隧道式锚碇承载机制的室内模型试验探究
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摘要
为揭示隧道式锚碇的承载机制,探究加载过程中锚碇及周围岩体的力学响应规律,依托绿枝江大桥隧道锚工程,开展隧道锚1∶100室内三维地质力学模型试验。通过有效模拟散索鞍、主缆散股、预应力管道、钢绞线、等传力构件,真实地还原了隧道式锚碇的传力路径和特征。通过分析从加载到破坏过程中锚–岩界面压力,围岩应力、变形响应,揭示出隧道式锚碇抗拔承载过程的时空演化机制,并在分析深部岩体位移峰值点迁移规律和表观裂纹扩展过程的基础上,预测隧道式锚碇的破坏形态。主要结论有:(1)从加载到破坏过程中,锚–岩界面应力呈无响应(0～5P)–弹性增长(5P～13P)–加速增长(13P～19P)–迅速衰减(21P～23P)的阶段性特征;(2)自加载至破坏过程中,锚塞体是由后向前、逐层挤压上覆岩体,由近及远、逐步调动周围岩体联合承载的;(3) 5P荷载前,锚塞体和围岩基本无变形,5P～13P荷载下,锚体和围岩位移低速线性增长,13P～21P荷载下,锚体和围岩位移均加速增长且锚体位移增长速度大于岩体,23P荷载下岩体损伤严重,锚体因克服岩体束缚被拔出;(4)隧道锚表观裂纹是在锚塞体、围岩的位移加速增长后才产生,极限荷载下形成的网状破裂区为:拱顶以上50cm、洞底以下35 cm、墙左墙右各35 cm,隧道式锚碇最终的破坏形态为不对称的喇叭状。
To have some insight into the bearing mechanism of tunnel-type anchorage and figure out the mechanical response law of anchor plug and surrounding rock under engineering load,the tunnel-type anchorage laboratory model test scaled 1∶100 is carried out. In this model test,the actual loading path and mechanic characteristic are simulated with the effective simulation of all transmission components such as saddles,cable strands,steels,anchor plug and surrounding rock and so on. Then the change law of interfacial additional stress between the anchor plug and rock,deformation response of surrounding rock are analyzed to study the temporal and spatial mechanism. And the possible failure mode is also predicted by analyzing the migration rule of the peak displacement point of deep rock mass. Main conclusions are draw as follows.(1) In the total loading process,the interfacial additional stress between the anchor plug and rock performs firstly as no response(under 0 to 5 times design loads) then increase elastically(5 to 13 times design loads) and grow quickly(13 to 19 times design loads)and sharp decrease at last(21 to 23 times design loads).(2) The anchor plug squeezes the burial surrounding rock layer-by layer from back parts to front parts in the total loading process and mobilizes the surrounding rock to bear together under the engineering load from the near to the distant.(3) Under 5 times design loads,the displacements of anchor plug and surrounding rock are negligible and then they will increase linear at low speed if the engineering load is between 5 to 13 times design loads. But the displacements growth will accelerate and the displacement of anchor plug will be greater than the displacement of surrounding rock when the engineering load reaches 13 to 21 times design load. Finally the anchor plug will be pulled out because of the serious damage of surrounding rock under 23 times design load. Last but not least,the cracks occur after at the displacements accelerated growth stage. The range of reticular fracture zone is 50 centimeters above the vault of anchor plug,35 centimeters below the bottom of anchor plug,35 centimeters within the left wall and 35 centimeters within the right wall of anchor plug. And the failure mode of tunnel-type anchorage is un-symmetrical trumpet-shape speculated by the fracture zone and displacement distribution law of deep-seated rock.
To have some insight into the bearing mechanism of tunnel-type anchorage and figure out the mechanical response law of anchor plug and surrounding rock under engineering load,the tunnel-type anchorage laboratory model test scaled 1∶100 is carried out. In this model test,the actual loading path and mechanic characteristic are simulated with the effective simulation of all transmission components such as saddles,cable strands,steels,anchor plug and surrounding rock and so on. Then the change law of interfacial additional stress between the anchor plug and rock,deformation response of surrounding rock are analyzed to study the temporal and spatial mechanism. And the possible failure mode is also predicted by analyzing the migration rule of the peak displacement point of deep rock mass. Main conclusions are draw as follows.(1) In the total loading process,the interfacial additional stress between the anchor plug and rock performs firstly as no response(under 0 to 5 times design loads) then increase elastically(5 to 13 times design loads) and grow quickly(13 to 19 times design loads)and sharp decrease at last(21 to 23 times design loads).(2) The anchor plug squeezes the burial surrounding rock layer-by layer from back parts to front parts in the total loading process and mobilizes the surrounding rock to bear together under the engineering load from the near to the distant.(3) Under 5 times design loads,the displacements of anchor plug and surrounding rock are negligible and then they will increase linear at low speed if the engineering load is between 5 to 13 times design loads. But the displacements growth will accelerate and the displacement of anchor plug will be greater than the displacement of surrounding rock when the engineering load reaches 13 to 21 times design load. Finally the anchor plug will be pulled out because of the serious damage of surrounding rock under 23 times design load. Last but not least,the cracks occur after at the displacements accelerated growth stage. The range of reticular fracture zone is 50 centimeters above the vault of anchor plug,35 centimeters below the bottom of anchor plug,35 centimeters within the left wall and 35 centimeters within the right wall of anchor plug. And the failure mode of tunnel-type anchorage is un-symmetrical trumpet-shape speculated by the fracture zone and displacement distribution law of deep-seated rock.
