A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eig...A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eighty-three people were killed or went missing and more than 103 houses were destroyed. In this paper, the geological conditions of the landslide are analyzed via field investigation and high-resolution imagery. The dynamic process and runout characteristics of the landslide are numerically analyzed using a depth-integrated continuum method and Mac Cormack-TVD finite difference algorithm.Computational results show that the evaluated area of the danger zone matchs well with the results of field investigation. It is worth noting that soil sprayed by the high-speed blast needs to be taken into account for such kind of large high-locality landslide. The maximum velocity is about 55 m/s, which is consistent with most cases. In addition, the potential danger zone of an unstable block is evaluated. The potential risk area evaluated by the efficient depthintegrated continuum method could play a significant role in disaster prevention and secondary hazard avoidance during rescue operations.展开更多
This study investigated the failure mechanism associated with the rock mass structure and the dynamic fragmentation process of blocky rocks of the 2018 Daanshan rockslide that occurred on 11 August,2018.It was found t...This study investigated the failure mechanism associated with the rock mass structure and the dynamic fragmentation process of blocky rocks of the 2018 Daanshan rockslide that occurred on 11 August,2018.It was found that the initially collapsed rock of this rockslide was partitioned along the unconformity and strata interfaces.We analyzed how the unique rock mass structure,coupled with the road cut and the antecedent rainfall,jointly resulted in its failure.Based on the rock types and geological structures,the initial stratified configuration of a discrete element model was setup to reveal the influences of the local structure.The numerical model was divided into three parts.Part 1 is the basalt of the Nandaling Formation,the normal and shear stiffnesses of the basalt particles are set as 80 MPa and 40 MPa.Parts 2 and 3 are the sandstones interbedded with mudstone and sandstone of the Shihezi Formation,and the normal and shear stiffnesses of these parts were set as 6 MPa and 10 MPa,respectively.The dynamic process of the rockslide,particularly the rock fragmentation process,was numerically analyzed using a 3D discrete element method.The numerical results were compared with real-time videos and field investigations.The results show that the rock fragmentation and the final deposition range match well with the real disaster phenomenon,and the calculation accuracy of the rockslide reaches 82.41%.Moreover,a parameter sensitivity analysis was conducted,and classical uniform models under different bonding forces were established;the stratified model can better restore the true state of the fragmentation,movement,and deposition processes of rockslides.Therefore,for complicated rocks with significant differences in lithology,clarifying the rock mass stratigraphy is essential for an accurate reconstruction of the dynamic process of rockslides.展开更多
The great diversity and complexity of geological hazards in terms of flowing materials,environment,triggering mechanisms and physical processes during the flow bring great difficulties to the numerical parameter selec...The great diversity and complexity of geological hazards in terms of flowing materials,environment,triggering mechanisms and physical processes during the flow bring great difficulties to the numerical parameter selection for the discrete element method.In order to identity the significance of individual parameters on the landslides dynamic process and provide valuable contribution to the runout analysis of similar landslide,the dynamic process and associated microscopic mechanism of the Turnoff Creek rock avalanche in Canada are simulated.The present numerical results are compared with the field survey data and the results of depth-integrated continuum method.The final deposit range matches well with the field survey data.It is illustrated that the discrete element method is robust and feasible to capture the dynamic characteristics of large rock avalanche over a complex terrain.Besides,a new method to assess the landslide hazard level based on the discrete element method is proposed.According to the parameter sensitivity analysis,it is demonstrated that the basal friction coefficient and bond strength are essential to the final deposit while rolling coefficient and restitution coefficient have little effects on it.展开更多
基金Financial support from National Nature Science Foundation of China (Grant No. 41572303, 41520104002)Chinese Academy of Sciences “Light of West China” Program and Youth Innovation Promotion Association
文摘A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eighty-three people were killed or went missing and more than 103 houses were destroyed. In this paper, the geological conditions of the landslide are analyzed via field investigation and high-resolution imagery. The dynamic process and runout characteristics of the landslide are numerically analyzed using a depth-integrated continuum method and Mac Cormack-TVD finite difference algorithm.Computational results show that the evaluated area of the danger zone matchs well with the results of field investigation. It is worth noting that soil sprayed by the high-speed blast needs to be taken into account for such kind of large high-locality landslide. The maximum velocity is about 55 m/s, which is consistent with most cases. In addition, the potential danger zone of an unstable block is evaluated. The potential risk area evaluated by the efficient depthintegrated continuum method could play a significant role in disaster prevention and secondary hazard avoidance during rescue operations.
基金funded by the Strategic Priority Research Program of CAS(Grant No.XDA23090303)the NSFC(Grant No.42022054)+1 种基金Sichuan Science and Technology Program(Grant No.2022YFS0543)the Science Foundation for Distinguished Young Scholars of Sichuan Province(Grant No.2020JDJQ0044)State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(SKLGP2019Z013).
文摘This study investigated the failure mechanism associated with the rock mass structure and the dynamic fragmentation process of blocky rocks of the 2018 Daanshan rockslide that occurred on 11 August,2018.It was found that the initially collapsed rock of this rockslide was partitioned along the unconformity and strata interfaces.We analyzed how the unique rock mass structure,coupled with the road cut and the antecedent rainfall,jointly resulted in its failure.Based on the rock types and geological structures,the initial stratified configuration of a discrete element model was setup to reveal the influences of the local structure.The numerical model was divided into three parts.Part 1 is the basalt of the Nandaling Formation,the normal and shear stiffnesses of the basalt particles are set as 80 MPa and 40 MPa.Parts 2 and 3 are the sandstones interbedded with mudstone and sandstone of the Shihezi Formation,and the normal and shear stiffnesses of these parts were set as 6 MPa and 10 MPa,respectively.The dynamic process of the rockslide,particularly the rock fragmentation process,was numerically analyzed using a 3D discrete element method.The numerical results were compared with real-time videos and field investigations.The results show that the rock fragmentation and the final deposition range match well with the real disaster phenomenon,and the calculation accuracy of the rockslide reaches 82.41%.Moreover,a parameter sensitivity analysis was conducted,and classical uniform models under different bonding forces were established;the stratified model can better restore the true state of the fragmentation,movement,and deposition processes of rockslides.Therefore,for complicated rocks with significant differences in lithology,clarifying the rock mass stratigraphy is essential for an accurate reconstruction of the dynamic process of rockslides.
基金Financial support from the National Natural Science Foundation of China(Grant No.41520104002,41572303)the Strategic Priority Research Program of CAS(Grant No.XDA23090303)the National Key Research and Development Program of China(Project No.2017YFC1501000)。
文摘The great diversity and complexity of geological hazards in terms of flowing materials,environment,triggering mechanisms and physical processes during the flow bring great difficulties to the numerical parameter selection for the discrete element method.In order to identity the significance of individual parameters on the landslides dynamic process and provide valuable contribution to the runout analysis of similar landslide,the dynamic process and associated microscopic mechanism of the Turnoff Creek rock avalanche in Canada are simulated.The present numerical results are compared with the field survey data and the results of depth-integrated continuum method.The final deposit range matches well with the field survey data.It is illustrated that the discrete element method is robust and feasible to capture the dynamic characteristics of large rock avalanche over a complex terrain.Besides,a new method to assess the landslide hazard level based on the discrete element method is proposed.According to the parameter sensitivity analysis,it is demonstrated that the basal friction coefficient and bond strength are essential to the final deposit while rolling coefficient and restitution coefficient have little effects on it.
