consulting engineers memorandum to: KDSA Development Corporation - Ms. Susan Anglin - susananglin6@gmail.com re: Pavement Structure Recommendations - Shady Maple Road Proposed Braeburn Estates Residential Development Building Supply Road - Burnstown date: July 6, 6 file: from: P55-MEMO.R Richard roniger Further to your request and authorization, Paterson roup (Paterson) completed a geotechnical investigation to review the subsoil and groundwater conditions for the proposed Shady Maple Road to be located along the south boundary of the subject site. The following memo summarizes our observations and provides our recommendations from a geotechnical perspective.. Field Investigation The field program for the geotechnical investigation was carried out on May 9 and, 6. At that time, a total of fourteen (4) test pits (TPs) were completed using a hydraulic shovel at approximately m spacing along the proposed roadway alignment. Relevant test holes completed completed as part of our previous Hydrogeological Study as been attached to the current report for reference purposes only. All fieldwork was conducted under the full-time supervision of Paterson personnel under the direction of a senior engineer from the geotechnical division. The location and ground surface elevation at each test hole location was surveyed by Adam Kasprzak Surveying Limited. It is our understanding that the elevations are referenced to a geodetic datum. The location and ground surface elevation at each test hole location are presented on drawing P55- - Test Hole Location Plan attached to the present report. Soil samples from the test pits were recovered from the side walls of the open excavation and all soil samples were initially classified on site. The grab samples were placed in sealed plastic bags and all samples were transported to our laboratory. The depths at which the grab samples were recovered from the test holes are shown as, on the Soil Profile and Test Data sheets presented in Appendix. The subsurface conditions observed in the test holes were recorded in detail in the field. The soil profiles are logged on the Soil Profile and Test Data sheets presented in Appendix of this report.
Ms. Susan Anglin Page File: P55-MEMO.R. Surface Conditions The subject section of the proposed roadway alignment was partially cleared of trees prior to our arrival to complete the field portion of our geotechnical investigation. Based on the ground surface elevations provided at the test hole locations by Adam Kasprzak Surveying Ltd., the undulating ground surface along the proposed roadway alignment was observed to vary up to 5.5 m. Surface water observed within the two depressed areas within the subject roadway alignment within the area of TP6-6 and TP-6.. Subsurface Profile Based on our review of the fourteen (4) test pits (TP-6 to TP4-6) completed during our field portion of our geotechnical investigation, a thin layer of topsoil was encountered overlying a loose to compact silty sand deposit and/or overlying a compact to very dense glacial till consisting of a silty sand with gravel, cobbles and boulders was encountered. It should be noted that a mm thick layer of peat overlying a loose sandy silt material was encountered at TP6-6 which was located within the depressed area of the subject alignment. All test pits terminated in the overburden material with the exception of TP-6, TP-6, TP-6 and TP4-6 which terminated on inferred bedrock at depth ranging between.7 to.6 m below existing ground surface. roundwater was observed within the open test holes varied between. to.4 m with the exception of TP-6, TP-6, TP-6 and TP-6 which were observed to be dry upon completion of the sampling program. Reference should be made to the Soil Profile and Test Data sheets in Appendix for the details of the soil profiles and groundwater conditions encountered at each test hole location. 4. eotechnical Assessment From a geotechnical perspective, the subject site is considered adequate for the proposed roadway located along the south boundary of the subject site. It is expected that the majority of the subgrade for the proposed roadway structure will consist of an undisturbed silty sand to glacial till material. Due to the undulating conditions within the subject section of the site, it will be critical to properly manage the storm water during heavy rain events to minimize surficial erosion. The above and other considerations are discussed in the following paragraphs.
Ms. Susan Anglin Page File: P55-MEMO.R Site rading and Preparation Topsoil and deleterious fill, such as those containing organic materials, should be stripped from under the proposed roadway structure. Fill used for grading beneath the proposed roadway should consist, unless otherwise specified, of clean imported granular fill, such as Ontario Provincial Standard Specifications (OPSS) ranular A or ranular B Type II. This material should be tested and approved prior to delivery to the site. The fill should be placed in lifts no greater than mm thick and compacted using suitable compaction equipment for the lift thickness. Engineered fill placed below the roadway structure should be compacted to at least 98 of its standard Proctor maximum dry density (SPMDD). Site excavated fill approved by the geotechncial consultant at the time of construction can be used to bring up the subgrade level to the underside of the roadway structure provided that the material is free of topsoil, deleterious fill and free of boulders greater than mm in its longest direction placed under dry conditions. The site excavated fill should be placed in lifts no greater than mm thick and compacted using the tracks of the levelling equipment (5 to 6 passes) per lift and using a smooth drum vibratory roller. The site excavated fill should be compacted to at least 95 of its standard Proctor maximum dry density (SPMDD). Non-specified existing fill along with site-excavated soil can be used as general landscaping fill where settlement of the ground surface is of minor concern. These materials should be spread in thin lifts and compacted by the tracks of the spreading equipment to minimize voids.
