盾构隧道管片施工期上浮特性

Characteristics of upward moving for lining during shield tunnelling construction

针对盾构隧道管片施工阶段的受力特点，建立包含管片与螺栓、盾构机作用、浆液和水土压力作用的管片施工期上浮三维分析模型．借助有限元软件ABAQUS进行求解，对管片施工期上浮变形规律及其引起的管片环接头变形、螺栓受力进行分析．结果表明：第1～5环管片环接头以错台变形为主，第6～12环管片环接头以张开变形为主；减小浆液初凝点与盾尾的距离对控制管片上浮最为有效；当千斤顶总推力较小时，可以通过增加千斤顶总推力进行上浮控制；增加螺栓预紧力对减小管片上浮量的作用比较有限．

Based on the loading features of lining during shield tunnelling construction, a 3D model of the lining for the upward moving analysis considering the effects of shield action, grouting pressure, pore water pressure, and soil pressure has been established. By using the FEM software ABAQUS, the upward moving of lining, the deformation of lining ring joint and the internal forces of bolt were studied. The results show that the main deformation of joint from the first to fifth rings is dislocation, while the main deformation of joint from sixth to twelfth rings is tensile. It is found that reducing the distance between initial hardening location of the grouting and the shield tail is the most effective way for decreasing the upward moving of lining. When the thrust is small, increasing the thrust can be used to control the upward moving of lining. Increasing the pre-tightening force of bolts has little effect on the upward moving of lining.