2014-122A - Laserfiche WebLink

Home Browse Search

13`h Street SW Bridge at 58`h Avenue -6- File No. 07-5535 Based on the provided working loads per pile in axial compression, we estimate that settlement of isolated individual piles, will range between 0.1 and 0.2 inches; most of which will be recoverable in elastic shortening of the pile if the loads are removed. Any modification to the above recommended procedures should be approved by Ardaman & Associates, Inc. based on observations during the pile installation operations. In order to verify compliance with recommendations and specifications, we recommend that Ardaman & Associates, Inc. observe the installation of all the driven piles used on the project. QUALITY CONTROL Any modification to the above recommended procedures should be approved by Ardaman & Associates, Inc. based on observations during the pile installation operations. In order to verify compliance with recommendations and specifications, we recommend that Ardaman & Associates, Inc. inspect the installation of all the driven piles used on the project. Stripping and Grubbing The "footprint" of the proposed bridge foundation areas, plus a minimum margin of five feet, should be stripped of all surface vegetation, stumps, debris, organic topsoil or other deleterious materials, as encountered. After stripping, the site should be grubbed or root -raked such that roots with a diameter greater than 1/2 inch, stumps, or small roots in a dense state, are completely removed. The actual depth(s) of stripping and grubbing must be determined by visual observation and judgment during the earthwork operation. Dewatering If the control of the groundwater is required to achieve the necessary stripping and subsequent construction, backfilling, and compaction operations, the actual method(s) of dewatering should be determined by the contractor. However, regardless of the method(s) used, we suggest drawing down the water table sufficiently, say 2 to 3 feet, below the bottom of any excavation or compaction surface to preclude "pumping" and/or compaction -related problems with the foundation soils. Dewatering should be accomplished with the knowledge that the permeability of soil decreases with an increasing silt and clay content. Therefore, silty and clayey fine sands are typically less permeable than a fine sand. The SP and SP -SM, and some SP -SC type soils, can usually be dewatered by well pointing or ditch/sump methods.