低强度桩在桥头软基处理中的应用研究

Application Study on Reinforcing Soft Foundation of Bridge Approach by Low Intensity Pile

在软土地基修建高等级公路中,"桥头跳车问题"是一个技术难题。低强度桩是一种新型处理桥头深厚软基工法,采用变桩长的思想,使沉降逐渐过渡。某大桥桥头段深厚软基采用该工法处理,对桩顶及桩间土沉降、土工格栅上沉降、深层土体水平位移、孔隙水压力、土压力等进行了现场监测,并进行了静载荷试验,对测试结果进行了分析。结果表明,该工法能大幅度减小沉降,形成沉降过渡,减小对桥台基础的水平推力,具有显著的经济效益。

In the highway construction on soft foundation, 'bump at bridge-head' is a difficult technical problem. Low intensity pile is a new method which can improve the soft foundation at bridge approaches and the mode of variable pile length can make settlement transition.The soft foundation at bridge approaches is improved by this method while the soil settlement on and between piles, geogrid settlement, sub-surface soil movement, pore water pressure, earth pressure and static load tests are monitored and the results are analysed. The results indicate that this method can deminish settlement largely, make the settlement transition, decrease horizontal thrusts on bridge abutment and its economic benefits are notable.