Effects of heterogeneity distribution on hillslope stability during rainfalls  

作　　者：Jing-sen Cai E-chuan Yan Tian-chyi Jim Yeh Yuan-yuan Zha 

机构地区：[1]Faculty of Engineering, China University of Geosciences [2]Department of Hydrology and Water Resources, University of Arizona

出　　处：《Water Science and Engineering》2016年第2期134-144,共11页水科学与水工程（英文版）

基　　金：supported by the China Scholarship Council(Grant No.201406410032);the National Natural Science Foundation of China(Grant No.41172282);the Strategic Environmental Research and Development Program(Grant No.ER-1365);the Environmental Security and Technology Certification Program(Grant No.ER201212);the National Science FoundationDivision of Earth Sciences(Grant No.1014594)

摘　　要：The objective of this study was to investigate the spatial relationship between the most likely distribution of saturated hydraulic conductivity(Ks) and the observed pressure head(P) distribution within a hillslope. The cross-correlation analysis method was used to investigate the effects of the variance of ln Ks, spatial structure anisotropy of ln Ks, and vertical infiltration flux(q) on P at some selected locations within the hillslope. The cross-correlation analysis shows that, in the unsaturated region with a uniform flux boundary, the dominant correlation between P and Ksis negative and mainly occurs around the observation location of P. A relatively high P value is located in a relatively low Kszone, while a relatively low P value is located in a relatively high Kszone. Generally speaking, P is positively correlated with q/Ksat the same location in the unsaturated region. In the saturated region, the spatial distribution of Kscan significantly affect the position and shape of the phreatic surface. We therefore conclude that heterogeneity can cause some parts of the hillslope to be sensitive to external hydraulic stimuli(e.g., rainfall and reservoir level change), and other parts of the hillslope to be insensitive. This is crucial to explaining why slopes with similar geometries would show different responses to the same hydraulic stimuli, which is significant to hillslope stability analysis.The objective of this study was to investigate the spatial relationship between the most likely distribution of saturated hydraulic conductivity(Ks) and the observed pressure head(P) distribution within a hillslope. The cross-correlation analysis method was used to investigate the effects of the variance of ln Ks, spatial structure anisotropy of ln Ks, and vertical infiltration flux(q) on P at some selected locations within the hillslope. The cross-correlation analysis shows that, in the unsaturated region with a uniform flux boundary, the dominant correlation between P and Ksis negative and mainly occurs around the observation location of P. A relatively high P value is located in a relatively low Kszone, while a relatively low P value is located in a relatively high Kszone. Generally speaking, P is positively correlated with q/Ksat the same location in the unsaturated region. In the saturated region, the spatial distribution of Kscan significantly affect the position and shape of the phreatic surface. We therefore conclude that heterogeneity can cause some parts of the hillslope to be sensitive to external hydraulic stimuli(e.g., rainfall and reservoir level change), and other parts of the hillslope to be insensitive. This is crucial to explaining why slopes with similar geometries would show different responses to the same hydraulic stimuli, which is significant to hillslope stability analysis.

关 键 词：CROSS-CORRELATION analysis HETEROGENEITY HILLSLOPE stability Saturated hydraulic conductivity Stochastic CONCEPTUALIZATION PORE-WATER pressure 

分 类 号：TU43[建筑科学—岩土工程]