seismic Components VIe G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep VIe G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt + F eqv + F ep r r2 - r3 Seismic Components VIf G + 0.2(Q 1 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 2 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 3 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep VIf G + 0.2(Q 4 +F cf +F b ) + F f + 0.3*F eql + 0.3*F eqt - F eqv + F ep Pile Arrangement A B C Traffic dn 4.35 D E F Y G H I 0.8 X Dia of Pile = 1.0 m Thickness of the pilecap = 1.5 m Total Weight of the Pilecap = = 3150 kn Height of soilfill over the pilecap = 0.0 m Weight of soilfill over pilecap = 0 kn No of piles = 9 Nos. M.I of pile group about x-axis = m 4 M.I of pile group about y-axis = 61.4 m 4 Section Modulus of piles Pile Z T Z L A B C D E 0 0 F G H I Calculation of depth of fixity Diameter of pile, d pl = 1.0 m Ground level = m Grade of concrete in pile = M35 Modulus of elasticity of concrete, E c (From Table 9 of IRC: ) = 3.15E+01 kn/mm 2 The depth of fixity and bending moments in the pile have been worked out as per IS 2911 Part 1/ sec2 Appendix C (clause 5.5.2). Fixed head condition of piles is applicable because of pile cap at the top. Scour level = m Free standing length (L 1 ) = m L & T Infrastructure Engineering Ltd. Page 25

32 R = (E * I / K 2 )^0.25 where E = Youngs Modulus of the concrete = kg/cm 2 I = Moment of Inertia of the pile cross section = cm 4 K 2 = Modulus of subgrade reaction as per Table 2 = 48.8 kg/cm 2 R = ( * / 48.8) ^ 0.25 ) = cm L 1 = Scour depth below pile cap = cm L 1 /R = 167.1/421.9 = 0.4 L f / R = (fig 2 - for fixed headed piles in sands ) = L f = 2.1 * = cm Thus Fixity length of pile L f = m Length to be considered for bending of pile = L F +L 1 = m Reduction factor, m = Load on Piles L/C Vertical Load on the pile (kn) A I B C H L On the pile (kn) Bending Moment (knm) Normal Case I I I I Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 VIa VIa VIa VIa r r2-0.3r3 VIb VIb VIb VIb r1 + r r3 VIc VIc VIc VIc r1 + r2-0.3r3 VId VId VId VId r r2 + r3 VIe VIe VIe VIe L & T Infrastructure Engineering Ltd. Page 26

33 0.3r r2 - r3 VIf VIf VIf VIf Load Summary Capacity (kn) Max Load Min Load Max H L kn kn kn Normal Case OK Normal+Wind Case OK Seismic Case OK Check for lateral deflection of scour level Allowable deflection under norml loads as per IRC 78 = 10 mm Q = Resultant horizontal force on pile - Normal case = 187 kn Y = Pile head deflection of equivalent cantilever for fixed head pile = Q * (L 1 + L f )^3 / (12 * E * I) = 0.70 cm say 7.1 mm Hence OK L & T Infrastructure Engineering Ltd. Page 27

34 3.6.4 Design of Pile Y M Y X Diameter "D" Radius 0.5 m Clear Cover Diameter of Transverse Reinforcement Effective Cover 75 mm 10 mm m No of bars 26 Nos. (in 2 layers) Diameter of bar m 1st layer 2nd layer Dia No. of bars Eff. Cover Spacer bar diameter m Code of Practise IRC 21 Modular Ratio m 10 Grade of Concrete 35 Permissible Stresses in Concrete for Direct Compression 8.75 N/mm 2 Normal Wind Seismic Permissible Stresses in Concrete for bending Compression N/mm 2 Permissible Stresses in Steel for Compression N/mm 2 Permissible Stresses in Steel for Tension N/mm 2 Allowable increase in perm. Stresses for Wind load cases 33 % Allowable increase in perm. Stresses for earthquake cases 50 % Area of concrete m 2 Area of Steel mm 2 Percentage of Steel 2.66 % Area of concrete to resist axial load only = / mm 2 Minimum Area of Reinforcement 0.8 % of area above =0.8/ mm % of gross area pile =0.4/ mm 2 Minimum area of reinforcement 3142 mm 2 Steel Prov > Min reqd Load P M Y σ CONCRETE σ ST COMP σ ST TENSION σ cbc σ sc, all σ st, all Case (T) (T-m) (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) Minimum Vertical Load & Moment case Normal Case I I L & T Infrastructure Engineering Ltd. Page 28