引文
[1]钱冬生,陈仁福.大跨悬索桥的设计与施工[M].成都:西南交通大学出版社,2015:13-15.(QIAN Dongsheng,CHEN Renfu.The design and construction of large-span suspension bridge[M].Chengdu:Southwest Jiao-tong University Press,2015:13-15.(in Chinese))
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[6]夏才初,程鸿鑫,李荣强.广东虎门大桥东锚碇现场结构模型试验研究[J].岩石力学与工程学报,1997,16(6):571-576.(XIA Caichu,CEHNG Hongxin,LI Rongqiang.Testing study on field structure model of the east anchorage of Guangdong Humen Bridge[J].Chinese Journal of Rock Mechanics and Engineering,1997,16(6):571-576.(in Chinese))
[7]肖本职,吴相超,彭朝全.重庆鹅公岩大桥隧道锚碇围岩稳定性[J].岩石力学与工程学报,2005,24(增2):5 591-5 597.(XIAO Benzhi,WU Xiangchao,PENG Chaoquan.Stability of the anchorage wall rock of tunnel for Chongqing Egongyan bridge[J].Chinese Journal Of Rock Mechanics And Engineering,2005,24(Supp.2):5 591-5 597.(in Chinese))
[8]朱杰兵,邬爱清,黄正加,等.四渡河特大悬索桥隧道锚模型拉拔试验研究[J].长江科学院院报,2006,23(4):51-55.(ZHU Jiebing,WU Aiqing,HUANG Zhengjia,et al.Pulling test of anchorage model of Siduhe suspension bridge[J].Journal Of Yangtze Rover Scientific Research Institute,2006,23(4):51-55.(in Chinese))
[9]胡波,曾钱帮,饶旦,等.锚碇-围岩系统在拉剪复合应力条件下的变形规律及破坏机制研究——以坝陵河特大岩锚悬索桥为例[J].岩石力学工程学报,2007,26(4):712-719.(HU Bo,ZENGQianbang,RAO Dan,et al.Study of deformation law and failure mechanism of anchorage-surrounding rock system under tensile-shear complex stresses-Taking super-large suspension bridge on Baling river for example[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(4):712-719.(in Chinese))
[10]张奇华,余美万,喻正富,等.普立特大桥隧道锚现场模型试验研究——抗拔能力试验[J].岩石力学与工程学报,2015,34(1):93-103.(ZHANG Qihua,YU Meiwan,YU Zhengfu,et al.Field model tests on Pull-out capacity of tunnel-type anchorages of pu-li bridge[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(1):93-103.(in Chinese))
[11]廖明进,王全才,袁从华,等.基于楔形效应的隧道锚抗拔承载能力研究[J].岩土力学,2016,37(1):185-192.(LIAO Mingjin,WANGQuancai,YUAN Conghua,et al.Research on the pull-out capacity of the tunnel-type anchorage based on wedge-effect[J].Rock and Soil Mechanics,2016,37(1):185-192.(in Chinese))
[12]汤华,熊晓荣,吴振君,等.隧道锚抗拔作用机理的室内模型试验[J].上海交通大学学报,2015,49(7):935-939.(TANG Hua,XIONG Xiaorong,WU Zhenjun,et al.Laboratory model test study of pull-out mechanism of tunnel anchorage[J].Journal of Shanghai Jiao Tong University,2015,49(7):935-939.(in Chinese))
[13]蒋昱州,王瑞红,朱杰兵,等.伍家岗大桥隧道锚三维地质力学模型试验研究[J].岩石力学与工程学报,2016,35(增2):4 103-4 113.(JIANG Yuzhou,WANG Ruihong,ZHU Jiebing,et al.geo-mechanical model test on global stability for Wujiagang bridge tunnel-type anchorages[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(Supp2):4 103-4 113.(in Chinese))
[14]董一鸣,王同民,郑宏伟.香溪长江大桥南岸边坡防护方案评价与优化[J].交通科技,2018,(1):22-24.(DONG Yiming,WANGTongmin,ZHENG Hongwei.Evaluation and optimization of slope protection scheme on the south bank of Xiang-xi Yangtze River bridge[J].Transportation Science and Technology,2018,(1):22-24.(in Chinese))
