路堤荷载下现浇筒桩复合地基性状分析

为了提高软土地基的稳定性和减少路基沉降，进行了现浇筒桩复合地基工作性状研究.通过对现场测试数据的分析，得到了复合地基顶部桩土平均应力随填土时间的变化曲线，研究路基中心和桩顶沉降随填土时间变化规律，并讨论了孔隙水压力随时间消散曲线和侧向位移沿深度变化规律.研究结果表明，桩间土平均应力随填土时间增加先增大后减小，而桩顶平均应力持续增大.复合地基的沉降随深度增加而递减，沉降主要发生在小于4 m深度范围内.地基侧向位移沿深度变化较小，筒桩及土工格栅的联合加固效应明显，侧向位移有回缩现象.

Performance analysis of cast-in-place tubular pile composite ground under embankment load

To improve the stabilization of soft soil foundation and reduce the settlement of road foundation, the service performance of cast-in-place tubular pile composite ground was investigated. Through analyzing the in-situ test data, the curves of pile and soil top average stress ratio of composite foundation changing with embanking time were obtained. The rules of road foundation settlements in the center and pile top varying with embanking time were studied, and the pore pressure laws changing with time were discussed. Research results indicate that the average soil stresses between piles increase first and then decrease with embanking time, but the average pile top stresses increase continuously. The settlements of composite foundation mainly decrease with the increasing depth, and arise in the range of depth less than 4 meters. The change of lateral displacement in foundation with depth is small, the combined reinforcement effects of tubular pile and geogrid are very obvious, and the shrinking of lateral displacements exists.