Impoundment and water level fluctuations in reservoirs can induce landslides,especially during initial filling and drawdown.Since the initial impoundment in April 2021,multiple landslides have occurred within the Baih...Impoundment and water level fluctuations in reservoirs can induce landslides,especially during initial filling and drawdown.Since the initial impoundment in April 2021,multiple landslides have occurred within the Baihetan(BHT) reservoir,which is located at the boundary of Sichuan and Yunnan province in southeast China.However,due to the complex terrain conditions of reservoir banks,traditional landslide research methods,such as surveys,deformation monitoring,and geotechnical experiments,cannot be effectively conducted in a timely manner.In recent years,the development of remote sensing technology has addressed the shortcomings of traditional landslide research methods that may not be promptly carried out.In particular,interferometric synthetic aperture radar(InSAR) technology,capable of measuring subtle deformations,and portable small unmanned aerial vehicles(UAVs) have played a significant role.This study integrates multiple remote sensing data sources,including InSAR results,optical remote sensing images,digital elevation model(DEM),and UAV imagery,to investigate and elucidate the deformation characteristics and mechanisms of the Xiaomidi(XMD) landslide developed on the left bank of Jinsha River,about 100 km from the BHT hydropower dam site.The spatial deformation distribution of the landslide before and after impoundment and the deformation time series during filling were examined.Monitoring water level variation and analysing the deformation process of the landslide were achieved by employing continuous synthetic aperture radar(SAR) intensity images and DEM.UAV photography was utilized to assist in the verification of ground deformation.The findings suggest that the weak strength of the reversed bedding strata structure and the steep slope eroded by the Jinsha River are inherent factors that contribute to the development of the landslide.The rise in the water level leads to softening of the rock mass at the slope toe,thereby directly facilitating the acceleration of landslide deformation.The toppling deformation of the lower rock mass initiates the formation of surface cracks and localized uneven subsidence in the overlying colluvial deposits.展开更多
Deep-seated large-scale toppling failure presents unique challenges in the study of natural slope deformation process in mountainous regions.An active deep-seated toppling process was identified in the Erguxi slope lo...Deep-seated large-scale toppling failure presents unique challenges in the study of natural slope deformation process in mountainous regions.An active deep-seated toppling process was identified in the Erguxi slope located in southwest China,which affected a large area and damaged critical transportation infrastructure with the volume of the deforming rock mass exceeding 24×10~6 m^3.It poses significant risks to the downstream Shiziping Hydropower Station by damming the Zagunao River.Field investigation and monitoring results indicate that the deformation of the Erguxi slope is in the advanced stage of deep-seated toppling process,with the formation of a disturbed belt but no identifiable master failure surface.It was postulated that the alternating tensile and shear strength associated with the hard/soft laminated rock strata of metasandstone and phyllite layers preclude the development of either a tensile or shear failure surface,which resulted in the continuous deformation and displacement without a catastrophic mass movement.The slope movement is in close association with the unfavorable geological conditions of the study area in addition to the construction of transportation infrastructure and the increase of the reservoir level.On the basis of the mechanism and intensity of the ongoing toppling deformation,a qualitative grading system was proposed to describe the toppling process and toevaluate the slope stability.This paper summarized the field observation and monitoring data on the toppling deformation for better characterizing its effect on the stability of the Erguxi slope.The qualitative grading system intends to provide a basis for quantitative study of large-scale deep-seated toppling process in metamorphic rocks.展开更多
During underground mining,accurate revelation on the deformation and failure mechanisms of a high-steep slope under multi-layer mining conditions facilitates the prevention and control of geological disasters in mines...During underground mining,accurate revelation on the deformation and failure mechanisms of a high-steep slope under multi-layer mining conditions facilitates the prevention and control of geological disasters in mines.Numerical simulation based on discrete element theory can be used to explore the characteristics and mechanism of action of deformation and failure of a slope under complex geological and multi-layer mining conditions.By utilising PFC2 D(particle flow code) software,the deformation and failure characteristics of a high-steep slope in Faer Coal Mine in Guizhou Province,China were investigated.Additionally,the mechanism of influence of different numbers of mining layers on the deformation and failure of the high and steep slope was elucidated.The result showed that after the goaf passed by the slope toe,multi-layer mining aggravated the subsidence and deformation of the slope toe:the slope toppled forward as it sank.The toppling of the slope changed the slope structures:the strata in the front of the slope were transformed from anti-dip to down-dip features.Extruded by collapsedtoppled rock mass,the slope toe and the rock mass located in the lower part of the slope toe generally exhibited a locking effect on the slope.Multi-layer mining degraded the overall stability of the slope,in that the total displacement of the slope was much greater than the total mining thickness of the coal seams.Based on the aforementioned research,ideas for preventing and controlling geological disasters during mining operations under a high-steep slope were proposed.展开更多
基金supported by the China Three Gorges Corporation (YMJ (XLD)/(19) 110)National Key R&D Program of China (2018YFC1505002)+1 种基金National Science Foundation of China (41672359, 41807299)China Geology Survey Project (DD20221738-2)。
