金沙江特大桥岩体结构特征及地质力学分析
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摘要
研究目的:丽(江)香(格里拉)线金沙江特大桥为国内首座重载铁路悬索桥,桥址区岸坡高陡,构造发育,地震活动频繁,河谷地质结构复杂。通过地质调绘,平硐、垂直钻探,工程物探等勘察方法,查明岩体的结构特征,并对岩体进行地质力学分类,确定岩体的宏观力学参数,为锚碇建基面的选择和锚碇围岩稳定性分析提供科学依据。研究结论:(1)桥址区岩体经历强烈的构造作用、表生改造作用,形成了片理化带、卸荷带、风化带相互叠加的三重地质结构;(2)锚碇区域的岩体可分为(1)～(3)区,(1)、(2)区属于Ⅳ类不良岩体,不能承受较大的拉应力及剪切应力,(3)区属于Ⅲ类一般岩体,完整性较好,可以作为锚碇的持力层;(3)基于Hoek-Browm准则获得的岩体力学参数是合理的、可靠的,可用于可研、初步阶段桥梁方案的论证及锚碇围岩稳定性分析;(4)本研究结论对高山峡谷区桥梁工程的勘察设计具有指导意义。
Research purposes: As the first heavy haul rail suspension bridge in China,the Jinshajiang extra large bridge in Lijiang-Shangri-la line had complex geological conditions,which contains very high and steep slope,developed structure,frequent earthquake activity and complex valley structure. Through the integrated survey methods,such as the geological annotation,horizontal and vertical drilling,and geophysical prospecting,the structure characteristics were found out,the classification of geological mechanics of rock mass was proposed,and then the macroscopic mechanical parameters of rock mass were determined. It provided a scientific basis for the selection of anchorage surrounding rock and stability analysis of rock mass.Research conclusions:( 1) The rock mass of the bridge site has a strong structural effect and epigenetic transformation effect,forming the schistosity zone,unloading belt and weathering zone.( 2) The anchorage zone of rock mass can be divided into(1) ～(3),and the(1) and(2) zones belong to the Ⅳ class poor rock mass,which unable to bear the large tensile stress and shear stress. The(3) zone belongs to the Ⅲ class generally rock mass,which the integrity is good,and it can be used as spindle bearing layer of anchor.( 3) The rock mass mechanical parameters obtained by the Hoek-Browm criterion are reasonable and reliable,and it can be used for the analysis of feasibility of bridge plan and thestability of anchorage surrounding rock.( 4) The research conclusions are of guiding significance for the investigation and design of bridge engineering in alpine canyon area.
Research purposes: As the first heavy haul rail suspension bridge in China,the Jinshajiang extra large bridge in Lijiang-Shangri-la line had complex geological conditions,which contains very high and steep slope,developed structure,frequent earthquake activity and complex valley structure. Through the integrated survey methods,such as the geological annotation,horizontal and vertical drilling,and geophysical prospecting,the structure characteristics were found out,the classification of geological mechanics of rock mass was proposed,and then the macroscopic mechanical parameters of rock mass were determined. It provided a scientific basis for the selection of anchorage surrounding rock and stability analysis of rock mass.Research conclusions:( 1) The rock mass of the bridge site has a strong structural effect and epigenetic transformation effect,forming the schistosity zone,unloading belt and weathering zone.( 2) The anchorage zone of rock mass can be divided into(1) ～(3),and the(1) and(2) zones belong to the Ⅳ class poor rock mass,which unable to bear the large tensile stress and shear stress. The(3) zone belongs to the Ⅲ class generally rock mass,which the integrity is good,and it can be used as spindle bearing layer of anchor.( 3) The rock mass mechanical parameters obtained by the Hoek-Browm criterion are reasonable and reliable,and it can be used for the analysis of feasibility of bridge plan and thestability of anchorage surrounding rock.( 4) The research conclusions are of guiding significance for the investigation and design of bridge engineering in alpine canyon area.
