scholarly journals Movement of the Donglingxin landslide, China, induced by reservoir inundation and rainfall

2015 ◽  
Vol 3 (4) ◽  
pp. 2537-2564
Author(s):  
J. Yu ◽  
R. B. Wang ◽  
W. Y. Xu ◽  
L. Yan ◽  
J. C. Zhang ◽  
...  

Abstract. With numerous high mountains, deep valleys and turbulent rivers, many hydropower plants have been constructed in the south-west China. Reservoir bank slopes are very common in this area, these slopes are widespread and quite often involved in deformation that can result in serious damage and casualties. In case of the Donglingxin landslide, for an in-depth study of processes that can trigger these events, the deformation characteristics and the failure mechanisms of the slope were performed on a detail scale, based on an intensive monitoring of rainfall events, reservoir level fluctuation and groundwater movement. The deformation of the upper part of slope is mainly induced by rainfall events, reservoir level fluctuation affects the deformation of the lower part of slope. The increase of pore water pressure may result in the failure of slope. The filed investigation suggest that the slope is unstable. Drainages is the only stabilization measure which can be implemented, due to very complex geological and geomorphology condition.

2013 ◽  
Vol 368-370 ◽  
pp. 1697-1700
Author(s):  
Long Zhang ◽  
Xue Wen Lei ◽  
Qing Shang Meng

Based on the characteristics of frequent land subsidence events caused by groundwater level fluctuation in coastal cities in China and studying on the quaternary sedimentary soft clay in Shanghai, the effects of groundwater level fluctuation on the deformation of soft clay is simulated by Geo-Studio finite element software. It has summarized the law of deformation, effective stress with the change of groundwater level fluctuation, especially the process of dissipation of pore water pressure with the groundwater level fluctuation. The low can be sued as a reference for similar engineering and land subsidence prevention.


2003 ◽  
Vol 40 (5) ◽  
pp. 1012-1032 ◽  
Author(s):  
Illias Tsaparas ◽  
Harianto Rahardjo ◽  
David G Toll ◽  
Eng-Choon Leong

This paper presents the analysis of a 12 month long field study of the infiltration characteristics of two residual soil slopes in Singapore. The field measurements consist of rainfall data, runoff data of natural and simulated rainfall events, and pore-water pressure changes during infiltration at several depths and at several locations on the two slopes. The analysis of the field measurements identifies the total rainfall and the initial pore-water pressures within the two slopes as the controlling parameters for the changes in the pore-water pressures within the slopes during infiltration.Key words: infiltration, rainfall, runoff, pore-water pressure, field measurements.


2012 ◽  
Vol 170-173 ◽  
pp. 1938-1943 ◽  
Author(s):  
Jin Bing Wei ◽  
Hong Chun Zheng ◽  
Yu Long Cui

Reservoir landslide is a severe geological hazard which is caused by the hydrodynamic change due to rainfall and fluctuation of reservoir level. The hydrodynamic change and its influence on landslide stability of Qianjiangping landslide before and after impoundment of the Three Gorges Reservoir are studied combining with its hydrogeological structure. There are two relatively independent hydrogeological units on both sides of the slipband. Before impoundment, the outlet of groundwater under slipband is above the river level, the supply and discharge of groundwater is in equilibrium, and the excess pore water pressure at the bottom of slipband is smaller or not exists. After impounding, the outlet of groundwater is under reservoir level and the discharge of groundwater is hindered, so the excess pore water pressure at the bottom of slipband will rises and the safety factor of the landslide will decreases. Combing with other factors, the stability of the landslide will further decreases and lead to landslide failure finally.


