黏土地层顶管开挖面主动支护压力极限分析上限解

    Upper bound solution of active support pressure limit analysis of pipe jacking excavation face in clay stratum

    • 摘要: 顶管施工覆土浅,常位于黏土层,对施工变形控制要求高,其中开挖面支护压力的确定是顶管开挖面稳定性与施工变形控制的关键。以成都市锦江区再生水综合利用工程为依托,对泥水压力现场监测结果进行深入分析;然后采用极限分析法,给出了黏土层顶管开挖面主动支护压力上限解,并对不同埋深、不同内径对主动支护压力的影响进行计算分析。结果表明:①随着水土侧压力的增大,现场泥水压力增大,且为控制施工变形现场泥水压力通常较水土侧压力增大10~20 kPa;②随着埋深的增大,主动支护压力均呈抛物线增大,而主动支护压力比均呈抛物线减小,埋深由2 m增大至10 m时,主动支护压力增大190.2%,主动支护压力比减少17.1%;③随着顶管内径的增大,主动支护压力、主动支护压力比均呈抛物线增大,内径由2.0 m增大至3.2 m时,主动支护压力和压力比均增大12.9%。研究成果可为黏土地层顶管施工提供参考。

       

      Abstract: The construction of pipe jacking is usually in shallow stratum, often embedded in the clay stratum, so it requires strict control on soil deformation.The determination of the support pressure of the excavation face is a key to the stability of the excavation face and the control of construction deformation.Based on the comprehensive utilization project of reclaimed water in Jinjiang District, Chengdu City, we carried out an in-depth analysis on the on-site monitoring results of slurry pressure.Then, the limit analysis method was used to solve the upper limit solution of the active support pressure on the pipe jacking excavation face in the clay stratum.The influences of different buried depths and different inner diameters on the active support pressure were calculated and analyzed.The results showed that: ① With the increasing of water and soil lateral pressure, the field slurry pressure increased, and to control the construction deformation, the field slurry pressure was 10~20 kPa higher than the water and soil lateral pressure.② The active support pressure increased with the increasing of buried depth, and the active support pressure ratio decreased, both in a parabolic shape.In detail, the active support pressure increased by 190.2%, and the active support pressure ratio decreased by 17.1%, when the buried depth increased from 2 m to 10 m.③ The active support pressure and active support pressure ratio all increased with the inner diameter of the pipe jacking in a parabolic shape.When the inner diameter increased from 2.0 m to 3.2 m, the active support pressure and the pressure ratio all increased by 12.9%.The results can provide reference for pipe jacking construction in clay stratum.

       

    /

    返回文章
    返回