Quantitative assessment of physical fragility of buildings to the debris flow on 20 August 2019 in the Cutou gully, Wenchuan, southwestern China

Chen, Ming; Tang, Chuan; Zhang, Xianzheng; Xiong, Jiang; Chang, Ming; Shi, Qingyun; Wang, Feilong; Li, Mingwei

doi:10.1016/j.enggeo.2021.106319

Cited by 38 publications

(9 citation statements)

References 54 publications

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“…To the best of our knowledge, the runout distances and planimetric deposition areas of debris flows are commonly predicted by the geomorphologic catchment parameters (Scheidl and Rickenmann, 2010;Chen et al, 2021). Recently, different machine learning methods, including back-propagation neural network (BPNN), support vector machine (SVM), and extreme learning machine (ELM), have been adopted to predict the flow volume and runout distance (Huang et al, 2020).…”

Section: Discussionmentioning

confidence: 99%

Control mechanisms of pore-pressure dissipation in debris flows

Zheng

Shi

Kaitna

et al. 2023

Engineering Geology

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Section: Discussionmentioning

confidence: 99%

Control mechanisms of pore-pressure dissipation in debris flows

Zheng

Shi

Kaitna

et al. 2023

Engineering Geology

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“…The initiation and features of debris flows can be characterized by this method, which enables the analysis of the risk in the study area. The accuracy of the modelled result depends on not only the quality of the input data, but also the rationality of rheological parameters (Ouyang et al 2019;Chen et al 2021). Firstly, the terrain data we adopted in this study was the digital elevation with high spatial resolution (2m) obtained from a photogrammetric survey using UAVs, which ensures the data is accurate and up-to-date.…”

Section: Discussionmentioning

confidence: 99%

Physical vulnerability curve construction and quantitative risk assessment of a typhoon-triggered debris flow via numerical simulation: A case study of Zhejiang Province, SE China

Wang¹,

Yin²,

Li³

et al. 2023

Preprint

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Typhoons are recurrent meteorological phenomena in the South-eastern coastal area of China. They often trigger debris flows and other types of slope failure which cause significant economic damage and loss of life in an area with dense population and high economic activities. Accurate prediction of Typhoon-triggered debris flows and determination of the potential risk zones are crucial for risk management. However, little effort has been devoted to risk assessment by constructing the physical vulnerability curves in the typhoon-affected area. To cope with this deficiency, this paper presented a quantitative method to build up the physical vulnerability curves of buildings by modeling the debris flow intensity and building damage features. In this study, the Wangzhuangwu (WZW) watershed was selected, which was impacted by a debris flow induced by Typhoon Lekima on 10 August 2019. At first, detailed field investigation and interpretation of remote sensing imagery were carried out to analyze the geological characteristics, mechanism of the debris flow, and construct a database of building damage features. The 2019 debris flow initiation, movement and deposition processes were modelled based on the Soil Conservation Service-curve number (SCS-CN) approach and a two-dimensional finite model (FLO-2D). The reconstructed debris flow depth and extend were validated with observed information. Then, we proposed physical vulnerability curves for different type of building structures by combining the damage degree of buildings and the modelled debris flow intensity (flow depth and impact pressure). Based on the validated rheological parameters, the potential intensity of future debris flows was modelled considering different recurrence frequency of the triggering rainfall. Finally, the vulnerability index and economic risk of buildings to debris flow events with different frequencies were calculated using different vulnerability functions. The uncertainty of quantitative risk assessment was considered in the intensity indictor and building structure. The RC (reinforced concrete) frame building has stronger resistance than the non-RC frame building under same intensity of debris flow, and the vulnerability function using the impact pressure as the intensity indictor is more conservative than which using the flow depth. The proposed approach efficiently generated the physical vulnerability curves and debris flow risk map that can be used for effective disaster prevention in debris flow-prone areas.

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“…Debris flows are common phenomena in mountainous regions worldwide (e.g., Iverson, 1997;de Haas and van Woerkom, 2016;Zheng et al, 2018Zheng et al, , 2022Chen et al, 2021). They often occur in steep gullies when landslides and loose debris initiate, driven by gravity (e.g., Iverson, 1997;Pudasaini, 2012;Wang et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Pore pressure evolution in bed sediment overridden by debris flow: A general formulation

Zheng

Shi

Hanley

et al. 2023

Earth Surf Processes Landf

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Debris flows can grow dramatically in volume and mobility as they override bed sediment due to the reduction in bed-friction resistance caused by high pore-fluid pressure (PP). However, the mechanisms that control PP evolution in overridden bed sediment are still unclear. Here, a new mathematical model clarifies how diverse styles and magnitudes of PP evolution can result from regulation of the flow diffusion and shear contraction of bed sediment. Normalization of the model equations shows that the propensity for PP generation depends on timescales of PP diffusion and deformation of the bed grains. The PP of saturated bed sediment under immobile conditions is equal to the fluid pressure at the bottom of the flow due to a non-flux basal boundary. However, the PP of unsaturated bed sediment is lower than that of the overlying flow. PP diffusion from a debris flow into an unsaturated bed increases with the bed's permeability and water content. The shear deformation behavior changes from undrained to drained with increasing permeability or decreasing shear velocity of the saturated bed sediment, leading to a reduced magnitude of pore pressure. By contrast, the shear deformation transitions from drained to undrained behavior with increasing permeability and water content of unsaturated bed sediment. The entrainment rate and erosion pattern of bed sediment are closely related to the PP evolution and liquefaction ratio of the bed sediment due to Coulomb-friction shear tractions. Our models can be used to interpret the feedback of PP on the flow momentum during debris-flow entrainment.

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Quantitative assessment of physical fragility of buildings to the debris flow on 20 August 2019 in the Cutou gully, Wenchuan, southwestern China

Cited by 38 publications

References 54 publications

Control mechanisms of pore-pressure dissipation in debris flows

Control mechanisms of pore-pressure dissipation in debris flows

Physical vulnerability curve construction and quantitative risk assessment of a typhoon-triggered debris flow via numerical simulation: A case study of Zhejiang Province, SE China

Pore pressure evolution in bed sediment overridden by debris flow: A general formulation

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