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HomeMy WebLinkAboutB12-0367 GEOTECHNICAL INVESTIGATIONBla-oa(017 GEOTECHNICAL INVESTIGATION PROPOSED RESIDENCE LOT 6, JUNIPER LANE BIGHORN SUBDIVISION VAIL, COLORADO Koechlein Consulting Engineers, Inc. Consulting Geotechnical Engineers 12364 W. Alameda Pkwy • Suite 115 • Lakewood, CO 80228 -2845 LAKEWOOD AVON SILVERTHORNE (303) 989 -1223 (970) 949 -6009 (970) 468 -6933 (303) 989 -0204 FAX (970) 949 -9223 FAX (970) 468 -6939 FAX KOECHLEIN CONSULTING ENGINEERS, INC. CONSULTING GEOTECHNICAL AND MATERIALS ENGINEERS GEOTECHNICAL INVESTIGATION PROPOSED RESIDENCE LOT 6, JUNIPER LANE BIGHORN SUBDIVISION VAIL, COLORADO Prepared for: Greg Cummings G & J Construction 5135 Main Gore Drive Vail, Colorado 81657 Job No. 05 -172 October 24, 2005 DENVER: 12364 West Alameda Prkwy., Suite 115, Lakewood, CO 80228 (303) 989 -1223 AVON /SIL PER THORNE: (970) 949 -6009 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnical Engineers ' TABLE OF CONTENTS SCOPE 1 1 EXECUTIVE SUMMARY SITE CONDITIONS PROPOSED CONSTRUCTION 3 INVESTIGATION 4 SUBSURFACE CONDITIONS RADON 5 5 MOLD 6 ' GROUND WATER 6 EXISTING FILL 6 EXCAVATIONS 7 ' FOUNDATIONS 8 SLABS -ON -GRADE 9 FOUNDATION DRAINAGE 11 LATERAL WALL LOADS 12 RETAINING WALLS 13 ' SURFACE DRAINAGE 13 IRRIGATION 14 COMPACTED FILL 15 LIMITATIONS 16 VICINITY MAP Fig. 1 LOCATIONS OF EXPLORATORY TEST PITS Fig. 2 ' LOGS OF EXPLORATORY TEST PITS LEGEND OF EXPLORATORY TEST PITS Fig. 3 Fig. 4 GRADATION ANALYSIS RESULTS Fig. 5 ' TYPICAL WALL DRAIN DETAIL Fig. 6 TYPICAL RETAINING WALL DRAIN DETAIL Fig. 7 SUMMARY OF LABORATORY TEST RESULTS Table I October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC Job No. 05 -172 Consulting Geotechnical Engineers SCOPE This report presents the results of a geotechnical investigation for the proposed residence to be constructed on Lot 6, Juniper Lane, Bighorn Subdivision in Vail, Colorado. The approximate site location is shown on the Vicinity Map, Fig. 1. The purpose of this investigation was to evaluate the subsurface conditions at the site and to provide geotechnical recommendations for the proposed residence. This report includes descriptions of subsurface soil and ground water conditions encountered in the exploratory test pits, recommended foundation systems, and recommended design and construction criteria. This report was prepared from data developed during our field investigation and our experience with similar projects and subsurface conditions in the area. The recommendations presented in this report are based on a residence being constructed at the approximate location indicated on the Locations of Exploratory Test Pits, Fig. 2. We should be contacted by the contractor and/or owner to review our recommendations when final plans for the residence have been completed. A summary of our findings and conclusions is presented in the following paragraphs. EXECUTIVE SUMMARY 1. The subsurface conditions encountered in the exploratory test pits varied. Subsurface conditions encountered in exploratory test pit TP -1 consisted of approximately 1.5 feet of topsoil overlying very dense sand and gravel with cobbles and boulders to the maximum depth explored of 5.0 feet. October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnical Engineers Practical excavator refusal on a boulder was encountered at a depth of 5.0 feet. Subsurface conditions encountered in exploratory test pit TP -2 consisted of approximately 1.5 feet of topsoil overlying existing fill to a depth of 5.5 feet. The existing fill consisted of medium dense, clayey, gravelly sand. Underlying the existing fill to the maximum depth explored of 8.0 feet, the subsurface conditions consisted of medium dense sand with scattered gravel. 2. Topsoil and existing fill were encountered to a depth of 5.5 feet on this site. Greater depths of topsoil and fill could be encountered in the areas of the proposed construction. The topsoil and existing fill should be removed from all construction areas prior to construction. The topsoil and existing fill may be used in landscaping areas. Provided the existing fill is free of deleterious material, it may be used as structural fill for this project. Refer to the EXISTING FILL section of this report for additional details. 