YAO Qing,ZHENG Da,WANG Yu,et al.Genetic Mechanism of Cataclastic Loose Rock Mass in the Alpine Mountain Regions and Deep Valley[J].Journal of Disaster Prevention and Mitigation Engineering,2020,40(05):706-713.
YAO Qing,ZHENG Da,WANG Yu,et al.Genetic Mechanism of Cataclastic Loose Rock Mass in the Alpine Mountain Regions and Deep Valley[J].Journal of Disaster Prevention and Mitigation Engineering,2020,40(05):706-713. DOI: 10.13409/j.cnki.jdpme.2020.05.004.
Genetic Mechanism of Cataclastic Loose Rock Mass in the Alpine Mountain Regions and Deep Valley
The object of the study is the cataclastic loose rock mass in the dam site of a hydropower station in Lancang River. Through site investigation of the rock slope, and by using ANSYS finite element software to simulate the valley evolution and freeze-thaw cycles, the causes of cataclastic rock mass is analyzed comprehensively. The results of the survey show that the formation of cataclastic loose rock mass is related to the in-situ stress field, stratum lithology, valley evolution and plateau frozen-thawed weathering. Numerical simulations reveal that the slope rock mass has experienced a decrease in principal stress and an increase in shear stress during the evolution of the valley. Stress releases lead to structure plane rupture of the slope rock mass, forming a great amount of unloading tensile cracks, showing the start of “loosening”. Under the effect of the severe temperature difference in freeze-thaw cycles, the rock mass with fissured surface continues to expand and extend until the occurrence of fatigue damage cracking, and evolves into the cataclastic shapes apparently. Thus, the genetic mechanism of cataclastic rock mass is summarized, which will provide the basis for the formation mechanism of cataclastic rock mass in the Alpine mountain regions and deep valley.
Chen W W , Liang Sh Y , Liu G , et al . Study on engineer characteristics of the dynamo-relaxed rock mass [J]. Chinese Journal of Solid Mechanics , 2000 , 19 ( 6 ): 751 - 755 . (in Chinese)
Wang C , Tannant D D , Lilly P A . Numerical analysis of the stability of heavily jointed rock slopes using PFC2D [J]. International Journal of Rock Mechanics and Mining Sciences , 2003 , 40 ( 3 ): 415 - 424 .
Tian X F , Sun J Zh , Jiang J , et al . Seismic stability of loosened rock slope of grand Buddha rock mass in west Jinyang mountain in Taiyuan [J]. Chinese Journal of Rock Mechanics and Engineering , 2007 , 26 ( 1 ): 3 432 - 3 437 . (in Chinese)
Zhou H F , Wei Y T , Nie D X . Some likely continuous medium features of cataclastic rock mass [J]. Journal of Engineering Geology , 2008 , 16 ( 1 ): 17 - 21 . (in Chinese)
Zhu Zh G , Wei Y J , Tao L J , et al . Formation mechanism of Yanjiatai cracked rock mass and engineering geological significance in Beijing [J]. Journal of Engineering Geology , 2010 , 18 ( Sup) : 71 - 75 . (in Chinese)
Yang Sh Sh , Wang K W , Wang L H , et al . Cause mechanism analysis of dynamo relaxed rock mass in Yagen hydropower station [J]. Water Resources and Power , 2010 , 28 ( 2 ): 61 - 64 . (in Chinese)
Zhao W H , Huang R Q , Zhao J J , et al . Rockfall mech anism of cataclastic rock mass and influence of back wall up on the stability of accumulation under strong earthquake [J]. Journal of Engineering Geology , 2011 , 19 ( 2 ): 205 - 213 . (in Chinese)
Pei X J , Huang R Q , Cui Sh H , et al . The rock mass cataclastic characteristic of Daguangbao landslide and its engineering geological significance [J]. Chinese Journal of Rock Mechanics and Engineering , 2015 , 34 ( 1 ): 3 106 - 3 115 . (in Chinese)
Zhu H Ch , Tao Zh Y , Huang D F . Influence of the trend on rock stress in valley [J]. Chinese Journal of Rock Mechanics and Engineering , 1995 , 14 ( 1 ): 17 - 24 . (in Chinese)
Shen J H , Wang L Sh , Wang Q H , et al . Deformation and fracture features of unloading rock mass [J]. Chinese Journal of Rock Mechanics and Engineering , 2003 , 22 ( 12 ): 2 028 - 2 031 . (in Chinese)
Huang R Q , Huang D . Experimental research on mechanical properties of granites under unloading condition [J]. Chinese Journal of Rock Mechanics and Engineering , 2008 , 27 ( 11 ): 2 206 - 2 213 . (in Chinese)
黄润秋 . 岩石高边坡稳定性工程地质分析 [M]. 北京 : 科学出版社 , 2012 .
Huang R Q . Engineering geological analysis of rock high slope stability [M]. Beijing : Science Press , 2012 . (in Chinese)
Qiao G W , Wang Y Sh , Chu F , et al . Failure mechanism of slope rock mass due to freeze-thaw weathering [J]. Journal of Engineering Geology , 2015 , 23 ( 3 ): 469 - 476 . (in Chinese)
Zhang Y J . Coupled thermo-hydro-mechanical model and numerical analysis for simulation of freezing-thawing process [J]. Chinese Journal of Solid Mechanics , 2009 , 30 ( 4 ): 409 - 415 . (in Chinese)
Liu Q Sh , Kang Y Sh , Liu B , et al . Water-ice phase transition and thermo-hydro-mechanical coupling at low temperature in fractured rock [J]. Chinese Journal of Rock Mechanics and Engineering , 2011 , 30 ( 11 ): 2 181 - 2 188 . (in Chinese)