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HomeMy WebLinkAboutSoils Report 06.04.2018Huddleston -Berry Lnginecting & Testing, LLC Jeff Nimon 2678 Cambridge Road Grand Junction, Colorado 81506 Subject: Geotechnical Investigation 99 Boulder Ridge Drive Battlement Mesa, Colorado Dear Mr. Nimon, 640 White Avenue Grand Junction, Colorado 81501 Phone: 970-255-8005 Fax: 970-255-6818 Info@huddlestonberry.com June 4, 2018 Project#01803-0001 This letter presents the results of a geotechnical investigation conducted by Huddleston -Berry Engineering & Testing, LLC (HBET) at 99 Boulder Ridge Drive in Battlement Mesa, Colorado. The site location is shown on Figure 1. The proposed construction is anticipated to consist of a single family residence. The scope of our investigation included evaluating the subsurface conditions at the site to aid in developing foundation recommendations for the proposed construction. Site Conditions At the time of the investigation, the site was open with a slight slope down to the north. Vegetation consisted primarily of grasses and weeds with scattered trees and brush. The site was bordered to the north by a golf course, to the south by Boulder Ridge Drive, to the west by an existing residence, and to the east by a vacant lot. Subsurface Investigation The subsurface investigation included two test pits as shown on Figure 2 — Site Plan. The test pits were excavated to a depth of 8.0 feet below the existing ground surface. Typed test pit logs are included in Appendix A. As indicated on the logs, the subsurface conditions at the site were fairly consistent. The test pits encountered 1.0 foot of topsoil above brown, moist, medium dense to loose silt with sand soils to the bottoms of the excavations. Groundwater was not encountered in the subsurface at the time of the investigation. 99 Boulder Ridge Dr. #01803-00010 06/04/18 Iiuddlcstnn-Berre 1••..�.-niA l•••.�-Ill Laboratory Testing Laboratory testing was conducted on samples of the native soils encountered in the test pits. The testing included grain size analysis, Atterberg limits determination, natural moisture content determination, and maximum dry density and optimum moisture content (Proctor) determination. The laboratory testing results are included in Appendix B. The laboratory testing results indicate that native silt soils are very slightly plastic. Due to the granular nature of the soils, undisturbed samples of the silt were unable to be collected for swell/consolidation testing. However, based upon our experience with similar soils in the vicinity of the subject site, the native silt soils are anticipated to be slightly collapsible. Foundation Recommendations Based upon the results of the subsurface investigation and nature of the proposed construction, shallow foundations are recommended. Spread footings and monolithic (turndown) structural slabs are both appropriate foundation alternatives. However, as discussed previously, the native soils are anticipated to be slightly collapsible. Therefore, in order to limit the potential for excessive differential movements, it is recommended that the foundations be constructed above a minimum of 24 -inches of structural fill. The native silt soils, exclusive of topsoil, are suitable for reuse as structural fill. Imported structural fill should consist of a granular, non -expansive, non -free draining material such as crusher fines or CDOT Class 6 base course. Unless it can be demonstrated that the materials are not free -draining, pit -run materials should not be used as structural fill. For spread footing foundations, the footing areas may be trenched. However, for monolithic slab foundations, the structural fill should extend across the entire building pad area to a depth of 24 - inches below the turndown edges. Structural fill should extend laterally beyond the edges of the foundations a distance equal to