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HomeMy WebLinkAboutFile Documents.909 E Hopkins Ave.0056-2021-BRES (16) I( Kumar&Associates,Inc.° Geotechnical and Materials Engineers 5020 County Road 154 and Environmental Scientists Glenwood Springs,CO 81601 phone: (970)945-7988 fax:(970)945-8454 email:kaglenwood@kumarusa.com An Employee Owned Company www.kumarusa.com Office Locations: Denver(HQ),Parker,Colorado Springs,Fort Collins,Glenwood Springs,and Summit County,Colorado SUBSOIL STUDY FOR FOUNDATION DESIGN PROPOSED RESIDENCE LOTS C AND D, EAST ASPEN ADDITION 905 EAST HOPKINS AVENUE ASPEN, COLORADO PROJECT NO. 20-7-782 JANUARY 25, 2021 PREPARED FOR: ANDY FROMM 5601 HIGH DRIVE MISSION HILLS, KANSAS 66208 afrommpersonal(agmail.com RECEIVED 04/01/2021 ASPEN BUILDING DEPARTMENT TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY - 1 - PROPOSED CONSTRUCTION - 1 - SITE CONDITIONS - 1 - MINE SUBSIDENCE - 2 - FIELD EXPLORATION - 2 - SUBSURFACE CONDITIONS - 2 - FOUNDATION BEARING CONDITIONS - 3 - DESIGN RECOMMENDATIONS - 3 - FOUNDATIONS - 3 - FOUNDATION AND RETAINING WALLS - 4 - FLOOR SLABS - 5 - UNDERDRAIN SYSTEM - 6 - SURFACE DRAINAGE - 6 - PERCOLATION TESTING - 7 - LIMITATIONS - 7 - FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURES 4 and 5 - GRADATION TEST RESULTS TABLE 1 - SUMMARY OF LABORATORY TEST RESULTS TABLE 2—PERCOLATION TEST RESULTS RECEIVED 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 .\SPEN BUILDING DEPARTMENT PURPOSE AND SCOPE OF STUDY This report presents the results of a subsoil study for a proposed residence to be located on Lots C and D, East Aspen Addition, 905 East Hopkins Avenue, Aspen, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for the foundation design. The study was conducted in accordance with our proposal for geotechnical engineering services to Andy Fromm dated December 30, 2020. A field exploration program consisting of exploratory borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths, and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, design recommendations, and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The proposed residence will be a two story structure and garage with structural floor above a full basement. The basement floor will be slab-on-grade. Grading for the structure is assumed to have a cut depth of about 12 to 14 feet. We assume relatively light foundation loadings, typical of the proposed type of construction. A slab-on-grade patio and driveway are proposed south of the residence as shown on Figure 1. If building loadings, location or grading plans change significantly from those described above, we should be notified to re-evaluate the recommendations contained in this report. SITE CONDITIONS The property was vacant at the time of our exploration and is vegetated with grass, aspen, and pine trees. Boulders are visible on the surface. The property was previously occupied with a structure above a basement which was removed and backfilled. The site has been graded relatively flat and slopes gently to the north. RECEIVED 04/01/2021 Kumar&Associates,Inc.® Project No.20-7-782 .\SPEN BUILDING DEPARTMENT -2 - MINE SUBSIDENCE Portions of the Aspen area are underlain by mine workings. The workings are primarily underground tunnels between Aspen and Smuggler Mountains southeast and east of the downtown area. The works consist of numerous tunnels beginning a few hundred feet below the ground surface becoming shallower to the south. Under certain conditions these workings may collapse and cause surface subsidence. Glory Hole Park, which is about four blocks south of the subject site, is believed to have been caused by the collapse of one or more tunnels. The subject site appears to be above these main tunnel works. Our borings were relatively shallow and for foundation design only, however, no indications of subsurface voids were found at the subject site. We believe the risk of subsidence due to the