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HomeMy WebLinkAboutHAR SHALOM MINOR SUBDIVISION - 45 93 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTMOI S T U R E -DENS ITY DETERMI NATION Samples of representative fill materials to be placed shall be fur- nished by the contractor to the soils engineer for determination of maximum density and optimum moisture or percent of Relative Density for these materials. Tests for this determination will be made using methods conforming to requirements of ASTM D 698, ASTM D 1557, or ASTM D 2049. Copies of the results of these tests will be furnished to the contractor. These test results shall be the basis of control for all compaction effort. DENSITY TESTS The density and moisture content of each layer of compacted fill will be determined by the soils engineer in accordance with ASTM D 1556, ASTM D 2167, or ASTM D 2922. Any material found not to comply with the minimum specified density shall be recompacted until the required density is obtained. The results of all density tests will be furnished to both the owner and the contractor by the soils engineer. c_a P L A C I N G F I L L No sod, brush, frozen material, or other unsuitable material shall be placed in the fill. Distribution of material in the fill shall be such as to preclude the formation of lenses of material differing from the surrounding material. The materials shall be delivered to and spread on the fill surface in a manner which will result in a uniformly com- pacted fill. Prior to compacting, each layer shall have a maximum thickness of eight inches, and its upper surface shall be approximately horizontal. MOISTURE CONTROL While being compacted, the fill material in each layer shall as nearly as practical contain the amount of moisture required for optimum com- paction or as specified, and the moisture shall be uniform throughout the fill. The contractor may be required to add necessary moisture to the fill material and to uniformly mix the water with the fill material if, in the opinion of the soils engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface. If, in the opinion of the soils engineer, the material proposed for use in the compacted fill is too wet to permit adequate compaction, it shall be dried in an acceptable manner prior to placement and compaction. COMPACTION When an acceptable, uniform moisture content is obtained, each layer shall be compacted by a method acceptable to the soils engineer and as specified in the foregoing report as determined by applicable standards. Compaction shall be performed by rolling with approved tamping rollers, pneumatic -tired rollers, three-wheelpower rollers, vibratory compactors or other approved equipment well -suited to the soil. being compacted. If a sheepfoot roller is used, it shall be provided with cleaner bars attached in•a manner which will prevent the accumulation of material between the tamper feet. The rollers should be designed so that the effective weight can be increased. r_'i APPENDIX C Suggested Specifications for Placement of Compacted Earth Fill and/or Backfills. GENERAL A soils engineer shall be the owner's representative to.inspect and control all compacted fill and/or compacted backfill placed on the project. The soils enqineer shall approve all earth materials prior to their use, the methods of placing, and the degree of compaction obtained. A verification of approval from the soils enaineer will be required prior to the owner's final acceptance of the filling opera- tions. MATERIALS Soils used for all compacted fill beneath interior floor slabs shall be a granular, nonexpansive type. The upper 12" to 18" of compacted earth backfill placed adjacent to exterior foundation walls shall be an impervious, nonexpansive material. No material having a maximum dimension greater than six inches shall be placed in any fill. All materials proposed for use in compacted fill and/or compacted back - fill shall be approved prior to their use by the soils engineer. PREPARATION OF S U B G R A D E All topsoil, vegetation, debris, and other unsuitable material shall be removed to a depth satisfactory to the soils engineer before begin- ning preparation of the subgrade. The subgrade surface of the area to be filled shall be scarified a minimum depth of six inches, mois- tened as necessary, and compacted in a manner specified below for the subsequent layers of fill. Fill shall not be placed on frozen or muddy ground. C-2 APPENDIX C. SUMMARY OF TEST RESULTS Atterberg Limits Boring No. . 2 Depth (Ft.) 3.0 Liquid Limit 38.1 Plastic Limit 19.3 Plasticity Index 18.7 % Passing 200 _ 83.4 .. _....; Group:Index ::;.:.. 15.2 Classification Unified CL AASHTO ..A-6(15) B-4 BORING NO, SUMMARY OF TEST RESULTS DEPTH DRY DENSITY UNCONFINED COMPRESSIVE FT. MOISTURE P.C.F. STRENGTH-P.S.F. 0.5-1.5 18.0.',. 