大型滑坡抗滑桩-桩板结构受力变形研究

在复杂艰险山区修建无砟轨道路基时，现有常规抗滑桩或桩板结构等均难以同时解决大型滑坡区潜在滑移和沉降控制问题。为适应无砟轨道路基通过大型滑坡区的需要，创新设计了抗滑桩-桩板结构，并结合贵阳至广州高速铁路建设，开展了大型滑坡抗滑桩-桩板结构现场监测试验。结果表明:抗滑桩和桩板结构基桩的最大侧向位移均位于桩顶，沿深度方向侧向位移先缓慢衰减再加速衰减；滑面附近侧向约束作用的差异，往往会导致桩身侧向位移发生突变；抗滑桩和基桩的桩身弯矩均呈先增大至峰值点再减小的趋势，沿桩深方向具有单峰曲线变化特征；雨季降水作用导致桩身弯矩增加，旱季蒸发作用导致桩身弯矩减小；结构系统中抗滑桩充分发挥了承担滑坡推力控制滑体稳定的作用，基桩则主要用于承担竖向荷载控制路基沉降，承担的滑坡推力较小。抗滑桩-桩板结构可作为滑坡区无砟轨道路基通过的加固型式，对今后类似复杂艰险山区高速铁路修建具有重要的参考价值。

A study of the deformation of anti-slide pile and pile-plate structure in large landslide

When the ballastless track subgrade is constructed in complex and dangerous mountainous areas,it is difficult to solve the potential slip constraint of landslides and settlement control of subgrade by using the existing conventional anti-slide piles or pile-plate structures.To meet the needs of the ballastless track subgrade passing through large landslides,an innovative anti-slide pile and pile-plate structure is designed,and combined with the construction of the Guiguang high-speed railway,the field monitoring tests of the combination structure in large landslides are carried out.The results show that the maximum lateral displacement of both the anti-slide pile and pile-plate structure is located at the top of piles,meanwhile,the lateral displacement decreases with depth.The difference in lateral constraint of the slip surface will cause sudden changes in the lateral displacement of the pile body.The bending moments of anti-slide piles and foundation piles first increase to the peak point and then decrease with the depth,which can be described as a unimodal curve along the pile depth.The bending moments of piles increase in the rainy season,but decrease in the dry season.The anti-slide pile of the combination structure system can be used to control the stability of landslides,and the pile-plate structure is mostly used to control the settlement of the ballastless track subgrade.Therefore,the combination structure can be used as a reinforcement type of ballastless track subgrade in landslides.