矩形顶管施工的环境效应研究

发布时间：2018-11-23 09:15

【摘要】：随着城市地下结构的日益复杂化,矩形顶管作为一种暗挖技术,具有扰动小,空间利用率高的优势,正越来越多地被运用于联络通道、立交道路、地下综合管廊等工程中,但矩形顶管环境效应的研究仍处于起步阶段,本文以深圳地铁7号线华强北站-华新站区间通道工程为背景,采用理论计算、数值模拟和实测分析等手段就矩形顶管施工的环境效应展开了多方面的研究。主要包括：(1)采用两阶段分析法计算了矩形顶管施工引起的下卧盾构隧道隆起。在顶管底面、侧面及开挖面卸载的作用下,应用Mindlin解求得隧道上的附加荷载；再采用Winkler地基梁模型简化隧道,求解平衡微分方程,计算得到的隧道整体隆起曲线与实测曲线基本吻合。(2)采用随机介质法计算了矩形顶管土体损失引起的地表沉降。Peck公式与均匀收敛模式下随机介质法的计算结果随埋深的增大趋于一致,但与不均匀收敛模式的结果存在较大差异。实测数据显示,不均匀收敛模式下采用随机介质法更为准确。(3)在矩形顶管的施工过程中对地表隆沉和隧道变形进行了高频率、大范围的监测。顶管施工仅对下方15m-20m范围内的隧道有较大影响。下方隧道的隆起曲线存在峰值区域,隧道管片的隆起主要发生在开挖面到达隧道边界和离开隧道边界的时间节点之间。顶管卸载作用影响范围内的隧道横断面呈蛋形变形。地表上一点在顶管通过时会出现沉降-隆起-沉降的变化过程。(4)采用Plaxis3D建立了三维有限元数值模型,土体本构采用硬化模型。模拟结果与实测结果较为接近。模拟结果表明管线的曲率半径、隧道的变形值和曲率半径都在允许范围内。采用分步推进的方法模拟了3#顶管的动态推进,分析了模拟时程曲线与实测时程曲线的异同。
[Abstract]:With the increasing complication of urban underground structure, rectangular pipe jacking, as a kind of underground excavation technology, has the advantages of small disturbance and high space utilization ratio, and is being used more and more in the engineering of connection passage, interchange road, underground integrated pipe corridor and so on. However, the research on the environmental effect of rectangular pipe jacking is still in its infancy. In this paper, based on the project between Hua-Qiang North Station and Huaxin Station of Shenzhen Metro Line 7, the theoretical calculation is used. The environmental effects of rectangular pipe jacking are studied by means of numerical simulation and measured analysis. The main contents are as follows: (1) the tunnel uplift caused by rectangular pipe jacking is calculated by using two-stage analysis method. Under the action of unloading the bottom, side and excavated surface of the pipe jacking, the Mindlin solution is used to obtain the additional load on the tunnel. Then the Winkler foundation beam model is used to simplify the tunnel and solve the equilibrium differential equation. The calculated integral uplift curve of the tunnel is basically consistent with the measured curve. (2) the surface settlement caused by the soil loss caused by the rectangular pipe jacking is calculated by using the stochastic medium method. Peck formula and the calculation of the random medium method under the uniform convergence mode The calculated results tend to be consistent with the increase of buried depth. However, there is a big difference between the results of the model and the non-uniform convergence model. The measured data show that the random medium method is more accurate under the non-uniform convergence mode. (3) during the construction of rectangular pipe jacking, the surface uplift and settlement and tunnel deformation are monitored at high frequency and in a wide range. Pipe-jacking construction only has a greater impact on the tunnel in the lower 15m-20m range. There is a peak region in the uplift curve of the lower tunnel, and the uplift of the tunnel segment mainly occurs between the time node between the excavated surface reaching the tunnel boundary and the time node leaving the tunnel boundary. The cross section of tunnel under the influence of pipe jacking is egg-shaped. At the point on the surface, the process of settlement, uplift and settlement will occur when the pipe jacking passes. (4) the three-dimensional finite element numerical model is established by Plaxis3D, and the soil constitutive model is hardening model. The simulation results are close to the measured results. The simulation results show that the radius of curvature of pipeline, the deformation of tunnel and the radius of curvature are all within the allowable range. The dynamic propulsion of pipe jacking was simulated by the method of stepwise propulsion, and the similarities and differences between the simulated time-history curve and the measured time-history curve were analyzed.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU990.3

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