【摘要】 目前建设于软土地区的盾构隧道在长期服役过程中出现了较大的沉降及差异沉降,影响了管片的结构性能及运营安全。为研究软土地层中盾构隧道长期沉降规律,文章以佛山市轨道交通3号线为工程背景,通过离心模型试验研究盾构隧道在不同厚度的软土地层中长期沉降的发展规律以及隧道周边地基土加固对长期沉降的影响。结果表明:隧道下卧土层性质越差且厚度越大,隧道的长期沉降量越大,长期沉降发展时间越长;同时,隧道埋深较大也会使长期沉降量增大;隧道长期沉降和地表变形都会随地基土加固深度的增加而减小,但减小幅度会逐渐降低,加固深度为3 m,6 m和穿透软弱层时,隧道最终沉降量分别减少了16.7%,30.2%和41.3%,隧道正上方地表变形分别减小了25.4%,44.9%和66.3%。更多还原

【Abstract】 Large settlement or differential settlement of shield tunnels built in soft soils occurs in long-term service,affecting performance of segment structure and operating safety. On the background of Foshan metro line 3, this article studied the development law of medium and long-term settlement of shield tunnels in soft soils with different thicknesses and the influence of subsoil reinforcement on long-term settlement by centrifugal model test. The results indicate that the worse and thicker the underlying stratum of tunnel is, the larger the long-term settlement is,and the longer the long-term settlement development is. At the same time, long-term settlement increases under large buried depth; long-term tunnel settlement and ground surface deformation decrease with an increase of foundation soil reinforcement depth, but the decrease extent reduces gradually, and the long-term settlement decreases by 16.7%, 30.2% and 41.3% respectively when the reinforcement depths of foundation soil are 3 m, 6 m and beyond the soft soil, and the ground surface deformation right above the tunnel decreases by 25.4%, 44.9% and 66.3% respectively.更多还原