the thickness of structural fill for both foundation types. Prior to placement of structural fill, it is recommended that the bottom of the foundation excavation be scarified to a depth of 6 to 9 inches, moisture conditioned, and compacted to a minimum of 95% of the standard Proctor maximum dry density, within ± 2% of the optimum moisture content as determined in accordance with ASTM D698. Structural fill should be moisture conditioned, placed in maximum 8 -inch loose lifts, and compacted to a minimum of 95% of the standard Proctor maximum dry density for fine grained soils and modified Proctor maximum dry density for coarse grained soils, within ± 2% of the optimum moisture content as determined in accordance with ASTM D698 and D1557, respectively. Structural fill should be placed to within 0.1 -foot of the bottom of foundation elevation. Clean gravel in excess of 0.1 -foot in thickness below foundations will not be acceptable. For structural fill consisting of the native soils or imported granular materials and foundation building pad preparation as recommended, a maximum allowable bearing capacity of 1,500 psf may be used. In addition, a modulus of subgrade reaction of 150 pci may be used for structural fill consisting of the native silt soils and a modulus of 250 pci may be used for structural fill consisting of crusher fines or base course. Foundations subject to frost should be at least 24 - inches below the finished grade. X:\2008 ALL PROJECTS\0] 803 - Jeff Nimon\01803-0001 99 Boulder Ridge Dr\200 - Geo\01803-0001 LR060418.doc 2 99 Boulder Ridge Dr. #01803-00010 Huddlcstnn-Bern 06/04/18 Any stemwalls or retaining walls should be designed to resist lateral earth pressures. For backfill consisting of the native soils or imported granular, non -free draining, non -expansive material, we recommend that the walls be designed for an active equivalent fluid unit weight of 45 pcf in areas where no surcharge loads are present. An at -rest equivalent fluid unit weight of 65 pcf may be used for braced walls. Lateral earth pressures should be increased as necessary to reflect any surcharge loading behind the walls. Water soluble sulfates are common to the soils in Western Colorado. Therefore, at a minimum, Type I -1I sulfate resistant cement is recommended for construction at this site. Non -Structural Floor Slab and Exterior Flatwork Recommendations In order to reduce the potential for excessive differential movements, it is recommended that non-structural floating floor slabs be constructed above a minimum of 18 -inches of structural fill with subgrade preparation, structural fill materials, and fill placement be in accordance with the Foundation Recommendations section of this report. It is recommended that exterior flatwork be constructed above a minimum of 12 -inches of structural fill. Drainage Recommendations Grading and drainage are critical far the long -cerin performance of the structure and grading around the structure should be designed to carry precipitation and runoff away from the structure. It is recommended that the finished ground surface drop at least twelve inches within the first ten feet away from the structure. It is also recommended that landscaping within five feet of the structure include primarily desert plants with low water requirements. In addition, it is recommended that automatic irrigation (including drip lines) within ten feet of foundations be minimized. HBET recommends that downspout extensions be used which discharge a minimum of ten feet from the structure or beyond the backfill zone, whichever is greater. However, if subsurface downspout drains are utilized, they should be carefully constructed of solid -wall PVC and should daylight a minimum of fifteen feet from the structure. In addition, an impermeable membrane is recommended below subsurface downspout drain lines. Dry wells should not be used. In