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Home My WebLink AboutSubsoil Study 06.04.2014HEPWORTH-PAWLAK GEOTECHNICAL June 4, 2014 Aspen Signature Homes of Ironbridge, LLC Attn: Llwyd Ecclestone P.O. Box 7628 Aspen, Colorado 81612 (lecclestone ;pblhfl.net) Hcrworda-Pawiak Getttcdanic;al, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970.945-7988 Fix 970-945-8454 etn aii: hrkco@hpgeorech.com Job No. 113 471C Subject: Observation of Excavation, Proposed Residence, Lot 247, Ironbridge Development, River Bend Way, Garfield County, Colorado Gentlemen: As requested by Dave Ockers, a representative of Hepworth-Pawlak Geotechnical, Inc. performed compaction testing on May 28 and 29, 2014 and observed the building excavation at the subject site on June 4, 2014 to document the soil conditions exposed for foundation support. The findings of our observations and testing, and recommendations for the foundation design are presented in this report. We previously conducted a subsoil study for design of foundations at the site and presented our findings in a report dated April 21, 2014, Job No. 113 471B. The proposed residence is essentially the same as described in our previous report and will be supported on spread footings placed on compacted structural fill in shallow cut areas and on the natural soils in basement cut areas and sized for an allowable bearing pressure of 1,000 psf. At the time of our site visits on May 28 and 29, we observed and tested compaction of the backfill below shallow footing areas. The compaction testing results are presented in the attached Earthwork Compaction Testing Reports and indicate satisfactory compaction. When observed on June 4, the basement area had been excavated and compacted, and footing forms were being placed. The excavation had been cut in 2 levels from 31/4. to 11 feet below the adjacent ground surface. The step between the upper and lower levels was about 4'z to 5 feet. The deeper cut was along the uphill, south side. The soils exposed in the bottom of the excavation consisted of compacted sandy silt in shallow cut areas and natural sandy silt at basement cut depth. No free water was encountered in the excavation. The natural soils were slightly moist and the compacted soils were moist. The natural soils and compacted soils exposed in the excavation are consistent with those expected at the site and suitable for support of spread footings designed for the recommended allowable bearing pressure of 1,000 psf with the risk of settlement. Any remaining loose disturbed soils should be removed or compacted in the footing areas_ The front (west) shallow footing trench was at the top of the step in grade with less than one foot setback. Structural fill should be placed to at least 98% between the basement Parker 303-841-7119 • Colorado Springs 719-633-5562 • Silverthorne 970-468.1989 Aspen Signature Homes of Ironbridge, LLC June 4, 2014 Page 2 wall and cut bank in this area for lateral support of the cut face. Other recommendations presented in our previous report which are applicable, especially those to keep the bearing soils dry, should also be observed. The recommendations submitted in this letter are based on our observation of the soils exposed within the foundation excavation and the previous limited subsurface exploration at the site. Variations in the subsurface conditions below the excavation could increase the risk of foundation movement. We should be advised of any variations encountered in the excavation conditions for possible changes to recommendations contained in this letter. 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. If you have any questions or need further assistance, please call our office. Sincerely, HEPWORTH PAWLAK GEOTECHNICAL, INC. Steven L. Pawlak, P.E. SLP/ljg Attachments: Earthwork Compaction Testing Reports, May 28 and 29, 2014 cc: Silich Construction Dave Ockers (dockers ''si1ichconstruction.com) Silich Construction John Silich (johnf i silichconstruction.com) Job No. 113 471C Gech HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hDaeoethoaeotech,com Earthwork Compaction Testing Report Client: Aspen Signature Homes of Ironbridge, LLC Attn: Llwyd Ecclestone P.O. Box 7628 Aspen, Colorado 81612 Job No.: 113 471C Day: Date: Page: Wednesday 5128114 1 of 2 Project: Ironbridge, Lot 247, River Bend Way, Ironbridge Development, Garfield County, Colorado Weather: Clear, calm, dry Temperature: 56-86° at 9:00 am -2:00 pm Earthwork Contractor: Western Colorado Excavating Equipment Used: Description of Earthwork Tested: Sample(s) Obtained: Verbal Communication: Wacker RT & Excavator Subexcavated footing areas were being backfilled in 1 foot lifts with on-site soils. Tests on first 3 lifts were acceptable. Dave Ockers and Western Colorado Excavating were informed of our test results. Placement and Compaction Procedure: Lift Thickness: 