框架锚杆支护多年冻土边坡的稳定性计算方法
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摘要
为了给出更符合工程实际的冻土边坡稳定性计算方法,通过考察青藏高原地区多年冻土边坡滑移实例、分析其破坏类型和影响因素,提出了高陡边坡的冻融折线型滑移面,基于热平衡理论和莫尔-库伦强度理论给出了折线型的滑移面确定方法;考虑土体在冻融循环作用下抗剪强度损伤、滑移面上水的渗流作用以及气温变暖三种因素,给出了框架锚杆支护多年冻土区高陡边坡的稳定性计算方法。算例分析表明:利用直线型滑面计算的多年冻土边坡稳定性系数比折线型滑移面更小,容易造成保守设计,使用折线型滑移面更为经济;边坡开挖后10a内,冻融循环作用对稳定性的发展趋势起主导作用,10a后气温变暖发挥主要作用,渗流作用对边坡稳定性的影响较为显著,对稳定性发展趋势没有影响,但三种因素都应当在工程设计中考虑。
In order to develop a more practical calculation method of permafrost slope stability,the freeze-thaw fold line slip plane is raised by investigating the permafrost slope sliding examples and analyzing the failure types and its influence factors.The method of fold line slip plane is determined,based on the thermal equilibrium theory and Mohr-Coulomb strength theory.Considering the damage of shear strength under freeze-thaw cycles,seepage on the frozen sliding surface and temperature variation,the stability calculation method of the permafrost slopes supported by frame structures with anchors is given.The results show that the stability coefficient of the permafrost slope calculated by the linear slip surface is smaller than that of the fold line slip plane,which tends to be conservative,and the fold line slip plane is more economical for design.Under the action of freeze-thaw cycle,the stability of the new slope decreases rapidly and will not remain unchanged until 10 years later.Within 10 years after excavation,freeze-thaw cycles play a dominant role in the evolution of slope stability.Temperature increase plays a major role after 10 years.Seepage action has a significant effect on slope stability,but has no effect on the development trend of slope stability.However,all three factors should be considered in engineering design.
In order to develop a more practical calculation method of permafrost slope stability,the freeze-thaw fold line slip plane is raised by investigating the permafrost slope sliding examples and analyzing the failure types and its influence factors.The method of fold line slip plane is determined,based on the thermal equilibrium theory and Mohr-Coulomb strength theory.Considering the damage of shear strength under freeze-thaw cycles,seepage on the frozen sliding surface and temperature variation,the stability calculation method of the permafrost slopes supported by frame structures with anchors is given.The results show that the stability coefficient of the permafrost slope calculated by the linear slip surface is smaller than that of the fold line slip plane,which tends to be conservative,and the fold line slip plane is more economical for design.Under the action of freeze-thaw cycle,the stability of the new slope decreases rapidly and will not remain unchanged until 10 years later.Within 10 years after excavation,freeze-thaw cycles play a dominant role in the evolution of slope stability.Temperature increase plays a major role after 10 years.Seepage action has a significant effect on slope stability,but has no effect on the development trend of slope stability.However,all three factors should be considered in engineering design.
引文
[1]武鹤,高伟,王国峰,等.寒区公路土质路堑边坡滑塌原因及其防治[J].自然灾害学报,2006,15(3):66-70.Wu H,Gao W,Wang G F,et al.Cause and control of soil-cutting’s sliding collapse in frigid zone[J].Journal of Natural Disasters,2006,15(3):66-70.(in Chinese)
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[3]Kumsar H,AydanO,Ulusay R.Dynamic and static stability assessment of rock slopes against wedge failures[J].Rock Mechanics&Rock Engineering,2000,33(1):31-51.
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[6]李忠,朱彦鹏.框架预应力锚杆边坡支护结构稳定性计算方法及其应用[J].岩石力学与工程学报,2005,24(21):3 922-3 926.Li Zh,Zhu Y P.Stability calculation methods for grillage supporting structure with prestressed anchor and its application[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(21):3 922-3 926.(in Chinese)
[7]朱彦鹏,郑恒,李忠.框架预应力锚杆边坡支护结构稳定性分析[J].岩土力学,2006,27(增):746-750.Zhu Y P,Zheng H,Li Zh.Stability analysis of grillage supporting structure with pestressed anchors[J].Rock and Soil Mechanics,2006,27(Sup):746-750.(in Chinese)
[8]Stamatopoulos C A,Bassanou M,Brennan A J,et al.Mitigation of the seismic motion near the edge of clifftype topographies[J].Soil Dynamics and Earthquake Engineering,2007,27(12):1 082-1 100.
