悬臂排桩支护结构空间变形分析

Spatial deformation analysis of cantilever soldier pile retaining structure in deep foundation pit

以矩形基坑悬臂排桩支护结构为研究对象,通过分析现场实测数据和数值计算,归纳出了冠梁和支护桩的空间变形模式,建立了整个支护系统的能量表达式。利用最小势能原理,推导了基坑中部桩顶最大位移的解析解,分析了各主要支护参数对该位移的影响。研究结果表明,桩顶最大位移随坡顶超载和桩间距的增大基本呈线性增大趋势;当嵌固深度系数逐渐增大时,桩顶最大位移也逐渐增大,但趋势渐缓;基坑长度对其影响也较大,当基坑长度超过一定数值后,最大位移值趋于稳定。最后利用所得的研究成果对某基坑进行了验证,并与现场实测结果进行了对比,计算结果能够满足工程要求。

According to a lot of field tests and numerical efforts,the spatial deformation mode of the top beam and pile is deduced for the cantilever soldier pile retaining structure in rectangular excavation;and the expression of the potential energy is derived for the total supporting system.Based on the principle of minimum potential energy,a new analytic solution to determine the maximum displacement of the pile head is derived;and the effects of the retaining structural parameters on the maximum displacement are discussed.Results show that the maximum displacement of the pile head increases with the increase of the surcharge and the spacing of the pile linearly.When the excavation length increases to a critical length,the maximum displacement will be a constant.In addition,the coefficient of the embedded depth of the pile has an dramatic effect on the maximum displacement.Finally,the result obtained from the proposed approach is compared with field tests and elastic resistance method.