Ms. Susan Anglin Page 4 File: P55-MEMO.R Minimum Pavement Structure It is anticipated that a pavement structure is being considered for the proposed roadway at the aforementioned site. The recommended minimum pavement structure is presented in Table below. Table - Recommended Pavement Structure - Shady Maple Road Thickness (mm) Material Description 4 Wear Course - HL- or Superpave.5 Asphaltic Concrete 5 Binder Course - HL-8 or Superpave 9. Asphaltic Concrete 5 BASE - OPSS ranular A Crushed Stone SUBBASE - OPSS ranular B Type II SUBRADE - Either in situ soils, acceptable fill or OPSS ranular B Type I or II material placed over in situ soil. Minimum Performance raded (P) 58-4 asphalt cement should be used for this project. If soft spots develop in the subgrade during compaction or due to construction traffic, the affected areas should be excavated and replaced with OPSS ranular B, Type II material. The pavement granular base and subbase should be placed in maximum mm thick lifts and compacted to a minimum of 98 of the material s SPMDD using suitable vibratory equipment. The pavement structure, where it abuts the existing pavement, should match the existing pavement layers. It is recommended that a mm wide and 5 mm deep stepped joint be provided where the new asphaltic layer joins with the existing asphaltic layer to provide more resistance to reflective cracking at the joint.
Ms. Susan Anglin Page 5 File: P55-MEMO.R Pavement Structure Drainage Satisfactory performance of the pavement structure is largely dependent on keeping the contact zone between the subgrade material and the base stone in a dry condition. Failure to provide adequate drainage under conditions of heavy wheel loading can result in the fine subgrade soil being pumped into the voids in the stone subbase, thereby reducing its load carrying capacity. The subgrade soil will consist predominantly of silty sand with gravel, cobbles and boulders. In this regard, the pavement granulars should be extended full width and the subgrade shaped to promote drainage towards the side ditches. Approach transitions should also be provided at trenches when the trench backfill within the frost zone (.8 m below the final grade) is not compatible with soil exposed on the excavation side walls (i.e. do not have similar frost heaving behaviour). It is recommended that the excavation side walls be profiled at a minimum H:V from a depth of.8 m to the underside of the pavement granulars when the trench is transverse to the traffic direction and.5h:v when it is longitudinal to the traffic lanes. Proposed Swales and Ditches The side slopes for the proposed roadway ditches and/or swales should be sloped at a minimum H:V and covered with a minimum of 5 mm of topsoil mixed with a hardy grass seed. In areas where ditches are in excess of 5H:V, it is recommended that the base of the ditch be lined with a non-woven geotextile liner such as a Terrafix 7R or equivalent and capped with a minimum thick layer of clear to mm diameter rip-rap to minimize surficial erosion.
Ms. Susan Anglin Page 6 File: P55-MEMO.R 5. Recommendations It is a requirement for the design data provided herein to be applicable that a suitable materials testing and observation program, including the following aspects, be performed by the geotechnical consultant. Observation of all bearing surfaces prior to the placement of concrete. Periodic observation of the condition of unsupported excavation side slopes in excess of m in height, if applicable. Observation of all subgrades prior to backfilling. Field density tests to determine the level of compaction achieved. A report confirming that these works have been conducted in general accordance with our recommendations could be issued, upon demand, following the completion of a satisfactory materials testing and observation program by the geotechnical consultant.