order to limit the potential for surface moisture to impact the structure, a perimeter foundation drain is recommended. In general, the perimeter foundation drain should consist of prefabricated drain materials or a perforated pipe and gravel system with the flowline of the drain at the bottom of the foundation (at the highest point). The perimeter drain should slope at a minimum of 1.0% to daylight or to a sump with pump. An impermeable membrane is also recommended at the base of the drain to limit the potential for moisture to infiltrate into the subsurface below the foundations. General Notes The recommendations included above are based upon the results of the subsurface investigation and on our local experience. These conclusions and recommendations are valid only for the proposed construction. X:\2008 ALL PROJECTS\01803 - Jeff Nimon\01803-0001 99 Boulder Ridge Dr\200 - Geo \01803-0001 LR060418.doc 3 99 Boulder Ridge Dr. #01803-00010 06/04/18 IuddIcston-Bern• As discussed previously, the subsurface conditions encountered in the test pits were fairly consistent. However, the precise nature and extent of subsurface variability may not become evident until construction. The recommendations contained herein are designed to reduce the risk and magnitude of movements and it is extremely critical that ALL of the recommendations herein be applied to the design and construction. However, HBET cannot predict long-term changes in subsurface moisture conditions and/or the precise magnitude or extent of any volume change in the native soils. Where significant increases in subsurface moisture occur due to poor 2radinR, improper stormwater mana'ement, utility line failure, excess irriEation, or other cause, durin# or after construction, siInificant movements are possible. In addition, the success of the structure foundations, slabs, etc. is critically dependent upon proper construction. Therefore, HBET should be retained to provide materials testing, special inspections, and engineering oversight during ALL phases of the construction to ensure conformance with the recommendations herein. We are pleased to be of service to your project. Please contact us if you have any questions or comments regarding the contents of this report. Respectfully Submitted: Huddleston -Berry Engineering and Testing, LLC Michael A. Berry, P.E. Vice President of Engineering X:\2008 ALL PROJECTS \01803 - Jeff Nimon\01803.0001 99 Boulder Ridge Dr\200 - Geo \01803-0001 LR060418.doc 4 Garfield County Garfield County Land Explorer 240706100139 Garfield County, Colorado 240705200006 5 240706400001 if 240707200018 240704100091 240708100152 240708100187 240708400186 :t 24167ouf oO157 _1 - Garfield County Land Explorer Printed by Web User 240708400182 Battlement 3. E 2;40705 240708400188 1 1 inch = 1,505 feet 1 inch = 0.28 miles 0.2 0.4 0.8 Mlles s Garfleld County Colorado Garfield County www.garfleld-county.com Colorado Disclaimer 7hls le a compilation of records es they appear In the Garfield County office s a8ectine the arae shown. This drawing Is to be used only 1or reference purposes end the County Is not responsible for any Ineccuredes herein contained. © Copyright Garfield County, Colorado !All Rights Reserved Printed: 5/31/2018 at 11:37:32 AM Garfield County Land Explorer Garfield County Garfield County, Colorado 2407053046i 4. Garfield County Land Explorer Printed by Web User 1 Inch = 94 feet 1 Inch = 0.02 miles 0,0125 0.025 0.05 Mlles Garfield County Colorado Garfield County www.garfleld-counly.com Colorado Disclaimer this Is a mmplietbn ofrecords a day appear In th•Garfleld County Of floamit•cting the area shown. This drawing la lo be used only for reference aurpates and the County is not rasp unable for any Inauwad•s benln contained. ® Copyright Garfield County, Colorado 1 All Rights Reserved Printed: 5/31/2018 at 11:39:31 AM APPENDIX A Typed Test Pit Logs GEOTECH BH COLUMNS 018Q3-fl0O1 99 BOULDER RIDGE DRNE.GPJ DINT US LAB.GDT 5/31/18 1 1 1 1 I +1 C.it 1 1 1 1 1 I I I 9' O 1 I ! 