小河沟2号滑坡治理设计与数值模拟分析

发布时间：2018-03-07 04:10

本文选题：小河沟2号滑坡　切入点：稳定性　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以拟建银川至百色高速公路为研究背景,选取小河沟2号滑坡为研究对象,通过前期的资料收集、野外实地调绘、钻探以及室内试验等手段,查明了滑坡的基本特征、产生原因及形成机理等,进而对其进行了稳定性计算和评价,并在此基础上通过滑坡推力计算、抗滑桩设计计算并结合滑坡具体的工程地质特征给出了具体的治理设计方案。在滑坡治理方案的基础上,进一步采用有限元数值模拟软件Midas/GTS,选取典型断面对不同工况布桩前后滑坡的稳定性进行了数值模拟,得出如下主要结论:(1)小河沟2号滑坡在平面上整体呈“M”形,由紧邻的南北两个大型黄土滑坡共同发育形成,其中南侧滑坡在流水的冲刷作用下前部滑体发生过二次滑移。(2)通过传递系数法对小河沟2号滑坡在两种工况下的稳定性进行评价,主要得出以下结论:在正常工况下,北侧滑坡稳定系数为1.122,其整体处于稳定状态,南侧滑坡整体处于基本稳定状态,但其前缘次级滑面的稳定系数为1.036,处于欠稳定状态;在非正常工况Ⅰ下,北侧滑坡整体处于欠稳定状态,南侧滑坡整体处于不稳定状态,前缘次级滑面的稳定系数为0.677,其失稳后可能导致后部土体的进一步失稳。(3)根据滑坡治理设计原则和滑坡推力计算结果并结合滑坡具体的工程地质特征,南侧滑坡选用抗滑桩支挡方案,北侧滑坡采用填土反压+抗滑桩支挡方案。(4)数值模拟典型断面选用南侧滑坡1-1′断面,通过对数值模拟结果的分析对比主要得出以下结论:前部次级滑体对后部主滑体起到了非常大的阻滑作用;在暴雨或连续降雨的影响下次级滑体将会沿着次级滑面发生剪切破坏;在非正常工况Ⅰ下1-1′断面前缘失稳后,后部主滑体会产生较大的位移变形并会进一步的失稳破坏,在布桩后,在抗滑桩的支挡作用下主滑体由不稳定状态转变为稳定状态,说明了抗滑桩在提高坡体稳定性方面的重要作用,同时,桩前土体对桩后土体有一定的抗滑作用,在对抗滑桩设计时应充分考虑桩前土体对桩后土体的抗滑力。(5)综合考虑滑坡治理设计方案和有限元数值模拟结果,对滑坡治理设计方案进行了优化。
[Abstract]:Based on the background of the proposed highway from Yinchuan to Baise, this paper selects Xiaohegou No. 2 landslide as the research object, and finds out the basic characteristics of the landslide by means of data collection, field mapping, drilling and laboratory tests. On the basis of the calculation and evaluation of the stability of the landslide, the cause and the formation mechanism of the landslide are calculated, and the landslide thrust is calculated on the basis of the calculation. The design and calculation of the anti-slide pile and the concrete engineering geological characteristics of the landslide are combined to give the concrete design scheme for the treatment of the landslide, and on the basis of the control scheme of the landslide, Further, using the finite element numerical simulation software Midas / GTS, the stability of landslide before and after distributing piles with typical fault face under different working conditions is numerically simulated. The main conclusions are as follows: 1) Xiaohegou No. 2 landslide is "M" shape on the plane as a whole. Formed by the co-development of two large loess landslides in the immediate vicinity of the North and the South, The south side landslide under income's scour action has had the secondary slip. 2) through the transfer coefficient method, the stability of Xiaohegou No. 2 landslide under two working conditions is evaluated. The main conclusions are as follows: under normal working condition, the stability of Xiaowegou No. 2 landslide is evaluated. The stability coefficient of the north side landslide is 1.122, its whole is in the stable state, the south side landslide is in the basic stable state, but the stability coefficient of the leading edge secondary slide surface is 1.036, which is in the unstable state. The whole landslide on the north side is in an unstable state, while the whole landslide in the south side is in an unstable state. The stability coefficient of the front secondary slip surface is 0.677, which may lead to further instability of the back soil mass after its instability.) according to the design principles of landslide control and the calculation results of landslide thrust, combined with the specific engineering geological characteristics of landslide, The anti-slide pile retaining scheme is selected for the south landslide, and the backpressure anti-slide pile retaining scheme for the north side is used to simulate the typical section of the south landslide by using 1-1 'section. Through the analysis and comparison of the numerical simulation results, the following conclusions are drawn: the front secondary sliding body plays a very important role in preventing the slip of the rear main slide body; Under the influence of torrential rain or continuous rainfall, shear failure will occur along the secondary slip surface, and after the front edge of 1-1 'section is unstable under abnormal working conditions I, the main slip in the rear part will produce large displacement deformation and further instability failure. After pile placement, the main sliding body changes from unstable state to stable state under the support of anti-slide pile, which shows that anti-slide pile plays an important role in improving the stability of slope body. At the same time, the soil in front of pile has certain anti-slide effect on soil body behind pile. In the design of the anti-slide pile, the anti-slide force of the soil in front of the pile to the soil behind the pile should be fully considered. (5) the design scheme of landslide treatment and the result of finite element numerical simulation should be considered synthetically, and the design scheme of landslide treatment should be optimized.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

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