Ms. Susan Anglin Page 7 File: P55-MEMO.R 6. Statement of Limitations The recommendations provided in this report are in accordance with our present understanding of the project. We request that we be permitted to review our recommendations when the drawings and specifications are complete. A geotechnical investigation of this nature is a limited sampling of a site. The recommendations are based on information gathered at the specific test locations and can only be extrapolated to an undefined limited area around the test locations. Should any conditions at the site be encountered which differ from those at the test locations, we request that we be notified immediately in order to permit reassessment of our recommendations. The present report applies only to the project described in this document. Use of this report for purposes other than those described herein or by person(s) other than KDSA Development Inc. or their agent(s) is not authorized without review by Paterson roup for the applicability of our recommendations to the altered use of the report. We trust that this information satisfies your immediate requirements. Best Regards, Paterson roup Inc. Richard roniger, C. Tech. Attachments Soil Profile and Test Data Sheets Drawing P55- - Test Hole Location Plan Report Distribution KDSA Development Inc. ( digital copy) Paterson roup ( copy)
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road P55 Excavator DATE May 9, 6 TP -6 ROUND SURFACE 9.9 5 mm Dia. Cone 4 6 8 FILL: Loose, brown silty sand, some cobbles and boulders..5 9.9 89.9 LACIAL TILL: Compact to dense, brown silty sand, some gravel and cobbles 88.9 4. 4 87.9 TP terminated in glacial till at 4.m depth (TP dry upon completion) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP -6 ROUND SURFACE 88.9 5 mm Dia. Cone 4 6 8 Compact, brown SILTY SAND, some gravel and cobbles.9 87.9 LACIAL TILL: Dense to very dense, brown silty sand, some gravel and cobbles, trace boulders 86.9 85.9 4. 4 84.9 TP terminated in glacial till at 4.m depth (TP dry upon completion) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP -6 ROUND SURFACE. 8. 5 mm Dia. Cone 4 6 8 Loose to compact, brown SILTY SAND, trace to some gravel, some boulders 8.. 79. TP terminated on bedrock surface at.m depth (WL @.m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP 4-6 ROUND SURFACE.4 79.6 5 mm Dia. Cone 4 6 8 78.6 Loose to compact, brown SILTY SAND, trace some gravel and cobbles, trace boulders 77.6. 76.6 TP terminated in silty sand at.m depth (WL @.m depth) 4 6 8 Undisturbed Remoulded
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road P55 Excavator DATE May 9, 6 TP 5-6 ROUND SURFACE.4 75.96 5 mm Dia. Cone 4 6 8 Loose, dark brown SILTY SAND, some cobbles and boulders.9 74.96 LACIAL TILL: Dense, brown silty sand, some gravel and cobbles 7.96. 7.96 TP terminated in glacial till at.m depth (WL @.5m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road P55 Excavator DATE May 9, 6 TP 6-6 ROUND SURFACE PEAT. 7.66 5 mm Dia. Cone 4 6 8 Compact, brown SILT, some sand 7.66 7.66.4 Compact, brown SILTY SAND, some gravel, cobbles and boulders.8 TP terminated in silty sand at.8m depth (WL @.m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Excavator eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. DATE May 9, 6 P55 TP 7-6 ROUND SURFACE. 7.5 5 mm Dia. Cone 4 6 8 Loose to compact, brown SILTY SAND, trace gravel and cobbles 7.5 7.5.5 LACIAL TILL: Dense, brown silty sand, some gravel, cobbles and boulders. 7.5 TP terminated in glacial till at.m depth (WL @.5m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP 8-6 ROUND SURFACE 7.8 5 mm Dia. Cone 4 6 8 Loose to compact, brown SILTY SAND, some gravel and cobbles.7 7.8 LACIAL TILL: Compact to very dense, brown silty sand, some gravel, cobbles and boulders 7.8 69.8.9 TP terminated in glacial till at.9m depth (WL @.m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP 9-6 ROUND SURFACE 65.9 5 mm Dia. Cone 4 6 8 Compact, dark brown SILTY SAND, some gravel and cobbles.7 64.9 LACIAL TILL: Dense to very dense, brown silty sand with gravel, trace cobbles and boulders 6.9 - grey by.m depth. 6.9 TP terminated in glacial till at.m depth (WL @.9m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP-6 ROUND SURFACE Loose to compact, dark brown SILTY SAND, trace gravel.4.9 65.69 64.69 5 mm Dia. Cone 4 6 8 Very dense, brown SILTY SAND with gravel, some cobbles and boulders 6.69.4 TP terminated on possible bedrock surface at.4m depth (roundwater infiltration at.5m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP-6 ROUND SURFACE. 