长板短桩复合地基试验研究

Field Test Study on Short PVD-Long DMM Composite Foundation

通过对长板短桩复合地基处理深厚软基的方法在广东省内某高速公路中的现场试验,表明该方法能够显著提高地基的极限承载力,加快填土速度。填土期间地基中搅拌桩能有效约束深层土体侧向位移,但路基沉降速率较大;相对常规排水预压法,该方法可以减少沉降总量,但后期沉降速率收敛缓慢,对于减少预压时间和工后沉降作用不明显;试验区桩土应力比较小,且总体上体现出填土期迅速增大,预压期逐渐减小的特征。

By field test on application of short PVD - long DMM composite foundation in deep soft soil treatment in a Guangdong expressway, the measured date show that this method can improve the bearing capacity of foundation, and can speed up fill works. The DMM can constrain deep soil lateral displacement, and can not reduce the settlement rate of Subgrade. Compared with conventional drainage preloading method, the method can reduce the total amount of settlement, but post subsidence rate of convergence is slow, the action to reduce preloading time and post -working settlement is not obvious. The soil stress within the test area is quite small, which has shown a characteristics of rapid increasing during filling and gradual reducing during prcloading.