35 Minimum. Vertical Load Cases I I Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 VIa VIa VIa VIa r r2-0.3r3 VIb VIb VIb VIb r1 + r r3 VIc VIc VIc VIc r1 + r2-0.3r3 VId VId VId VId r r2 + r3 VIe VIe VIe VIe r r2 - r3 VIf VIf VIf VIf Maximum Vertical Load & Moment case Normal Case I I I I L & T Infrastructure Engineering Ltd. Page 29

36 Maximum Verical Load Cases Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 VIa VIa VIa VIa r r2-0.3r3 VIb VIb VIb VIb r1 + r r3 VIc VIc VIc VIc r1 + r2-0.3r3 VId VId VId VId r r2 + r3 VIe VIe VIe VIe r r2 - r3 VIf VIf VIf VIf L & T Infrastructure Engineering Ltd. Page 30

37 Percentage of pile reinforcement provided = % Below the fixity + development length, 50% of bars are proposed for curtailment So, Depth of curtailment below pile cut off level = 12 m Hence, Percentage of reinforcement at curtailment level = 0.92 % Ast provided = mm Design of Pile Cap a b 8.4 Steel Prov > Min reqd 10.0 Traffic dn Y X 4.0 a b Size of the pilecap = 8.40 x 10.0 m Size of the pier = 10.0 x 0.80 m Thickness of the pilecap = 1.5 m Clear cover to the tension reinforcement = 75 mm Grade of concrete for pilecap = 35 N/mm 2 Grade of steel = 500 N/mm 2 Permissible flexural comp stress in concrete σ bc = N/mm 2 Permissible flexural tensile stress in steel σ st = 240 N/mm 2 Permissible tensile stress of steel in shear σ st = 200 N/mm 2 modular ratio m = 10.0 Neutral axis depth factor N = Lever arm factor J = Moment resistance factor Q = Dia of reinforcement in x-direction (At bottom face) = 25 mm Spacing of reinforcement = 150 mm Dia of reinforcement in x-direction (At top face) = 20 mm Spacing of reinforcement = 150 mm Effective depth of the pilecap in x-direction = 1413 mm Minimum percentage of steel to be provided = 0.12%bD Min Percentage of steel reqd. in x-direction (At bottom face) = mm 2 Min Percentage of steel reqd. in x-direction (at Top face) = 7560 mm 2 Area of steel provided in x-direction (At bottom face) = mm 2 OK L & T Infrastructure Engineering Ltd. Page 31

38 Area of steel provided in x-direction (At top face) = mm Design of Pilecap for flexure L/C BM at Sec d eff. d eff. Ast reqd. BM at Sec b-b a-a Reqd. Reqd. Ast reqd. Material factor knm mm mm 2 knm mm mm 2 Normal Case I I I I Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down 1.33 IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 VIa VIa VIa VIa r r2-0.3r3 1.5 VIb VIb VIb VIb r1 + r r3 1.5 VIc VIc VIc VIc r1 + r2-0.3r3 1.5 VId VId VId VId r r2 + r3 1.5 VIe VIe VIe VIe r r2 - r3 1.5 VIf VIf VIf VIf Sample calculation Load Case = I Bending Moment at section a-a = 6425 knm Minimum effective depth of the pilecap required = 615 mm Area of steel required = mm 2 Area of steel provided = mm 2 OK OK L & T Infrastructure Engineering Ltd. Page 32

