7 results
Search Results
2. Quantitative risk assessment of landslides with direct simulation of pre-failure to post-failure behaviors.
- Author
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Cui, Qi, Zhang, Lulu, Chen, Xiangyu, Cao, Zijun, Wei, Xin, Zhang, Jie, Xu, Jiabao, Liu, Dongsheng, and Du, Chunlan
- Subjects
LANDSLIDES ,LANDSLIDE hazard analysis ,HAZARD mitigation - Abstract
Most previous studies on the quantitative risk assessment (QRA) of landslides focused on the probability of slope failure at the pre-failure stage and adopted empirical models for consequence analysis. The conventional approaches simplify the relationship between the pre-failure state and the post-failure behavior and cannot reasonably account for the effects of uncertainty on the entire landslide process. In this paper, an efficient QRA method that involves the direct simulation of the entire landslide process is proposed. A QRA formula that considers the probability of only those landslides that can impact the element at risk is used. The coupled Eulerian–Lagrangian method is used to simulate the entire landslide process and to identify slopes that can impact the element at risk and determine the failure consequences. The subset simulation method is adopted to efficiently estimate the probability of landslide impact, and parameter uncertainty is considered. Two case histories of landslides are investigated. First, the 2011 Baqiao loess landslide in Xi'an, China, is investigated, and the results of the proposed method are compared with those of the conventional approaches. Second, the proposed method is applied to assess the risk of the 2015 Ganjingzi landslide in the Three Gorges Reservoir. The effects of the risk mitigation works are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Performance evaluation of underground pipelines subjected to landslide thrust with fiber optic strain sensing nerves.
- Author
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Wang, De-yang, Zhu, Hong-hu, Wu, Bing, Ye, Xiao, Wang, Jing, Tan, Dao-yuan, and Shi, Bin
- Abstract
High-accuracy deformation monitoring is crucial for investigating landslide–pipeline interaction problems, in which the fiber optic nerve system (FONS) holds enormous potential. This paper presents a theoretical framework for interpreting landslide–pipeline interactions using the FONS and proposes a novel method for calculating characteristic parameters of pipe–soil interfaces based on distributed strain measurements. The feasibility of this method is validated through a full-scale model test, and its application for studying pipeline behaviors is demonstrated in the Xinpu landslide, situated in the Three Gorges Reservoir region, China. The field monitoring results reveal that short-duration, high-intensity rainfall events triggered immediate acceleration of landslide movements, leading to pipeline elongation and flexure. Strain measurements of the underground pipeline allow for the identification of the local slipping interface of the landslide. Furthermore, the relationships between reservoir water level (RWL) fluctuations, rainfall events, landslide deformation, and the structural response of the pipe are analyzed. The findings suggest that the deformation of the landslide in the leading and middle parts exhibits high correlations with the combined effect of rainfall and RWL drawdown. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. An InSAR and depth-integrated coupled model for potential landslide hazard assessment.
- Author
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Zhou, Shu, Ouyang, Chaojun, and Huang, Yu
- Subjects
LANDSLIDES ,LANDSLIDE hazard analysis ,HAZARD mitigation ,EMERGENCY management - Abstract
Assessing the hazard of potential landslides is crucial for developing mitigation strategies for landslide disasters. However, accurate assessment of landslide hazard is limited by the lack of landslide inventory maps and difficulty in determining landslide run-out distance. To address these issues, this study developed a novel method combining the InSAR technique with a depth-integrated model. Within this new framework, potential landslides are identified through InSAR and their potential impact areas are subsequently estimated using the depth-integrated model. To evaluate its capability, the proposed method was applied to a landslide event that occurred on November 3, 2018 in Baige village, Tibet, China. The simulated results show that the area with a probability of more than 50% to be affected by landslides matched the real trimlines of the landslide and that the accuracy of the proposed method reached 85.65%. Furthermore, the main deposit characteristics, such as the location of maximum deposit thickness and the main deposit area, could be captured by the proposed method. Potential landslides in the Baige region were also identified and evaluated. The results indicate that in the event of landslides, the collapsed mass has a high probability to block the Jinsha River. It is therefore necessary to implement field monitoring and prepare hazard mitigation strategies in advance. This study provides new insights for regional-scale landslide hazard management and further contributes to the implementation of landslide risk assessment and reduction activities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Continuum hydrodynamics of dry granular flows employing multiplicative elastoplasticity.