3. At the time of this investigation, ground water was not encountered in either of the exploratory test pits to the maximum depth explored of 8.0 feet. However, this investigation was conducted during a dry time of year and ground water could be encountered during construction at wetter times of the year. Refer to the GROUND WATER section of this report for further recommendations. 4. We anticipate that the subsurface conditions at the foundation elevations for the proposed residence will consist of the natural sand and gravel or the existing fill overlying natural sand. In our opinion, the natural sand and gravel and/or natural sand will safely support a spread footing foundation system for the proposed residence. Refer to the FOUNDATIONS section of this report for complete recommendations. 5. Due to the presence of existing fill, special considerations should be taken into account when constructing slabs -on -grade for the proposed residence. Refer to the SLABS -ON -GRADE section of this report for complete recommendations. 6. Open cuts and excavations require precautions as outlined in this report in order to maintain the stability of slopes and sides of excavations. Refer to the EXCAVATION section of the report for additional details. 2 October 24, 2005 Job No. 05 -] 72 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers 7. Because cobbles and boulders were encountered in the exploratory test pits, heavy -duty excavation equipment may be required to complete the required excavations. 8. Drainage around the proposed residence should be designed and constructed to provide for rapid removal of surface runoff and avoid concentration of water adjacent to foundation walls. Refer to the SURFACE DRAINAGE section of this report for additional recommendations. 9. The potential for radon gas is a concern in the area. Refer to the RADON section of this report for additional recommendations 10. The potential for mold is a concern in new construction. Refer to the MOLD section of this report for additional recommendations. SITE CONDITIONS The proposed residence will be constructed on Lot 6, Juniper Lane in the Bighorn subdivision in Vail, Colorado. Currently the site is a vacant lot. The lot is bordered on the northeast by Juniper Lane; on the southeast, southwest, and northwest by single family residences. The topography of the lot slopes down to the northeast at a grade of approximately 3 to 4 percent. Vegetation on the lot consists of grasses, weeds, and several small bushes. PROPOSED CONSTRUCTION At the time of this investigation, no plans for the proposed residence were available. However, based on a conversation with the owner, we understand that the October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC Job No. 05 -172 Consulting Geotechnical Engineers proposed residence will consist of a two -story, single family residence. No basement is planned for the residence. We anticipate the residence will be of cast -in -place concrete and wood frame construction with slab -on -grade floors. Access to the residence will be from Juniper Lane. Maximum column and wall loads were assumed to be those normally associated with residential construction. INVESTIGATION Subsurface conditions were investigated at this site on October 3, 2005 by observing the excavation of two exploratory test pits with a mini- trackhoe at the approximate locations shown on the Locations of Exploratory Test Pits, Fig. 2. An engineer from our office was on site to observe the excavation of the exploratory test pits and visually classify and document the subsurface soil and ground water conditions. A description of the subsurface soils encountered in the exploratory test pits is shown on the Logs of Exploratory Test Pits, Fig. 3; and on the Legend of Exploratory Test Pits, Fig. 4. Representative soil samples obtained from the exploratory test pits were tested in our laboratory in order to determine their natural moisture content and gradation properties. The results of the laboratory tests are presented on the Logs of Exploratory, Test Pits, Fig. 3; on the Gradation Test Results, Fig. 5; and in the Summary of Laboratory Test Results, Table I. 4 October 24, 2005 Job No. 05 -172 SUBSURFACE CONDITIONS KOECHLEM CONSULTING ENGINEERS, INC Consulting Geotechnical Engineers The subsurface conditions encountered in the exploratory test pits varied. The subsurface conditions encountered in