富水昔格达组软弱易滑地层PBA进洞法实践
|
摘要
针对攀西地区昔格达组地层软弱易滑、隧道进洞易产生边仰坡开裂造成进洞困难的问题,以成昆铁路前家山隧道进口浅埋富水昔格达地层进洞施工为例,分别进行以锚固桩、旋喷桩及PBA法为主的3次进洞工法尝试,前2次方案均导致地表开裂、大尺度变形和开挖陡立面蠕动变形,第3次方案采用PBA进洞法施作桩(P)-梁(B)-拱(A)组成的明洞体系,再实施结构外回填,有效解决富水昔格达组软弱易滑地层的不稳定问题。通过实践及分析认为:1)富水昔格达特殊地质条件的隧道进洞困难,原因不仅在于隧道双侧挖掘临空引起的横断面不稳定,而且也因为隧道进洞纵向单侧临空导致的纵向不稳定十分显著。2) PBA法处置隧道进洞纵向不稳定性有明确的力学基础,是颇具针对性的有效措施。
The water-rich Xigeda formation in Panzhihua-Xichang Region is characterized by soft and easy-sliding and the difficult tunnel portal excavation due to slope cracking. Hence,the schemes of anchor pile,jet grouting pile and PBA( piles, beams and arches) method are tentatively used for shallow-buried water-rich Xigeda formation of Qianjiashan Tunnel on Chengdu-Kunming Railway. The surface cracks,large-scale deformation and creep deformation of steep facade excavation occur when adopting anchor pile method and jet grouting pile method,while the instability of water-rich Xigeda formation can be guaranteed by adopting PBA method for open-cut tunnel and cavity backfilling. The applicable and analytical results show that:( 1) The difficult tunnel portal excavation in Xigeda formation are mainly induced by tunnel cross-section instability caused by bilateral empty space and tunnel longitudinal instability caused by unilateral empty space.( 2) The PBA method has clear mechanical mechanism,which can guarantee instability of tunnel portal excavation effectively.
The water-rich Xigeda formation in Panzhihua-Xichang Region is characterized by soft and easy-sliding and the difficult tunnel portal excavation due to slope cracking. Hence,the schemes of anchor pile,jet grouting pile and PBA( piles, beams and arches) method are tentatively used for shallow-buried water-rich Xigeda formation of Qianjiashan Tunnel on Chengdu-Kunming Railway. The surface cracks,large-scale deformation and creep deformation of steep facade excavation occur when adopting anchor pile method and jet grouting pile method,while the instability of water-rich Xigeda formation can be guaranteed by adopting PBA method for open-cut tunnel and cavity backfilling. The applicable and analytical results show that:( 1) The difficult tunnel portal excavation in Xigeda formation are mainly induced by tunnel cross-section instability caused by bilateral empty space and tunnel longitudinal instability caused by unilateral empty space.( 2) The PBA method has clear mechanical mechanism,which can guarantee instability of tunnel portal excavation effectively.
引文
[1]中国中铁二院工程集团有限责任公司.铁路工程地质实例(西南及相邻地区分册)[M].北京:中国铁道出版社,2011.China Railway Eryuan Engineering Group Co.,Ltd. Railway engineering geology example(southwest and adjacent areas)[M]. Beijing:China Railway Publishing House,2011.
[2]刘思妤.四川昔格达组形成机制的研究[J].城市建设理论研究,2012(6):53.LIU Siyu. Study of formation mechanism of Xigeda stratum in Sichuan Province[J]. Urban Construction Theory Research,2012(6):53
[3]丁文富,张广泽,宋章.成昆铁路昔格达地层工程地质特性及对策研究[J].铁道工程学报,2017,34(4):1.DING Wenfu,ZHANG Guangze,SONG Zhang. Research on the engineering geological characteristics and engineering countermeasures of Xigeda strata of Chengdu-Kunming Railway[J]. Journal of Railway Engineering Society,2017,34(4):1.
