基于强度折减法的边坡稳定分析及其防护研究

发布时间：2018-04-08 17:36

本文选题：拓宽路基　切入点：强度折减法　出处：《重庆交通大学》2014年硕士论文

【摘要】：本文针对目前拓宽路基过程中需要不封路的施工要求,基于常用的路基边坡稳定性分析中的强度折减法,对此种特殊工程状况的边坡进行了有限元分析。为了准确掌握实际工程中的断面几何形态以及土质力学强度因素对不封路状态拓宽路基边坡施工稳定性的影响,通过现场调研选择有代表性的土样进行室内试验,测试土样的物理力学特性,并且以试验结果为建模基础,研究建立了ABAQUS的强度折减法边坡稳定模型,同时在此基础上对断面几何参数、材料力学指标和模型计算参数进行影响分析；根据模型计算结果,提出了两种边坡稳定防护方法,从理论上上对整个施工过程做出了详细的数值分析。结果表明： (1)利用强度折减法建立的边坡稳定分析模型可以很好的表达这种特殊的施工模式,分析过程中以斜坡内某点的位移与折减系数的关系曲线的突变点作为判别准则； (2)对于本模型中,路基的填土高度不宜过高,且边坡坡率以1：1.5以上为宜；且开挖过程中台阶数量增多,安全系数逐渐增大,多级开挖可以保证施工更加安全；路基土的C,φ以及剪胀角会显著影响边坡安全稳定系数,而土基的C、剪胀角基本不会影响,φ会影响安全系数,但是影响程度小于路基土。无论是路基土还是土基,回弹模量对边坡稳定性的影响都极小；压路机荷载是一个重要的影响因素,且当荷载达到最大的4500KN时,安全稳定系数急剧下降,边坡失稳破坏。 (3)土工格栅和换填处治土均是两种经济、实用的边坡防护方法。设置了土工格栅后,安全系数提高两倍,说明土工格栅能给予较大的承力支持；而换填处治土后安全稳定系数增长了38.2%,说明换填法对于边坡稳定性的提高有十分重要的作用。
[Abstract]:In view of the construction requirement of not sealing the road in the process of widening the roadbed at present, based on the strength reduction method commonly used in the stability analysis of subgrade slope, the finite element analysis of the slope with this special engineering condition is carried out in this paper.In order to accurately understand the influence of section geometry and soil mechanical strength factors on the stability of roadbed slope construction without road closure, the representative soil samples are selected for indoor test through field investigation.On the basis of testing the physical and mechanical properties of the soil samples, and based on the experimental results, the stability model of ABAQUS's strength reduction slope is established, and the geometric parameters of the section are also analyzed.According to the results of model calculation, two methods of slope stability protection are put forward, and the detailed numerical analysis of the whole construction process is made theoretically.The results show that:1) the slope stability analysis model established by the strength reduction method can well express this special construction mode. In the process of analysis, the catastrophe point of the curve between the displacement and the reduction coefficient of a certain point in the slope is taken as the criterion;2) for this model, the filling height of roadbed should not be too high, and the slope ratio of side slope should be above 1: 1.5, and the number of steps increases and the safety factor increases gradually during the excavation process, and the multi-stage excavation can ensure the construction to be safer.The C, 蠁 and the angle of shear expansion of subgrade soil will significantly affect the coefficient of slope safety stability, but the C and the angle of expansion of soil foundation will not affect the safety factor, 蠁 will affect the safety factor, but the influence degree is smaller than that of subgrade soil.Whether subgrade soil or soil foundation, the modulus of resilience has very little influence on slope stability, and the load of roller is an important factor, and when the load reaches the maximum 4500KN, the coefficient of safety stability decreases sharply and the slope loses stability.Geogrid and soil replacement are two economic and practical slope protection methods.After the geogrid is set up, the safety factor is increased by two times, which indicates that the geogrid can give greater support to the force, while the coefficient of safety and stability increases by 38.2% after the replacement of the soil, which indicates that the replacement method plays a very important role in the improvement of slope stability.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.14

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