暗挖重叠地铁隧道地表变形特性分析

发布时间：2018-07-07 07:31

本文选题：隧道工程 + 重叠隧道　；参考：《岩石力学与工程学报》2014年12期

【摘要】：城市地下工程建设中,交错重叠隧道施工对地层的多次扰动通常无法避免,对周围环境产生一系列负面影响,对于地铁隧道穿越北京市老城区,此类问题更加突出。依托北京地铁6号线北海北至南锣鼓巷区间隧道工程,该工程为北京地区首例暗挖交错重叠隧道工程,采用数值模拟和现场实测相结合的方法,对5种典型断面在不同开挖顺序、不同空间位置关系、不同超前深孔注浆厚度下的地表变形特性进行研究,取得以下认识:(1)"先下后上"施工方式引起的地表最大沉降值及沉降槽宽度都比"先上后下"施工方式小,更有利于隧道的整体稳定性。(2)随着双线隧道角度的增大,双线隧道逐渐接近,地表变形显著增大。当双线隧道角度大于60°时,地表最大沉降值超过30 mm的控制标准,需要采取深孔注浆的方式对地层进行预加固。(3)随着注浆厚度的加大,地表和隧道拱顶最大沉降值逐渐减小。综合考虑经济效益和过大注浆压力的不利影响,建议注浆厚度定为1.5~2.0 m。(4)实际监测数据显示采取超前深孔注浆后地表沉降满足控制标准,表明超前深孔注浆加固方式可以有效减少双线隧道开挖引起的地表沉降和沉降槽宽度,降低隧道开挖对周围环境的影响。研究成果可为今后北京同类工程提供参考。
[Abstract]:In the construction of urban underground engineering, it is inevitable to avoid the repeated disturbance to the strata caused by the staggered and overlapping tunnel construction, which has a series of negative effects on the surrounding environment, especially for the subway tunnel passing through the old urban area of Beijing. Relying on the Beihai North to South Ggong Guxiang Tunnel Project of Beijing Metro Line 6, this project is the first case of the underground excavation staggered and overlapping tunnel project in Beijing area. The method of combining numerical simulation with field measurement is adopted. The surface deformation characteristics of five typical cross-sections under different excavation sequence, different spatial position relations and different grouting thickness of advanced deep holes are studied. The following conclusions are obtained: (1) the maximum settlement value and the width of the settlement trough caused by the "first down later" construction mode are smaller than that of the "first top and second bottom" construction mode, which is more beneficial to the overall stability of the tunnel. (2) with the increase of the angle of the double-line tunnel, The surface deformation of the double-line tunnel increases significantly as the tunnel approaches. When the angle of double-line tunnel is more than 60 掳, the control standard of the maximum subsidence value of surface is more than 30 mm, so it is necessary to pre-strengthen the ground with deep hole grouting. (3) with the increase of grouting thickness, the maximum settlement value of surface and tunnel arch gradually decreases. Considering the adverse effects of economic benefit and excessive grouting pressure, it is suggested that the grouting thickness should be 1.5 ~ 2. 0 m. (4) the actual monitoring data show that the surface subsidence after advanced deep hole grouting meets the control standard. The results show that the advanced deep hole grouting method can effectively reduce the surface settlement and settlement slot width caused by double-line tunnel excavation and reduce the influence of tunnel excavation on the surrounding environment. The research results can provide reference for similar projects in Beijing in the future.
【作者单位】：北京交通大学城市地下工程教育部重点实验室;
【基金】：国家重点基础研究发展计划(973)项目(2010CB732102) 北京市科委计划项目(Z121100000312021) 中央高校基本科研业务费专项资金资助项目(2012JBZ013)
【分类号】：U451;U231.3

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