盾构在矿山法隧道中空推管片纵向受力分析

On analysis of longitudinal stress of airy pushing tunnel segment of shield in mined method

以某地铁盾构在矿山法隧道中空推为背景,对盾构施工时管片的应变过程进行了详细的监测和分析,对盾构施工过程中管片应变的规律进行了总结,管片轴向压应变沿时间变化分为两个明显阶段,千斤顶施加反力阶段应变急剧增加,后逐渐减小至稳定;管片壁后压浆阶段,会造成局部管片发生侧向剪切位移,使得同一管片不同位置上的混凝土轴向压应变升降不一;同一监测断面上的应变沿环向分布极不均匀,易出现渗漏水现象;断面整体预压力基本满足要求。

Taking some subway shield in the airy pushing of the mined tunnel as the background,the paper undertakes the detailed supervision and analysis of the strain process of the segment in the shield construction,sums up the strain law for the segment in the shield construction process,indicates the two obvious steps can be classified of the axial pressure strain of the segment along the time,indicates the strain is increased dramatically at the counterforce stage of the jack and it gradually reduces to the stability,and the side shearing displacement can occur at the partial segment at the grouting stage of the segment＇s wall back,so the same segment has different lifting of the concrete axial pressure strain,the leakage can happen with the uneven distribution of the strain along the ring direction at the same supervision section,so the general prepressure of the section can meet the demand.