FOUNDATION CONCRETE PILE DESIGNED AGAINST BUOYANCY

摘要

PURPOSE: To provide a foundation concrete pile which is designed to protect against pulling force attributable to buoyancy produced by boosted water pressure by introducing a prestress with corrosion proofing prestress strand. ;CONSTITUTION: PS strands 2 are inserted into spiral bars 8 and at least four strands are installed symmetrically on the horizontal surface of a foundation pile 1. Where the tensile stress determined from a long time allowable pulling resistant force _tRa of the foundation pile 1 is defined as σ(f) (kg/cm²), the prestress σ(PS) (kg/cm²), which satisfies the value σ(PS)≥σ(f) is introduced by the PS strands 2. In addition, the long time allowable pulling resistant force _tRa is represented by _tRa=_tRu/3+Wp when the underwater weight of the pile is defined as Wp. Therefore, it is necessary to use a pile skin friction force to prevent buoyancy. However, the degree of skin friction force must be 2/3 that when it is driven. This construction makes it possible to reduce the cost of anchors or foundations and shorten a construction period. It is also possible to rationalize and diversify building work at a high elevation of high water head.;COPYRIGHT: (C)1995,JPO