collapse of underground mine works throughout the service life of the proposed residence to be low. If further evaluation of the mine works subsidence potential is desired, we should be contacted. FIELD EXPLORATION The field exploration for the project was conducted on January 4, 2021. Three exploratory borings were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. The borings were advanced with 4 inch diameter continuous flight augers powered by a truck- mounted CME-45B drill rig. The borings were logged by a representative of Kumar& Associates, Inc. Samples of the subsoils were taken with a 1% inch I.D. spoon sampler. The sampler was driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site are shown on Figure 2. Aat Beneath about one foot of topsoil, the subsoils consist of about 9 to 11 feet of silty claye CEIVED 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 •\SPEN BUILDING DEPARTMENT - 3 - with gravel fill overlying silty sandy gravel with cobbles and boulders that extended down to the explored depths of 16 to 21 feet. Laboratory testing performed on samples obtained from the borings included natural moisture content and gradation analyses. Results of gradation analyses performed on small diameter drive samples (minus 11/2-inch fraction) of the coarse granular subsoils are shown on Figures 4 and 5. The laboratory testing is summarized in Table 1. No free water was encountered in the borings at the time of drilling and the subsoils were slightly moist to very moist. FOUNDATION BEARING CONDITIONS The natural granular soils encountered below the fill material are adequate for support of spread footings. The fill material from previous site development should be removed from beneath proposed building footprint including floor slab,patio and driveway areas. The building as planned with a full basement is expected to penetrate the existing fill material. The City of Aspen requires an engineered excavation stabilization plan if proposed foundations are within 15 feet of a neighboring structure or public travel way. The plan is not required if excavations are less than 5 feet below existing grades or further than 15 feet from travel ways and less than 15 feet deep. Slope bracing through use of a variety of systems such as chemical grouting, micro-piles, and soil nails may be feasible at the site if required. A shoring contractor should provide design drawings to support the proposed excavation slopes where needed. Other City requirements may also be applicable. The suitability of the onsite fill soils for use as structural fill should be evaluated at the time of construction. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the building be founded with spread footings bearing on the natural granular soils or suitable compacted structural fill. The design and construction criteria presented below should be observed for a spread footing foundation system. 1) Footings placed on the undisturbed natural granular soils or compacted structural fill should be designed for an allowable bearing pressure of 3,000 psf. Ba 1E E 1VE 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 ASPEN BUILDING DEPARTMENT -4 - experience, we expect settlement of footings designed and constructed as discussed in this section will be about 1 inch or less. 2) The footings should have a minimum width of 16 inches for continuous walls and 2 feet for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 42 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 10 feet. Foundation walls acting as retaining structures should also be designed to resist lateral earth pressures as discussed in the "Foundation and Retaining Walls" section of this report. 