69.77 5 mm Dia. Cone 4 6 8 Loose, dark brown SILTY SAND, some gravel and cobbles. 68.77 LACIAL TILL: Very dense, brown silty sand with gravel, cobbles and boulders 67.77. 66.77 TP terminated in glacial till at.m depth (WL @.4m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP-6 ROUND SURFACE. 84.96 5 mm Dia. Cone 4 6 8 8.96 Loose to compact, brown SILTY SAND, some gravel, cobbles and boulders 8.96 8.96 4. 4 8.96 TP terminated in silty sand at 4.m depth (TP dry upon completion) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP-6 ROUND SURFACE Loose to compact, dark brown SILTY SAND, some cobbles and boulders..8 8.7 5 mm Dia. Cone 4 6 8 8.7 LACIAL TILL: Compact to very dense, brown silty sand, some gravel, cobbles and boulders 8.7 79.7.6 TP terminated on possible bedrock surface at.6m depth (WL @.m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY round surface elevations at borehole locations provided by Adam Kasprzak Surveying Limited. Excavator DATE eotechnical Investigation - Proposed Roadway Residential Development - Building Supply Road May 9, 6 P55 TP4-6 ROUND SURFACE Loose to dense, dark brown SILTY SAND, some boulders.5.7 78.77 5 mm Dia. Cone 4 6 8 Dense to very dense, brown SILTY SAND with gravel, cobbles and boulders 77.77.7 TP terminated on bedrock surface at.7m depth (TP dry upon completion) 4 6 8
patersongroup 54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP ROUND SURFACE 87. 5 mm Dia. Cone 4 6 8. Compact, reddish brown SAND-RAVEL, some cobbles, silt and clay. 86. Compact, grey SANDY SILT, some gravel.7 (TP dry upon completion) 4 6 8
patersongroup 54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP ROUND SURFACE 8.5 5 mm Dia. Cone 4 6 8.5 Dense, light brown SILTY SAND, some gravel and cobbles 8.5. Dense, grey-brown SILTY SAND, some fine sand seams 4.7 (TP dry upon completion) 4 6 8
patersongroup 54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP ROUND SURFACE 79. 5 mm Dia. Cone 4 6 8.5 Loose, reddish brown SAND, trace silt 5.8 78. Light brown FINE SAND 6.7 (TP dry upon completion) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP 4 ROUND SURFACE 79. 5 mm Dia. Cone 4 6 8. Reddish brown SILTY FINE SAND, some cobbles and boulders. 78. rey-brown SANDY SILT.5 (TP dry upon completion) 4 6 8
patersongroup 54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP 5 ROUND SURFACE 74. 5 mm Dia. Cone 4 6 8. Compact, reddish brown SILTY SAND, some gravel, cobbles and boulders 7 7.. Compact, grey-brown SILTY SAND, some gravel 8.8 (TP dry upon completion) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP 6 ROUND SURFACE 66.5 5 mm Dia. Cone 4 6 8.5 Compact to dense, light brown SANDY SILT, some clay 9.7 Loose, grey-brown coarse SAND. 65.5 rey-brown CLAYEY SILT, some sand and gravel.7 (roundwater infiltration at.7m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP 7 ROUND SURFACE 65. 5 mm Dia. Cone 4 6 8. Compact, reddish brown SILTY SAND with cobbles and boulders. 64. Compact, grey-brown SANDY SILT, some gravel. Loose, grey-brown coarse SAND with gravel.5 (roundwater infiltration at.m depth) 4 6 8
54 Colonnade Road South, Ottawa, Ontario KE 7J5 BORINS BY Braeburn Estates - Building Supply Road round surface elevation interpolated from topographic plan prepared by Adam Kasprzak Surveying Ltd. Backhoe DATE March, 5 PH6 TP 8 ROUND SURFACE. 49. 5 mm Dia. Cone 4 6 8 Compact, red-brown SILTY SAND with cobbles and boulders 48.. Refusal on inferred boulders at.m depth (TP dry upon completion) 4 6 8
SYMBOLS AND TERMS Behavioural properties, such as structure and strength, take precedence over particle gradation in describing soils. Terminology describing soil structure are as follows: Desiccated - having visible signs of weathering by oxidation of clay minerals, shrinkage cracks, etc. Fissured - having cracks, and hence a blocky structure. Varved - composed of regular alternating layers of silt and clay. Stratified - composed of alternating layers of different soil types, e.g. silt and sand or silt and clay. Well-raded - Having wide range in grain sizes and substantial amounts of all intermediate particle sizes (see rain Size Distribution). Uniformly-raded - Predominantly of one grain size (see rain Size Distribution). The