exploratory test pit TP -1 consisted of approximately 1.5 feet of topsoil overlying red - brown, dry, very dense sand and gravel with cobbles and boulders to the maximum depth explored of 5.0 feet. Practical excavator refusal on a boulder occurred at a depth of 5.0 feet. The subsurface conditions encountered in exploratory test pit TP -2 consisted of approximately 1.5 feet of topsoil overlying existing fill to a depth of 5.5 feet. The existing fill consisted of dark brown, slightly moist, medium dense, clayey, gravelly sand. Underlying the existing fill to the maximum depth explored of 8.0 feet, the subsurface conditions consisted of red - brown, moist, medium dense sand with scattered gravel. At the time of this investigation no ground water was encountered in either of the exploratory test pit to the maximum depth explored of 8.0 feet. is s6►I In recent years, radon gas has become a concern. Radon gas is a colorless, odorless gas that is produced by the decay of minerals in soil and rock. The potential for radon gas in the subsurface strata is likely. Because no below grade areas are planned for the proposed residence ventilation for below grade areas will not be necessary. However, if plans change, we recommend that below grade areas be constructed with ventilation. 5 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnical Engineers MOLD Mold tends to grow in areas that are dark and damp, such as bathrooms, crawlspaces or other below grade areas. Recommendations for mold prevention, mitigation, or remediation are outside the scope of this investigation. We recommend that the contractor and /or owner contact a professional Industrial Hygienist to provide specific recommendations for the prevention and /or remediation of mold. GROUND WATER At the time of this investigation no ground water was encountered in either of the exploratory test pits to the maximum depth explored of 8.0 feet. However, this investigation was performed during a dry time of year. During wetter times of the year ground water may be encountered. If ground water is encountered during excavation for the proposed residence, we should be contacted immediately to provide recommendations on how to control the ground water. EXISTING FILL Existing fill was encountered to a depth of 5.5 feet in exploratory test pit TP -2. Greater amounts of fill may be encountered across the site. The existing fill consisted of dark brown, slightly moist, medium dense clayey, gravelly sand. Because we anticipate el October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC Job No. 05 -172 Consulting Geotechnical Engineers that the existing fill was not placed in a controlled manner, all existing fill should be removed from construction areas prior to beginning construction. The existing fill may be used as structural fill for this project provided it is free from deleterious material such as organics, trash, and construction debris. EXCAVATIONS We anticipate that excavations up to 5.5 feet in depth may be required to remove the existing fill. However, greater amounts of fill may be encountered across the site, resulting in excavations deeper than 5.5 feet. Care needs to be exercised during construction so that the excavation slopes remain stable. The subsurface soils, which consisted of the existing fill, natural sand and gravel with cobbles and boulders, and natural sand classify as Type C soils in accordance with OSHA regulations. OSHA regulations should be followed in all excavations and cuts. Because cobbles and boulders were encountered in the exploratory test pits, it is our opinion that heavy -duty construction equipment may be required to complete the necessary excavations. Up to 1.5 feet of topsoil was encountered in the exploratory test pits. Greater depths of topsoil could be encountered throughout the site. All topsoil beneath the proposed construction should be removed. The topsoil may be used in landscape areas. 