5) All existing fill, topsoil, and any loose or disturbed soils should be removed and the footing bearing level extended down to the relatively dense natural granular soils. The exposed soils in footing area should then be moistened and compacted. Structural fill placed to reestablish design bearing level should be a relatively well graded granular material compacted to at least 98% of standard Proctor density at near optimum moisture content. The structural fill should extend laterally beyond the footing edges a distance equal to at least one-half the depth of fill below the footing 6) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions. FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 50 pcf for backfill consisting of the on-site granular soils. Cantilevered retaining structures which are separate from the building (if any) and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 40 pcf for backfill consisting of the on-site granular soils. Backfill should not contain organics, debris, or rock larger than about 6 inches. RECEIVED 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 .\SPEN BUILDING DEPARTMENT - 5 - All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials, and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. Backfill should be placed in uniform lifts and compacted to at least 90% of the maximum standard Proctor density at a moisture content near optimum. Backfill placed in pavement and walkway areas should be compacted to at least 95% of the maximum standard Proctor density. Care should be taken not to overcompact the backfill or use large equipment near the wall, since this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill including areas below the patio slab and driveway should be expected, even if the material is placed correctly, and could result in distress to facilities constructed on the backfill. The settlement potential can be limited by using a relatively well graded granular material and increasing compaction to at least 98% of standard Proctor density. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.45. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 400 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be a granular material compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The natural on-site granular soils below the topsoil and existing fill are suitable to support lightly loaded slab-on-grade construction. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should RE 1 E IVE 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 .\SPEN BUILDING DEPARTMENT - 6 - established by the designer based on experience and the intended slab use. A minimum 4 inch layer of free-draining gravel should be placed beneath basement level slabs to facilitate drainage. This material should consist of minus 2-inch aggregate with at least 50%retained on the No. 4 sieve and less than 2%passing the No. 200 sieve. All fill materials for support of floor slabs should be compacted to at least 95% of maximum standard Proctor density at a moisture content near optimum. Required fill can consist of the on-site granular soils devoid of vegetation, topsoil, and oversized rock. We recommend vapor retarders conform to at least the minimum requirements of ASTM E1745 Class C material. Certain floor types are more sensitive to water vapor transmission than others. For floor slabs bearing on angular gravel or where flooring system sensitive to water vapor transmission are utilized, we recommend a vapor barrier be utilized conforming to the minimum requirements of ASTM E1745 Class A material. The vapor retarder should be installed in accordance with the manufacturers' recommendations and ASTM E1643. UNDERDRAIN SYSTEM Although free water was not encountered during our exploration, it has been our experience in the area that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a perched condition. We recommend below-grade construction, such as retaining walls, crawlspace, and basement areas be protected from wetting and hydrostatic pressure buildup by an underdrain system. The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free-draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1%to a suitable