地铁隧道盾构法施工变形及控制措施研究

发布时间：2018-01-08 06:28

本文关键词：地铁隧道盾构法施工变形及控制措施研究　出处：《南昌航空大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着社会经济迅猛发展，地上空间的开发利用已经远远不能满足城市发展的需要，如何更好地开发利用地下空间是解决城市交通发展瓶颈的第一要务。盾构法以其地层适应强、速度快、施工质量有保证等显著的优点被广泛地应用于城市地铁建设中，然而在盾构掘进施工过程中，无法避免对周围岩体产生扰动，因而引发程度不同的土体变形和地层位移。因此，必需掌握盾构施工对土体的扰动机理和范围，分析得出扰动土体的分布规律和控制因素，才能在盾构施工阶段准确预测和控制地表沉降。本文以南昌地铁某盾构区间隧道工程为背景，结合有限差分软件FLAC3D进行数值模拟和现场实测方法，对地铁隧道盾构施工引起的地层变形进行研究，，主要研究内容以及取得成果有： (1)回顾了盾构法隧道的发展及在中国的应用现状，并对盾构隧道施工引起的地层变形预测方法进行了概括和总结，分析了盾构隧道施工导致地表沉降的机理。 (2)采用有限差分法FLAC3D能较好地模拟土压平衡盾构在富水砂砾石地层施工，得到计算结果与现场实测值较好吻合，可以应用于实际工程进行变形预测，以及对地层位移影响因素进行分析。 (3)运用FLAC3D可以模拟盾构施工引起的隧道横向地表沉降规律和隧道纵向地表沉降规律，得出横向地表沉降呈“V”形，从隧道中心正上方向两边扩散且沉降量逐渐减小；纵向地表沉降呈“S”形，离盾构开挖面前方一定距离表现为隆起，开挖面后方表现为沉降且随开挖深度增加而逐渐加大，最终趋于稳定。 (4)结合实际盾构工程进行地表沉降监测，在富水砂砾石地层通过添加膨润土或者泡沫进行渣土改良施工，使得渣土具有较好的流动性和止水性效果，利于开挖面保持稳定，有效控制地表沉降。
[Abstract]:With the rapid development of social economy, the development and utilization of aboveground space has been far from meeting the needs of urban development. How to develop and utilize underground space better is the most important task to solve the bottleneck of urban traffic development. The obvious advantages such as guarantee of construction quality have been widely used in urban subway construction, but in the shield tunneling construction process, it is impossible to avoid disturbance to surrounding rock mass. Therefore, it is necessary to master the disturbance mechanism and scope of shield construction to soil, and to analyze the distribution law and control factors of disturbed soil. In order to accurately predict and control the surface subsidence in shield construction stage. In this paper, the ground deformation caused by shield tunneling in Nanchang Metro is studied based on the numerical simulation and field measurement method of finite difference software FLAC3D. The main contents of the study and the results achieved are as follows: 1) the development of shield tunneling and its application in China are reviewed, and the prediction methods of formation deformation caused by shield tunnel construction are summarized and summarized. The mechanism of ground subsidence caused by shield tunnel construction is analyzed. (2) the finite difference method (FLAC3D) is used to simulate the soil pressure balance shield construction in water-rich sand and gravel strata, and the calculated results are in good agreement with the field measured values. It can be applied to actual engineering to predict deformation and analyze the influencing factors of stratum displacement. 3) FLAC3D can be used to simulate the law of tunnel lateral surface subsidence and tunnel longitudinal surface subsidence caused by shield tunneling, and it is concluded that the horizontal surface subsidence is "V" shape. It diffuses from the center of the tunnel in the upper direction and the settlement decreases gradually. The longitudinal surface subsidence is "S" shape, the distance from the shield excavation surface is uplift, and the settlement behind the excavating surface is increasing gradually with the increase of excavation depth, and finally tends to be stable. In combination with the actual shield engineering, the residual soil is improved by adding bentonite or foam in the water-rich sand and gravel formation, which makes the residual soil have better fluidity and water sealing effect. 4) in combination with the actual shield engineering, the residual soil can be improved by adding bentonite or foam in the water-rich sand and gravel formation. It is propitious to keep the excavating surface stable and effectively control the surface subsidence.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.43

【参考文献】