Effects of obstacle's curvature on shock dynamics of gravity-driven granular flows impacting a circular cylinder

doi:10.1016/j.enggeo.2021.106343

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > 山地灾害与地表过程重点实验室

	Effects of obstacle's curvature on shock dynamics of gravity-driven granular flows impacting a circular cylinder
	Chen, Zheng 1,2,3; Rickenmann, Dieter 2; Zhang, Yi 1,3; He, Siming 3
刊名	ENGINEERING GEOLOGY
	2021-11-01
卷号	293 页码:20
关键词	Granular flow Obstacle curvature Shock wave Impact pressure Seismic signal
ISSN号	0013-7952
DOI	10.1016/j.enggeo.2021.106343
英文摘要	Granular flows, such as rock avalanches and debris flows, are gravity-driven and often hit engineering structures that are placed in their paths, generating dynamic impact pressures and potentially causing hazard to infrastructures. To improve the design of protective structures and the hazard assessment, it is important to understand the physical mechanism of such granular flows impacting on obstacles with variable sizes and shapes. In this study, the dynamics of granular shock waves generated by experimental flows impacting on a circular cylinder varying in diameter and on a closed barrier were investigated by conducting systematic laboratory experiments. Pressure sensors were mounted at the bottom of the experimental chute and the upstream cylinder surface to measure the dynamic impact pressures in the granular shock area. Accelerometers that were installed at the underside of the chute bed were used to record the seismic signals of granular flows during the entire impacting process. The velocity and depth of a granular flow impacting (or just before impacting) on a cylinder were estimated using an image processing method. The results showed that the dimensionless standoff distance DDstandoff of the granular shock wave decreases nonlinearly with increasing Froude number ranging from 5.8 to 12.3. The values of DDstandoff tend to change less for the larger investigated Froude numbers, approaching a limit of about 0.19. The dimensionless runup and the pinch-off distance correlated linearly with increasing Froude number and can be affected by the radius of curvature (R-C) of the obstacle at the stagnation point. The impact pressures grow linearly as Froude number increases, and the R-C with a smaller value usually excites a larger impact pressure. Additionally, the effect of R-C on the dimensionless pressures was observed to be weakened by an increase in Froude number. The mean frequency of the seismic signals produced by the impacts of a granular flow also indicates a dependency on R-C. The findings of this study contribute to the understanding of the dynamic signal response generated by a granular flow, which may result in improving the design of the protective structures.
资助项目	Natural Science Foundation of China[41772312] ; Natural Science Foundation of China[41790433] ; Key Deployment Project of CAS[KFZD-SW-424] ; China Scholarship Council CSC[201904910867]
WOS关键词	LABORATORY FLUME EXPERIMENTS ; CATASTROPHIC DEBRIS FLOWS ; 2008 WENCHUAN EARTHQUAKE ; 13 AUGUST 2010 ; JIANGJIA RAVINE ; HYDRAULIC JUMPS ; PRESSURE ; AVALANCHES ; LANDSLIDE ; FORCE
WOS研究方向	Engineering ; Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000696814500055
资助机构	Natural Science Foundation of China ; Key Deployment Project of CAS ; China Scholarship Council CSC
内容类型	期刊论文
源URL	[http://ir.imde.ac.cn/handle/131551/56227]
专题	成都山地灾害与环境研究所_山地灾害与地表过程重点实验室
通讯作者	He, Siming
作者单位	1.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 2.Swiss Fed Inst Forest Snow & Landscape Res WSL, CH-8903 Birmensdorf, Switzerland 3.Chinese Acad Sci, Inst Mt Hazards & Environm, Chengdu 610041, Peoples R China
推荐引用方式 GB/T 7714	Chen, Zheng,Rickenmann, Dieter,Zhang, Yi,et al. Effects of obstacle's curvature on shock dynamics of gravity-driven granular flows impacting a circular cylinder[J]. ENGINEERING GEOLOGY,2021,293:20.
APA	Chen, Zheng,Rickenmann, Dieter,Zhang, Yi,&He, Siming.(2021).Effects of obstacle's curvature on shock dynamics of gravity-driven granular flows impacting a circular cylinder.ENGINEERING GEOLOGY,293,20.
MLA	Chen, Zheng,et al."Effects of obstacle's curvature on shock dynamics of gravity-driven granular flows impacting a circular cylinder".ENGINEERING GEOLOGY 293(2021):20.