gravity outlet, drywell in the native gravel soils, or sump and pump. Free-draining granular material used in the underdrain system should contain less than 2%passing the No. 200 sieve, less than 50%passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 11/2 feet deep. SURFACE DRAINAGE The following drainage precautions should be observed during construction and maintained at all times after the building has been completed: RECEIVED 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 •\SPEN BUILDING DEPARTMENT - 7 - 1) Inundation of the foundation excavations and underslab areas should be avoided during construction. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90% of the maximum standard Proctor density in landscape areas. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 6 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. Free-draining wall backfill should be covered with filter fabric and capped with about 2 feet of the on-site finer graded soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be located at least 5 feet from foundation walls. PERCOLATION TESTING Percolation testing was conducted on January 4, 2021 by a representative of Kumar& Associates. The percolation test results are summarized on Table 2. Based on the subsurface conditions encountered and the percolation test results, the tested area should be suitable for a drywell or bio-swale. The perforated section of the drywell should penetrate the natural gravel soils and begin at least 2 feet below basement floor level. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1, the proposed type of construction, and our experience in the area. Our services do not include determining the presence, prevention, or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variatREC EWE() 04/01/2021 Kumar&Associates,Inc.° Project No.20-7-782 .\SPEN BUILDING DEPARTMENT - 8 - the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report,we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, Kumar & Associates,Inc. David A. Noteboom, Staff Engineer Reviewed by: ;� 0 REG/S,'l'k.: 0 Steven L. Pawlak 4 .EI`� 22 SLP/kac '00 p• i`�1/Z t •••, Cc: Z Group Architec � 'ale(scott@zgrouparchitects.com) RECEIVED 04/01/2021 Kumar&Associates,Inc. Project No.20-7-782 ASPEN BUILDING DEPARTMENT HOPKINS AVE PROPERTY LINE 2265 SF TARGET 1304 SF MAIN LVL EXIST 950 SF UPPERI TREE 2254 TOTAL(11 under) tSd' + I FRONT SETBACK FRONT PORCH I `7 I STAIR BORING 2 S.D ENTRY - I FGYER s (BRIDGE)_� 12'6 %I sLn,.scAEEN WhI--__ I���N - Y_ O O O „,„ ON UP KITCHEN I --- E M M M POOP h I 6 wne to 0 1—_ , DINING , M 0000 I •• J 8 2' I yo r �r - 1 b rc Ir �A.E �J` I w FUTURE 1 V LIVING MUDRM n1 11 FP I ROOM II I 1Fxn SO ——J GARAGE TE Wm TOO SF 4 I I T OIV BIKES II ELEC CART • �i ' V BORING 3 L w. I 3 PATIO I II ) II m 3 I II airII J DRIVEWAY (SNOWMELTED) BORING 1 I I I LAWN L REAR SETBACK AVOID TREE PRIVACY FENCE/WALL -EXIST 1 TREE PROPERTY LINE 3 R ii e 10 0 10 20 ITtP- 0 APPROXIMATE SCALE—FEET RECEIVED '?i, 0 401/2021 oP 20-7-782 Kumar & Associates LOCATION OF EXPLORATORY BORINGS -Fig. 1 ASPEN BUILDING DEPARTMENT BORING 1 BORING 2 BORING 3 EL. 7924' EL. 7923' EL. 7925' 0 -. J 0 . X1 18/12 t 5 jj2 5 WC=10.0 12/12 12/12 +4=28 WC=7.8 _ —200=17 —200=19 tA 14/12 1— —L.:— 10 tA 21/12 24/12 > 36/12 10 w w ,�''o .., w w w 415 4 15 o 54/1 2 77/12 ::;�I 79/1 2 . WC=3.5 WC=5.6 — +4=36 +4=25 ••• .• —200=10 —200=20 20 20 — •.• 55/12 — 25 25 0 s r' Ej ..,,, RECEIVED Eql fi' 04/F01/2021 it 20-7-782 Kumar & Associates LOGS OF EXPLORATORY BORINGS Ig. 2 » ASPEN BUILDING DEPARTMENT LEGEND TOPSOIL, SAND AND CLAY, GRAVEL, ROOTS AND ORGANICS, FIRM, MOIST, BROWN. FILL: SILTY SAND WITH GRAVEL AND COBBLES, LOOSE TO MEDIUM DENSE, MOIST, BROWN. X GRAVEL (GM-GP); SILTY, SANDY, DENSE TO VERY DENSE, LIGHT BROWN. DRIVE SAMPLE, 1 3/8-INCH I.D. SPLIT SPOON STANDARD PENETRATION TEST. 18/12 E P LE UDTS A 18 BLOWS OF A 140-POUND HAMMER FALLING SAMPLE 30 INCHESBLOW WERECO NT.REQUIRED IN INDICATES ET O DRIVETHT THE SAMPLER 12 INCHES. NOTES 1. THE EXPLORATORY BORINGS WERE DRILLED ON JANUARY 4, 2021 WITH A 4-INCH-DIAMETER CONTINUOUS-FLIGHT POWER AUGER. 