某高速路改造工程盾构下穿商业综合体试验段沉降控制

Settlement Control of a Highway Reconstruction Project Shield under Commercial Complex

为了研究掘进参数及沉降控制措施对于分离式双洞盾构隧道合理性的影响,选取地层更类似的非加固区段(距始发井22m~192m)作为试验段,共分为三个单元三个试验项目进行分析。1单元(11环~40环)除常规掘进参数控制外,主要增加中盾注克泥效控制沉降,2单元(41环~60环)在1单元的基础上增加深孔注浆措施,3单元(61环~85环)在1单元的基础上增加二次注浆措施。研究结果表明:盾构施工过程引起沉降大致分为盾构到达前、到达时、通过时、通过后及后期固结稳定5个阶段,除常规的掘进参数控制,及时跟进同步注浆等措施外,主要针对第3、5阶段沉降进行控制,增加中盾注克泥效及管片壁后深孔注浆措施,能够快速稳定地层,有效控制地层沉降。

In order to study the influence of tunnelling parameters and settlement control measures on the rationality of split double shield tunnels,a unreinforced section with more similar stratigraphy(22m~192m from the starting shaft)was selected as the test section and divided into three units and three test projects for analysis.Unit 1(ring 11~40)mainly added mid-shield injection of gram mud effect to control settlement in addition to the control of conventional tunnelling parameters,unit 2(ring 41~60)added deep hole grouting measures to unit 1,and unit 3(ring 61~85)added secondary grouting measures to unit 1.The research results showed that the settlement caused by the shield construction process is roughly divided into five stages:before the shield arrives,when it arrives,when it passes,after it passes and after it is consolidated and stabilized.In addition to the conventional measures such as control of boring parameters and timely follow-up of synchronous grouting,the settlement control is mainly carried out for the 3rd and 5th stages,and the increase of mid-shield injection of kerdi effect and deep-hole grouting measures after the pipe sheet wall can quickly stabilize the ground and effectively control the ground settlement.