深大基坑开挖引起地层动态变形的研究

发布时间：2018-03-28 08:58

本文选题：深大基坑　切入点：分步开挖　出处：《河北工业大学》2013年硕士论文

【摘要】：针对深大基坑开挖对邻近历史风貌建筑产生的影响，本文对天津市津湾广场二期深大基坑工程支护体系内力和变形及周围土体变形的监测成果进行整理。并采用FLAC3D分析了基坑在挖至不同深度时，地下连续墙变形、支撑轴力、桩顶变形以及坑周土体变形的规律。最后将模拟结果与实测结果进行了对比分析，预测了基坑南侧历史风貌建筑（原法国兵营）的最大水平变形值。研究结果表明：(1)开挖完毕，基坑南侧围护墙的最大水平位移值为106.2mm，出现在距地表-9m深度处。开挖过程中，支撑以承受轴压力为主，，支撑轴压力的最大值为14230KN，出现在东西向对撑Z1-13上。地表沉降的影响范围约为40m，约两倍的基坑开挖深度，基坑南侧地表沉降最大值为12.3mm，出现在距坑边约7m处。(2)基坑变形有很强的空间性和整体性。坑边土体深层水平位移场与围护墙变形规律相似。围护墙和桩在竖向卸荷和坑底隆起的作用下，均表现为先沉降后隆起的现象。(3)通过在不同开挖步下，模拟结果与实测结果的对比发现，模拟规律和实测规律基本一致，模拟值与监测值基本吻合。(4)根据模拟值预测：挖至坑底时，基坑南侧历史风貌建筑地表处水平位移值为12.1mm；最大水平变形量为20.2mm，出现在距地表4m深度处。根据已有文献，分析结果认为，津湾广场二期基坑工程施工对南侧历史风貌建筑（原法国兵营）会产生一定的影响。本文的分析结果可用于指导工程安全施工和南侧历史风貌建筑的保护。
[Abstract]:In view of the influence of deep and large foundation pit excavation on adjacent historical buildings, In this paper, the monitoring results of the internal force and deformation of the support system and the deformation of surrounding soil in the deep and large foundation pit of Tianjin Jinwan Square Phase II are sorted out, and the deformation of the underground continuous wall and the supporting axial force are analyzed by FLAC3D when the foundation pit is excavated to different depths. The law of pile top deformation and soil deformation around the pit is analyzed. Finally, the maximum horizontal deformation of historic buildings (former French Barracks) on the south side of foundation pit is predicted by comparing the simulation results with the measured results. The results show that after excavation, the maximum horizontal displacement of the retaining wall on the south side of the foundation pit is 106.2 mm, which appears at a depth of -9 m from the surface. During the excavation, the support is mainly supported by axial pressure. The maximum pressure of the supporting shaft is 14230KN, which appears on the east-west bearing Z1-13. The influence range of surface subsidence is about 40m, which is about twice the excavation depth of foundation pit. The maximum value of ground subsidence on the south side of foundation pit is 12.3 mm, which appears at about 7 m from the edge of pit.) the deformation of foundation pit has strong spatial character and integrity. The horizontal displacement field of deep soil around the pit is similar to that of retaining wall. The surrounding wall and pile are discharged vertically. Under the influence of the heave of the bottom of the pit, Through the comparison between the simulation results and the measured results, it is found that the simulation law is basically consistent with the measured law. The simulated value is basically in agreement with the monitoring value.) according to the prediction of the simulated value, the horizontal displacement of the historical landscape building on the south side of the foundation pit is 12.1mm, and the maximum horizontal deformation is 20.2mm, which appears at the depth of 4m from the ground surface. The results show that the construction of the second phase foundation pit of Jinwan Square will have a certain influence on the historical architecture (former French Barracks) on the south side. The results of this paper can be used to guide the safety construction of the project and the protection of the historic buildings on the south side.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU470;TU433

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