【摘要】 运用plaxis有限元软件分析地震作用下桩-网复合地基的路堤破裂面,揭示了地震荷载作用下复合地基路堤产生路面拉裂破坏,桩-网复合地基的破裂面发生在路堤两边缘的现象,表明土工格栅加筋可起到裂缝隔断作用和变形控制作用,路面张拉裂缝由于长筋的存在而不能向下继续扩展,坡面土体的侧向变形由于短筋的存在受到抑制,进而防止了路堤坡面滑塌。同时利用有限元强度折减法对桩一网复合地基的路堤加筋方式进行优化设计,得出不同加筋情况下的安全系数。研究表明,常规加筋设计时,动力安全系数为1.55,顶部增设通长筋时,动力安全系数为1.78,在中部再增设8 m短筋时,动力安全系数提高至2.35,比常规加筋情况下提高了51.6%。更多还原

【Abstract】 Based on the finite element software-plaxis,a subgrade failure surface of pile-net composite foundation is analyzed under the seismic action,which reveals the phenomenon of crack destruction in the pavement.Failure surface of pile-net composite foundation occurs in both edges of subgrade,which indicates that the long reinforced geo-textile can prevent the development of cracks,while the short one can restrain the lateral deformation.So the sliding of the subgrade slope can be controlled,it shows that the reinforced geo-textile can play the role of cutting off the cracks and deformation control.The optimum design of means of reinforced geo-textile in pile-net composite foundation is also analyzed based on the FEM of strength reduction,which figures out the safety factors in different cases.The study results show that the dynamic safety factor is 1.55 in the common reinforced design,and it will be 1.78 when the long reinforced geo-textile is additionally set on the top,but it will be increased to 2.35 when the short one of 8m is also additionally set in the middle,which increases by 51.6% than the common design.更多还原