双线盾构扭矩分析及邻近管线变形影响研究

研究目的:为研究双线盾构隧道施工引起的管线横向及纵向变形规律,本文依托杭州地铁2号线某盾构区间段工程,采用适合杭州软土地区的土压平衡盾构刀盘扭矩计算方法,计算本工程对应的各种刀盘扭矩因子并得出最大理论扭矩值,将计算得到的刀盘扭矩因子与其他学者的研究成果进行对比分析,并研究盾构掘进时管线变形与刀盘扭矩的相关性。研究结论:(1)软土区双线盾构引起的管线横向变形在研究断面上呈现"W双峰"形状,且后行线施工引起的变形量大于先行线;(2)对于双线盾构施工引起的管线纵向变形,测得盾构接近时与刚通过时对管线变形影响较大,盾尾通过研究断面4 d左右纵向变形趋于稳定;(3)通过对比不同案例下刀盘扭矩计算因子得出影响盾构施工刀盘扭矩的主要因子是T4与T5;(4)分析得出管线变形与刀盘扭矩和单环排土量的比值呈现正相关的趋势;(5)本研究成果对控制杭州软土区双线盾构施工引起的管线变形具有参考价值。

Torque Analysis of Double-line Shield and Influence on the Deformation of Adjacent Pipelines

Research purposes:Based on a shield section project of Hangzhou Metro Line 2,the transverse and longitudinal deformation law of pipeline caused by the construction of double shield tunnel is studied.The calculation method of cutter head in shield tunneling in soft soil area of Hangzhou is adopted to calculate various cutter head torque factors corresponding to this project and obtain the maximum theoretical torque value.The obtained cutter head torque factor which will be calculated is compared with other scholars’research results,and the correlation between pipeline deformation and cutter head torque during shield tunneling is studied.Research conclusions:(1)The lateral deformation of pipeline caused by double shield tunneling in soft soil area presents a"W double-peak"shape on the research section,and the deformation caused by the construction of the backward line is greater than that of the leading line.(2)For the longitudinal deformation of pipeline caused by the construction of double shield,it is measured that the pipeline deformation is greatly affected when the shield is close to and just passes through,and the longitudinal deformation of shield tail tends to be stable through the study of section 4 d or so.(3)By comparing the torque calculation factors of cutter head in different cases,it is concluded that the main factors affecting the torque of cutter head in shield construction are T4 and T5.(4)The results show that the ratio of pipeline deformation to the torque of cutter head and the amount of soil discharged by a single ring is positively correlated.(5)The research result has reference value for controlling pipeline deformation caused by double shield construction in Hangzhou soft soil area.