scholarly journals The indoor model test of loess landslide instability induced by artificial rainfall in Tianshui area

2019 ◽  
Vol 79 ◽  
pp. 02011
Author(s):  
Jing Meng ◽  
Peng Xin ◽  
Chengjun Feng ◽  
Peng Zhang ◽  
Chengxuan Tan ◽  
...  
Keyword(s):  
Slope Stability ◽  
Model Test ◽  
Heavy Rainfall ◽  
Rainfall Intensity ◽  
Infiltration Rate ◽  
Gansu Province ◽  
Slope Instability ◽  
Loess Landslide ◽  
Light Rain ◽  
Loess Slope

The loess slope stability is influenced by rainfall and other factors. In order to find out the mechanism of loess slope instability, especially the influence of rainfall intensity and slope, the indoor model test was performed to study rainfall-induced loess landslide in Tianshui area, Gansu Province. Slope gradient and rainfall intensity are considered as variables, and their influence on slope stability are analyzed based on monitoring of soil suction and water content, and slope deformation process. The results show that the higher the rainfall intensity, the faster the infiltration rate. The volumetric moisture rate under heavy rainfall is more than 10% under small rainfall intensity. The steeper the slope, the lower the infiltration rate for the slope model. The loess slope is prone to overall sliding from bottom to top under the heavy rainfall, and easily lead to down-top retrogressive landslide under light rain.

The Records of Slope Reinforcement Engineering in a Loess City

2012 ◽  
Vol 226-228 ◽  
pp. 1365-1370
Author(s):  
Qi Xia Liu ◽  
Liang Fan
Keyword(s):  
Slope Stability ◽  
Good Practice ◽  
Stability Study ◽  
Practice Effect ◽  
Slope Instability ◽  
Loess Landslide ◽  
Loess Area ◽  
Loess Slope ◽  
Geological Conditions ◽  
Reinforcement Measures

This article selected a typical loess slope engineering as the research object, and through the characteristics of loess landslide, landslide environmental geological conditions, the formation mechanism of the landslide study of the loess area of urban slope instability factors, loess slope stability of the calculation method and reinforcement measures. This paper adopts the theory of Morgenstern-Price to analyzing the stability of the slope, referencing with Sweden finite slice method, Simplified Bishop method, Simplify Janbu method. The reinforcement adopts the technology of possessed anchor to disposing the loess slope, and has good Practice effect. The loess slope stability study area has a large reference.

The Records of Slope Reinforcement Engineering in a Loess City

2012 ◽  
Vol 190-191 ◽  
pp. 1227-1233
Author(s):  
Qi Xia Liu ◽  
Liang Fan
Keyword(s):  
Slope Stability ◽  
Stability Study ◽  
Slope Instability ◽  
Loess Landslide ◽  
Loess Area ◽  
Loess Slope ◽  
Slope Engineering ◽  
Slope Reinforcement ◽  
Geological Conditions ◽  
Reinforcement Measures

This article selected a typical loess slope engineering as the research object, and through the characteristics of loess landslide, landslide environmental geological conditions, the formation mechanism of the landslide study of the loess area of urban slope instability factors, loess slope stability of the calculation method and reinforcement measures, the loess slope stability study area has a large reference.

scholarly journals Physical Model Test Study of the Relationship Between Loess Landslide and Rainfall

2015 ◽  
Vol 9 (1) ◽  
pp. 968-973
Author(s):  
Jiaming Han
Keyword(s):  
Moisture Content ◽  
Safety Factor ◽  
Model Test ◽  
Rainfall Intensity ◽  
Unit Weight ◽  
Loess Landslide ◽  
Rainfall Duration ◽  
Loess Slope ◽  
Test Study ◽  
The Relationship

Launching research has important theoretical and practical value on model test study of the relationship between loess landslide and rainfall. According to the monitoring data of model test of loess slope, formula expression of safety factor has been fitted on landslide. Firstly, the loess slope damage process was monitored at different rainfall intensity, rainfall duration through rainfall landslide model tests. Secondly, some parameters were determined by laboratory tests, such as loess unit weight, moisture content, shear strength. Thirdly, the relational expression was fitted between moisture and rainfall intensity, rainfall duration, cohesion, internal friction angle, unit weight. Finally, moisture content being an intermediate variable, the expression was got between landslide safety factor and rainfall intensity, rainfall duration.

