隧道下穿厂房结构整体稳定性研究

STUDY ON THE OVERALL STABILITY OF SHALLOW BURIED AND UNDERCUT TUNNEL UNDERGROUND INDUSTRIAL STRUCTURE

地铁项目快速发展催生隧道下穿地表既有建筑时有发生,如何确保隧道结构及既有建筑结构整体稳定性,对地铁隧道工程提升建造技术及运营期高效管理意义重大。基于此考虑,依托某市7#线地铁隧道下穿工业区为工程背景,结合理论分析、现场测试和数值模拟等相结合的方法,对浅埋暗挖隧道下穿工业区厂房整体稳定性进行分析。结果表明,隧道开挖地层变形主要位于隧道洞口上方,呈沉降"槽"状态分布;隧道开挖应力释放打破原有地层应力平衡,地层受力及变形随隧道开挖支护是动态调整过程;隧道上方地表最大沉降约为6mm,横行影响范围约为3.5D(D为隧道直径);工业厂房最不利荷载条件对隧道围岩变形影响较小,自身在隧道整个施工期沉降及侧向变形均小于3mm;隧道施工能满足自身及厂房结构安全,研究成果可为类似工程实践提供参考依据。

The rapid development of Subway project makes it often necessary to build a tunnelacross the surface of the existing building, how to ensure the overall stability of the tunnel structureand the existing building structure is of great significance to the efficient management of the construc-tion technology and the operation period of the subway tunnel engineering. Based on this considera-tion, relying ona city on the 7th subway tunnel under the industrial area for the project background,combined with theoretical analysis, field testing and numerical simulation of a combination of shallowburied tunnel under the industrial area of the overall stability of the plant analysis.The results showthat the deformation of tunnel excavation is mainly located at the top of the tunnel, which is the distri-bution of “trough” .The stress relief of tunnel excavation breaks the stress balance of the original stra-ta,and the strata stress and deformation are dynamic adjustment process.The maximum subsidence ofthe tunnel above the tunnel is about 6mm,and the influence of the horizon is about 3.5D （D is thediameter of the tunnel） . The most unfavorable load conditions of the industrial plant have little effecton the deformation of the surrounding rock, and the settlement and lateral deformation Less than 3mm;The tunnel construction can satisfy the safety of the structure of itself and the building, and the re-search results can provide reference for similar engineering practice.