桩锚协同作用与桩锚支护结构永久化研究

发布时间：2018-05-01 11:25

本文选题：桩锚协同作用 + 群锚效应　；参考：《山东大学》2017年硕士论文

【摘要】：基于济南市基坑桩锚支护结构工程案例,借助PLAXIS-3D有限元软件,采用土体硬化本构模型,对桩锚协同作用及支护桩遮拦效应展开研究,在此基础上构建基于桩锚支护的深基坑永久支护结构体系,论文取得如下成果:1、桩锚协同作用(1)桩锚支护结构中,群锚效应发生的锚索水平临界间距随预应力的增加而减小,针对济南市工程地质,明确不同预应力条件下的临界间距;(2)锚索预应力自上而下依次增大、纵向间距自上而下依次减小的布置方式更有利于支护结构位移控制;(3)支护结构位移控制要以锚索控制位主、支护桩控制为辅,设计过程采用"强锚弱桩"的搭配原则。2、支护桩遮拦作用支护桩的存在能显著减少地下室外墙土压力,通过对多个工程模拟结果进行拟合,得到支护桩存在条件下的地下室外墙土压力分布曲线,并在静止土压力计算公式的基础上引入折减系数k,建立的支护桩存在条件下的土压力折减公式,为类似工程提供参照。3、基坑永久支护结构体系通过设置连接构件,构建支护桩与地下主体结构相结合的永久支护结构体系。模拟结果表明:永久支护结构中,坑外土压力主要由支护桩和地下水平结构共同承担,地下室外墙只承担肥槽回填土体土压力,且远小于静止土压力,无水条件下,地下室外墙设计只需满足构造要求。
[Abstract]:Based on the case of pile-anchor supporting structure engineering in Jinan City, by means of PLAXIS-3D finite element software and soil hardening constitutive model, the synergistic effect of pile and anchor and the shielding effect of supporting pile are studied. On this basis, the permanent support structure system of deep foundation pit based on pile and anchor support is constructed. In this paper, the following results are obtained: 1) in the pile-anchor support structure, the critical horizontal spacing of anchor cable decreases with the increase of prestress. In view of the engineering geology of Jinan City, it is clear that the critical spacing of anchor cables increases from top to bottom under different prestressing conditions. The arrangement of decreasing the longitudinal distance from top to bottom is more favorable to the displacement control of the supporting structure. The displacement control of the supporting structure should be mainly controlled by the anchor cable and supplemented by the control of the supporting pile. In the design process, the collocation principle of "strong anchor and weak pile" is adopted. The existence of supporting pile can significantly reduce the earth pressure on the exterior wall of basement. The earth pressure distribution curve of the exterior wall of the basement under the condition of the existence of the supporting pile is obtained, and the formula of earth pressure reduction under the condition of the existence of the supporting pile is established by introducing the reduction coefficient k on the basis of the calculation formula of the static earth pressure. In order to provide reference for similar engineering, the permanent supporting structure system of foundation pit is constructed by setting up connecting members and combining the supporting pile with the underground main body structure. The simulation results show that in the permanent support structure, the earth pressure outside the pit is mainly borne by the supporting pile and the underground horizontal structure, and the external wall of the basement only bears the earth pressure of the fertilizer groove backfill, and it is much smaller than the static earth pressure, and under the condition of no water, The exterior wall design of basement only needs to meet the construction requirements.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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