局部承载黏土地层浅埋隧道稳定机制的连续上界极限分析

发布时间：2018-05-31 01:36

本文选题：黏土地层 + 浅埋隧道　；参考：《土木工程学报》2017年08期

【摘要】：针对局部承载黏土地层浅埋隧道施工的横断面稳定机制问题,采用上界极限分析理论和基于Peck公式及不排水不可压缩条件的地层位移模式,分别计算研究了地层物理力学参数、浅基础荷载参数、桩基础荷载参数对隧道必要支护压力下确界的影响。在其他参数不变的前提下,隧道必要支护力下确界随地层抗剪强度的增大而线性地减小,随地层重度的增大而线性地增大;随浅基础荷载量值的增大而线性地增大,随浅基础荷载横向距离的增大而非线性地减小并趋于定值,随浅基础荷载横向范围的增大而非线性地增大并趋于定值;随桩基础侧面剪力荷载量值、底面压力荷载量值的增大而线性地增大,随桩基础荷载横向距离的增大而非线性地减小并趋于定值;对端承桩而言,当桩基长度小于(或大于)地层沉降竖向分布曲线极大值点对应的深度时,随桩基长度的增大而非线性地增大(或减小)。
[Abstract]:Aiming at the problem of cross-section stability mechanism of shallow buried tunnel construction in local bearing clay stratum, the physical and mechanical parameters of stratum are calculated and studied by using the theory of upper limit analysis and the displacement model of stratum based on Peck formula and undrained incompressible condition. The influence of load parameters of shallow foundation and pile foundation on the bottom boundary of necessary supporting pressure of tunnel. On the premise of invariant other parameters, the shear strength increases linearly with the increase of the shear strength of the necessary support force, and increases linearly with the increase of the floor weight of the tunnel, and increases linearly with the increase of the load value of the shallow foundation. With the increase of lateral distance of shallow foundation load, the nonlinear value decreases and tends to a constant value, and with the increase of lateral range of shallow foundation load, the value of shear load on the side of pile foundation increases nonlinearly and tends to constant value. With the increase of lateral distance of pile foundation load, the value of bottom pressure load increases linearly, which decreases and tends to a constant value with the increase of lateral distance of pile foundation load; for end bearing pile, When the length of pile foundation is less than (or greater than) the depth corresponding to the maximum point of vertical distribution curve of ground settlement, it increases (or decreases) nonlinear with the increase of pile foundation length.
【作者单位】：北京交通大学;中铁二院华东公司;
【基金】：国家重点基础研究发展计划(973计划)项目(2015CB057800)
【分类号】：U451

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