The URL can be used to link to this page

Home My WebLink AboutB14-0033 CR2 soils report s • � v � � �� : LKP :� Engineering, Inc. �( � CI VIIJGEOTEG'�Il�iICAL August 27,2014 Mr.Bob Boymer RE: Open Hole Observation-Garage and Staircase P.O. Box 1001 Excavation Vail, CO 81658 Lot 30, Glen Lyon Subdivision 1250 Westhaven Circle,Town of Vail Eagle County,Colorado Project No. 14-2943 Dear Mr. Boymer: At your request,on August 25,2014,we visited the construction site for the proposed addition at 1250 Westhaven Circle, Town of Vail, Eagle County, Colorada The purpose of our site visit was to observe the soils exposed in the foundation excavation far the proposed garage and staircase.An assumed soil bearing pressure of 2000 psf was used on the structural drawings done by Mr. Tim Boyle, File No. Ferg-S4,dated March 14,2014. The excavation consisted of a"L"shaped trench that was approximately 15 feet by 30 feet. The trench was adjacent to the northwest corner of the existing residence. The soil exposed in the foundation excavation consisted of slightly moist(from the rain), clayey sandy gravel with some cobbles. The excavation cuts ranged from about four to six feet below the existing grade. The sail exposed in the foundation excavation,f'or the proposed addition is suitable for the desi,gned marimum allowable soil bearing pressure of 2000 psf. The bottom of the excavation was compaeted. 5oft spots were not reported. We recommend a minimum of 48 inches of backfill cover for frost protection of the footing subsoils. The bottom of the excavation was compacted. Soft spots were not reported. Foundation walls retaining earth and retaining structures that are laterally supported should be designed to resist an equivalent fluid density of 60 pcf for an"at-rest"condition. Laterally unrestrained structures, retaining the on-site earth, should be designed to resist an equivalent fluid density of 40 pcf for the"active"case. The above design recommendations assume drained backfill conditions and a horizontal backfill surface. Surcharge loading due to adjacent structures, weight of temporary stored construction materials and equipment, inclined backfill and hydrostatic pressure due to undrained backfill should be incorporated in the design. They should try to prevent the buildup of hydrostatic pressure behind the retaining wall. The site surrounding the building structure should slope away from the building in all directions. A minimum of 12 inches in the first 10 feet is recommended in unpaved areas, and three inches in the first 10 feet in paved areas. The top of the granular foundation backfill should be covered with a minimum of 1 foot of relatively impervious fill to reduce the potential of surface water infiltrating the foundation subsoils. Surface water naturally draining toward the proposed building site should be diverted P.O. Box 2837, Edwards, CO 81632 Tel(970) 926-9088 Mr. Bob Boymer Page 2- Project No. 14-2943 August 27, 2014 around and away from it by means of drainage swales or other approved methods. The roof drains and downspouts should extend and discharge beyond the limits of the backfill. It is not recommended to introduce excess water to the foundation soils by installing sprinkler systems next to the building. The installation of the sprinkler heads should insure that the spray from the heads will not fall within 10 feet of foundation walls,porches or patio slabs. Lawn irrigation must be controlled. To reduce the risk of surface water infiltrating the foundation subsoil, we recommend installation of a foundation perimeter drain. The foundation perimeter drain should consist of a 4-inch diameter,perforated pipe, sloped to a suitable gravity outlet, at a 1/4 inch per foot for flexible or at a 1/8 of an inch for rigid pipe. The bottom of the trench adjacent to the footing should be lined with a polyethylene moisture barrier glued to the foundation wall. The drain pipe should be covered with a minimum of 6 inches of-3/4-inch free-draining granular material. Geotextile (Mirafi 140N or equivalent) should be used to cover the free-draining gravel to prevent siltation and clogging of the drain. The backfill above the drain should be granular material to within 2 feet of the ground surFace to prevent a buildup of hydrostatic pressure. This report has been prepared according to locally accepted Professional Geotechnical Engineering standards for similar methods of testing and soil conditions at this time. The findings and recommendation stated above are based on the soil conditions observed and tested in the foundation excavarion only. There is no other warranty either expressed or implied. Sincerel . ��•�� t��,� LKP ENGINEERING,INC. \,�,.��'�e,,O�.RE,�'.�tS'j�;'%,,�� 4�' PETR�IS •.� '� , �. � .� . _O�� '� �Q " i ?.s�� -v� � : . 29526 ;�_ ;-o; .�uc i 4+� • Luiza Petrovska, PE %�90,�'.,� �: �� %, ��+••....••' �►��' �"''�% s�ON A��'� '� ,. --,,,,�.... .., . \�SERVER\Shared\_WP X4-LKP\ 2014\14-2943open-stair-garage.wpd P.O. Box 2837,Edwards, CO 81632 Tel(970) 926-9088