通过不同隧道埋深、支护压力和掘进速度的盾构隧道施工地表沉降的大型物理模型试验,总结不同条件下的地表沉降规律,分析土压力的变化特性,归纳不同条件下的地表沉降曲线;探讨隧道埋深、支护压力和掘进速度对地表沉降值的影响,推导地表横断面沉降槽计算的经验公式。结果表明:随着隧道埋深增加,地表沉降值减小,地表横向沉降槽影响范围加宽;地表最终沉降值随支护超压比增加而增大;掘进速度变化对地表沉降的影响程度较小;施工扰动损伤围岩对地表沉降值有较大影响。
The influence of cover height,face supporting pressure and penetration rate on shield tunneling-induced ground surface settlement was studied with three-dimensinal physical model test.The mechanism of shield tunneling-induced ground surface settlement was analyzed,the ground settlement curves in different conditions were obtained,the influence of cover depth,face supporting pressure and penetration rate of shield tunnel on the surface settlement were discussed,and a newly-modified tunneling-induced ground settlement calculation method was presented.It is revealed that the maximum surface settlement decreases and the transverse settlement trough is widened with the increase of cover height,while the surface settlement increases with the augment of the face supporting pressure.The surface settlement is hardly influenced by the shield penetration,but obviously influenced by boundary soil disturbance induced by shield tunneling.