软土盾构隧道纵向长期稳定性研究分析

离心模型中的固结时间是原型固结时间的1／n2，能够在较短的时间内模拟软土地基的长期沉降。以上海地铁4号线修复段双线盾构隧道为研究对象，利用离心模型试验研究了隧道的纵向长期沉降及稳定性特性，预测了15-20a之后完好段、连接段和修复段隧道纵向沉降量和沉降分布。最后，得出了连接段两端差异沉降最大的结论。并提出隧道与修复段的连接刚度应采用刚性连接，以提高连接点附近隧道适应变形能力的修复意见。

Study of Longitudinal Long-term Stability of Shield Tunnel in Soft Clayed Soil

According to the similitude relations for the centrifuge rmdd test, the consolidation time of centrifugal model is 1 / n2 of the prototype, which could simulating the soft soil foundation long--term settlement in a relatively short time. The method was used to study the longitudinal long term settlement and stability of the paralld shield tunnel of the subway line 4 in Shanghai. Form the results, the longitudinal settlement of the intact, repaired and connected tunnel could be predicted. The conclusion was that the differential settlement of connected tunnel is the largest, and the connection with the repair section of the tunnel should be rigid, which should be used to improve the ability adapting to the defon＇nation the tunnel.