7 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnical Engineers FOUNDATIONS We anticipate that the subsurface soils at the foundation elevations for the proposed residence will consist of the existing fill and natural sand and gravel with cobbles and boulders. The existing fill is not suitable for the construction of foundations and must be removed prior to the construction of foundations to expose the underlying natural sand. In our opinion, the proposed residence may be supported by a spread footing foundation system bearing on the natural sand and gravel with cobbles and boulders or natural sand. We recommend that the spread footing foundation system be designed and constructed to meet the following criteria: 1. Footings should be supported by the undisturbed, natural sand and gravel with cobbles and boulders; natural sand; or properly moisture conditioned and compacted structural fill, as described below in Items 5, 8, and 9. I 2. We recommend wall and column footings be designed for a maximum allowable soil bearing pressure of 3,000 psf. 3. Spread footings constructed on the natural sand and gravel with cobbles and boulders or natural sand could experience up to 0.5 inch of differential movement between foundation elements. Because the soils are granular, ' we anticipate that the majority of the differential settlement will occur during construction. ' 4. Wall footings and foundation walls should be designed to span a distance of at least 10.0 feet in order to account for anomalies in the soil or fill. 5. Foundation wall backfill should not be considered for support of load bearing footings. Footings should be stepped and supported by undisturbed natural soils and should not be constructed on foundation wall backfill. Foundation walls or grade beams should be designed to span across an excavation backfill zone and should not be constructed with footings twithin this zone. i 1 8 r October 24, 2005 Job No. 05 -172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers 6. The base of the exterior footings should be established at a minimum depth below the exterior ground surface, as required by the local building code. We believe that the depth for frost protection in the local building code in this area is 4.0 feet. 7. Column footings should have a minimum dimension of 24 inches square and continuous wall footings should have a minimum width of 16 inches. Footing widths may be greater to accommodate structural design loads. 8. We anticipate that cobbles and boulders will be encountered at the foundation elevation. Removal of the cobbles and boulders may result in depressions and rough bottoms in the excavation. The resulting depressions can be backfilled with compacted backfill or lean concrete. Refer to the COMPACTED FILL section of this report for backfill requirements. 9. Fill should be placed and compacted as outlined in the COMPACTED FILL section of this report. We recommend that a representative of our office observe and test the placement and compaction of each lift of structural fill used in foundation construction. It has been our experience that without engineering quality control, inappropriate construction techniques occur which result in poor foundation performance. 10. We recommend that a representative of our office observe the completed foundation excavation. Variations from the conditions described in this report, which were not indicated by our test pits, can occur. The representative can observe the excavation to evaluate the exposed subsurface conditions. SLABS -ON -GRADE Based on subsurface conditions encountered in our exploratory test pits, we anticipate that the subsurface conditions at the approximate floor slab and exterior slab- on -grade elevations consist of either topsoil, existing fill or the natural sand and gravel. 0 October 24, 2005 Job No. 05 -172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnicol Engineers The topsoil is not suitable for the construction of slabs -on -grade and must be removed from all construction areas prior to the beginning of construction. Slabs -on -grade constructed on the existing fill could experience up to 1.0 inch of movement. If the owner is willing to accept the risk of slab movement, then slabs -on -grade may be constructed on the existing fill. If the owner would like to reduce the risk of slab movement, we recommend that all of the existing fill be removed and replaced with properly moisture conditioned and compacted, non - expansive structural fill. In our opinion, slabs -on -grade may be constructed on the natural sand and gravel with cobbles and boulders with a low risk of movement. We recommend the following precautions for the construction of slab -on -grade floors at this site. 1. If the owner is willing to take the risk of slab movement, slabs -on -grade may be constructed on the existing fill. If the owner would like to reduce the risk of slab movement, all of the existing fill should be removed and replaced with properly moisture conditioned and compacted structural fill. Slabs -on -grade may also be constructed on the natural sand and gravel with cobbles and boulders. 