文摘Impoundment and water level fluctuations in reservoirs can induce landslides,especially during initial filling and drawdown.Since the initial impoundment in April 2021,multiple landslides have occurred within the Baihetan(BHT) reservoir,which is located at the boundary of Sichuan and Yunnan province in southeast China.However,due to the complex terrain conditions of reservoir banks,traditional landslide research methods,such as surveys,deformation monitoring,and geotechnical experiments,cannot be effectively conducted in a timely manner.In recent years,the development of remote sensing technology has addressed the shortcomings of traditional landslide research methods that may not be promptly carried out.In particular,interferometric synthetic aperture radar(InSAR) technology,capable of measuring subtle deformations,and portable small unmanned aerial vehicles(UAVs) have played a significant role.This study integrates multiple remote sensing data sources,including InSAR results,optical remote sensing images,digital elevation model(DEM),and UAV imagery,to investigate and elucidate the deformation characteristics and mechanisms of the Xiaomidi(XMD) landslide developed on the left bank of Jinsha River,about 100 km from the BHT hydropower dam site.The spatial deformation distribution of the landslide before and after impoundment and the deformation time series during filling were examined.Monitoring water level variation and analysing the deformation process of the landslide were achieved by employing continuous synthetic aperture radar(SAR) intensity images and DEM.UAV photography was utilized to assist in the verification of ground deformation.The findings suggest that the weak strength of the reversed bedding strata structure and the steep slope eroded by the Jinsha River are inherent factors that contribute to the development of the landslide.The rise in the water level leads to softening of the rock mass at the slope toe,thereby directly facilitating the acceleration of landslide deformation.The toppling deformation of the lower rock mass initiates the formation of surface cracks and localized uneven subsidence in the overlying colluvial deposits.
基金financially supported by the National Natural Science Foundation of China (Grant No.41572302 and Grant No.41130745)the Funds for Creative Research Groups of China (Grant No.41521002)the Open Research Fund from the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology) (Grant No.SKLGP2015K001)
文摘Deep-seated large-scale toppling failure presents unique challenges in the study of natural slope deformation process in mountainous regions.An active deep-seated toppling process was identified in the Erguxi slope located in southwest China,which affected a large area and damaged critical transportation infrastructure with the volume of the deforming rock mass exceeding 24×10~6 m^3.It poses significant risks to the downstream Shiziping Hydropower Station by damming the Zagunao River.Field investigation and monitoring results indicate that the deformation of the Erguxi slope is in the advanced stage of deep-seated toppling process,with the formation of a disturbed belt but no identifiable master failure surface.It was postulated that the alternating tensile and shear strength associated with the hard/soft laminated rock strata of metasandstone and phyllite layers preclude the development of either a tensile or shear failure surface,which resulted in the continuous deformation and displacement without a catastrophic mass movement.The slope movement is in close association with the unfavorable geological conditions of the study area in addition to the construction of transportation infrastructure and the increase of the reservoir level.On the basis of the mechanism and intensity of the ongoing toppling deformation,a qualitative grading system was proposed to describe the toppling process and toevaluate the slope stability.This paper summarized the field observation and monitoring data on the toppling deformation for better characterizing its effect on the stability of the Erguxi slope.The qualitative grading system intends to provide a basis for quantitative study of large-scale deep-seated toppling process in metamorphic rocks.
基金funded by the National Natural Science Foundation of China (Grants No. 41877273)the Innovative Research Groups of the National Natural Science Foundation of China (Grants No. 41521002)+1 种基金the State Key Laboratory of Geohazard Disaster Prevention and Geoenvironment Protection (Chengdu University of Technology) (Grants No. SKLGP2017Z016)the Guizhou Provincial Geological Environment Monitoring Institute, and the Faer Coal Mine。
文摘During underground mining,accurate revelation on the deformation and failure mechanisms of a high-steep slope under multi-layer mining conditions facilitates the prevention and control of geological disasters in mines.Numerical simulation based on discrete element theory can be used to explore the characteristics and mechanism of action of deformation and failure of a slope under complex geological and multi-layer mining conditions.By utilising PFC2 D(particle flow code) software,the deformation and failure characteristics of a high-steep slope in Faer Coal Mine in Guizhou Province,China were investigated.Additionally,the mechanism of influence of different numbers of mining layers on the deformation and failure of the high and steep slope was elucidated.The result showed that after the goaf passed by the slope toe,multi-layer mining aggravated the subsidence and deformation of the slope toe:the slope toppled forward as it sank.The toppling of the slope changed the slope structures:the strata in the front of the slope were transformed from anti-dip to down-dip features.Extruded by collapsedtoppled rock mass,the slope toe and the rock mass located in the lower part of the slope toe generally exhibited a locking effect on the slope.Multi-layer mining degraded the overall stability of the slope,in that the total displacement of the slope was much greater than the total mining thickness of the coal seams.Based on the aforementioned research,ideas for preventing and controlling geological disasters during mining operations under a high-steep slope were proposed.
