大直径江底盾构隧道衬砌结构受力现场测试与分析

以长沙南湖路湘江隧道为背景,对管片衬砌在施工期和后期所受外荷载和结构内力进行长期现场追踪测试,总结衬砌结构外荷载和内力随时间的变化规律,并采用梁-弹簧计算模型对不同施工阶段管片结构内力分布形态进行研究,与现场测试结果相互验证。研究结果表明:1)施工期管片衬砌脱环后容易形成偏压状态;2)注浆对管片内力影响较大,受注浆影响,管片内力增幅明显;3)随着监测的进行,管片内力特别是轴力仍然有小幅度增长。

Field Test and Analysis on Stress of Lining of Large-Diameter River-crossing Shield Tunnel

Long-term field test is made on the stress of the segments of Nanhu Road Tunnel in Changsha,the rule of the time-dependent variation of the applied load and internal force is summarized,the distribution of the internal force in different construction stages is studied by means of beam-spring model and comparison is made between the study result and the field test result.The research result shows that：1 ）Eccentric load state is easily formed when the segments move out of the shield tail;2）Grouting has great effect on the distribution of the internal force,which increases significantly because of the grouting;3）With the monitoring going on,the internal force,especially the axial force,still has a small increase.