INSTALL 2003 - Laserfiche WebLink

Home Browse Search

Project No. JB -314 24 March 2003 Page 10 with concrete to "float" the water above the concrete with the tremie hose maintaining a minimum 5 -foot head of concrete at all times during hose removal. If a different type of foundation system is desired, this office should be called for supplemental recommendations. Such recommendations will be presented as an addendum to this report. 6.3 Lateral Load Design Criteria Lateral loads may be resisted by soil friction and by the passive resistance of the soils. For engineered fill or native soil, we recommend the following lateral load design criteria: Coefficient of Friction ................................ 0.30 Passive Pressure ............................... 300 psf/ft The passive pressure and the frictional resistance of the soils may be combined without reduction in determining the total lateral resistance. These values are ultimate and an appropriate factor of safety should be applied by the structural engineer. 6.4 Concrete Slabs -on -Grade If the earthwork recommendations are complied with, concrete slabs -on -grade may be protected from unwanted moisture vapor by an underlainment of a 4 -inch thick capillary break of Class 2 drain rock, clean '/2 by %-inch crushed drain rock, or pea gravel. We recommend that Class 2 base rock not be used as the capillary break. If the potential for a damp slab is undesirable or if moisture sensitive floor coverings are used, we recommend that an impermeable membrane of 10 -mil minimum thickness be placed on the drain rock and overlain by a minimum of 2 inches of clean sand to assist in the proper curing of the slab. The select material or sand should be moistened but not saturated prior to placement of concrete. We recommend reducing the water -cement ratio of the concrete mix design for slabs as low as possible to help further reduce the potential for moisture passing through the concrete slab -on -grade. The structural engineer should determine the final requirements of the concrete mix design. We recommend concrete slab -on -grade floors and exterior flatwork be a minimum thickness of 4 inches and the trash enclosure area slab be a minimum thickness of 6 inches. The actual slab thickness must be determined by the project structural engineer. The trash enclosure area pavement section should be a minimum of 6 inches of concrete over 6 inches of aggregate base and designed according to the recommendations presented in Section 6.7 Pavements. Korbmacher Engineering, Inc.