2039 N Victoria Drive #2 - Plan - Laserfiche WebLink

Home Browse Search

24-8009 Page 10 undocumented fill shall be ignored. As a minimum the caisson capacity (axial and lateral) shall be ignored in the upper 10 feet. The above values may be increased by one-third when considering short duration seismic or wind loads. Foundation design details such as concrete strength, reinforcements, etc. should be established by the Structural Engineer. The total settlement is not expected to exceed ½ inch. The differential settlement between piers is estimated as ¼ inch. For caissons spaced at less than three (3) diameters on center, additional group capacity reduction effects should be taken into account on evaluating the allowable axial capacity of the pile groups. The drilling and installation of caissons should be performed under the observation of TGR Geotechnical. Precautions should be taken during installation of caissons. The caisson excavation should be filled with concrete as soon as possible after the drilling is completed. The excavation should not be left open overnight. The concrete should not be allowed to fall freely more than five (5) feet; vibration should take place throughout the full length of the pile to eliminate voids in either the pile base or the shaft. Placement procedure such as tremie, should ensure that aggregate segregation does not occur. Where pile spacing is less than three (3) diameters, caissons should be drilled and filled alternately, allowing the previously poured pile concrete to set for at least twenty-four (24) hours, or as permitted by the geotechnical engineer. Slab-on-Grade Design Slab-on-Grade which will receive relatively light loads on low expansive soils should be a minimum of 5-inches thick, underlain by 4-inches of crushed aggregate base (CAB) and reinforced with a minimum of No. 4 reinforcing bars on 18-inch centers in two horizontally perpendicular directions. Reinforcing should be properly supported to ensure placement near the vertical midpoint of the slab. "Hooking" of the reinforcement is not considered an acceptable method of positioning the steel. The subgrade material should be compacted to a minimum of ninety (90) percent of the maximum laboratory dry density (ASTM D1557) to a minimum depth of three (3) feet or the bottom of undocumented fill (whichever is deeper). Prior to placement of concrete, the subgrade soils should be moistened to optimum moisture content and verified by our field representative. For moisture sensitive flooring, the floor slab should be underlain by a minimum 15-mil impermeable polyethylene membrane (Stego Wrap, Moistop Plus, or any equivalent meeting the requirements of ASTM D1745) as a capillary break. The polyethylene membrane joints should be lapped not less than 6 inches. Sand may be placed above and below the impermeable polyethylene membrane at the discretion of the project structural engineer/concrete contractor for proper curing and finish of the concrete slab-on-grade and protection of the membrane and is considered outside the scope of geotechnical engineering. 2039 N Victoria Drive #24/28/2025