[9]陈玉超,杨更社,范建兵.寒区边坡冻融灾害及其分类探讨[J].山西建筑,2006(14):82-83.Chen Y Ch,Yang G Sh,Fan J B.The discussion of freezing-thawing disaster and classification in permafrost slope[J].Shanxi Architecture,2006(14):82-83.(in Chinese)
[10]马巍,吴紫汪,盛煜.冻土的蠕变及蠕变强度[J].冰川冻土,1994,16(2):113-118.Ma W,Wu Z W,Sheng Y.Creep and creep strength of frozen soil[J].Journal of Glaciology and Geocryology,1994,16(2):113-118.(in Chinese)
[11]陈玉超.冻融环境下岩土边坡稳定性研究初探[D].西安:西安科技大学,2006.Chen Y Ch.Preliminary study on rock and soil slope stability under the freezing-thawing condition[D].Xi’an:Xi’an University of Science and Technology,2006.(in Chinese)
[12]魏永幸,薛新华.多年冻土区斜坡路堤稳定性的探索[J].铁道工程学报,2011(12):35-39.Wei Y X,Xue X H.Exploration on the stabilization of embankment on slope in permafrost regions[J].Journal of Railway Engineering Society,2011(12):35-39.(in Chinese)
[13]苏联科学院西伯利亚分院冻土研究所.普通冻土学[M].郭东信,译.北京:科学出版社,1988:46-48.Geocryology Research Institute of Siberia Branch of Soviet Union.General geocryology[M].Guo D X.Beijing:Science Press,1988:46-48.(in Chinese)
[14]徐学祖,傅连弟.根据修正的斯蒂芬公式确定寒区最大季节融化深度[C]//青藏冻土论文集.北京:科学出版社,1983:165-168.Xu X Z,Fu L D.Determining permafrost table by the corrected Stefan formula[C]//Professional Papers on Permafrost Studies of Qinghai-Xizang Plateau.Beijing:Science Press,1983:165-168.(in Chinese)
[15]陈赵育,李国玉,穆彦虎,等.不同升温模式下冻土地区装配式基础热稳定性研究[J].地震工程学报,2013,35(4):877-884.Chen Zh Y,Li G Y,Mu Y H,et al.Thermal stability of fabricated foundations with different warming patterns in permafrost regions[J].China Earthquake Engineering Journal,2013,35(4):877-884.(in Chinese)
[16]张中琼,吴青柏.气候变化情景下青藏高原多年冻土活动层厚度变化预测[J].冰川冻土,2012,34(3):505-511.Zhang Zh Q,Wu Q B.Predicting changes of active layer thickness on the Qinghai-Tibet plateau as climate warming[J].Journal of Glaciology and Geocryology,2012,34(3):505-511.(in Chinese)
[17]葛琪.基于冻融界面强度损伤的季冻区土质边坡稳定性研究[D].长春:吉林大学,2010.Ge Q.Research on the soil slope stability in seasonal frozen areas based on strength deterioration of the freeze-thaw surface[D].Changchun:Jilin University,2010.(in Chinese)
[18]董旭光,董建华,何天虎,等.多年冻土区框架热锚管边坡支护结构的提出及简化设计方法初探[J].铁道学报,2017,39(7):142-150.Dong X G,Dong J H,He T H,et al.Invention and simplified design method of slope supporting structure of frame and heat anchor pipe in permafrost regions[J].Journal of the China Railway Society,2017,39(7):142-150.(in Chinese)
[19]丁靖康,赫贵生.年平均气温临界值---设计青藏高原寒区路堤临界高度的一个重要因素[J].冰川冻土,2000,22(4):333-339.Ding J K,He G Sh.The critical value of mean annual air temperature-an important factor for designing the critical height of embankment in permafrost regions of the Tibetan plateau[J].Journal of Glaciology and Geocryology,2000,22(4):333-339.(in Chinese)
[2]王超.季冻区哈大高铁边坡冻融滑塌机理研究[D].哈尔滨:哈尔滨工业大学,2014.Wang Ch.Research on freeze-thaw slumping mechanism of Harbin-Dalian High-speed railway slope in seasonal frozen[D].Harbin:Harbin Institute of Technology,2014.(in Chinese)
[3]Kumsar H,AydanO,Ulusay R.Dynamic and static stability assessment of rock slopes against wedge failures[J].Rock Mechanics&Rock Engineering,2000,33(1):31-51.