[4]舒东利,杨建民,朱麟晨.昔格达地层隧道围岩及初期支护变形规律研究[J].隧道建设(中英文),2017,37(12):1544.SHU Dongli, YANG Jianmin, ZHU Linchen. Study of deformation law of tunnel surrounding rock and primary support in Xigeda formation[J]. Tunnel Construction,2017,37(12):1544.
[5]周平,王志杰,徐海岩,等.考虑含水率的昔格达地层隧道围岩稳定及亚级分级研究[J].土木工程学报,2017(12):97.ZHOU Ping,WANG Zhijie,XU Haiyan,et al. Stability and sub-classification study of the tunnel surrounding rock of Xigeda strata considering the influence of moisture content[J]. China Civil Engineering Journal,2017(12):97.
[6]廖珩云.昔格达组粘土岩蠕变特性试验研究及其边坡蠕变变形分析:以四川江铜稀土工业园区边坡为例[D].四川:成都理工大学,2016.LIAO Hengyun. Experimental study of creep characteristics of Xigeda'clay rock and its slope creep analysis:a case analysis of a slope in industrial park of Sichuan Jiang Tong[D]. Sichuan:Chengdu University of Technology,2016.
[7]许瑞宁,王志杰.昔格达组地层大断面隧道施工工法比选分析[J].公路,2017,62(1):231.XU Ruining, WANG Zhijie. Comparative analysis of construction methods of large section tunnels in Xigeda formation strata[J]. Highway,2017,62(1):231.
[8]解超平.全断面穿越昔格达地层高速公路隧道塌方的预防和处治[D].成都:西南交通大学,2015.XIE Chaoping. Prevention and treatment of expressway tunnel collapse in Xigeda stratum[D]. Chengdu:Southwest Jiaotong University,2015.
[9]魏建贵,黄双华,汪杰.施工隧道穿越昔格达地层失效机制及对策[J].山西建筑,2016(6):164.WEI Jiangui,HUANG Shuanghua,WANG Jie. The failure mechanism and countermeasures of construction tunnel through the Xigeda stratum[J]. Shanxi Architecture,2016(6):164.
[10]张强.冉家湾隧道出口围岩稳定性控制方法研究[J].低碳世界,2016(28):223.ZHANG Qiang. Study of stability control method of surrounding rock in Ranjiawan Tunnel exit section[J]. Low Carbon World,2016(28):223.
[11]朱泽民.地铁暗挖车站洞桩法(PBA)施工技术[J].隧道建设,2006,26(5):63.ZHU Zemin. Pile-beam-arch(PBA)construction technology for mined metro stations[J]. Tunnel Construction,2006,26(5):63.
[12]李晓霖.地铁车站PBA工法的数值模拟研究[J].地下空间与工程学报,2007(5):928.LI Xiaolin. Numerical simulation on PBA job practice of metro station[J]. Chinese Journal of Underground Space and Engineering,2007(5):928.
[13]李皓,葛克水. PBA工法导洞开挖顺序数值模拟研究[J].施工技术,2015,44(7):110.LI Hao,GE Keshui. Research on numerical simulation of heading pilot's excavation of PBA method[J].Construction Technology,2015,44(7):110.
[14]韦京,王芳,孙明志. PBA工法地铁车站下穿桥梁方案优化研究[J].现代隧道技术,2014,51(6):101.WEI Jing, WANG Fang, SUN Mingzhi. On scheme optimization of the PBA subway station underneath a bridge[J]. Modern Tunnelling Technology,2014,51(6):101.
[15]罗富荣,汪玉华.北京地区PBA法施工暗挖地铁车站地表变形分析[J].隧道建设,2016,36(1):20.LUO Furong,WANG Yuhua. Analysis of ground surface deformation of mined metro station constructed by PBA method in Beijing[J]. Tunnel Construction,2016,36(1):20.
[2]刘思妤.四川昔格达组形成机制的研究[J].城市建设理论研究,2012(6):53.LIU Siyu. Study of formation mechanism of Xigeda stratum in Sichuan Province[J]. Urban Construction Theory Research,2012(6):53
[3]丁文富,张广泽,宋章.成昆铁路昔格达地层工程地质特性及对策研究[J].铁道工程学报,2017,34(4):1.DING Wenfu,ZHANG Guangze,SONG Zhang. Research on the engineering geological characteristics and engineering countermeasures of Xigeda strata of Chengdu-Kunming Railway[J]. Journal of Railway Engineering Society,2017,34(4):1.
