大断面隧道穿越接触带施工稳定性分析
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摘要
大断面隧道穿越接触带段施工过程中多发围岩失稳与支护开裂、大变形现象。以兰海高速马林隧道工程穿越不整合接触带段为背景,采用数值模拟手段,分析隧道跨度和隧道与接触带竖向距离变化对隧道稳定性的影响,结果表明:随着隧道跨度增大,隧道围岩塑性区与接触带塑性区越易发生联通,支护结构安全性会突然降低;接触带影响段可根据隧道稳定性变化程度划分为次要影响段和主要影响段,主要影响段的隧道设计、施工方案应开展专项研究工作。研究结果可为类似工程设计和施工提供依据和参考。
Instability of surrounding rock,supporting structure crack and large deformation often happens during construction of large cross-section tunnel through contact belt. Taking Malin tunnel project of Lanhai expressway through unconformable contact belt as background,and using numerical simulation method,impact of tunnel span and vertical distance between tunnel and contact belt on tunnel stability is analyzed. The results indicates that surrounding rock plastic zone and that of contact belt are more prone to link together with the increase of tunnel span,and supporting structure safety would suddenly reduceat certain distance; The zone affected by contact belt is divided into secondary section and primary section according to variations of tunnel stability,and special research work on tunnel design and construction scheme should be carried out in primary section. The results could provide basis and reference for the design and construction of similar projects.
Instability of surrounding rock,supporting structure crack and large deformation often happens during construction of large cross-section tunnel through contact belt. Taking Malin tunnel project of Lanhai expressway through unconformable contact belt as background,and using numerical simulation method,impact of tunnel span and vertical distance between tunnel and contact belt on tunnel stability is analyzed. The results indicates that surrounding rock plastic zone and that of contact belt are more prone to link together with the increase of tunnel span,and supporting structure safety would suddenly reduceat certain distance; The zone affected by contact belt is divided into secondary section and primary section according to variations of tunnel stability,and special research work on tunnel design and construction scheme should be carried out in primary section. The results could provide basis and reference for the design and construction of similar projects.
引文
[1]万明富.超大跨公路隧道开挖力学行为研究[D].沈阳:东北大学,2009.
[2]李斌.软弱围岩大断面隧道开挖面稳定性及控制研究[D].成都:西南交通大学,2012.
[3]陈真才.软弱围岩大断面隧道结构稳定性研究[D].西安:西安工业大学,2016.
[4]麦骐,闫常赫,白雪飞.某不整合接触带地质特征及隧道工程实例分析[J].铁道标准设计,2014(Z1):174-176.
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[6]巩江峰.广昆铁路隧道通过地层不整合接触带的工程问题及对策[J].高速铁路技术. 2011(S1):259-263.
[7]牛洪涛.黄土覆盖土岩接触带复杂围岩隧道成洞技术研究[D].西安:西安理工大学,2010.
[8] JTG/T D70-2010,公路隧道设计细则[S].
[9]何平,赵子都.突变理论及其应用[M].大连:大连理工大学出版社,1989.
[10]侯朝炯,勾攀峰.巷道锚杆支护围岩强度强化机理研究[J].岩石力学与工程学报,2000,19(3):342-345.
[11]万飞,赵恒,王琪喆,等.大断面公路隧道穿越接触带段施工方案优化研究[J].公路,2017(1):240-245.
[2]李斌.软弱围岩大断面隧道开挖面稳定性及控制研究[D].成都:西南交通大学,2012.
[3]陈真才.软弱围岩大断面隧道结构稳定性研究[D].西安:西安工业大学,2016.
[4]麦骐,闫常赫,白雪飞.某不整合接触带地质特征及隧道工程实例分析[J].铁道标准设计,2014(Z1):174-176.
[5]严中,阳军生,王飞,等.半江子隧道岩体接触带施工风险分析与评估[J].公路工程,2012,37(6):171-175.
[6]巩江峰.广昆铁路隧道通过地层不整合接触带的工程问题及对策[J].高速铁路技术. 2011(S1):259-263.
[7]牛洪涛.黄土覆盖土岩接触带复杂围岩隧道成洞技术研究[D].西安:西安理工大学,2010.
[8] JTG/T D70-2010,公路隧道设计细则[S].
[9]何平,赵子都.突变理论及其应用[M].大连:大连理工大学出版社,1989.
[10]侯朝炯,勾攀峰.巷道锚杆支护围岩强度强化机理研究[J].岩石力学与工程学报,2000,19(3):342-345.
[11]万飞,赵恒,王琪喆,等.大断面公路隧道穿越接触带段施工方案优化研究[J].公路,2017(1):240-245.