塑料排水板超载预压处理下高速公路软基沉降的数值模拟

Numerical Simulation of Expressway Soft Foundation Settlement under Overload Prepressing Treatment of Plastic Drainage Plate

通过对某核电站进厂公路塑料排水板超载预压处理路段调研工程地质条件,得到土体参数,采用等价竖墙法建立有限元模型,分析软基沉降过程中路堤有效应力、超孔隙水压力和沉降的变化情况。结果显示在填土开始至达到设计填土高度过程中,土体内的超静孔隙水压力增大。超静孔隙水压力的增大会导致路基土体的有效应力减小,进而降低土体的抗剪强度,影响路基稳定。因此路基填筑过程中应加强沉降以及侧向水平位移的监测,确保路基的稳定。同时通过现场沉降监测的结果验证了有限元模型的合理性,证实等价竖墙法用于解决塑料排水板超载预压处理下公路软基沉降模拟的合理性。

According to the investigation and survey of engineering geological conditions in the overload prepressed treated road section of plastic drainage plate in the highways into a nuclear power plant, the parameters of soil body are achieved. The equivalent straight wall method is used to establish the finite element model to analyze the effective stress of embankment, and the variations of excess static pore water pressure and settlement in the settlement process of soft foundation. The result shows that the excess static pore water pressure within the soil body increases in the process from the start of filling to the design filling height. The increment of excess static pore water pressure will lead to the effect stress decrement of roadbedsoil body so as to reduce the shearing strength of soil body and to influence the roadbed stability. Therefore,it should be to strengthen the settlement and monitor the lateral horizontal displacement in the process of roadbed filling for the guarantee of roadbed stability. The monitoring result of filed settlement verifies the rationality of finite element software, and affirms the rationality of equivalent straight method used for solving the simulation of soft foundation settlement under the overload prepressing treatment of plastic drainage plate in highway.