考虑施工过程的盾构隧道沉降数值分析

地铁隧道施工引起的地面沉降已成为我国城市地面沉降的主要根源之一，威胁着地铁沿线附近建筑物和地铁隧道上方地下管线的安全，因此，准确预测盾构隧道施工引起的沉降对维护地铁施工安全至关重要。基于K. M. Lee等提出的等效地层损失参数法，利用数值分析方法研究注浆压力和掌子面推力这2个重要参数对盾构隧道施工沉降的影响规律。并在此基础上将注浆压力对于隧道上覆土体的重力及掌子面推力对土体侧向静止土压力进行归一化处理，提出可以考虑施工因素对隧道沉降的计算方法。算例与数值计算结果的对比，证实提出的修正计算方法的有效性。

NUMERICAL ANALYSIS OF SHIELD TUNNEL SETTLEMENT CONSIDERING CONSTRUCTION PROCESS

Ground settlement induced by subway tunneling is becoming one of the main causes of ground subsidence. It strongly affects the serviceability of superstructures and pipelines around the subway tunnel. Therefore，it is very important to predict the settlement accurately. Numerical simulation was conducted to investigate the influence of grouting pressure and working face thrust force on the ground settlement caused by tunneling. The grouting pressure and working face thrust force were normalized using the gravity of the overburden soil and the lateral static earth pressure，respectively. Based on the equivalent ground loss method proposed by K. M. Lee et al.，procedures considering the construction effect during shield tunneling were put forward to estimate the ground settlement. Comparison numerical and calculated results demonstrates the effectiveness of the proposed method.