39 Distribution steel in 'Y' direction (at bottom face) = 250 mm 2 Provide 12 mm dia bars at 150 mm spacing as distribution reinforcement in 'x' direction = 754 mm 2 OK Distribution steel in 'Y' direction (at top face) = 250 mm 2 Provide 12 mm dia bars at 150 mm spacing as distribution reinforcement in 'y' direction = 754 mm 2 OK Design of Pilecap for Shear Percentage of steel provided = 0.23 % Permissible shear stress = 0.22 N/mm 2 L/C τ c SF at Sec1-1 Shear Stress Excess Shear/m SF at Sec2-2 Shear Stress Excess Shear/m 377 Asv Reqd. N/mm 2 kn N/mm 2 kn kn N/mm 2 kn mm 2 Normal Case I I I I Normal Case with wind up IIIA IIIA IIIA IIIA IIIA Normal Case with wind down IIIA IIIA IIIA IIIA IIIA VI Seismic Load Combinations r r r3 VIa VIa VIa VIa r r2-0.3r3 VIb VIb VIb VIb r1 + r r3 VIc VIc VIc VIc r1 + r2-0.3r3 VId VId VId VId r r2 + r3 VIe VIe VIe VIe r r2 - r3 VIf VIf VIf VIf * Critical section for Shear is considered at the face of the pile Sample Calculation Load Case = I Shear Force at Section 1-1 = 4627 kn L & T Infrastructure Engineering Ltd. Page 33

40 Permissible Shear stress = 0.22 N/mm 2 Shear stress at this section = 0.33 N/mm 2 Excess Shear Per meter width = 146 kn Shear Force at Section 2-2 = 2043 kn Shear stress at this section = 0.14 N/mm 2 Excess Shear Per meter width = 0 kn Area of shear reinforcement required = mm 2 Minimum Shear reinforcement required A sw = = mm 2 Provide 12 mm dia links at 300 x 300 spacing as Shear reinforcement Shear reinforcement Provided = 377 mm Check for Punching shear (0.4 x b x s)/(0.87 x Fy) OK Pile WALL Critical section for punching of pile =1413/2 = 706 mm Perimeter of punching shear for pile =3.14 ( /1000)/4+2 1 = 3.89 m Permisible punching shear stress =0.16 (35)^0.5 = 0.95 N/mm 2 Punching stress on pile - normal case- max reaction is considered = 0.28 N/mm 2 OK Permisible punching shear stress =0.16 (35)^0.5 = 0.95 N/mm 2 Critical section for punching of abutment = 706 mm Perimeter of punching shear for abutment =2 (10.0) = m Punching stress on abutment - normal case- max reaction is considered N/mm 2 OK L & T Infrastructure Engineering Ltd. Page 34

41 3.8 Design of Corbel for the Abutment cap Reference is made to Chapter 24 of "Concrete Bridge Practise, Analysis, Design & Economics" by Dr. V. K. Raina Grade of concrete = M 35 Grade of steel = Fe 500 Size of the Abt. Pier cap (in plan) = 10.0 x 2.20 m Clear Cover for reinforcement = 50 mm Size of Bearing = 225 x 400 mm Size of Bearing pedestal = 550 x 700 mm Effective Depth of Corbel = 830 mm Load Factors for Dead Load SIDL Live Load = = = Load Case Bearing B1 Bearing B2 Bearing Reaction (kn) Bearing B3 Bearing B4 Bearing B5 Bearing B6 DL SIDL LL (70R Ecc to G1) Total Vertical Load from Bearing Braking force Bearing Deformation force Horizontal force H L kn Load Case Bearing B1 Bearing B2 Horizontal force H L (kn) Bearing B3 Bearing B4 Bearing B5 Bearing B6 Braking force per bearing Bearing Defor. Per bearing L & T Infrastructure Engineering Ltd. Page 35

42 Considering Bearing B2 loads for the design of corbel and considering 1:1 dispersion of load from the pedestal at the mid depth of abutment cap, the width of dispersion would be 1380 mm B2 Pedestal Abutment cap V u a = 450 mm a H u D = 900 mm d' = 830 mm D d b = 1380 mm a/d' = 450/830 = < 1 Hence Corbel action takes place Total Shear force, (V u ) = 965 kn Shear stress (B1) = 0.84 N/mm 2 Shear stress Shall be less than = 5.5 N/mm 2 Depth Provided is Sufficient Ultimate Horizontal Force, H u = 193 kn (Should not be less than 0.2 V u ) L & T Infrastructure Engineering Ltd. Page 36