[15]汤华,熊晓荣,邓琴,等.普立特大桥隧道式锚碇围岩系统的变形规律及破坏机制[J].上海交通大学学报,2015,49(7):961-967.(TANG Hua,XIONG Xiaorong,DENG Qin,et al.Deformation law and failure mechanism of anchorage-surrounding rock system of puli extra-large bridge[J].Journal of Shanghai Jiao Tong University,2015,49(7):961-967.(in Chinese))
[16]陈宁.云南临沧某机场岩溶发育规律及地基稳定性研究[硕士学位论文][D].成都:成都理工大学,2012.(CHEN Ning.Research on karst growth law and foundation stability of some airport in Lin-cang,Yunnan Province[M.S.Thesis][D].Chengdu:Chengdu University of Technology,2012.(in Chinese))
[17]水利水电科学研究院.岩石力学参数手册[M].北京:水利电力出版社,1991:461-501.(China Institute of Water Resources and Hydropower Research.Manual of rock mechanics parameters[M].Beijing:Water Resources and Electric Power Press,1991:461-501.(in Chinese))
[18]王东英,汤华,尹小涛,等.隧道锚抗拔承载力及安全性评估方法[J].中国公路学报,2018,31(9):95-103.(WANG Dongying,TANG Hua,YIN Xiaotao,et al.Uplift capacity and safety assessment method of tunnel-type anchorage[J].China Journal of Highway and Transport,2018,31(9):95-103.(in Chinese))
[19]中华人民共和国行业标准编写组.JTC/T D65-05-2015公路悬索桥设计规范[R].北京:人民交通出版社,2015.(The Professional Standards Compilation Group of the People′s Republic of China.JTC/T D65-05-2015 Specifications for Design of Highway Suspension Bridge[R].Beijing:China Communication Press,2015.(in Chinese))
[2]孟凡超.悬索桥[M].北京:人民交通出版社,2011:12-20.(MENGFanchao.Suspension Bridge[M].Beijing:China Communications Press,2011:12-20.(in Chinese))
[3]邵国建,冯兆祥,徐洪钟,等.深厚覆盖层下的悬索桥锚碇基础[M].北京:科学出版社,2015:7-10.(SHAO Guojian,FENG Zhaoxiang,XU Hongzhong,et al.The anchorage foundation of suspension bridge buried by deep coverage[M].Beijing:Science Press,2015:7-10.(in Chinese))
[4]王勇,曹化明.悬索桥隧道式锚碇施工技术[J].桥梁建设,2004,(2):53-55.(WANG Yong,CAO Huaming.The construction technology for tunnel-type anchorage of suspension bridge[J].Bridge Constructions,2004,(2):53-55.(in Chinese))
[5]江南.铁路悬索桥隧道式锚碇承载机理及计算方法研究[硕士学位论文][D].西南交通大学,2014.(JIANG Nan.Research on bearing mechanism of tunnel anchorage of railway suspension bridge and its calculation method[M.S.Thesis][D].Chengdu:Southwest Jiao-tong University,2014.(in Chinese))
[6]夏才初,程鸿鑫,李荣强.广东虎门大桥东锚碇现场结构模型试验研究[J].岩石力学与工程学报,1997,16(6):571-576.(XIA Caichu,CEHNG Hongxin,LI Rongqiang.Testing study on field structure model of the east anchorage of Guangdong Humen Bridge[J].Chinese Journal of Rock Mechanics and Engineering,1997,16(6):571-576.(in Chinese))
[7]肖本职,吴相超,彭朝全.重庆鹅公岩大桥隧道锚碇围岩稳定性[J].岩石力学与工程学报,2005,24(增2):5 591-5 597.(XIAO Benzhi,WU Xiangchao,PENG Chaoquan.Stability of the anchorage wall rock of tunnel for Chongqing Egongyan bridge[J].Chinese Journal Of Rock Mechanics And Engineering,2005,24(Supp.2):5 591-5 597.(in Chinese))
[8]朱杰兵,邬爱清,黄正加,等.四渡河特大悬索桥隧道锚模型拉拔试验研究[J].长江科学院院报,2006,23(4):51-55.(ZHU Jiebing,WU Aiqing,HUANG Zhengjia,et al.Pulling test of anchorage model of Siduhe suspension bridge[J].Journal Of Yangtze Rover Scientific Research Institute,2006,23(4):51-55.(in Chinese))
