堆载下桩+地下墙水平承载组合基础模型试验研究

Model test of combined foundation of piles-diaphragm wall under surcharge

桩–地下墙组合基础是一种新型的水平承载基础,具有水平承载力高、造价低的优点。通过进行新型组合基础的室内模型试验,研究堆载作用下该组合基础内力及变形的规律,同时进行常规桩–承台基础的室内模型的比对试验,得到新型组合基础的变形控制机制,为进一步推广这种技术提供理论和实践依据。试验结果表明,(1)组合基础相对于桩承台基础具有较高的水平承载力;(2)组合基础主要由前墙受力,且组合基础桩身下部受力较小;(3)组合基础与桩承台基础的变形性状不同,前者由于受较大负摩阻力作用,基础向堆载侧倾斜且呈整体下沉趋势,后者向远离堆载侧位移;(4)上部荷载对组合基础水平承载力影响较小但增加基础的倾斜。

The combined foundation of pile-underground diaphragm wall is a new type of foundation, which has the advantages of high horizontal bearing capacity and low cost. The internal force distribution and deformation regularity of the new combined foundation under surcharge are studied by conducting a new type of combinatorial indoor model test. At the same time, a comparison test of the conventional model of the pile-concrete foundation is conducted to obtain the deformation control mechanism of the new combined foundation, for which in order to provide further theoretical and practical basis for the further promotion of this technology. The experimental results show that:(1) The combined foundation has a high bearing capacity relative to the foundation of the pile bearing platform.(2) The combined foundation is mainly driven by the front wall and the lower part of the combined foundation pile is small.(3) The combined foundation and the foundation of the pile are different in the shape of the deformation. The combined foundation is inclined to the stacking side and is in the direction of the whole subsidence due to the larger negative friction resistance. The pile foundation is shifted away from the stacking side.(4) The upper load has less influence on the horizontal bearing capacity of the combined foundation but increases the inclination of the foundation.