葫芦形基坑地下连续墙施工监测与数值分析

发布时间：2019-04-11 20:34

【摘要】：葫芦形地下连续墙作为基坑的一种新形式的支护结构,更加地适应基础结构经济与安全的要求。目前葫芦形地下连续墙的相关理论与施工技术均没有可以借鉴的成功经验,其变形与受力特征尚不明确。针对以上问题本文以大岳高速洞庭湖大桥岳阳侧锚碇地下连续墙监控项目为工程依托,对葫芦形地下连续墙进行了分析研究。通过常用的有限元计算软件MIDAS/GTS对其进行数值模拟分析,并对地下连续墙的内力与变形进行相关指标的监测,将二者得到的数据进行对比分析,得到有关葫芦形地下连续墙的变形与受力特征。本次研究表明葫芦形地下连续墙的应力以环向压应力为主,内衬结构则以拉应力为主。基坑开挖过程中应力逐步缓慢增大,地下连续墙的应力分布相对均匀,只在Y形连接处以及垂直桥向的圆弧顶部出现相对较大的应力集中,地下连续墙的形状对内力的影响有限。地下连续墙的水平位移和其环向应力相似,墙体下部小、中上部大。随着开挖的进行,两者的最大值点逐渐下降,最大值逐渐增大,最后稳定在开挖面附近。葫芦形结构地下连续墙即使不是完整的圆形地下连续墙,但圆弧形墙体的拱效应还是有效地限制了墙体的变形,变形趋势缓慢,不均匀沉降程度低。数值模拟与监测结果都反映出墙体在Y形连接处出现应力与变形相对集中,应在以后的设计和施工中引起注意。
[Abstract]:As a new type of retaining structure of foundation pit, cucurbit-shaped diaphragm wall can meet the needs of infrastructure economy and safety. At present, there is no successful experience in the theory and construction technology of cucurbitum-shaped diaphragm wall, and its deformation and stress characteristics are still not clear. Based on the monitoring project of Yueyang side Anchorage diaphragm wall of Dongting Lake Bridge in Danyue high-speed highway, this paper analyzes and studies the cucurbit-shaped diaphragm wall. Through the commonly used finite element calculation software MIDAS/GTS, it carries on the numerical simulation analysis, and carries on the monitoring to the underground continuous wall internal force and the deformation correlation index, carries on the contrast analysis to the two data. The deformation and mechanical characteristics of gourd-shaped diaphragm wall are obtained. This study shows that the stress of gourd-shaped diaphragm wall is mainly circumferential compressive stress, while the lining structure is dominated by tensile stress. In the process of foundation pit excavation, the stress increases slowly, and the stress distribution of the diaphragm wall is relatively uniform, only at the Y-shaped junction and the top of the vertical bridge arc, there is a relatively large stress concentration. The shape of diaphragm wall has limited influence on internal force. The horizontal displacement of the diaphragm wall is similar to its circumferential stress, the lower part of the wall is small and the middle and upper parts of the wall are large. As the excavation goes on, the maximum point of the two points decreases gradually, and the maximum value increases gradually, and finally stabilizes near the excavation surface. Even if the diaphragm wall of cucurbit-shaped structure is not a complete circular diaphragm wall, the arch effect of circular wall still effectively limits the deformation of the wall, the deformation trend is slow, and the degree of uneven settlement is low. The results of numerical simulation and monitoring show that the stress and deformation of the wall at the Y-shaped junction are relatively concentrated, which should be paid attention to in the future design and construction.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

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