[4]舒东利,杨建民,朱麟晨.昔格达地层隧道围岩及初期支护变形规律研究[J].隧道建设(中英文),2017,37(12):1544.SHU Dongli, YANG Jianmin, ZHU Linchen. Study of deformation law of tunnel surrounding rock and primary support in Xigeda formation[J]. Tunnel Construction,2017,37(12):1544.
[5]周平,王志杰,徐海岩,等.考虑含水率的昔格达地层隧道围岩稳定及亚级分级研究[J].土木工程学报,2017(12):97.ZHOU Ping,WANG Zhijie,XU Haiyan,et al. Stability and sub-classification study of the tunnel surrounding rock of Xigeda strata considering the influence of moisture content[J]. China Civil Engineering Journal,2017(12):97.
[6]廖珩云.昔格达组粘土岩蠕变特性试验研究及其边坡蠕变变形分析:以四川江铜稀土工业园区边坡为例[D].四川:成都理工大学,2016.LIAO Hengyun. Experimental study of creep characteristics of Xigeda'clay rock and its slope creep analysis:a case analysis of a slope in industrial park of Sichuan Jiang Tong[D]. Sichuan:Chengdu University of Technology,2016.
[7]许瑞宁,王志杰.昔格达组地层大断面隧道施工工法比选分析[J].公路,2017,62(1):231.XU Ruining, WANG Zhijie. Comparative analysis of construction methods of large section tunnels in Xigeda formation strata[J]. Highway,2017,62(1):231.
[8]解超平.全断面穿越昔格达地层高速公路隧道塌方的预防和处治[D].成都:西南交通大学,2015.XIE Chaoping. Prevention and treatment of expressway tunnel collapse in Xigeda stratum[D]. Chengdu:Southwest Jiaotong University,2015.
[9]魏建贵,黄双华,汪杰.施工隧道穿越昔格达地层失效机制及对策[J].山西建筑,2016(6):164.WEI Jiangui,HUANG Shuanghua,WANG Jie. The failure mechanism and countermeasures of construction tunnel through the Xigeda stratum[J]. Shanxi Architecture,2016(6):164.
[10]张强.冉家湾隧道出口围岩稳定性控制方法研究[J].低碳世界,2016(28):223.ZHANG Qiang. Study of stability control method of surrounding rock in Ranjiawan Tunnel exit section[J]. Low Carbon World,2016(28):223.
[11]朱泽民.地铁暗挖车站洞桩法(PBA)施工技术[J].隧道建设,2006,26(5):63.ZHU Zemin. Pile-beam-arch(PBA)construction technology for mined metro stations[J]. Tunnel Construction,2006,26(5):63.
[12]李晓霖.地铁车站PBA工法的数值模拟研究[J].地下空间与工程学报,2007(5):928.LI Xiaolin. Numerical simulation on PBA job practice of metro station[J]. Chinese Journal of Underground Space and Engineering,2007(5):928.
[13]李皓,葛克水. PBA工法导洞开挖顺序数值模拟研究[J].施工技术,2015,44(7):110.LI Hao,GE Keshui. Research on numerical simulation of heading pilot's excavation of PBA method[J].Construction Technology,2015,44(7):110.
[14]韦京,王芳,孙明志. PBA工法地铁车站下穿桥梁方案优化研究[J].现代隧道技术,2014,51(6):101.WEI Jing, WANG Fang, SUN Mingzhi. On scheme optimization of the PBA subway station underneath a bridge[J]. Modern Tunnelling Technology,2014,51(6):101.
[15]罗富荣,汪玉华.北京地区PBA法施工暗挖地铁车站地表变形分析[J].隧道建设,2016,36(1):20.LUO Furong,WANG Yuhua. Analysis of ground surface deformation of mined metro station constructed by PBA method in Beijing[J]. Tunnel Construction,2016,36(1):20.