1' loose Compactor(s) Used: Wacker RT Test No. Location Observed by HP Geotech. Max. Rock Size: 1" Moisture Conditioning: Number of Passes: Mixed in stockpile Nuclear Gauge Moisture/Density Test Results Depth or Elev. Field Dry Density (Pc) Field Moisture Content Not observed Field Comp. (%) 9' N. of SW garage corner 3' below footing grade 111.5 15.2 104 Min. Comp. Req. (%) 98 Proctor Lab No. 068-14 2 12' E. of NW garage corner 3' below footing grade 112.2 14.1 104 98 068-14 6' S. of NE garage corner 3' below footing grade 112.0 14.5 104 98 068-14 4 Center of east side of porch 3' below footing grade 111.2 14.9 104 98 068-14 5 6' N. of SW garage corner 2' below footing grade 104.7 15.7 98 98 068-14 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 068-14 ASTM D 698 Sandy Silt with Gravel (Lot 248) 107.2 16.8 THIS noun i OPINIONS A5 A RESULT OF OUR U tICVATIDNSUF FILL PLACEMENT WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORTFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6936 Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (lecclestonecpblhfl.net) Silich Construction — Dave Ockers(dave(FD_sllichconstruction.com) Silich Construction —John Silich (Is illchl silichconatruction.com) /ljg Tom Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By H P 5020 County Road 154 Geotech Glenwood Springs, Colorado 81650 Phone -45-988 HEPWORTH-PAWLAK GEOTECHNICAL Fax 5-8 hpgeo@hp@hpgeotechch com Earthwork Compaction Testing Report Client: Aspen Signature Homes of Ironbridge, LLC Job No.: 113 471C Day: Wednesday Attn: Llwyd Ecclestone P.O. Box 7628 Date: 5128114 Aspen, Colorado 81612 Page: 2 of 2 Project: Ironbridge, Lot 247, River Bend Way, Ironbridge Development, Garfield County, Colorado Nuclear Gauge Moisture/Density Test Results Test No. Location Depth or Elev. Field Dry Density (pcf) Field Moisture Content (%) Field COmp' (%) Min, Comp. Req. (%) Proctor Lab No. 6 3' E. of NW garage corner 2' below footing grade 107.6 15.7 100 98 068-14 7 7' W. of NE garage corner 2' below footing grade 111.0 14.8 104 98 068-14 8 porch SE corner 2' below footing grade 110.1 15.3 103 98 068-14 9 5' S. of NE garage corner 1' below footing grade 113.7 14.8 106 98 068-14 10 _ 4' W. of porch SE corner 1' below footing grade 111.5 15.7 104 98 068-14 11 3' W. of porch NE corner 1' below footing grade _ 110.9 14.4 103 98 068-14 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (pcf) Opt. Moist. (%) 068-14 ASTM D 698 Sandy Silt with Gravel (Lot 248) 107.2 16.8 THE NUCLEAR DENSOMETER Distribution: Aspen Signature Silich Construction Silich Construction lll9 METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE Homes of Ironbridge, LLC - Llwyd Ecclestone — Dave Ockers (davensilichconstruction.com) — John Silich (isiIich{6 silichconstruction.com) WITH ASTM DBK2 ilacclestone pblhfi.net) Steven L. Pawlak, P.E. CET Tom Westhoff, Field Technician Reviewed By Gech HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hoaeoc hooeotech.com Earthwork Compaction Testing Report Client: Aspen Signature Homes of Ironbridge, LLC Job No.: 113 471C Day: Thursday Attn: Llwyd Ecclestone Date: 5129114 P.O. Box 7628 Page: 1 of 1 Aspen, Colorado 81612 Project: Ironbridge, Lot 247, River Bend Way, Ironbridge Development, Garfield County, Colorado Weather: Partly cloudy, calm, dry Temperature: 58° at 7:30 am Earthwork Contractor: Western Colorado Excavating Equipment Used: Wacker RT Roller, Excavator Description of Earthwork Below footing backfill was completed. Tests were acceptable. Tested: Sample(s) Obtained: Verbal Communication: Western Colorado Excavating was informed of our test results. Placement and Compaction Procedure: Not observed by HP Geotech. Lift Thickness: Max. Rock Size: Compactor(s) Used: Test No. Location Moisture Conditioning: Number of Passes: Nuclear Gauge Moisture/Density Test Results Depth or Elev. Field Dry Density (Pcf) Field Moisture Content Field Comp. (%) 1 15' W. of garage NE corner 0.5 below footing grade 112.3 14.0 105 Min. Comp. Req. (%) 98 Proctor Lab No. 068-14 2 garage NW corner 0.5 below footing grade 110.0 14.2 103 98 068-14 3 8' E. of garage SW corner footing grade 113.9 14.8 106 98 068-14 4 garage NW corner footing grade 111.9 14.0 104 98 068-14 5 garage SW corner footing grade 112.4 15.3 105 98 068-14 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 068-14 ASTM D 698 Sandy Silt with Gravel (Lot 248) 107.2 16.8 THIS Ktrun i rntstNTS OPINIONS A5 A RESULT OF OUR U 5 RVATION5OF FILL PLACEMENT WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER 15 NOT OBSERVING OPERATIONS THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938 Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (lecciestone a{apbihfl.net) Silich Construction — Dave Ockers (dave@silichconstruction.com) Silich Construction—John Silich(isilichOsilichconstruction.com) /ljg Tom Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By