2. Slabs should be separated from exterior walls and interior bearing members. Vertical movement of the slabs should not be restricted. I Exterior slabs should be separated from the residence. These slabs should be reinforced to function as independent units. Movement of these slabs should not be transmitted directly to the foundations or walls of the residence. 4. Frequent control joints should be provided in all slabs to reduce problems associated with shrinkage of the concrete. 5. Structural fill should be placed and compacted as outlined in the COMPACTED FILL section of this report. We recommend that a 10 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnicnl Engineers representative of our office observe and test the placement and compaction of structural fill used in slab -on -grade construction. It has been our experience that without engineering quality control, inappropriate construction techniques can occur which result in poor slab performance. FOUNDATION DRAINAGE Surface water, especially that originating from snowmelt, tends to flow through relatively permeable backfill typically found adjacent to foundations. The water that flows through the fill collects on the surface of relatively impermeable soils occurring at the foundation elevation. Both this surface water and possible ground water can cause wet or moist below grade conditions after construction. Because no below grade areas are planned for the proposed residence, it is our opinion that a foundation drain will not be necessary. However, if plans change and below grade areas are constructed for the residence, we recommend the installation of a drain along the below grade foundation walls. The drain should consist of a 4 -inch diameter perforated pipe encased in free draining gravel and a manufactured wall drain. The gravel should have a maximum size of 1.5 inches and have a maximum of 3 percent passing the No. 200 sieve. The drain should be sloped so that water flows to a sump where the water can be removed by pumping, or to a positive gravity outlet. Recommended details for a typical foundation wall drain are presented in the Typical Wall Drain Detail, Fig. 6. October 24, 2005 Job No. 05 -172 LATERAL WALL LOADS KOECHLEIN CONSULTING ENGINEERS, INC Consulting Geotechnical Engineers We do not anticipate the construction of walls that will require lateral earth loads for design. However, if plans change, we have provided the following information. Lateral earth pressures depend on the type of backfill and the height and type of wall. Walls that are free to rotate sufficiently to mobilize the strength of the backfill should be designed to resist the "active" earth pressure condition. Walls that are restrained should be designed to resist the "at rest" earth pressure condition. Below grade foundation walls are typically restrained. The following table presents the lateral wall pressures that may be assumed for design. Earth Pressure Condition Equivalent Fluid Pressure (pcf) Active 40 At -rest 50 Passive 300 Notes: 1. Equivalent fluid pressures are for a horizontal backfill condition with no hydrostatic pressures or live loads. 2. A coefficient of friction of 0.4 may be used at the base of spread footings to resist lateral loads. Backfill placed behind or adjacent to foundation walls and retaining walls should be placed and compacted as recommended in the COMPACTED FILL section of this report. All foundation walls must be properly braced before placing and compacting backfill. Placement and compaction of the fill should be observed and tested by a representative of our office. 