standard terminology to describe the strength of cohesionless soils is the relative density, usually inferred from the results of the Standard Penetration Test (SPT) N value. The SPT N value is the number of blows of a 6.5 kg hammer, falling 76 mm, required to drive a 5 mm O.D. split spoon sampler mm into the soil after an initial penetration of 5 mm. Relative Density N Value Relative Density Very Loose <4 <5 Loose 4-5-5 Compact - 5-65 Dense -5 65-85 Very Dense >5 >85 The standard terminology to describe the strength of cohesive soils is the consistency, which is based on the undisturbed undrained shear strength as measured by the in situ or laboratory vane tests, penetrometer tests, unconfined compression tests, or occasionally by Standard Penetration Tests. Consistency Undrained N Value Very Soft < < Soft -5-4 Firm 5-5 4-8 Stiff Very Stiff 5- - 8-5 5- Hard > >
SYMBOLS AND TERMS (continued) (continued) Cohesive soils can also be classified according to their sensitivity. The sensitivity is the ratio between the undisturbed undrained shear strength and the remoulded undrained shear strength of the soil. Terminology used for describing soil strata based upon texture, or the proportion of individual particle sizes present is provided on the Textural Soil Classification Chart at the end of this information package. ROCK DESCRIPTION The structural description of the bedrock mass is based on the Rock Quality Designation (RQD). The RQD classification is based on a modified core recovery percentage in which all pieces of sound core over mm long are counted as recovery. The smaller pieces are considered to be a result of closelyspaced discontinuities (resulting from shearing, jointing, faulting, or weathering) in the rock mass and are not counted. RQD is ideally determined from NXL size core. However, it can be used on smaller core sizes, such as BX, if the bulk of the fractures caused by drilling stresses (called mechanical breaks ) are easily distinguishable from the normal in situ fractures. RQD ROCK QUALITY 9- Excellent, intact, very sound 75-9 ood, massive, moderately jointed or sound 5-75 Fair, blocky and seamy, fractured 5-5 Poor, shattered and very seamy or blocky, severely fractured -5 Very poor, crushed, very severely fractured S SS - Split spoon sample (obtained in conjunction with the performing of the Standard Penetration Test (SPT)) TW - Thin wall tube or Shelby tube PS - Piston sample AU - Auger sample or bulk sample WS - Wash sample RC - Rock core sample (Core bit size AXT, BXL, etc.). Rock core samples are obtained with the use of standard diamond drilling bits.
SYMBOLS AND TERMS (continued) RAIN SIZE DISTRIBUTION MC - Natural moisture content or water content of sample, LL - Liquid Limit, (water content above which soil behaves as a liquid) PL - Plastic limit, (water content above which soil behaves plastically) PI - Plasticity index, (difference between LL and PL) Dxx - rain size which xx of the soil, by weight, is of finer grain sizes These grain size descriptions are not used below.75 mm grain size D - rain size at which of the soil is finer (effective grain size) D6 - rain size at which 6 of the soil is finer Cc - Concavity coefficient = (D) / (D x D6) Cu - Uniformity coefficient = D6 / D Cc and Cu are used to assess the grading of sands and gravels: Well-graded gravels have: < Cc < and Cu > 4 Well-graded sands have: < Cc < and Cu > 6 Sands and gravels not meeting the above requirements are poorly-graded or uniformly-graded. Cc and Cu are not applicable for the description of soils with more than silt and clay (more than finer than.75 mm or the # sieve) CONSOLIDATION TEST p o - Present effective overburden pressure at sample depth p c - Preconsolidation pressure of (maximum past pressure on) sample Ccr - Recompression index (in effect at pressures below p c ) Cc - Compression index (in effect at pressures above p c ) OC Ratio Overconsolidaton ratio = p c / p o Void Ratio Initial sample void ratio = volume of voids / volume of solids Wo - Initial water content (at start of consolidation test) PERMEABILITY TEST k - Coefficient of permeability or hydraulic conductivity is a measure of the ability of water to flow through the sample. The value of k is measured at a specified unit weight for (remoulded) cohesionless soil samples, because its value will vary with the unit weight or density of the sample during the test.