[9]胡波,曾钱帮,饶旦,等.锚碇-围岩系统在拉剪复合应力条件下的变形规律及破坏机制研究——以坝陵河特大岩锚悬索桥为例[J].岩石力学工程学报,2007,26(4):712-719.(HU Bo,ZENGQianbang,RAO Dan,et al.Study of deformation law and failure mechanism of anchorage-surrounding rock system under tensile-shear complex stresses-Taking super-large suspension bridge on Baling river for example[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(4):712-719.(in Chinese))
[10]张奇华,余美万,喻正富,等.普立特大桥隧道锚现场模型试验研究——抗拔能力试验[J].岩石力学与工程学报,2015,34(1):93-103.(ZHANG Qihua,YU Meiwan,YU Zhengfu,et al.Field model tests on Pull-out capacity of tunnel-type anchorages of pu-li bridge[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(1):93-103.(in Chinese))
[11]廖明进,王全才,袁从华,等.基于楔形效应的隧道锚抗拔承载能力研究[J].岩土力学,2016,37(1):185-192.(LIAO Mingjin,WANGQuancai,YUAN Conghua,et al.Research on the pull-out capacity of the tunnel-type anchorage based on wedge-effect[J].Rock and Soil Mechanics,2016,37(1):185-192.(in Chinese))
[12]汤华,熊晓荣,吴振君,等.隧道锚抗拔作用机理的室内模型试验[J].上海交通大学学报,2015,49(7):935-939.(TANG Hua,XIONG Xiaorong,WU Zhenjun,et al.Laboratory model test study of pull-out mechanism of tunnel anchorage[J].Journal of Shanghai Jiao Tong University,2015,49(7):935-939.(in Chinese))
[13]蒋昱州,王瑞红,朱杰兵,等.伍家岗大桥隧道锚三维地质力学模型试验研究[J].岩石力学与工程学报,2016,35(增2):4 103-4 113.(JIANG Yuzhou,WANG Ruihong,ZHU Jiebing,et al.geo-mechanical model test on global stability for Wujiagang bridge tunnel-type anchorages[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(Supp2):4 103-4 113.(in Chinese))
[14]董一鸣,王同民,郑宏伟.香溪长江大桥南岸边坡防护方案评价与优化[J].交通科技,2018,(1):22-24.(DONG Yiming,WANGTongmin,ZHENG Hongwei.Evaluation and optimization of slope protection scheme on the south bank of Xiang-xi Yangtze River bridge[J].Transportation Science and Technology,2018,(1):22-24.(in Chinese))
[15]汤华,熊晓荣,邓琴,等.普立特大桥隧道式锚碇围岩系统的变形规律及破坏机制[J].上海交通大学学报,2015,49(7):961-967.(TANG Hua,XIONG Xiaorong,DENG Qin,et al.Deformation law and failure mechanism of anchorage-surrounding rock system of puli extra-large bridge[J].Journal of Shanghai Jiao Tong University,2015,49(7):961-967.(in Chinese))
[16]陈宁.云南临沧某机场岩溶发育规律及地基稳定性研究[硕士学位论文][D].成都:成都理工大学,2012.(CHEN Ning.Research on karst growth law and foundation stability of some airport in Lin-cang,Yunnan Province[M.S.Thesis][D].Chengdu:Chengdu University of Technology,2012.(in Chinese))
[17]水利水电科学研究院.岩石力学参数手册[M].北京:水利电力出版社,1991:461-501.(China Institute of Water Resources and Hydropower Research.Manual of rock mechanics parameters[M].Beijing:Water Resources and Electric Power Press,1991:461-501.(in Chinese))
[18]王东英,汤华,尹小涛,等.隧道锚抗拔承载力及安全性评估方法[J].中国公路学报,2018,31(9):95-103.(WANG Dongying,TANG Hua,YIN Xiaotao,et al.Uplift capacity and safety assessment method of tunnel-type anchorage[J].China Journal of Highway and Transport,2018,31(9):95-103.(in Chinese))
[19]中华人民共和国行业标准编写组.JTC/T D65-05-2015公路悬索桥设计规范[R].北京:人民交通出版社,2015.(The Professional Standards Compilation Group of the People′s Republic of China.JTC/T D65-05-2015 Specifications for Design of Highway Suspension Bridge[R].Beijing:China Communication Press,2015.(in Chinese))