桩端存在“孤石”的桩基的优化设计

Optimization Design of Pile End Existing in"Solitary Stone"of Pile Foundation

该文介绍了花岗岩分布区,在其残积层及风化带中常发育有球状风化体(孤石),给钻(冲)孔灌注桩的成孔施工带来了极大的困难,增大了工程成本,延误了工期。为了降低钻(冲)孔灌注桩的施工难度和成本,缩短工期,对桩端具有足够大直径"孤石"的基桩按扩底桩的原理作了优化设计。通过工程实例对该方法进行了验证,结果说明是可行的。

This paper introduces the granite areas, where globale weathered rock mass (solitary stone) often develops in the residual soil and weathered zone. This has brought great difficulty in cast-in-place piles formed by drilling (percussion), which augments project cost and delays time limit for the project. To lower the cost and shorten time limit as well as construction difficulty caused by cast-in-place formed by drilling (percussion), an optimization design, based on the principle of belled pile, has been made for the foundation piles of the pile end having the enough large-diameter'solitary stone'. The method is proved by the engineering cases, and the result makes clear that it is feasible.