引文
[1]柴春阳,张广泽,蒋良文,等.金沙江特大桥综合勘察与分析[J].铁道工程学报,2015(4):1-5.Chai Chunyang,Zhang Guangze,Jiang Liangwen,etc.Comprehensive Prospecting and Analysis of the Super Major Jinsha River Bridge[J]. Journal of Railway Engineering Society,2015(4):1-5.
[2]宋章,王朋,张广泽,等.金沙江特大桥岸坡岩体结构特征及工程力学性状[J].高速铁路技术,2017(4):38-43.Song Zhang,Wang Peng,Zhang Guangze,etc. Structure Characteristics and Its Engineering Mechanics Behaviors of Slope Rock Mass of Chin-sha River Super Major Bridge[J]. High Speed Railway Technology,2017(4):38-43.
[3]王运生,王士天,李渝生.云南中甸-丽江地区新构造特征[J].成都理工学院学报:自然科学版,1999(1):68-72.Wang Yunsheng, Wang Shitian, Li Yusheng.Neotectonic Characteristics of the Zhongdian-Lijiang Region,Yunnan[J]. Journal of Chengdu University of Technology:Science&Technology Edition,1999(1):68-72.
[4]铁道第一勘察设计院.铁路工程地质手册[M].北京.中国铁道出版社,2002.The First Survey and Design Institute of Railway. The Railway Engineering Geology Handbook[M]. Beijing:China Railway Publishing House,2002.
[5]明庆忠,史正涛,苏怀,等.金沙江虎跳峡成因及形成时代探讨[J].热带地理,2007(5):400-404.Ming Qingzhong,Shi Zhengtao,Su Huai,etc. A Discussion on the Formation of the Hutiaoxia Gorge on the Jinsha River[J]. Tropical Geography,2007(5):400-404.
[6] GB/T 50218—2014,工程岩体分级标准[S].GB/T 50218—2014, Standard for Engineering Classification of Rockmass[S].
[7] Bieniaski Z. T. Engineering Classification of Jointed Rock Masses[J]. Transaction of the South African Institution of Civil Engineering,1973(15):335-344.
[8] Hoek E,Carranza-Torres C,Corkum B. HoekBrown Failure Criterion[C]//Toronto:Proceedings of NARMS-TAC Conference,2002:267-273.
[2]宋章,王朋,张广泽,等.金沙江特大桥岸坡岩体结构特征及工程力学性状[J].高速铁路技术,2017(4):38-43.Song Zhang,Wang Peng,Zhang Guangze,etc. Structure Characteristics and Its Engineering Mechanics Behaviors of Slope Rock Mass of Chin-sha River Super Major Bridge[J]. High Speed Railway Technology,2017(4):38-43.
[3]王运生,王士天,李渝生.云南中甸-丽江地区新构造特征[J].成都理工学院学报:自然科学版,1999(1):68-72.Wang Yunsheng, Wang Shitian, Li Yusheng.Neotectonic Characteristics of the Zhongdian-Lijiang Region,Yunnan[J]. Journal of Chengdu University of Technology:Science&Technology Edition,1999(1):68-72.
[4]铁道第一勘察设计院.铁路工程地质手册[M].北京.中国铁道出版社,2002.The First Survey and Design Institute of Railway. The Railway Engineering Geology Handbook[M]. Beijing:China Railway Publishing House,2002.
[5]明庆忠,史正涛,苏怀,等.金沙江虎跳峡成因及形成时代探讨[J].热带地理,2007(5):400-404.Ming Qingzhong,Shi Zhengtao,Su Huai,etc. A Discussion on the Formation of the Hutiaoxia Gorge on the Jinsha River[J]. Tropical Geography,2007(5):400-404.
[6] GB/T 50218—2014,工程岩体分级标准[S].GB/T 50218—2014, Standard for Engineering Classification of Rockmass[S].
[7] Bieniaski Z. T. Engineering Classification of Jointed Rock Masses[J]. Transaction of the South African Institution of Civil Engineering,1973(15):335-344.
[8] Hoek E,Carranza-Torres C,Corkum B. HoekBrown Failure Criterion[C]//Toronto:Proceedings of NARMS-TAC Conference,2002:267-273.
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