太浦河泵站水泥搅拌桩复合地基桩土应力比测试研究

 根据太浦河泵站水泥搅拌桩复合地基中桩顶土压力及该桩旁侧桩间土压力的实测数据，结合静载试验和沉降监测成果，分析桩土应力比n随荷载变化的规律，桩间土土质对n的影响，泵站通水对n的影响；并进一步从桩土承载力的转化、变化机理来探求n的变化规律和机理。实测试验结果表明：施工期n随荷载的增加而增加，泵站通水后n值反而下降；当持力层相同时，桩周土土质越差，桩土应力比n值越大；泵站下闸通水对n的影响很大，泵站运行1年后，n值在1.0附近；n处于动态变化过程中。

Test Analysis on Pile-Soil Stress Ratio of Compound Foundation Formed by Cement Mixing Piles in Taipu River Pumping Station

Based on measured data obtained from earth pressures on pile-top and sidewise earth pressures between piles in the compound foundation formed by cement mixing piles in the Taipu River Pumping Station, and in combination with static load tests and settlenent monitoring results, the law of pile-soil stress ratio(n) changing with load and the effects of soil quality and pumping station operation on n were respectively analysed. The measared data showed that: the n is increased with load increase under constrution, but begins to be decreased after the pumping station operation; with the same exerting force acting on the top of foundation mat, the more bad the soil quality, the greater the n; the effect of the pumping station operation on n is greatest, at that time, the n equals (1.0); the n is still in dynamically changing at present.