盾构长距离小净距斜穿大直径污水干管施工技术研究

Construction technology of shield tunnel by long distance and small clearance obliquely crossing large diameter sewage pipe

地铁盾构下穿既有管线时,如何减小地表沉降保证盾构机安全穿越管线成为盾构施工中的重难点。以郑州地铁某区间盾构长距离小净距斜穿DN2000污水管工程为背景,建立盾构斜穿污水管有限元模型,分析污水管的受力与变形情况,在袖阀管注浆加固污水管前提下,通过控制盾构掘进参数、调整盾构姿态、优化改良渣土配比、精确把控出土量等措施,以地表间接监测和污水管直接监测为保障,将变形值控制在3.2mm以内,最后成功穿越污水管。

When metro shield tunneling through existing pipelines, how to reduce ground settlement and ensure the safe passage of shield tunneling through pipelines has become an important issue and difficult problem in shield tunneling construction. Based on the project of long distance and small clearance for shield tunnel obliquely penetrating DN2000 sewage pipe in a section of Zhengzhou metro, a finite element model of shield tunnel obliquely penetrating DN2000 sewage pipe is established. This paper also analyzes the stress and deformation of sewage pipe. On the premise of reinforcing sewage pipe by sleeve valve pipe grouting, shield tunneling parameters are controlled, shield attitude is adjusted, and the ingredient ratio of slag and soil is optimized. Precise control of excavation, indirect monitoring of the surface and direct monitoring of sewage pipes are taken as guarantee measures. Deformation value is controlled within 3.2 mm, and finally it successfully crossed the sewage pipe.