邢汾高速路堑边坡坡率优化设计评估

发布时间：2018-04-03 21:52

本文选题：削坡　切入点：离散元　出处：《河北工业大学》2014年硕士论文

【摘要】：本论文研究依托于河北省高速公路管理局科技项目:“类土质路堑高边坡稳定性分析与支护技术研究。”类土质边坡的特性不同于单纯的均质土边坡及岩质边坡，而是介于两者之间，既有土边坡的特性，也有岩石边坡的特性。高速公路边坡滑塌问题成为近年来影响高速公路安全的主要因素。在邢汾高速公路深路堑一次削坡完成之后，有部分路堑发生了滑塌现象，工程上可能是由于施工过程中对路堑应力产生了较大的扰动，加之一次削坡边坡坡率较大，在暴雨等情况下极易发生滑塌，于是决定对边坡进行二次削坡。为此本课题利用离散元软件UDEC建立不同坡率下的二维离散元数值模型，分析不同坡率下坡体各高程点位移变化，岩体和节理的应力变化以及在渗流条件下高程点位移和节理剪应力变化，得出两次削坡之后以及渗流条件下边坡的安全系数，取得以下结论：一次削坡之后产生较大的水平位移，在坡顶出现局部张拉区域，在坡脚产生剪应力集中带，节理剪应力接近节理抗剪强度，安全系数较低，使边坡处于临界平衡状态；二次削坡之后水平位移减小，坡顶张拉区基本消失或不存在张拉区，坡脚处剪应力集中带减小，，节理剪应力有较大程度降低，安全系数有较大提高，增大边坡安全储备，使边坡处于较稳定状态。根据上述对比研究的结果，本文对邢汾高速边坡二次削坡坡率的优化设计做理论上的评估，为其他边坡坡率的优化设计提供参考，对类似工程的施工具有指导意义。
[Abstract]:The research of this paper is based on the science and technology project of Hebei Expressway Administration Bureau: "the stability analysis and support technology research of high slope of similar soil cut."The characteristics of soil-like slope are different from those of homogeneous soil slope and rock slope, but lie between them, which have the characteristics of both soil slope and rock slope.Slope collapse has become a major factor affecting highway safety in recent years.After the completion of deep cutting slope in Xingfen Expressway, part of the cutting has been sloughed, which may be due to the great disturbance to the cutting stress in the construction process and the high slope ratio at the edge of the cutting slope at the same time.It is easy to collapse in the case of heavy rain, so it is decided to cut the slope twice.In this paper, a two-dimensional discrete element numerical model with different slope ratios is established by using discrete element software UDEC, and the displacement changes of different elevation points under different slope ratios are analyzed.The variation of stress of rock mass and joint, the displacement of elevation point and shear stress of joint under seepage condition, and the safety factor of slope after twice slope cutting and under seepage condition are obtained.The following conclusions are obtained: after the first slope cutting, a large horizontal displacement occurs, a local tension area appears at the top of the slope, and a shear stress concentration zone occurs at the foot of the slope. The joint shear stress is close to the shear strength of the joint, and the safety factor is low.The slope is in critical equilibrium state, the horizontal displacement decreases after the second slope clipping, the tension area of the top of the slope disappears basically or there is no tension zone, the shear stress concentration zone at the foot of the slope decreases, the joint shear stress decreases to a large extent, and the safety factor is greatly improved.Increase the slope safety reserve, make the slope in a more stable state.Based on the results of the above comparative study, this paper makes a theoretical evaluation on the optimal design of the slope rate of secondary cutting of Xingfen high speed slope, which provides a reference for the optimization design of the slope rate of other sides, and has a guiding significance for the construction of similar projects.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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