12 October 24, 2005 Job No. 05 -172 RETAINING WALLS KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers Although we do not anticipate that retaining walls will be constructed as part of the development of the site. If plans change, foundations for retaining walls may be designed and constructed as outlined in the FOUNDATIONS section of this report. Lateral earth loads for retaining wall designs are presented in the LATERAL WALL LOADS section of this report. In order to reduce the possibility of developing hydrostatic pressures behind retaining walls, a drain should be constructed adjacent to the wall. The drain may consist of a manufactured drain system and gravel. The gravel should have a maximum size of 1.5 inches and have a maximum of 3 percent passing the No. 200 sieve. The manufactured drain should extend from the bottom of the retaining wall to within 2 feet of subgrade elevation. The water can be drained by a perforated pipe with collection of the water at the bottom of the wall leading to a positive gravity outlet. A typical detail for a retaining wall drain is presented in the Typical Retaining Wall Drain Detail, Fig. 7. SURFACE DRAINAGE Reducing the wetting of structural soils can be achieved by carefully planned and maintained surface drainage. We recommend the following precautions be observed during construction and maintained at all times after the residence is completed. 1. Wetting or drying of the open excavations should be minimized during construction. 13 October 24, 2005 Job No. 05 -172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnica[ Engineers 2. All surface water should be directed away from the top and sides of the excavations during construction. 3. The ground surface surrounding the exterior of the residence should be sloped to drain away from the structure in all directions. We recommend a slope of at least 12 inches in the first 10 feet. 4. Hardscape (concrete and asphalt) should be sloped to drain away from the residence. We recommend a slope of at least 2 percent for all hardscape adjacent to the residence. 5. Backfill, especially around foundation walls, should be placed and compacted as recommended in the COMPACTED FILL section of this report. 6. Roof drains should discharge at least 10 feet away from foundation walls with drainage directed away from the residence. 7. Surface drainage for this site should be designed by a Professional Civil Engineer. IRRIGATION Irrigation systems installed next to foundation walls or sidewalks could cause consolidation of backfill below and adjacent to these areas. This can result in settling of exterior steps, patios and /or sidewalks if they are constructed on these soils. We recommend the following precautions be followed: 1. Do not install an irrigation system next to foundation walls. The irrigation system should be at least 10 feet away from the residence. 2. Irrigation heads should be pointed away from the residence or in a manner that does not allow the spray to come within 5 feet of the residence. 14 5. Control valve boxes, for automatic irrigation systems, should be located at least 10 feet away from the structure and periodically checked for leaks and flooding. COMPACTED FILL Structural fill for this project may consist of the existing fill free of deleterious material; the natural sand and gravel with cobbles and boulders; the natural sand; or approved imported, non - expansive fill. Deleterious material consists of materials such as organics, construction debris and trash. The imported fill may consist of non - expansive silty or clayey sands or gravels with up to 30 percent passing the No. 200 sieve and a maximum plasticity index of 10. No cobbles or boulders larger than 6 inches should be placed in fill areas. Fill areas should be stripped of all vegetation, existing fill, and topsoil; scarified; and then compacted. Topsoil may be used in landscape areas. Fill should be placed in thin loose lifts and moisture conditioned and compacted to the recommended compaction shown in the following table. Recommended compaction varies for the given use of the fill. 15 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC Job No. 05 -172 Consulting Geotechnical Engineers 3. The landscape around the irrigation system should be sloped so that no ponding occurs at the irrigation heads. 4. Install landscaping geotextile fabrics to inhibit growth of weeds and to allow normal moisture evaporation. We do not recommend the use of a plastic membrane to inhibit the growth of weeds. 