TBM高内压输水隧洞双层衬砌结构力学性能对比研究

Comparative Study on Mechanical Properties of Double Lining Structure of TBM Water Conveyance Tunnel with High Internal Pressure

TBM技术以其掘进速度快、成洞质量好、安全性高等优势,越来越多地应用在输水隧洞工程中。为充分利用深层地下空间,TBM输水隧洞一般埋深较大,内水压力高。为保证输水隧洞在高内水压情况下的结构安全,本文针对TBM输水隧洞分离式双层衬砌结构和叠合式双层衬砌结构分别建立了较为精细的二维有限元模型,进行了不同围岩条件下的计算分析,并得出以下结论:在高内压情况下,叠合式双层衬砌结构受力相对复杂,且受地质条件及施工因素的影响较大,而分离式双层衬砌结构传力路径清晰,不同地质条件下均具有较为稳定的力学性能,故对于TBM高内压输水隧洞,本文推荐采用分离式双层衬砌结构。

TBM technology is increasingly used in the water conveyance tunnel engineering for its advantages of fast tunneling speed,good quality and high safety.In order to make full use of the deep underground space,TBM water conveyance tunnel generally has a large buried depth and high internal water pressure.In order to ensure the structural safety of the water conveyance tunnel under the condition of high internal pressure,this paper established two-dimensional finite element models respectively for the separated double lining structure and the overlapped double lining structure of the TBM water conveyance tunnel.The calculation and analysis under different surrounding rock conditions was made,and the following conclusions were obtained:under the condition of high internal pressure,the stress of the overlapped double lining structure was relatively complex,and it was greatly influenced by geological conditions and construction factors;The transmission path of the separated double lining structure was clear,and it had relatively stable mechanical properties under different geological conditions.Therefore,for the TBM water conveyance tunnel with high internal pressure,the separated double lining structure was recommended in this paper.