2013 ◽  
Vol 184 (1-2) ◽  
pp. 171-181
Author(s):  
Hugues Georges Rameau ◽  
Claude Prepetit ◽  
Jean-Claude Verbrugge

Abstract Water precipitation in road slopes, pavements, and shoulders may cause disturbances such as erosion, increase of the water table level, decrease of the carriageway bearing capacity, and so on. Roads are normally equiped with drainage systems that are sized and implemented in accordance with the rules of art. These equipments are used for the collection and quick evacuation of water precipitation estimated on the basis of the return period that is taken into account. Despite that, rainwater can still infiltrate unprotected cut or fill slopes, and pavements for repeated and intense rainfalls, which may cause a raise in pore-water pressure and a decrease of the factor of safety of road slopes. Using laboratory rainfall simulation techniques, infiltration measurements were made on intact samples to determine with respect to soil properties, how cumulative rainfalls cause decrease in apparent cohesion and lead to slope failure. This paper focuses on describing the relationship between the rainfall characteristics, the changes in soil water profile, and the changes in apparent cohesion for sandy clay samples collected on the national road RN3 located in Haiti. For a set of consecutive rainfall events at around an interval of 24 hours, the results prove that when wetting front depth approaches 2 meters or more, the risk of landslide is proportionally high in a soil with apparent cohesion (Ca) initially high and an effective cohesion (c′) relatively low.


Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wen Nie ◽  
Yong-chang Liang ◽  
Lin Chen ◽  
Wei Shao

A multitank model experiment is employed to simulate the river-groundwater interaction under rainfall events. These experiments involve coarse and fine materials and rainfall events of 45 and 65 mm/hr. We developed a modified tank model for estimation of the groundwater table and river levels in these experiments. Parameter training of our tank model includes two algorithms: (i) the nonincremental learning algorithm-based model can predict the pore water pressure (PWP) in a slope and river under a 65 mm/hr rainfall event (coarse material) with Nash–Sutcliffe efficiency (NSE) = 0.427 and −0.909 and (ii) the incremental learning algorithm-based model can predict the PWP in a slope and river with NSE = 0.994 and 0.995. Then, the river-groundwater interaction was reproduced by a numerical case. The results of the deterministic method of the numerical case and optimized method of the modified tank model matched well.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-13
Author(s):  
Alfrendo Satyanaga Nio

Field measurements of residual soil slopes are valuable for the assessment of slope stability during rainfall. Several residual soil slopes, which are predominantly unsaturated due to their deep groundwater table, were instrumented with tensiometer and rainfall gauge in order to study the response characteristics of the slopes during rainfall. Comprehensive field measurement results involving a large number of rainfall events are presented in the paper. The results show that the pore-water pressures in all instrumented slopes increased in a similar fashion during rainfall, but at different magnitudes depending on soil type. The pore-water pressure response characteristics can then be used to estimate the variation in factor of safety of the slope during rainfall.


Author(s):  
Trần Thanh Nhàn

In order to observe the end of primary consolidation (EOP) of cohesive soils with and without subjecting to cyclic loading, reconstituted specimens of clayey soils at various Atterberg’s limits were used for oedometer test at different loading increments and undrained cyclic shear test followed by drainage with various cyclic shear directions and a wide range of shear strain amplitudes. The pore water pressure and settlement of the soils were measured with time and the time to EOP was then determined by different methods. It is shown from observed results that the time to EOP determined by 3-t method agrees well with the time required for full dissipation of the pore water pressure and being considerably larger than those determined by Log Time method. These observations were then further evaluated in connection with effects of the Atterberg’s limit and the cyclic loading history.


1981 ◽  
Vol 27 (97) ◽  
pp. 503-505 ◽  
Author(s):  
Ian J. Smalley

AbstractRecent investigations have shown that various factors may affect the shear strength of glacial till and that these factors may be involved in the drumlin-forming process. The presence of frozen till in the deforming zone, variation in pore-water pressure in the till, and the occurrence of random patches of dense stony-till texture have been considered. The occurrence of dense stony till may relate to the dilatancy hypothesis and can be considered a likely drumlin-forming factor within the region of critical stress levels. The up-glacier stress level now appears to be the more important, and to provide a sharper division between drumlin-forming and non-drumlin-forming conditions.


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