2.0-3.0 24.5 .94.8 27800 3.0-4.0 7.0-8.0 7 11:2.8 .7,020 8.0-9.0 13.5-14.5 20.2 0.5-1.5 :. 213 3.0-4.0 27.3 89.0 2,240 4.0-5.0 7.0-8.0 18.6 104.1 - 3,060 8.0-9.0 13.5-14.5 20.3 PENETRATION BLOWS/INCHES 16/12 6/12 10/12 2/12 15/12 7112 6/12 5/12 jW11111W CONSOLIDATION --SWELL TEST BORING NO `� 1 DEPT}L2_� ' DRY DENSITY H, 90#/Ft3 % MOISTURE 24.5% .69 .68 o .67 INS a ix H o .66 .65 z •` .64 .63 ppRp 'APPLIED PRESSURE-TONS/SQ. FT. J `! 1 it �. t 2 O V APPLIED PRESSURE-TONS/SQ. FT. EMPIRE LABORATORIES, INC. APPENDIX B. No2 i A 5040 .: 5035 -`'' ` ., , 5030 KEY TO BORING LOGS �'�✓ TOPSOIL �•' • GRAVEL ® FILL '�� SAND & GRAVEL � // SILT =77. SILTY SAND & GRAVEL //I CLAYEY SILT o p e COBBLES •� SI LT ILT �' o� SAND, GRAVEL & COBBLES ® CLAY ® WEATHERED BEDROCK SILTY CLAY P SILTSTONE BEDROCK ZA SANDY CLAY ® CLAYSTONE BEDROCK SAND � SANDSTONE BEDROCK �. • SILTY SAND LIMESTONE CLAYEY SAND xxx x x ■ X X GRANITE SANDY SILTY CLAY a ' SHELBY TUBE SAMPLE STANDARD PENETRATION DRIVE SAMPLER WATER TABLE 4 DAYS AFTER DRILLING C HOLECAVED T 5/12 Indicates that 5 blows of a 140 pound hammer falling 30 inches was requires A- 3 EMPIRE LABORATORIES, INC. . � a t � j Na .. ,.A/v _ , ._ Pi?OPO SAD ST eVC7 a RC APPENDIX A. (t) It is recxmvended that all compaction requirements specified herein be verified in the field with density tests perfor:ied under thin direction of the sails engineer. {5) It is recommended that a registered professional engineer design the substructure .and that he take into account the findings and recommendations of this report. GENERAL COi?iE'rTS This report has been prepared to aid in the evaluation of the property and to assist the architect and/or engineer in the design of this project. In the event that any changes in the design of the structure or its location are planned, the conclusions and recommen- dations contained in this report will not be considered valid unless said changes are reviewed and conclusions of this report modified or approved in writing by Empire Laboratories, Inc., the soils engineer of record. Every effort was made to provide comprehensive site coverage through careful locations of the test borings, while keeping the site investigation economically feasible. Variations in soil and groundwater conditions between test borings may be encountered during construction. In order to pernit correlation between the reported subsurface conditions and the actual conditions encountered during construction and to aid in carrying out the plans and specifications as originally contemplated, it is recomwnded that Empire Laboratories, Inc. be retained to perform continuous construction review during the excavation and foundation phases of the work. Empire Laboratories, Inc. assumes no responsibility for compliance with the recommendations included in this report unless they have been retained to perform adequate on -site construction review during the course of construction. Sieve siza Passing 1" �Q-10u 4" 60-90 #4 "V-ti5 #10 2C-55 12 f)O 5-15 Liquid Limit - 25 Maximum Plasticity Index - 5 laxislur► The base course should be placed on the subgrade at or near optimum moisture and compacted to at least ninety-five percent (95%) of Standard Proctor Density ASTH D 698-73. It is important that the base course be shaped to grade so that proper drainage of the parking area is obtained. GEIiERAL RECOI-t;1 MOM T IONS (1} Laboratory test results indicate that water soluble sulfates in the soil are negligible, and a Type I cenent neay be used in all concrete exposed to subsoils. All slabs on grade sub- jected to de-icing chemicals should be composed of a more durable concrete using a Type II cenent with low dater-ca.,ent ratios and higher air contents. (2) Finished grade should be sloped away from the structure on all sides to give positive drainage. 'Ten percent (10 ) for the first ten (10) feet away from the structure is the suggested slope. (3) Gutters and downspouts should be designed to carry roof runoff water well beyond the backfill area. (d) Footing sizes should be proportioned to equalize the unit loads applied to the soil and thus nininize differential settlem. nts. area contained within these Joints be no greater than six hundred twenty-five (a5) square feet. Tire upper clay soils encountered at the site are plastic and iaay be susceptible to swelling if they are allotirud to dry below their in situ noisture levels dnd are then rewetted. Therefore, to prevent drying of the clay soils below their in -place moisture levels, all foundation and building excavations should not be allowed to remain open for extended periods of time. Parking The required total thickness for the pavement structure is de- pendent primarily upon the foundation soil, or subgrade, and upon traffic conditions. In