- Author
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Fávero Neto, Alomir H. and Borja, Ronaldo I.
- Subjects
HYDRODYNAMICS ,GRANULAR flow ,ELASTOPLASTICITY ,DEFORMATIONS (Mechanics) ,BOUNDARY value problems - Abstract
We present a Lagrangian formulation for simulating the continuum hydrodynamics of dry granular flows based on multiplicative elastoplasticity theory for finite deformation calculations. The formulation is implemented within the smoothed particle hydrodynamics (SPH) method along with a variant of the usual dynamic boundary condition. Three benchmark simulations on dry sands are presented to validate the model: (a) a set of plane strain collapse tests, (b) a set of 3D collapse tests, and (c) a plane strain simulation of the impact force generated by granular flow on a rigid wall. Comparison with experimental results suggests that the formulation is sufficiently robust and accurate to model the continuum hydrodynamics of dry granular flows in a laboratory setting. Results of the simulations suggest the potential of the formulation for modeling more complex, field-scale scenarios characterized by more elaborate geometry and multi-physical processes. To the authors’ knowledge, this is the first time the multiplicative plasticity approach has been applied to granular flows in the context of the SPH method. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
6. Landsliding triggered by reservoir operation: a general conceptual model with a case study at Three Gorges Reservoir.
- Author
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Wang, Jinge, Xiang, Wei, and Lu, Ning
- Subjects
LANDSLIDES ,RESERVOIRS ,CONCEPTUAL models ,CIVIL engineering ,DAMS ,PORE water pressure ,SAN Xia Reservoir (China) - Abstract
The Three Gorge Reservoir, one of the largest civil engineering projects in human history, dams the Yangtze River to form a 660-km-long and 1.13-km-wide reservoir. Today, although the project has been completed and is in normal operation, the on-going landslide initiation and movement in response to the reservoir operating is one of the main geologic hazards. The Huangtupo (meaning 'yellow soil slope' in Chinese) Slope typifies such on-going landslides along the reservoir. Observations from a multi-year monitoring program conducted on this slope indicate that there are multiple slides on the reservoir banks that move episodically into the reservoir and their movements appear to be highly correlated with the initial and seasonal changes in the reservoir pool level. A hydro-mechanical numerical model is constructed to investigate the quantitative links among the episodic movements and the variations in pore water pressure, suction stress, hydrostatic reservoir water loading, and slope self-weight induced by the fluctuating water levels. Modeling results identify regions within the variably saturated slope where significant changes in stress occur during the periods of the initial impoundment that raised water levels from 68 to 135 m and that occur in response to seasonal fluctuations of the reservoir pool level between 145 and 175 m. We find that the rise or decline of reservoir pool level can either increase or decrease the stability of landslide. In general, hydrostatic reservoir water loading has positive correlation with the stability; pore water pressure and suction stress have negative correlation with the stability; and the effects of slope self-weight depend on the dip angle and mechanical properties of sliding surface. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
7. A landslide in stiff, intact clay.
- Author
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Maiorano, R., Russo, G., and Viggiani, C.
- Subjects
LANDSLIDES ,CLAY ,EXCAVATION ,TUNNELS ,FINITE element method - Abstract
A landslide in a stiff clay formation, interrupting the excavation of a tunnel for a major railway in Sicily, is reported. Limit equilibrium and FEM undrained and drained analyses of the slope before tunnel excavation agree in showing that the slope was stable with a relatively high factor of safety and the critical slip surface is located well above the tunnel. The undrained stability of the tunnel checked both via FEM and via standard analytical solutions for face stability is also verified. The FEM analyses of the slope have been repeated considering the excavation of the tunnel in undrained and drained conditions. The advancement of the tunnel face is simulated in a plane strain analysis by the Panet method. In undrained conditions, the system keeps stable. In drained conditions with a stress release factor of 50 %, the slope is on the verge of failing with a very low safety factor, while with a stress release factor of 80 %, it fails following a complex mechanism that matches the observed failure surface. These findings are discussed and some conclusions attempted. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
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