考虑时间及位移相关土压力的地下连续墙成槽变形分析  

Deformation analysis of the trenching construction of diaphram wall considering time and displacement related soil pressure

作　　者：黄明[1,2] 江松[1] 钟祖良[2] 黄欣[3] 沈启炜[3] 

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]重庆大学土木工程学院,重庆400045 [3]中铁十八局集团有限公司,天津300222

出　　处：《自然灾害学报》2017年第5期198-205,共8页Journal of Natural Disasters

基　　金：国家自然科学基金(41672290);福建省自然科学基金(2016J01189)~~

摘　　要：土层中地下连续墙开槽容易引起较大的地层变形,且与地层侧向土压力的变化特征有较大关系。基于弹性理论,考虑侧压力与时间及位移相关条件下,建立了地下连续墙开槽引起地层应力和位移变化的理论计算方法。结合地下连续墙开槽的特点,考虑极限情况下,开挖初期作用于地下连续墙槽段周围的有效土压力分布情况,得到与时间和位移有关的土压力计算公式;地下连续墙槽段开挖完成后在远场应力的作用下,槽段周围的应力将重新分布,利用变分原理和保角变换方法,计算得到重分布后的应力计算公式;在此基础上,综合分析地下连续墙矩形槽段施工过程中的水平方向的应力转移问题和竖直方向向下的荷载转移问题,建立了地下连续墙槽段周边沉降量的计算模型,并结合Mindlin解得到三维应力状态下的地表沉降量解析解。通过仿真,将理论成果应用于依托工程,与实际监测结果相对比表明该理论结果正确可行,为规避地下连续墙施工风险提供了理论依据。The diaphram wall in the soil layer causes greater deformation at the bottom,and has a relationship with the variation characteristic of side soil pressure. An analytic elastic solution is derived to predict the stress and the displacement caused by construction of rectangular diaphragm wall panel trenches by using the elastic theory. Taking into account of the limit case and the characteristic of construction of underground continuous wall,the calculation formula of soil related to time and displacement is made to express the pressure distribution of soil acting on the surrounding of the underground continuous wall at the beginning of the early days of excavation. The stress of the surrounding of underground continuous wall makes redistribution under the far-field stress after the finish of the excavation. The formula of stress redistribution is calculated based on the complicated variable principle and conformal transformation method. The calculation model is established to calculate the peripheral settlement of underground continuous wall and the stress-transfer of horizontal direction and the load-transition of vertical direction are also analyzed in the process of construction of underground continuous wall. Moreover,the analytic solution of the surface subsidence under the three dimensional stress state is obtained combined with the Mindlin solution. Theproposed theory is applied to an engineering example through simulation. By comparing with the actual monitoring results,the theory is proved to be effective and correct. Therefore,it has a positive influence on the design and construction of the diaphragm wall.

关 键 词：地下连续墙 侧向土压力 应力重分布 保角变换 地表沉降量 

分 类 号：P315.93[天文地球—地震学] X9[天文地球—固体地球物理学]