43 Step 1: Check for Nominal Shear Strength (V u /bd): V u /bd <= 0.15f c V u = ultimate vertical load f c = 28 day standard cylinder strength of concrete = 0.87*f c = 30 N/mm 2 d = 0.8 times of effective depth = 0.8*(d') = = 664 mm V u /bd = =(965) 1000/( ) = N/mm 2 Nominal Shear Stress 0.15*f c ' = = 4.57 N/mm 2 Safe Step 2: Check for A vf Calculation of shear friction reinforcement A vf A vf = Vu/(0.85f sy µ) f sy = Yield stress = 500 N/mm 2 µ = 1.4 (Concrete placed monolithically across interface) A vf = =( /( ))/ = 1097 mm 2 /m Step 3: Check for A t Calculation of direct tension reinforcement A t A t = H u /(0.85f sy ) = =( /( ))/(1380/1000) = 329 mm 2 /m Step 4: Check for A f Calculation of flexural - tension reinforcement A f A f = {V u a+h u (h-d')}/(0.85f sy d) = =( /( ))/1.38+(193 ( ) 1000/( ))/1.38 = 1150 mm 2 /m Step 5: Check for A s Calculation of total primary reinforcement requirement A s A s = A f +A t = = 1479 mm 2 /m = 2/3A vf +A t = (2/3) L & T Infrastructure Engineering Ltd. Page 37

44 = 1060 mm 2 /m = 0.04(f c /f y )bd' = =0.04 (30/500) = 2022 mm 2 /m Hence A s required = 2022 mm 2 /m Provide 140 c/c in the 1 st layer A s Provided = 2244 mm 2 /m Safe Step 6: Check for A h Calculation of total area of ties (horizontal shear reinforcement) A h A h = 0.5A f = = 575 mm 2 /m = 0.333A vf = = 365 mm 2 /m Hence A h required = 575 mm 2 /m This reinforcement shall be provided within a depth of 2/3d' below A s i.e., = 553 mm below As Reinf. Provided in 3 Layers of Y 280 c/c A h provided = 1212 mm 2 /m Safe Step 7: Calculation of total area of shear reinforcement A v A v /s v = 0.5(V u -V c )/f sy d s v = pitch V c = Shear capacity of the section without shear reinforcement 100A s /bd = 0.27 % τ c = 0.24 N/mm 2 (Permissible Shear Stress) V c = = /1000 = 271 KN A v /s v = 0.5*(V u - V c )/(f sy *d) = =(0.5 ( ) 1000/500/664)/ = 0.44 mm 2 / m Hence providing Y 300 c/c 280 c/c A v,prov /s v = 1.35 mm 2 / m Safe L & T Infrastructure Engineering Ltd. Page 38

45 4. ANALYSIS AND DESIGN OF RETURN WALL The retaining wall is designed for active earth pressure and live load surcharge pressure. The loads for the purpose of design are calculated per meter length. 4.1 BASIC DESIGN: Height of the wall above Bed Level = m Depth of Pile cap below bed level = m Slope of surcharge is = 0 deg 4.2 MATERIALS: Grade of concrete = M 35 Permissible flexural compressive stress σ cbc = N/mm 2 modular ratio m = 10 Neutral axis depth factor n = Lever arm factor j = Moment resistance factor Q = Maximum shear stress = 2.3 N/mm 2 Clear cover to the reinforcement = 50 mm Density of Concrete = 25 kn/m 3 Development length factor L d = 42 Ø Grade of steel = Fe 500 Tension in flexure, shear or combined bending σ st = 240 N/mm 2 Back Fill : Angle of slope of the embankment or backfill β = 0 deg Angle of internal friction φ = 35 deg Angle of friction with wall to soil δ = deg Inclination of wall with respect to vertical α = 0 deg Cohesion c = 0.0 kn/m 2 Density of earth γ = 18.0 kn/m 3 Density of water γ W = 10.0 kn/m 3 Coefficient of active earth pressure in horizontal direction Ka Cos 2 (φ-α) * Cos 2 α * Cos (δ+α) 1 1+ Sin(φ+δ)*Sin(φ-β) Cos (α-β) * Cos(δ+α) 1/2 2 = LOADS : Active earth pressure at bottom of footing leve K a γ h = kn/m 2 Depth of potensial tension crack due to cohesion ""z"" = 0.0 m 2c/(γ(K a )0.5) Live load surcharge = 1.2 m of back fill 0.80 Stem A Active Earth Pressure 2.60 Liveload 5.00 Surcharge Bed Level kn/m 2 kn/m (0.251*18*1.2) L & T Infrastructure Engineering Ltd. Page 39

