浅埋偏压隧道CRD法施工方案优化研究
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摘要
浅埋偏压隧道CRD法施工中隔壁偏向和施工工序直接影响到隧道的结构应力分布和变形,甚至影响隧道施工安全。基于隧道施工监控量测对隧道CRD法施工进行反分析和数值模拟分析,结果表明:中隔壁偏向于围岩压力较小侧时,围岩扰动小,塑性区范围小,先开挖隧道浅埋一侧时,隧道的收敛和沉降较小,中隔壁轴力和弯矩较小,有利于隧道的安全施工;当隧道中隔壁偏向围岩压力较大侧或先开挖深埋侧时会对隧道顶部围岩和中夹岩柱产生较大扰动,围岩的收敛和沉降速率增加,中隔壁轴力和弯矩也明显增加,不利于隧道施工安全。因此建议浅埋偏压隧道CRD法中隔壁应偏向围岩压力较小一侧,同时应先开挖浅埋侧。
The direction of the middle wall and the construction process of CRD method in shallow buried bias tunnel directly affect the stress distribution and deformation of the tunnel,and even affect the safety of the tunnel construction. Based on the monitoring measurement of tunnel construction,the reverse analysis and numerical simulation analysis of tunnel CRD method are carried out. The results show that when the middle wall is biased toward the smaller side of the surrounding rock pressure,the surrounding rock disturbance and the plastic zone is small. When the tunnel is firstly excavated on the shallow side of the tunnel,the convergence and settlement of the tunnel is small,and the axial force and bending moment of the middle wall are small,which is beneficial to the safe construction of the tunnel. When the middle wall of the tunnel is inclined to the larger side of the surrounding rock pressure or the tunnel is firstly excavated on the deep buried side,the surrounding rock and the middle rock column will be greatly disturbed,the convergence and settlement rate of the surrounding rock increases,and the axial force and bending moment of the middle wall also increase obviously,which is not conducive to the safety of the tunnel construction. Therefore,it is suggested that the middle wall of CRD method should be inclined to the smaller side of the surrounding rock and the shallow side should be excavated first.
The direction of the middle wall and the construction process of CRD method in shallow buried bias tunnel directly affect the stress distribution and deformation of the tunnel,and even affect the safety of the tunnel construction. Based on the monitoring measurement of tunnel construction,the reverse analysis and numerical simulation analysis of tunnel CRD method are carried out. The results show that when the middle wall is biased toward the smaller side of the surrounding rock pressure,the surrounding rock disturbance and the plastic zone is small. When the tunnel is firstly excavated on the shallow side of the tunnel,the convergence and settlement of the tunnel is small,and the axial force and bending moment of the middle wall are small,which is beneficial to the safe construction of the tunnel. When the middle wall of the tunnel is inclined to the larger side of the surrounding rock pressure or the tunnel is firstly excavated on the deep buried side,the surrounding rock and the middle rock column will be greatly disturbed,the convergence and settlement rate of the surrounding rock increases,and the axial force and bending moment of the middle wall also increase obviously,which is not conducive to the safety of the tunnel construction. Therefore,it is suggested that the middle wall of CRD method should be inclined to the smaller side of the surrounding rock and the shallow side should be excavated first.
引文
[1]孔祥兴,夏才初,仇玉良,等.平行小净距盾构与CRD法黄土地铁隧道施工力学研究[J].岩土力学,2011,32(2):516-524.
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[4]郑宏扬.不同地形条件对不等高程小净距隧道的偏压影响研究[J].施工技术,2018,47(14):8-11,24.
[5]孙永超,陈玮.软岩浅埋大断面地铁隧道施工方法优选研究[J].施工技术,2017,46(24):48-53.
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[8]石熊,张家生,刘宝琛.大断面浅埋偏压隧道CRD法施工工序研究[J].现代隧道技术,2015,52(3):193-199.
[9]黄强,李之达,吴延贞.浅埋隧道施工中围岩应力分析[J].湘潭大学自然科学学报,2010,32(1):25-29.
[10]徐燕,陈振邦,黄耀龙,等.基于ANSYS的偏压隧道CRD法开挖顺序数值分析[J].路基工程,2016(1):173-177.
[2]刘小军,张永兴.浅埋偏压隧道洞口段合理开挖工序及受力特征分析[J].岩石力学与工程学报,2011,30(S1):3066-3073.
[3]邓洪亮,陈鸽,郭洋,等.浅埋隧道围岩位移及应力变化规律研究[J].施工技术,2016,45(7):113-117.
[4]郑宏扬.不同地形条件对不等高程小净距隧道的偏压影响研究[J].施工技术,2018,47(14):8-11,24.
[5]孙永超,陈玮.软岩浅埋大断面地铁隧道施工方法优选研究[J].施工技术,2017,46(24):48-53.
[6]杨小礼,眭志荣.浅埋小净距偏压隧道施工工序的数值分析[J].中南大学学报:自然科学版,2007,38(4):764-770.
[7]聂建春,郑文博,袁成海.不同偏压大断面浅埋隧道施工力学分析及优化[J].隧道建设,2012,32(3):315-322.
[8]石熊,张家生,刘宝琛.大断面浅埋偏压隧道CRD法施工工序研究[J].现代隧道技术,2015,52(3):193-199.
[9]黄强,李之达,吴延贞.浅埋隧道施工中围岩应力分析[J].湘潭大学自然科学学报,2010,32(1):25-29.
[10]徐燕,陈振邦,黄耀龙,等.基于ANSYS的偏压隧道CRD法开挖顺序数值分析[J].路基工程,2016(1):173-177.