北京地铁16号线盾构施工引起的地表沉降规律研究

发布时间：2018-04-28 16:17

本文选题：盾构施工 + 地表沉降　；参考：《西安科技大学》2017年硕士论文

【摘要】：地铁隧道盾构法施工不可避免的会引起地表沉降,研究其沉降规律对地铁施工安全和运营至关重要。本文以北京地铁16号线温阳路站~稻香湖路站区间为工程背景,采用理论分析、现场监控量测和数值模拟的方法,对盾构法施工引起地表沉降规律进行了分析研究,主要工作和结论如下:(1)盾构法施工引起的地表沉降机理主要是由于施工过程中对土体的扰动,其大小主要取决于隧道所在岩层及上覆岩层的特性。该地铁为双线隧道,沿线地质条件复杂多变,穿越粉土层、粉质粘土层和中粗砂层,上覆填土层、粉土层、粉质粘土层,稳定性较差强度低,易发生坍塌和涌水现象。(2)通过对沿线13个地表沉降监测数据综合分析可以看出:各断面沉降值差异较大,最大沉降为14.3mm,最小为7.3mm,这主要是由各区段地质条件不同引起的,但区段内地表沉降值均小于20mm的北京地区盾构法施工引起地表沉降的控制标准。(3)通过对典型断面现场监测和数值模拟分析可知:单线开挖时横向地表沉降表现为凹槽形沉降规律,双线隧道横向地表沉降呈“W”型沉降规律,其影响范围和沉降量呈明显的叠加效应。主要影响区域为中心线以外7~12m范围内,总的地表沉降区域为各自中心线以外22~30m范围内。同时土层地质条件(密实性,自稳能力)越好,地表沉降越小;隧道埋深越大,地表沉降越小。(4)纵向地表沉降规律具有明显的阶段性,盾构机到达前,地表沉降量仅占总沉降量的5~15%,通过过程中沉降量占总沉降量的45~50%,后续沉降量占40~45%。其沉降曲线近似于以反弯点对称的两条平滑分段指数函数,影响区域为盾构机刀盘前方15m到刀盘通过监测断面30m范围内。
[Abstract]:The ground subsidence will inevitably be caused by shield tunneling, so it is very important to study the settlement law for the safety and operation of subway construction. Based on the engineering background of Wenyang Road Station ~ Daoxianghu Road Station of Beijing Metro Line 16, using the methods of theoretical analysis, field monitoring measurement and numerical simulation, this paper analyzes and studies the law of ground subsidence caused by shield tunneling construction. The main work and conclusions are as follows: (1) the mechanism of ground subsidence caused by shield method is mainly due to the disturbance of soil mass during construction, and its size mainly depends on the characteristics of the rock strata and overlying strata in which the tunnel is located. The subway is a double-line tunnel. The geological conditions along the subway line are complex and changeable. It passes through silty soil, silty clay and medium coarse sand, overburden soil, silt and silty clay, and has low stability and low strength. Through the comprehensive analysis of 13 surface subsidence monitoring data along the route, it can be seen that the settlement value of each section is quite different, the maximum settlement is 14.3 mm, and the minimum is 7.3 mm, which is mainly caused by the different geological conditions of each section. But the value of surface subsidence in the interior of the section is smaller than that of 20mm in Beijing area. The control standard of ground subsidence caused by shield tunneling in Beijing area. (3) based on the field monitoring and numerical simulation analysis of typical sections, it can be concluded that the lateral surface settlement during single-line excavation is as follows: Grooved settlement law, The horizontal surface subsidence of double-track tunnel is of "W" type, and its influence range and settlement amount are obviously superimposed. The main influence area is within 712m beyond the center line, and the total surface subsidence area is 2230m beyond the respective central line. At the same time, the better the geological conditions of soil layer (compactness, self-stability ability), the smaller the surface subsidence, the greater the tunnel depth, the smaller the surface settlement. The surface subsidence only accounts for 515% of the total settlement. During the process of settlement, the amount of settlement accounts for 4550% of the total settlement, and the subsequent settlement amount accounts for 40% of the total settlement. The settlement curve is similar to two smooth piecewise exponential functions with symmetry of reverse bending point, and the influence area is from 15m in front of the cutter head of shield machine to 30m from the cutter head passing through the monitoring section.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43;U231.3;P642.26

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