view of the soil conditions encountered at the site and the type and volume of traffic, it is recomr^ended that a mini- num thickness of nine (9) incnes �)e provided for the pavement structure. This thickness should consist of seven (7) inches of a veil -graded base course overlain by two (Z) inches of asphaltic concrete. All topsoil, organic natter, and other unsuitable material should be removed from the proposed parking area. All subgrade should be scarified a minimum of six (6) inches and reconpacted to at least ninety- five percent (95A) of Standard Proctor Density ASTci 0 698-78. (See Appendix C.) ? i Fill :'material placed in the parking area .should be an approved, granular -type material compacted at or near optimum moisture to at least ninety-five percent (95%) of Standard Proctor Density ASTM 0 69€3-78. The surface of the subgrade should be hard, uniform, smooth, and true to grads. To prevent the growth of weeds, it 1s suggested that all sub - grade under parking areas be treated with a soil sterilant. The base course overlying the subgrade should consist of a hard, durable, crushed rock or stone and filler and should have a minimum C.B.R. value of 80. The composite base course material should be free from vegetable matter and lumps or balls of clay and should meet the City of Fort Collins specifications which follow: basement slabs should be underlain by a minimm of eight (8) inches of clean, graded gravel or crushed rock devoid of fines. All backfill placed around the outside perimeter of the structure should be mechanically compacted at optimum moisture to at least ninety percent (901) of Standard Proctor Uensity ASTM U 69340. (See Appendix C.) The backfill should be placed in uniform six (6) to eight (o) inch lifts, and puddling should not be perraitted as amethod of compaction. Berms backfill should also be compacted to the above requirements. It is recommended that all backfill requirements specified herein be verified in the field with density tests performed under the direction of a soils engineer. It is estimated that the red granular sandy silty clay used as backfill will exert an equivalent fluid pressure of forty (40) pounds per cubic foot on the foundation wall. The upper brown silty clay material is estimated to exert an equivalent fluid pressure of fifty (5.0) pounds per cubic foot on the foundation wall. It is strongly recommended that vegetation placed on the berm; along the northern and western sides of the structure be a type that has low moisture require- ments. The underground sprinkling system should not be installed in a manner which allows water to be sprayed along the foundation wall of the structure, especially in a berm area. This should be taken into account in the landscape planning. We further recorsmend that all base- ment foundation walls and the foundation wall along the berm be thorough- ly waterproofed to help minimize seepage through the walls. Subgrade below slabs on grade should be prepared in accordance with the recommendations discussed in the "Site Grading and Utilities° section of this report. All slabs on grade at the upper level should be underlain by a minimum of four (4) inches of gravel or crushed rock devoid of fines. The gravel layer will act as a capillary break and will help to distribute floor loads. Basement floor slabs should be underlain by a minimum of eight (8) inches of clean, graded gravel or crushed rock as discussed above. All slabs on grade should be designed for the imposed loading. To minimize and control shrinkage cracks which will develop on the slabs on grade, it is suggested that control Joints be placed every twenty (20) to twenty-five (25) feet and that the total All stripping, grubbing, subgrade preparation, and fill and back - fill placement should be done under continuous observation of the soils engineer. Field density tests should be taken daily in the compacted subgrade, fill, and backfill under the direction of the soils engineer. Foundations In view of the loads transmitted by proposed structure and the soil conditions encountered at the site, it is recommended that the structure be supported by conventional spread footings founded on the original undisturbed soil. The undisturbed nature of the soil should be verified by the soils engineer prior to placement of any foundation concrete. All footings should be placed a minimum of thirty (30) inches below finished grade for frost protection, and when founded at this level may be designed for a maximum bearing capacity of two thousand (2000) pounds per square foot (dead load plus maximum live load). The predicted settlement under the above maximum loading, as determined by laboratory consolidation tests, should be less than one- half (1/2) inch, generally considered to be within acceptable