[4]刘红军,王丕祥.公路土质边坡冻融失稳稳定性分析[J].哈尔滨工业大学学报,2006,38(5):764-766.Liu H J,Wang P X.Stability analysis of loss of stability caused by freeze and melt of earthen side slopes of highways[J].Journal of Harbin Institute of Technology,2006,38(5):764-766.(in Chinese)
[5]韩继国,王选仓,时成林,等.季节性冰冻地区公路边坡侵蚀破坏模式[J].长安大学学报(自然科学版),2008,28(1):41-45.Han J G,Wang X C,Shi Ch L,et al.Erosion collapse mode of highway slope in seasonal frost area[J].Journal of Chang’an University(Natural Science Edition),2008,28(1):41-45.(in Chinese)
[6]李忠,朱彦鹏.框架预应力锚杆边坡支护结构稳定性计算方法及其应用[J].岩石力学与工程学报,2005,24(21):3 922-3 926.Li Zh,Zhu Y P.Stability calculation methods for grillage supporting structure with prestressed anchor and its application[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(21):3 922-3 926.(in Chinese)
[7]朱彦鹏,郑恒,李忠.框架预应力锚杆边坡支护结构稳定性分析[J].岩土力学,2006,27(增):746-750.Zhu Y P,Zheng H,Li Zh.Stability analysis of grillage supporting structure with pestressed anchors[J].Rock and Soil Mechanics,2006,27(Sup):746-750.(in Chinese)
[8]Stamatopoulos C A,Bassanou M,Brennan A J,et al.Mitigation of the seismic motion near the edge of clifftype topographies[J].Soil Dynamics and Earthquake Engineering,2007,27(12):1 082-1 100.
[9]陈玉超,杨更社,范建兵.寒区边坡冻融灾害及其分类探讨[J].山西建筑,2006(14):82-83.Chen Y Ch,Yang G Sh,Fan J B.The discussion of freezing-thawing disaster and classification in permafrost slope[J].Shanxi Architecture,2006(14):82-83.(in Chinese)
[10]马巍,吴紫汪,盛煜.冻土的蠕变及蠕变强度[J].冰川冻土,1994,16(2):113-118.Ma W,Wu Z W,Sheng Y.Creep and creep strength of frozen soil[J].Journal of Glaciology and Geocryology,1994,16(2):113-118.(in Chinese)
[11]陈玉超.冻融环境下岩土边坡稳定性研究初探[D].西安:西安科技大学,2006.Chen Y Ch.Preliminary study on rock and soil slope stability under the freezing-thawing condition[D].Xi’an:Xi’an University of Science and Technology,2006.(in Chinese)
[12]魏永幸,薛新华.多年冻土区斜坡路堤稳定性的探索[J].铁道工程学报,2011(12):35-39.Wei Y X,Xue X H.Exploration on the stabilization of embankment on slope in permafrost regions[J].Journal of Railway Engineering Society,2011(12):35-39.(in Chinese)
[13]苏联科学院西伯利亚分院冻土研究所.普通冻土学[M].郭东信,译.北京:科学出版社,1988:46-48.Geocryology Research Institute of Siberia Branch of Soviet Union.General geocryology[M].Guo D X.Beijing:Science Press,1988:46-48.(in Chinese)
[14]徐学祖,傅连弟.根据修正的斯蒂芬公式确定寒区最大季节融化深度[C]//青藏冻土论文集.北京:科学出版社,1983:165-168.Xu X Z,Fu L D.Determining permafrost table by the corrected Stefan formula[C]//Professional Papers on Permafrost Studies of Qinghai-Xizang Plateau.Beijing:Science Press,1983:165-168.(in Chinese)
[15]陈赵育,李国玉,穆彦虎,等.不同升温模式下冻土地区装配式基础热稳定性研究[J].地震工程学报,2013,35(4):877-884.Chen Zh Y,Li G Y,Mu Y H,et al.Thermal stability of fabricated foundations with different warming patterns in permafrost regions[J].China Earthquake Engineering Journal,2013,35(4):877-884.(in Chinese)
[16]张中琼,吴青柏.气候变化情景下青藏高原多年冻土活动层厚度变化预测[J].冰川冻土,2012,34(3):505-511.Zhang Zh Q,Wu Q B.Predicting changes of active layer thickness on the Qinghai-Tibet plateau as climate warming[J].Journal of Glaciology and Geocryology,2012,34(3):505-511.(in Chinese)
[17]葛琪.基于冻融界面强度损伤的季冻区土质边坡稳定性研究[D].长春:吉林大学,2010.Ge Q.Research on the soil slope stability in seasonal frozen areas based on strength deterioration of the freeze-thaw surface[D].Changchun:Jilin University,2010.(in Chinese)
[18]董旭光,董建华,何天虎,等.多年冻土区框架热锚管边坡支护结构的提出及简化设计方法初探[J].铁道学报,2017,39(7):142-150.Dong X G,Dong J H,He T H,et al.Invention and simplified design method of slope supporting structure of frame and heat anchor pipe in permafrost regions[J].Journal of the China Railway Society,2017,39(7):142-150.(in Chinese)
[19]丁靖康,赫贵生.年平均气温临界值---设计青藏高原寒区路堤临界高度的一个重要因素[J].冰川冻土,2000,22(4):333-339.Ding J K,He G Sh.The critical value of mean annual air temperature-an important factor for designing the critical height of embankment in permafrost regions of the Tibetan plateau[J].Journal of Glaciology and Geocryology,2000,22(4):333-339.(in Chinese)