5. Control valve boxes, for automatic irrigation systems, should be located at least 10 feet away from the structure and periodically checked for leaks and flooding. COMPACTED FILL Structural fill for this project may consist of the existing fill free of deleterious material; the natural sand and gravel with cobbles and boulders; the natural sand; or approved imported, non - expansive fill. Deleterious material consists of materials such as organics, construction debris and trash. The imported fill may consist of non - expansive silty or clayey sands or gravels with up to 30 percent passing the No. 200 sieve and a maximum plasticity index of 10. No cobbles or boulders larger than 6 inches should be placed in fill areas. Fill areas should be stripped of all vegetation, existing fill, and topsoil; scarified; and then compacted. Topsoil may be used in landscape areas. Fill should be placed in thin loose lifts and moisture conditioned and compacted to the recommended compaction shown in the following table. Recommended compaction varies for the given use of the fill. 15 October 24, 2005 Job No. 05 -172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers Use of Fill Recommended Compaction Percentage of the Standard Proctor Maximum Dry Density (ASTM D -698) Percentage of the Modified Proctor Maximum Dry Density (ASTM D -1557) Below Structure Foundations 98 95 Below Slab -On -Grade Floors 95 90 Utility Trench Backfill 95 90 Backfill (Non- Structural) 90 90 Notes: 1. For clay soils the moisture content should be 0 to +3 percent of the optimum moisture content. 2. For granular soils the moisture content should be —2 to +2 of the optimum moisture content. We recommend the contractor and /or owner contact us so that a representative from our office can observe and test the placement and compaction of each lift of structural fill placed. Fill placed behind retaining walls and below foundations, slab -on- grade floors, and exterior slabs -on -grade is considered structural. It has been our experience that without engineering quality control, inappropriate construction techniques can occur which result in poor foundation and slab perfonnance. LIMITATIONS Although the exploratory test pits were located to obtain a reasonably accurate determination of subsurface conditions, variations in the subsurface conditions are always possible. Any variations that exist beneath the site generally become evident during construction of the foundation for the residence. Therefore, we must be contacted by the contractor and /or owner so that a representative of our office can observe the completed 16 October 24, 2005 KOECHLEIN CONSULTING ENGINEERS, INC. Job No. 05 -172 Consulting Geotechnical Engineers excavations and foundation construction to confirm that the soils are as indicated by the exploratory test pits and to verify our foundation and floor slab recommendations. The placement and compaction of fill, as well as installation of foundations, should also be observed and tested. The design criteria and subsurface data presented in this report are valid for 3 years, provided that a representative from our office observes the site at that time and confirms that the site conditions are similar to the conditions presented in the SITE CONDITIONS section of this report and that the recommendations presented in this report are still applicable. We recommend that final plans and specifications for proposed construction be submitted to our office for study, prior to the beginning of construction, to determine compliance with the recommendations presented in this report. 17 October 24, 2005 Job No. 05-172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnicnl Engineers We appreciate the opportunity to provide this service. If we can be of further assistance in discussing the contents of this report or in analysis of the proposed residence from a geotechnical viewpoint, please contact our office. KOECHLEIN CONSULTING ENGINEERS, INC. Richard M. Wenzel III, P.E. Project Engineer Reviewed by: 4 0;4� -4 William H. Koechlein, P.E. President (4 copies sent) 18 i 1 1 JOB NO. 05-172 VICINITY MAP KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers SITE NOT TO SCALE FIG. 1 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers LOT 5 I LOCATIONS OF EXPLORATORY TEST PITS IJOB NO. 05 -172 FIG.2 TP -1 8545 EL. 8543.2 . �pQ D:d 8540 o °a oaa WC =2 -200 =5 8535 8530 I— w w u_ 8525 z O 1= Q w W 8520 8515 8510 8505 JOB NO. 05 -172 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers TP -2 EL. 8540.9 -200 =8 LOGS OF EXPLORATORY TEST