46 4.4 DESIGN OF STEM: Base of the stem: Dry condition: Force due to active earth pressure (0.5*23.074*5.11) = 59.0 kn Lever arm (0.42*5.11) = 2.1 m Bending moment (58.955*2.146) = kn-m Force due to surcharge (5.419*5.110) = 27.7 kn Lever arm (5.110*0.5) = 2.56 m Bending moment (27.689*2.555) = 70.7 kn-m Total Design BM ( ) = kn-m Design BM = kn-m d, Required (SQRT(( * /(1.700*1000))) = mm d, Provided (0.8*1000) = mm Safe Ast Required ( * /(240*0.891*726)) = mm 2 Minimum steel required in each face is 0.12% = mm 2 Provide Y 150 mm (tension face) Steel provided = mm 2 Safe Provide Y 200 mm (Comp. face) Steel provided = Safe Distribution Reinf. 0.12% bd = mm 2 Provide Y 150 mm (tension face) Y 150 mm (Comp. face) Steel provided = mm 2 Safe Check for Shear: Overall depth provided = mm Effective depth = mm Overall depth provided at the critical section = mm Effective Thickness at the critical section = mm Force due to active earth pressure 59.0 kn Force due to surcharge = 27.7 kn Total Shear = 86.6 kn Shear stress τ = V/bd = N/mm As/bd = Permissible Shear stress in concrete with out shear steel = N/mm 2 Hence Shear Reinforcement is NOT required. L & T Infrastructure Engineering Ltd. Page 40

47 5 Analysis and Design of Dirt Wall Dirt Wall is subjected to the following loads. a. G - Dead Load due to self weight & SIDL due to wearing course and Crash barrier b. Q - Vehicular Live Loads (Class A and 70R loadings are considered for the design) c. E p - Earth pressure due to backfill behind the dirt Wall d. F b Braking force Data: Total width of the deck = m Width of crash barrier = 0.50 m Width of median = 0 m Total Width of carriageway = 9.50 m Depth of Dirt Wall = m Thickness of Dirt Wall = 0.30 m Clear cover = 40 mm Grade of Concrete = M35 Grade of Steel = Fe500 σ st = 240 N/mm 2 σ c = 35/3 = N/mm 2 m = 10 Q = = 1.7 N/mm 2 K = ( )/( ) = J = /3 = Back Fill : Angle of slope of the embankment or backfill β = 0 deg Angle of internal friction φ = 35 deg Angle of friction with wall to soil δ = deg Inclination of wall with respect to vertical α = 0 deg Cohesion c = 0.0 kn/m 2 Density of earth γ = 18.0 kn/m 3 Density of water γ W = 10.0 kn/m 3 Coefficient of active earth pressure in horizontal dire Ka Cos 2 (φ-α) * Cos 2 α * Cos (δ+α) 1 1+ Sin(φ+δ)*Sin(φ-β) Cos (α-β) * Cos(δ+α) 1/2 2 = Live load surcharge = 1.2 m of back fill Dead Load SIDL ( i ) Due to wearing course Thickness of wearing course = m Load due to wearing course = 1.40 kn/m 2 Assume it as = 3.15 kn/m ( ii ) Due to Crash Barrier Cross sectional area of crash barrier = 0.31 m 2 Load over dirt wall = 3.41 kn/m (iii) Approach Slab Weight of approach slab over dirt wall = kn/m Live Load Class A single lane loading is considered Impact factor = 1+ (4.5/(L+6)) =1+(4.5/( )) = 1.57 Load on the dirt wall Due to Class A (R ) = 57 kn L & T Infrastructure Engineering Ltd. Page 41

