盾构隧道下穿既有铁路桥梁桩基的加固措施

依托武汉地铁3号线盾构隧道下穿既有铁路桥梁桩基工程,分别对不加固、桩基周围土体注浆加固、采取隔离桩防护3种工况隧道下穿过程进行有限元数值模拟。结果表明:2种加固措施均能减少地表沉降和桩基位移,满足既有结构物变形控制要求;与注浆加固相比,隔离桩防护对地层沉降和桩基位移的控制效果更显著。在此前提下,可综合考虑工程量、工程造价等因素,根据工程实际情况合理选用加固措施。

Reinforcement Measures for Bridge Pile Foundation of Existing Railway Under-crossed by Shield Tunnel

Based on the bridge pile foundation project of existing railway under-crossed by the shield tunnel of W uhan metro line No. 3,the finite element numerical simulation of tunnel under-crossing process in such three conditions as non-reinforcement,grouting reinforcement of soil around pile foundation and isolation pile protection were carried out respectively.The results show that both reinforcement measures can reduce ground settlement and pile foundation displacement,which could meet the deformation control requirements of existing structures,the control effect of isolation pile protection on ground settlement and pile foundation displacement is more significant by comparing with grouting reinforcement. On this premise,the factors such as engineering quantity,engineering cost and so on can be considered comprehensively,and the reinforcement measures can be selected reasonably according to the actual situation of the project.