PITS 8545 8540 8535 8530 m r m 8525 < D O z m m 8520 --1 8515 8510 8505 FIG. 3 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers LEGEND: TOPSOIL p Q:: SAND and GRAVEL with Cobbles and Boulders, Dry, Very dense, Red - brown. FILL, Sand, Clayey, Gravelly, Slightly moist, Medium dense, Dark brown. SAND, Scattered gravel, Moist, Medium dense, Red - brown. T REFUSAL. Indicates practical excavator refusal on a boulder. BULK SAMPLE. Obtained from excavation spoils. Notes: 1. Exploratory test pits were excavated on October 3, 2005 using a rubber - tracked mini - trackhoe 2. No free ground water was encountered at the time of excavation in either of the exploratory test pits to the maximum depth explored of 8.0 feet. 3. The Test Pit Logs are subject to the explanations, limitations, and conclusions as contained in this report. 4. Laboratory Test Results: WC - Indicates natural moisture ( %) -200- Indicates percent passing the No. 200 sieve ( %) 5. Approximate elevations were measured with a Stanley Compulevel Elevation Measurement System using the piece of No. 5 rebar near the northwest property corner as a benchmark. Based on the site survey map provided by the owner, the elevation of the benchmark is 8549.4. LEGEND OF EXPLORATORY TEST PITS JOB NO. 05 -172 FIG. 4 KOECHLEIN CONSULTING ENGINEERS 1 314 112 1,318 .10 tjO 930 92 960 0100 #140 9200 100 0 0 10 8 10 20 70 20 30 Z M 60 U) 30 -v z U) 40 m < M Q 6 < z i 40 z 50 50 50 z 50 X Z M ui m U 40 i: 40 W I 60 60 Z M0 CL I Z M 30 it0 - 30 7 70 20 80 10 20 90 0 80 100 200 100 10 1 0.1 0.01 0.001 DIAMETER OF PARTICLE IN MM COBBLES GRAVEL SAND SILT CLAY Sample of Source SAND and GRAVEL TP-1 Sample No. Elev./Depth 4.0 feet GRAVEL 46 % SAND 49 % SILT & CLAY 5 % LIQUD LIMIT % PLASTICITY INDEX % 12 l,31811 m .110 'j0 VT30 90 *60 9100 *140 00 100 7 0 0 10 8 20 70 30 Z M 60 U) 40 m < z 50 50 z M ui 40 60 Z M 30 70 20 80 10 90 1100 200 100 10 1 0.1 0.01 0.001 DIAMETER OF PARTICLE IN MM COBBLES GRAVEL SAND SILT CLAY Sample of Source TP-2 SAND Sample No. Elev./Depth 7.0 feet GRAVEL 5 % SAND 87 % SILT & CLAY 8 % LIQUID LIMIT % PLASTICITY INDEX % GRADATION TEST RESULTS Job No. 05-172 FIG. 5 CLAYEY BACKFILL 10 - COMPACTED BACKFILL EDGE OF EXCAVATION (EXCAVATE AS PER OSHA REGULATIONS) MANUFACTURED WALL DRAIN FILTER FABRIC GRAVEL - 12" KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers BELOW GRADE WALL WATERPROOFING OR DAMPPROOFING � PLASTIC SHEETING F- --r- PERFORATED PIPE 12" MIN. NOTES: 1. DRAIN SHOULD BE AT LEAST 12 INCHES BELOW TOP OF FOOTING AT THE HIGHEST POINT AND SLOPE DOWNWARD TO A POSITIVE GRAVITY OUTLET OR TO A SUMP WHERE WATER CAN BE REMOVED BY PUMPING. 2. EXCAVATIONS ADJACENT TO FOOTINGS SHOULD BE CUT AT A 1 TO 1 (HORIZONTAL TO VERTICAL) OR FLATTER SLOPE FROM THE BOTTOM OF THE FOOTINGS. EXCAVATIONS ADJACENT TO FOOTINGS SHOULD NOT BE CUT VERTICALLY. 3. THE DRAIN SHOULD BE LAID ON A SLOPE RANGING BETWEEN 1/8 INCH AND 1/4 INCH DROP PER FOOT OF DRAIN. 4. GRAVEL SPECIFICATIONS: 1.5 INCH TO NO. 4 GRAVEL WITH LESS THAN 3 % PASSING THE NO. 200 SIEVE. 5. THE BELOW GRADE CONCRETE FOUNDATION WALLS SHOULD BE PROTECTED FROM MOISTURE INFILTRATION BY APPLYING A SPRAYED ON MASTIC WATERPROOFING, DAMPPROOFING, OR AN EQUIVALENT PROTECTION METHOD. TYPICAL WALL DRAIN DETAIL JOB NO. 05 -172 FIG. 6 CLAYEY BACKFILL 10 -11ElI - - iii —ii F A COMPACTED BACKFILL EDGE OF EXCAVATION (EXCAVATE AS PER OSHA REGULATIONS) FILTER FA G PERFORATED PIPE `►N11944 KOECHLEIN CONSULTING ENGINEERS, INC. Consulting Geotechnical Engineers MANUFACTURED WALL DRAIN - RETAINING WALL WATERPROOFING OR DAMPPROOFING 1. DRAIN SHOULD BE SLOPED DOWNWARD TO A POSITIVE GRAVITY OUTLET OR TO A SUMP WHERE WATER CAN BE REMOVED BY PUMPING. 2. THE DRAIN SHOULD BE LAID ON A SLOPE RANGING BETWEEN 1/8 INCH AND 1/4 INCH DROP PER FOOT OF DRAIN. 3. GRAVEL SPECIFICATIONS: 1.5 INCH TO NO. 4 GRAVEL WITH LESS THAN 3 PASSING THE NO. 200 SIEVE. 4. THE BELOW GRADE CONCRETE RETAINING WALLS SHOULD BE PROTECTED FROM MOISTURE INFILTRATION BY APPLYING A SPRAYED ON MASTIC WATERPROOFING, DAMPPROOFING, OR AN EQUIVALENT PROTECTION METHOD. TYPICAL RETAINING WALL DRAIN DETAIL JOB NO. 05 -172 FIG. 7 C/] O 0 0 p C U z C6 W W z_ U z W ( V z J z O U Z_ W J U w O Y c� r` 0 O z m 0 C. � v z O J_ J z s U-�oo U3° C7 o w F- p w n a z ¢oo Z � U w - w - Q p w J - N O - U z C6 W W z_ U z W ( V z J z O U Z_ W J U w O Y c� r` 0 O z m 0