1 1 I 1 1 N L71 1 f I -"v, F udd1eston-I3crry Enginmring & Testing, LLC TEST PIT NUMBER TP -1 640 Whfte Avcnue, Chit L3 PAGE 1 OF 1 c,,, Grond Junction, CO 81501 970-255-8005 f w 970-255-6818 CLIENT JIff Nimon PROJECT NAME 99 Boulder Ridge Drive PROJECT NUMBER 01803-0001 PROJECT LOCATION Battlement Mesa, CO .•1 • ,.•.r:L 3 0 FI)* m co o �, co m 1n cn a, a 3co cs 3 vco 3 o (1)O `~ 3 g c 3 a co cn m co 0 0 0 01 CD 0) g.s co 0) a Q O 3 0 1n =I 0 tTED 4/26/18 COMPLETED 4/26/18 _ GROUNE )N CONTRACTOR Client GROUNC )N METHOD Trackh/Backhoe AT Y CM CHECKED BY MAB AT AF GEOTECH BH COLUMNS 01803-0001 99 BOULDER RIDGE DRIVE.GPJ GINT US LAB GDT 5/31/18 cn C7 rT DEPTH o (ft) DATE STARTED 4/26/18 COMPLETED 4126/18 GROUND ELEVATION _ TEST PIT SIZE EXCAVATION CONTRACTOR Client GROUND WATER LEVELS: EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry LOGGED BY CM CHECKED BY MAB AT END OF EXCAVATION dry NOTES AFTER EXCAVATION — Cax Huddlcston l3crry Engineering & Testing, LLC TEST PIT NUMBER TP -2 .640 White Avenue, Unit B �Grand Junction, CO 81501 PAGE 1 OF 1 1 970-255-8005 970-255-6818 CLIENT Jiff Nimon PROJECT NAME 99 Boulder Ridge Drive PROJECT NUMBER 01803-0001 PROJECT LOCATION Battlement Mesa, CO ..,--7.-.:r: GRAPHIC ;.�._:_I; LOG Bottom of test pit at 8.0 feet. m 1 1 --I m $ :T 0 5- c7) c 0) rn y N W o.0 03 cr O 3 3 0 m 3 co0: 3 0_ m 0, cD m O O O to co MATERIAL DESCRIPTION SILT with Sand and Organics (TOPSOIL) —, 0 En SAMPLE TYPE NUMBER RECOVERY % (RQD) BLOW COUNTS (N VALUE) POCKET PEN. (tsf) DRY UNIT WT. (Pcf) a, MOISTURE CONTENT (%) 41. LIQUID LIMIT ATTERBERG LIMITS N PLASTIC LIMIT N r11101 I1i11 I INDEX FINES CONTENT (%) APPENDIX B Laboratory Testing Results FIGURES CLIENT F`.---. Huddleston-Beny Engineering & Testing, LLC GRAIN SIZE DISTRIBUTION 640 White Avenue, Unit B Grand Junction, CO 81501 970-255-8005 ••- 970-255-6818 Jiff Nimon PROJECT NAME 99 Boulder Ridge Drive PROJECT NUMBER 01803-0001 PROJECT LOCATION Battlement Mesa, CO U.S. SIEVE OPENING 6 4 3 IN NCHES I 2 1.5 13/4 1!2318 3 4 6 U.S. SIEVE NUMBERS I HYDROMETER 1416 20 30 40 50 80 100140200 100 95 I I I III 11 L'\11\-- 1 1': 90 85 80 ' 75 70 65 z 0 60 w 3 >- 55 m o' 50 z LL I— 45 z w 40 o(-) w 0. 35 ' 30 25 • 20 15 10 5 0 100 10 1 GRAIN SIZE IN MILLIMETERS 0 1 0.01 0.001 COBBLES GRAVEL SAND coarse fine coarse medium fine SILT OR CLAY Specimen Identification Classification LL PL PI Cc Cu • TP-2, GB1 4/2018 SILT with SAND(ML) 24 22 2 Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt %Clay • TP-2, GB1 4/2018 2.36 0.0 23.2 76.8 x CLIENT .. , Huddleston -Berry Engineering & Testing, LLC ATTERBERG LIMITSRESULTS 640 White Avenue, Unit B Grand Junction, CO 81501 970-255-8005 970-255-6818 Jiff Nimon PROJECT NAME 99 Boulder Ridge Drive . PROJECT NUMBER 01803-0001 PROJECT LOCATION Battlement Mesa, CO 60 CL CH - 50 P L A 40 s T I C T 30 Y I N 20 E X 10 CL -ML ML MH 0 • 0 20 40 60 80 100 LIQUID LIMIT Specimen Identification LL PL PI #200 Classification • TP -2, GB1 4/2018 24 22 2 77 SILT with SAND(ML) CLIENT PROJECT Huddleston -Berry Engineering & Testing, LLC Q 640 White Avenue, Unit B Grand Junction, CO 81501 970-255-8005 970-255-6818 Jiff Nimon MOISTURE PROJECT NAME PROJECT LOCATION -DENSITY RELATIONSHIP 99 Boulder Ridge Drive NUMBER 01803-0001 Battlement Mesa, CO 150 ' Sample Date: Sample No.: 4/26/2018 GB1 145 Source of Material: Description of Material: Test Method: TP -2 SILT with SAND(ML) \\\\\ ASTM D698A 140 DRY DENSITY, pcf o —cn to 1 - 1 cn Cfl CO O O /Ca � r1 0 0 cn Maximum Optimum Dry Water TEST Density Content GRADATION #2004 RESULTS ATTERBERG RESULTS 112.0 PCF PASSING) 3/4 r 14.0 % (% 100 77 100 LL Curves for LIMITS PL PI \\\\\ \\ 24 22 Specific of 100% Gravity 2.80 2.70 2.60 2 Saturation Equal to: IN\ \-\\\\, \ , N\:\ \\\ 5 10 15 20 25 30 WATER CONTENT,