软土地区某基坑施工稳定性分析及安全监测

发布时间：2018-08-05 11:10

【摘要】：软土地区高层建筑的兴建,导致基坑工程处于富水的施工环境,由于软弱土施工场地渗流场复杂,地下施工环境难以掌控,就不可避免的带来一系列安全问题。因此针对基坑围护结构和近邻建筑物稳定性分析及安全监测研究,对进一步完善基坑支护方案,减少安全事故发生具有巨大的经济意义和社会价值。本文以软土地区某文化广场基坑工程为研究背景,借助数值模拟及现场安全监测相结合的方法,对基坑围护结构和近邻建筑物的稳定性进行了分析。论文的主要研究工作如下:(1)采用有限元软件对基坑的分步施工过程,以及2倍基坑深度范围内的建筑物基础变形进行数值模拟计算。计算得出:地下连续墙在基坑开挖深度2/3处出现最大水平位移,基坑围护墙轴向变形出现两头小、中间大的“括号”形状;基坑底部浅层地下水位降形成明显的漏斗状,导致周围土体固结沉降,引起近邻建筑物基础产生不均匀沉降。(2)分析基础在不同距基坑边沿距离、支护锚杆埋置深度、基础刚度、上部荷载条件下近邻建筑物的变形情况。结果表明:距基坑开挖深度1倍范围内是建筑物变形的主要影响区;浅层锚杆成孔引起基础两端地基反力增大,导致近邻建筑物基础沉降越大;增强基础刚度可控制建筑物沉降和倾斜变形;(3)通过数值模拟方法对软土地区某文化广场基坑工程的前期计算分析,结合安全监测的报警情况,提出对基坑底部浅层土体进行水泥土搅拌硬化处理和围护墙后1倍基坑深度范围的水泥注浆加固处理,跟踪安全监测信息,得出该措施成功控制了周围土体的沉降速率,稳固了基坑的施工安全,验证了施工方案的可行性。
[Abstract]:The construction of the high-rise building in the soft soil area leads to the foundation pit engineering in the water rich construction environment. Because the seepage field of the soft soil construction site is complex and the underground construction environment is difficult to control, it inevitably brings a series of safety problems. Therefore, the stability analysis and safety monitoring of the foundation pit enclosure and adjacent buildings and the safety monitoring are further studied. It is of great economic and social value to improve the foundation pit supporting scheme and reduce the occurrence of safety accidents. In this paper, the foundation pit engineering of a cultural square in the soft soil area is taken as the research background, and the stability of the foundation pit enclosure structure and near adjacent construction is analyzed with the help of numerical simulation and site safety monitoring. The following work is as follows: (1) the finite element software is used to simulate the step construction process of the foundation pit and the foundation deformation of the building in the depth of 2 times the depth of the foundation pit. The calculation shows that the maximum horizontal displacement of the diaphragm wall appears at the depth of 2/3 in the depth of the excavation, and the axial deformation of the retaining wall in the foundation pit has two small ends and the big "brackets" in the middle. Shape; the shallow groundwater level in the bottom of the foundation pit forms an obvious funnel shape, which leads to the consolidation and settlement of the surrounding soil and causes the uneven settlement of the adjacent building foundation. (2) the deformation of the adjacent buildings under different distance from the foundation pit, the buried depth of the anchoring bolt, the foundation stiffness and the upper loading condition. 1 times the depth of foundation pit excavation is the main influence area of the deformation of the building; the reinforcement of the foundation at the two ends increases with the shallow bolt hole forming, which leads to the greater settlement of the adjacent building foundation; the strengthening foundation stiffness can control the settlement and the tilting deformation of the building; (3) the early stage of the foundation pit engineering of a cultural square in the soft soil area by numerical simulation method Combined with the alarm situation of safety monitoring, the cement grouting reinforcement treatment for shallow soil soil in the bottom of foundation pit and 1 times the depth range of foundation pit depth after retaining wall is put forward, and the safety monitoring information is tracked, and the settlement rate of surrounding soil is controlled successfully, and the construction safety of foundation pit is stabilized and verified. The feasibility of the construction scheme is feasible.
【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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