2. THE LOCATIONS OF THE EXPLORATORY BORINGS WERE MEASURED APPROXIMATELY BY PACING FROM FEATURES SHOWN ON THE SITE PLAN PROVIDED. 3. THE ELEVATIONS OF THE EXPLORATORY BORINGS WERE OBTAINED BY INTERPOLATION BETWEEN CONTOURS ON THE SITE PLAN PROVIDED. 4. THE EXPLORATORY BORING LOCATIONS AND ELEVATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE IMPLIED BY THE METHOD USED. 5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING LOGS REPRESENT THE APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL. 6. GROUNDWATER WAS NOT ENCOUNTERED IN THE BORINGS AT THE TIME OF DRILLING. 7. LABORATORY TEST RESULTS: WC = WATER CONTENT (%) (ASTM D2216); +4 = PERCENTAGE RETAINED ON NO. 4 SIEVE (ASTM D6913); -200= PERCENTAGE PASSING NO. 200 SIEVE (ASTM D1140). Ej :, RECEIVED _o 04/E01/32021 20-7-782 Kumar & Associates LEGEND AND NOTES lg. ASFLN BUILDING DEPARTMENT HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS 24 HRS 7 HRS 100 45 MIN 15 MIN BONIN 19MIN 4MIN 1MIN #200 #100 #50#40#30 #16 #10#8 #4 3/8" 3/4" 1 1 2" 3" 5"6" 8"0 90 - 10 80 20 70 - 30 60 - 40 G 50 50 a 40 so s 30 70 20 80 10 90 0 I I I I I I I I I I I I I II I I II I I I I I' I I I IIIII I I I I I I I I I too .001 .002 .005 .009 .019 .037 .075 .150 .300 .600 1.18 2.36 4.75 9.5 19 38.1 76.2 127 200 .425 2.0 152 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE GRAVEL 28 % SAND 55 % SILT AND CLAY 17 % LIQUID LIMIT PLASTICITY INDEX SAMPLE OF: Silty Sand with Gravel (Fill) FROM: Boring 1 ® 4' & 7' (Combined) HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS 24 HRS 7 HRS 100 45 MIN 15 MIN 60MI11 19MIN 41.1IN 1MIN #200 #100 #50#40#30 #16 #10#8 #4 3/8" 3/4" 1 1 2" 3" 5"6" 8"0 90 10 80 20 70 30 II g 60 40 61 c u 50 50 y!� ' 40 60 6 30 70 20 80 10 90 0 I I 1 1 1 1.1 1 1 I 1 1 1 1 1 1 ' I 1 I I I III I I 1 1 1 1 1 1 1 1 100 I I 1 1 1 1 .001 .002 .005 .009 .019 .037 .075 .150 .300 .600 1.18 2.36 4.75 9.5 19 38.1 76.2 127 200 .425 2.0 152 DIAMETER OF PARTICLES IN MILLIMETERS CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE R GRAVEL 36 % SAND 54 % SILT AND CLAY 10 % B LIQUID LIMIT PLASTICITY INDEX These test results apply only to the e SAMPLE OF: Slightly Silty Sand with Gravel FROM: Boring 1 © 15' samples which were tested. The on testing report shall not be reproduced, except In full, without the written DR approval of Kumar & Associates, Inc. Sieve analysis testing is pertormed in IH accordance with ASTM D6913, ASTM D7928, o ASTM C136 and/or ASTM D1140. od 20-7-782 Kumar & Associates GRADATION TEST RESULTS ' 04% 1,2021 ASPEN BUILDING DEPARTMENT I( i Kumar&Associates,Inc.° Gumar&Aland Materials Engineers and Environmental Scientists TABLE 1 SUMMARY OF LABORATORY TEST RESULTS Project No.20-7-782 SAMPLE LOCATION NATURAL NATURAL GRADATION ATTERBERG LIMITS UNCONFINED MOISTURE DRY GRAVEL SAND PERCENT PLASTIC COMPRESSIVE BORING DEPTH CONTENT DENSITY (%) (%) PASSING 200 S EVE LIQUID LIMIT INDEX STRENGTH SOIL TYPE (ft) (%) (pcf) (%) (%) (psf) 1 4 and 7 10.0 28 55 17 Silty Sand with Gravel combined (Fill) 15 3.5 36 54 10 Slightly Silty Sand with Gravel 2 5 7.8 19 Silty Clayey Sand with Gravel (Fill) 3 15 5.6 25 55 20 Silty Sand with Gravel RECEIVED 04/01/2021 ASPEN BUILDING DEPARTMENT I C A Kumar&Associates,Inc.° Geotechnical and Materials Engineers and Environmental Scientists TABLE 2 PERCOLATION TEST RESULTS PROJECT NO.20-7-782 HOLE NO. HOLE DEPTH LENGTH OF WATER DEPTH WATER DEPTH DROP IN AVERAGE (INCHES) INTERVAL AT START OF AT END OF WATER LEVEL PERCOLATION (MIN) INTERVAL INTERVAL (INCHES) RATE (INCHES) (INCHES) (MIN./INCH) 45 39 6 0.83 39 34 5 1 B-1 180 5 34 30 4 1.25 30 271/2 2'/z 2 27'/z 251/2 2 2.5 25'/z 231/2 2 2.5 Note: The percolation test was conducted in the completed 4-inch diameter borehole on January 4, 2021. RECEIVED 04/01/2021 ASPEN BUILDING DEPARTMENT