深层滑坡体特长抗滑桩加固机理分析

发布时间：2018-01-09 23:27

本文关键词：深层滑坡体特长抗滑桩加固机理分析　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文依托重庆奉溪高速公路孙家崖隧道大坪滑坡抗滑桩治理工程为研究背景，由于孙家崖隧道穿越深层滑坡地段，所以采用特长抗滑桩治理深层滑坡体，以保证隧道不受滑坡的破坏，同时借助有限元数值模拟与现场实际监测数据相结合的方法，对特长抗滑桩加固大坪滑坡的加固机理进行研究。研究内容和方法：（1）对特长抗滑桩护壁进行混凝土应力、钢筋轴力及桩后土压力进行现场监测，通过各项监测数据研究抗滑桩施工过程中护壁的受力情况。（2）通过7根测斜孔的监测数据分析深层土体的位移变化情况，并根据位移峰值确定滑动面的位置。（3）采用MIDAS-GTS有限元软件建立抗滑桩加固滑坡体的二维和三维模型，通过分析滑坡的安全系数和位移变化情况研究滑坡体的安全性和稳定性。（4）建立特长抗滑桩施工过程的三维有限元模型，对模拟计算结果与监测数据进行对比分析，研究桩开挖对桩周土体变形和应力的影响。主要研究成果：（1）通过测斜孔监测数据分析得到大坪滑坡深层土体的位移变化情况，同时根据位移峰值得到该滑坡的浅层和深层滑动面深度分别为16~20m和36~40m。（2）通过测斜孔监测的滑动位移峰值绘制了滑坡体的浅层和深层滑动面。（3）通过抗滑桩加固滑坡体的二维模拟得到，，滑坡经过抗滑桩加固后安全系数由0.8875增大为1.2125，坡脚处最大位移由71.27cm降低为5.59cm。（4）通过抗滑桩加固滑坡体的三维模拟得到，滑坡经过抗滑桩加固后安全系数由0.9125增大为1.3225，坡脚处最大位移由91.63cm降低为9.54cm。（5）对特长抗滑桩施工过程的监测数据与数值模拟数据进行对比分析，并结合抗滑桩开挖深度的变化，总结得到抗滑桩在施工过程中围岩应力和位移随着开挖深度的增大而增大。
[Abstract]:Based on the research background of Daping landslide anti-slide pile treatment project of Chongqing Fengxi Expressway Sun Jia Ya Tunnel, because Sun Jiaya Tunnel passes through the deep landslide section, the super long anti-slide pile is used to control the deep landslide body. In order to ensure that the tunnel will not be destroyed by landslide, the reinforcement mechanism of Daping landslide strengthened by super-long anti-slide pile is studied by combining the finite element numerical simulation with the actual monitoring data on the spot at the same time. Contents and methods of the study: 1) the concrete stress, the axial force of steel bar and the earth pressure behind the pile are monitored on the spot, and the stress of the protective wall during the construction of the anti-slide pile is studied through the monitoring data of the concrete stress, the axial force of the steel bar and the earth pressure behind the pile. 2) based on the monitoring data of 7 oblique holes, the displacement of deep soil is analyzed, and the position of sliding surface is determined according to the displacement peak value. MIDAS-GTS finite element software is used to establish 2D and 3D models of landslide body strengthened by anti-slide pile. The safety and stability of landslide are studied by analyzing the safety factor and displacement variation of landslide. (4) the 3D finite element model of the construction process of super-long anti-slide pile is established. The results of simulation calculation and monitoring data are compared and analyzed, and the influence of pile excavation on soil deformation and stress around pile is studied. Main findings: 1) the displacement of deep soil in Daping landslide is obtained by analyzing the monitoring data of inclined hole. At the same time, according to the peak displacement, the depth of the shallow and deep sliding surface of the landslide is 16 ~ 20 m and 36 ~ 40 m, respectively. 2) the shallow and deep sliding surfaces of the landslide are plotted by measuring the peak value of sliding displacement monitored by slanting holes. 3) the safety coefficient of landslide strengthened by anti-slide pile is increased from 0.8875 to 1.2125 by two-dimensional simulation. The maximum displacement at the foot of the slope was reduced from 71.27 cm to 5.59 cm. 4) the safety coefficient of landslide strengthened by anti-slide pile is increased from 0.9125 to 1.3225 through 3D simulation. The maximum displacement at the foot of the slope was reduced from 91.63 cm to 9.54 cm. 5) comparing and analyzing the monitoring data and numerical simulation data of the construction process of anti-slide pile, and combining with the variation of excavation depth of anti-slide pile. It is concluded that the stress and displacement of surrounding rock increase with the increase of excavation depth during the construction of anti-slide pile.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P642.22;U457.3

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