地铁车站洞桩法施工诱发地面沉降分析

发布时间：2018-04-30 12:57

  本文选题：地铁车站 + 洞桩法　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：近年来地铁建设发展迅猛,地铁车站施工工艺很多,其中地铁车站洞桩法施工以自身独特的优势受到各方的关注。洞桩法是在暗挖的小导洞内施作盖挖法的桩梁框架体系作为初期支护,其具体原理为先在地下将大断面洞室拆分为若干个小导洞开挖,再从小导洞内施作“桩”“柱”“拱”“梁”框架形成牢固的初期支护体系,在该支护体系的初期保护下,便可在桩梁柱的初期支护体系内侧施作防水和永久性二衬,同时依次向下开挖施作内部洞室结构。洞桩法主要特点是地层适应性强,在各种地层条件下施工都能很好的控制地表沉降变形,相比传统的浅埋暗挖法更为安全可靠,洞桩法既能降低大断面暗挖施工带来的沉降风险,同时也能避免盖挖法需要提前进行明挖施工的繁杂工序。但是洞桩法的工序转换较多,受力转化复杂,在不同地层表现出的沉降影响差异性也很大。针对复杂粘土地层中进行洞桩法施工对地表沉降的影响,本文进行了数值模拟分析,以北京某地铁车站洞桩法施工项目为参考,根据模拟结果指导该车站施工地表沉降监测点的布置。通过收集了标准断面加密监测点的实测沉降数据,对实测数据和之前做的模拟计算值进行了对比分析,研究证明数值模拟计算得出的沉降数据与实测数据相符,验证了数值模拟法的合理性,同时表明数值建模方法能有效的指导洞桩法施工的地表沉降监测点布置。该地层条件下导洞开挖阶段、桩拱施作阶段、二衬施作阶段产生的地表沉降量分别为16.37mm、2.91mm、18.88mm,分别占比为42.9%、7.6%、49.5%,并结合实际施工情况探讨控制地表沉降的关键措施。
[Abstract]:In recent years, subway construction has developed rapidly, and there are many construction techniques in subway station. Among them, tunnel pile construction of subway station has attracted attention from all sides for its own unique advantages. The pile-pile method is to use the pile-beam frame system as the initial support in the small guide tunnel. The concrete principle is that the large section cavern is divided into several small guide holes in the underground first, and the concrete principle is that the large section cavern is divided into several small guide holes in the underground excavation. Then the frame of "pile", "column", "arch" and "beam" is applied from the small guide hole to form a solid initial support system. Under the initial protection of the supporting system, the waterproof and permanent secondary lining can be applied to the inner side of the initial support system of the pile Liang Zhu. At the same time, the structure of the inner cavern is excavated downward in turn. The main characteristic of the tunnel pile method is that it has strong adaptability to the strata, and it can control the ground subsidence and deformation well under various stratum conditions, which is more safe and reliable than the traditional shallow excavation method. The tunnel pile method can not only reduce the settlement risk brought by the large section excavation construction, but also avoid the complicated working procedure of the cover excavation method which needs to carry out the open excavation construction in advance. However, the hole pile method has a lot of process conversion and complex force transformation, and the difference of settlement effect in different strata is also great. In view of the influence of tunnel pile construction on surface settlement in complex clay strata, this paper carries out numerical simulation and analysis, taking the construction project of hole pile method for a subway station in Beijing as a reference. According to the simulation results, the layout of the ground subsidence monitoring points in the construction of the station is guided. Through collecting the measured settlement data of the standard section encryption monitoring point, comparing and analyzing the measured data and the previous simulated calculation value, it is proved that the settlement data obtained by the numerical simulation is in accordance with the measured data. The rationality of the numerical simulation method is verified, and it is shown that the numerical modeling method can effectively guide the ground subsidence monitoring points arrangement in the construction of the hole pile method. Under this condition, the ground subsidence in the excavation stage, the pile arch stage and the second lining stage are 16.37mm / 2.91mm / 18.88mm respectively, with the ratio of 42.9mm / 7.6m / 49.5mm, respectively, and the key measures to control the surface subsidence are discussed in the light of the actual construction conditions.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U231.3;P642.26
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本文编号：1824648