系梁式桩网结构加固斜坡软弱地基路堤的数值模拟

Numerical simulation of embankment on sloped weak ground reinforced by pile-net structure with collar beam

为研究系梁式桩网结构应用于斜坡软弱地基路堤工程的工作机制,建立了系梁式桩网结构加固斜坡软弱地基路堤的有限元模型,开展了与无处治措施时潜在滑动面形态、稳定安全系数、土工格栅拉力、路基顶面沉降及地基侧向位移等力学响应的对比,并进行了系梁布置形式、弹性模量与厚度等核心设计参数的敏感性分析。研究结果表明:系梁式桩网结构加固后的斜坡软弱地基路基最大沉降、差异沉降以及地基侧向变形分别减小了88.7%、90.3%、96.6%,路基的稳定安全系数提高了26.2%;纵横交叉布置系梁有利于提高路堤稳定安全性,削减地基侧向位移;适当降低系梁弹性模量不会造成较大不利影响,系梁厚度不宜过薄。

To investigate the working mechanism of pile-net structure with collar beam applied in the embankment on sloped weak ground,the finite element model of embankment on sloped weak ground reinforced by pile-net structure with collar beam was established.Some mechanical responses with or without reinforcement,including potential slip surface behaviors,stability safety factors, geogrid tensions, embankment top surface settlements and ground lateral displacements,were compared.The sensitivities of core design parameters,such as collar beam location type,elastic modulus and thickness,were analyzed.Study result shows that the pile-net structure with collar beam can decrease the embankment maximum settlement, differential settlement and ground lateral deformation by 88.7%,90.3% and 96.6%,respectively,and improve the stability safety factor by 26.2%.Arranging the collar beam crossbar is beneficial to nbsp;improve the embankment stability safety and reduce the ground lateral displacement.Decreasing the elastic modulus of collar beam appropriately will not cause relatively large unfavorable effect, and too thin collar beam is not suitable.2 tabs,10 figs,20 refs.