地基注浆加固法在地铁盾构施工中对减少建筑物沉降的研究

发布时间：2018-10-18 10:31

【摘要】：伴随着国民经济的高速增长和国家城镇化建设步伐的加快，交通拥堵现象称为现代城市的交通常态。而地铁交通以其运送乘客量大和不占用地面空间等特点已成为解决城市交通拥堵问题的第一选择。盾构法施工作为城市地铁施工中主要的施工方法，其施工过程不可避免的会对周围岩体产生扰动，引起地表变形，当地表变形过大时可能会危及隧道上方地面建筑物的安全，造成严重的经济损失和社会影响。因此，研究盾构隧道穿越地表既有建筑物时建筑物的保护措施势在必行。本文以武汉某地铁区间下穿地表建筑物为工程实例，应用有限元软件ABAQUS对建筑物地基注浆加固前和加固后两种不同工况下的施工过程进行了三维数值模拟，具体研究工作及取得的成果如下：应用有限元软件ABAQUS对注浆加固前的隧道开挖过程进行数值模拟。通过对模拟结果的分析，得出建筑物基础横向沉降曲线呈正态分布，符合经典Peck沉降曲线。位于隧道中轴线上各点的沉降量最大，距离隧道中轴线越远，沉降值越小。分析了建筑物基础纵向的历时沉降曲线，得出基础在纵向上先后经历了微小沉降（隆起）阶段、沉降激增阶段和沉降稳定阶段。建筑物基础横向和纵向的最大沉降值和局部倾斜值均超过了允许值，，建筑物有可能发生破坏。为了防止地表建筑物发生破坏，采取了地基注浆加固法。应用有限元软件ABAQUS对注浆加固后的隧道开挖进行数值模拟，将现场监测数据与数值模拟结果进行对比分析，得出两者的沉降趋势基本一致，证明了数值模拟的可行性与可靠性。结果表明，注浆加固后基础横向和纵向的最大沉降值和局部倾斜值均较加固前的值小且均小于控制值。由此可知，建筑物地基注浆加固是一种可行有效的保护措施。
[Abstract]:With the rapid growth of the national economy and the acceleration of the pace of urbanization, traffic congestion is called the traffic normal of modern cities. Subway traffic has become the first choice to solve the problem of urban traffic congestion because of its characteristics of large number of passengers and not occupying ground space. As the main construction method in urban subway construction, shield tunneling will inevitably disturb the surrounding rock mass and cause surface deformation. If the local surface deformation is too large, it may endanger the safety of the ground buildings above the tunnel. Causing serious economic losses and social impacts. Therefore, it is imperative to study the protective measures when shield tunnel passes through existing buildings. In this paper, the construction process of building foundation under two different working conditions before and after grouting reinforcement is simulated by finite element software ABAQUS. The results are as follows: finite element software ABAQUS is used to simulate the excavation process of the tunnel before grouting reinforcement. Through the analysis of the simulation results, it is concluded that the transverse settlement curve of the building foundation is normal distribution, which accords with the classical Peck settlement curve. The settlement at each point on the central axis of the tunnel is the largest, and the farther away from the tunnel axis, the smaller the settlement value. The diachronic settlement curve of building foundation is analyzed, and it is concluded that the foundation has experienced small settlement (uplift) stage, settlement surge stage and settlement stabilization stage successively. The maximum settlement value and local inclination value of the foundation exceed the allowable value, and the building may be destroyed. In order to prevent the ground building from being destroyed, the foundation grouting reinforcement method is adopted. The finite element software ABAQUS is used to simulate the tunnel excavation after grouting. The results of field monitoring and numerical simulation are compared and analyzed. It is concluded that the settlement trend is basically the same, which proves the feasibility and reliability of the numerical simulation. The results show that the maximum settlement value and local tilt value of the foundation after grouting reinforcement are smaller than those before reinforcement and are smaller than those of the control value. Therefore, grouting reinforcement of building foundation is a feasible and effective protection measure.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231.3;U455.43

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