toler- ances. Basements. Backfill, and _Slabs on Grade In view of the depth to groundwater encountered at the site,.it is our opinion that basement construction is feasible on the property, providing the finished basement floor is placed a minimum of three (3) feet above existing groundwater or above elevation 5031.3. However, as a precaution against possible rising groundwater due to the proximity of the site to the existing irrigation ditch and the detention pond located Hest and south of the property, it is recommended that a sump be pro- vided in the basement area. The sump should have a minimum diameter of eighteen (18) inches and be a minimum of three (3) feet deep. The sump should be surrounded by a one (1) foot layer of clean, graded gravel three -fourths (3/4) to one and one-half (1-1/2) inch in size. The - 5- Site Grading and utilities It is recowmended that the upper six (6) inches of all topsoil below filled and paved areas be stripped and stockpiled for reuse in planted areas. The upper six (6) inches of all subgrade below filled areas should be scarified and recompacted two percent (2%) Bret of optimur, moisture to at least ninety percent (904%) of Standard Proctor Density AMI D 698-78. (See Appendix C.) Finished subgrade in cut sections should be scarified a minimum of six (6) inches and recompacted two percent (2%) wet of optimum moisture to at least ninety-five percent (951) of Standard Proctor Density AST11 0 698-78. All fill should con- sist of the on -site soils or imported material approved by the soils engineer. The fill should be placed in uniform six (6) to eight (8) inch lifts and compacted two percent (2S) wet of optimur. moisture to at least ninety-five percent (95%) of Standard Proctor Density ASTH 0 693- 78. All utility trenches dug in the upper clay soils four (4) feet or more in depth should be excavated on slopes no steeper than'1:1. Where utilities are excavated below groundwater, dewatering will be required during placement of pipe and backfilling to insure proper construction. All piping should be bedded to insure proper load distribution and to eliminate breakage during the backfilling operations. All backfill placed in utility trenches in open and planted areas should be compacted in uniform lifts at optima moisture to at least ninety percent (90%) of Standard Proctor Density ASIIA 0 698-78 the full depth of the trench. The upper four (4) feet of backfill placed in utility trenches under roadways and paved areas should be compacted at or near optimum moisture to at least ninety-five percent (95%) of Stand- ard Proctor Density ASTM 0 698-78, and the lower portion of these trenches should be compacted to at least ninety percent (90%) of Stand- ard Proctor tensity ASTM 0 698-78. Addition of roisture to and/or drying of the subsoils may be required to assure proper compaction. -A- (1) Silty Topsoil: The site is overlain by a one (1) foot layer of silty topsoil. The upper six (6) inches of topsoil have been penetrated by root growth and organic matter and should not be used as bearing and/or backfill material. (2) Silty Clay: A layer of brown silty clay underlies the topsoil and extends to depths three and one-half (3-1/2) to five (5) feet below the surface. The silty clay is plastic and ex- hibits moderate bearing characteristics in its generally moist in situ condition. When wetted, the shearing strength of the clay is reduced; and upon loading, consolidation readily occurs. (3) Sandy Silty Clay: A layer of red sandy silty clay underlies the upper clay and extends to the depths explored. The silty clay is plastic, contains varying amounts of sand and lenses of sand and gravel, and exhibits moderate bearing character- istics in its moist to near -saturated in situ condition. (4) Groundwater: At the time of the investigation, free ground- water was encountered at depths eleven and one-half (11-1/2) to twelve (12) feet below the surface. Water levels in this area are subject to change due to seasonal variations, irri- gation demands on or adjacent to the site,, flows in the . irrigation ditch located adjacent to the property, and fluctu- ations in the detention pond located south of the site. RECOMMENDATIONS AND DISCUSSION It is our understanding that the proposed synagogue is to be a single -story frame structure having a partial full -depth basement. An eatth berm approximately the full height of the building will be placed around the north and west sides of the structure. A parking area is proposed along the west and south sides of the property. SITE LOCATION AND DESCRIPTION The proposed site is located at 725 Test Drake Road in southwest Fort Collins, Colorado. More particularly, the site is described as a tract of land situate in the northwest 1/4 of Section 26, Township 7 Borth, Range 69 West