48 Load on the dirt wall Due to 70R (Axial (R ) = 85 kn Live Load R R = Reaction due to Class A/70R Vehicle over dirtwall Beam Class A (With Impact) = R Vehicle (Axial L) (With Impact) = Design of Vertical Reinforcement Eccentricity of Loads R Lever arm to the tensile reinf. From R =0.3/ /2 = 0.30 mm 0.30 Reaction Due to 70R =133 2 = 266 kn Despersion width = = 6.00 m Live Load per meter width =266/6.00 = kn/m Reaction Due to Class A =89 2 = 179 kn Despersion width = = 4.64 m Live Load per meter width =179/4.64 = kn/m Reaction due to Dead Loads & SIDL = =( )+3.4 = 20 kn (70R+Class A is Governing) Moment due to Eccentricity of Loads/meter =(44+20) 0.30 = 19 knm Earth pressure Dry condition: Force due to active earth pressure 8.5 kn L & T Infrastructure Engineering Ltd. Page 42

49 Lever arm = 0.8 m Bending moment = 7.0 knm/m Force due to surcharge = 10.5 kn Lever arm = 0.97 m Bending moment = 10.2 knm/m Total Design BM = 17.2 kn-m Braking Force Axial Load of Class A =(89+89) = 179 kn Axial Load of 70R (Axial L) =( ) = 266 kn Force due to Braking effect 70R =0.2 ( )/5.816 = 9 kn/m Class A =0.2 (89+89)/4.64 = 8 kn/m Max = 9 kn This Force is acting at = 1.2 m above FRL BM due to Braking force = =9 ( ) = 28.8 knm/m Frictional Force Youngs Modulus E = N/mm 2 Moment of Inertia I = 2.E+09 mm 4 Maximum Elongation/Contraction of the approach slab due to Temperature = ^ /2 = 0.67 mm Maximum Frictional force over the dirt wall/meter width =0.5 (44+20) = 32 kn/m Deflection at the top of Dirtwall due to this frictional force = ( )^3/( E+09) = 1.1 mm Load to be considered in calculating Long. Moment due to friction =(0.67/1.1) 32 = 19 kn/m Moment at the bottom of the dirt wall due to friction = = 37 knm/m Design Moment = = 103 knm/m Effective depth required = (M/Qb)^0.5 = (103 10^6/( ))^0.5 = 246 mm Effective depth provided at bearing location = /2 = 250 > 246 Safe Area of steel required = M/(σ st *j*d) = =103 10^6/( ) = 1920 mm 2 Provide Y 150 mm c/c Area of steel provided = ^2/4/ = 2093 > 1920 Safe Design of Side Face Reinforcement Minimum Side face reinforcement = 0.1% of cross sectional area therefore, area of steel = ^6/100 = 583 mm 2 Steel required on one face = 583/2 = 291 mm 2 Provide Y 200 mm c/c Area of steel provided = = ^2/ /(200/1000) = 1098 > 291 Safe L & T Infrastructure Engineering Ltd. Page 43

50 Annexure:1 Scour depth Calculation Effective Linear waterway Effective Linear waterway = 21.4 m Highest Flood Level (HFL) = m Bed Level = 2.67 m Velocity of flow (assumed) = 3 m/s Discharge (Q) = cumecs Design Discharge per unit width (Db=Q/LW W) = cumecs Silt factor (Ksf) = 1.5 Mean depth of scour (d sm =1.34*((Db^2/Ksf) 1/3 )) = 4.42 m Max. scour depth, (d m =1.27*d sm ) = 5.61 m Maximum scour level (HFL-d m ) = m L & T Infrastructure Engineering Ltd. Page 44