of the Sixth P.M., Fort Collins, Larimer County, Colorado. The site consists of a vacant lot vegetated with alfalfa and weeds. Relatively flat, the property exhibits generally poor surface drainage. A concrete -lined irrigation ditch lies along the west and south property lines, and a large detention pond is located south of the irrigation ditch. A fence lies along the irrigation ditch and along the east property line. The site is bordered on the east by an existing residential area and on the north by West Drake Road. Approximately eight (S) inches of pit -run fill has been placed along the northern edge of the site adjacent to Wiest Drake Road. LABORATORY TESTS AND EXAMINATION Samples obtained from the test borings were subjected to testing and inspection in the laboratory to provide a sound basis for deter- mining the physical properties of the soils encountered. Moisture contents, dry unit weights, unconfined compressive strengths,, water soluble sulfates, and the Atterberg limits were determined. A summary of the test results is included .in Appendix B. Consolidation character- j istics were also determined, and a curve showing this data is included in Appendix B. SOIL AND GRO UDWATER CONDITIONS The soil profile at the site consists of strata of materials ar-. ranged in different combinations. In order of increasing depths, they are as follows: REPORT OF A SOILS AND FOUNDATION INVESTIGATION SCOPE This report presents the results of a soils and foundation investi- gation prepared for the proposed structure to be located on West Drake Road in southwest Fort Collins, Colorado. The investigation was carried out by means of test borings and laboratory testing of samples obtained from these borings. The objectives of this investigation were to (1) determine the suitability of the site for construction purposes, (2) make recommenda- tions regarding the design of the substructure, and (3) recommend certain precautions which should be taken because of adverse soil and/or groundwater conditions. SITE INVESTIGATION The field investigation, carried out on April 23, 1980, consisted of drilling, logging, and sampling two (2) test borings. The locations of the test borings are shown on the Test Boring Location Plan included in Appendix A of this report. Boring logs prepared from the field logs are shown in Appendix A. These logs show soils encountered, location of sampling, and groundwater at the time of the investigation. All borings were advanced with a four -inch diameter, continuous - type, power -flight auger drill. During the drilling operations, an engineering geologist from Empire Laboratories, Inc. was present and made a continuous visual inspection of the soils encountered. I -1- Empire LaToratories, Inc. MATERIALS AND FOUNDATION ENGINEERS 214 No. Howes Fort Collins, Colorado 80522 P.O. Box 429 (303) 484-0359 May 28, 1580 Congregation Har Shalom 1201 Grovewood Court Fort Collins, Colorado 80525 Attention: Building Committee Gentlemen: Branch Offices 1242 Bramwood Place Longmont, Colorado 80501 P.O. Box 1135 (303)776-3921 3151 Nation Way Cheyenne, Wyoming 82001 P.O. Box 10076 1307) 632.9224 We are pleased to submit our Report of a Soils and Foundation Investi- gation prepared for the proposed synagogue to be located in southwest Fort Collins, Colorado. Based upon our findings in the subsurface, we feel that the site is suitable for the proposed construction, providing the design criteria and recommendations set forth in this report are met. The accompanying report presents our findings in the subsurface and our recommendations based upon these findings. Very truly yours, EMPIRE LABORATORIES, ItiC. Heil R. Sherrod Senior Engineering Geologist Reviewed by: Chester C. Smith, P.E. President cic tt::ZVFK, Architects/Planners EMBER OF CONSULTING ENGINEERS COUNCIL om 4808 , i*= 'Se sj1 e°, �: 0 : ''rr,0F 1C0N-,.,` 'di I TABLE OF CONTENTS Table of Contents .............................................. i Letter of Transmittal .......................................... Report......................................................... 1 A-1 test Boring Location Plan.........o.......................... A-C Key to Borings ............................................... J Loa of wrings ............................................... A - Appendix d..................................................... 3-1 Consolidation Test Data ...................................... E-t Sumviary of Test Results ...................................... 3-1 Appendix C..................................................... C-1 REPORT OF A SOILS AND FOUNDATION INVESTIGATION FOR CONCREGATIOn HAR SHAL04 FORT COLLINS* COLORADO PROJECT NO. 3916-80 RE: PROPOSED SYNAGOGUE FART COLLINS, COLORADO BY WIRE LAGORATORIES, I'!C. 214 NORTH HOLIES STREET FORT COLLINS* COLORADO 80521