scholarly journals Characteristics of ground motion and threshold values for colluvium slope displacement induced by heavy rainfall: a case study in northern Taiwan

2016 ◽  
Vol 16 (6) ◽  
pp. 1309-1321 ◽  
Author(s):  
Ching-Jiang Jeng ◽  
Dar-Zen Sue
Keyword(s):  
Slope Stability ◽  
Heavy Rainfall ◽  
Slope Failure ◽  
Drainage System ◽  
Threshold Value ◽  
Slope Instability ◽  
Disaster Prevention ◽  
Strain Gages ◽  
Slope Displacement ◽  
Northern Taiwan

Abstract. The Huafan University campus is located in the Ta-lun Shan area in northern Taiwan, which is characterized by a dip slope covered by colluvium soil of various depths. For slope disaster prevention, a monitoring system was constructed that consisted of inclinometers, tiltmeters, crack gages, groundwater level observation wells, settlement and displacement observation marks, rebar strain gages, concrete strain gages, and rain gages. The monitoring data derived from hundreds of settlement and displacement observation marks were analyzed and compared with the displacement recorded by inclinometers. The analysis results revealed that the maximum settlement and displacement were concentrated on the areas around the Hui-Tsui, Zhi-An, and Wu-Ming buildings and coincided with periods of heavy rainfall. The computer program STABL was applied for slope stability analysis and modeling of slope failure. For prevention of slope instability, a drainage system and tieback anchors with additional stability measures were proposed to discharge excess groundwater following rainfall. Finally, threshold value curves of rainfall based on slope displacement were proposed. The curves can be applied for predicting slope stability when typhoons are expected to bring heavy rainfall and should be significant in slope disaster prevention.

scholarly journals Spatial and Temporal Evolution of the Infiltration Characteristics of a Loess Landslide

2020 ◽  
Vol 9 (1) ◽  
pp. 26 ◽  
Author(s):  
Dongdong Yang ◽  
Haijun Qiu ◽  
Yanqian Pei ◽  
Sheng Hu ◽  
Shuyue Ma ◽  
...  
Keyword(s):  
Slope Stability ◽  
Slope Failure ◽  
Temporal Evolution ◽  
Infiltration Rate ◽  
Middle Part ◽  
Loess Landslide ◽  
Infiltration Rates ◽  
Disturbed Soil ◽  
Landslide Body ◽  
Over Time

Infiltration plays an important role in influencing slope stability. However, the influences of slope failure on infiltration and the evolution of infiltration over time and space remain unclear. We studied and compared the infiltration rates in undisturbed loess and disturbed loess in different years and at different sites on loess landslide bodies. The results showed that the average initial infiltration rate in a new landslide body (triggered on 11 October 2017) were dramatically higher than those in a previous landslide body (triggered on 17 September 2011) and that the infiltration rates of both landslide types were higher than the rate of undisturbed loess. The initial infiltration rate in the new landslide body sharply decreased over the 4–5 months following the landslide because of the appearance of physical crusts. Our observations indicated that the infiltration rate of the disturbed soil in a landslide evolved over time and that the infiltration rate gradually approached that of undisturbed loess. Furthermore, in the undisturbed loess, both the initial and quasi-steady infiltration rates were slightly higher in the loess than in the paleosol, and in the previous landslide body, the infiltration rate was highest in the upper part, intermediate in the middle part, and lowest in the lower part. This study can help us to better understand the evolution process of infiltration in undisturbed loess, previous landslides, and new landslides.

Study on Slope Instability Disciplinarian on the Condition of Rainfall

2013 ◽  
Vol 353-356 ◽  
pp. 654-658
Author(s):  
Nan Tong Zhang ◽  
Xiao Chun Zhang ◽  
Hua Rong Wang ◽  
Chen Yan
Keyword(s):  
Slope Stability ◽  
Tensile Stress ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Road Construction ◽  
Slope Instability ◽  
Slope Surface ◽  
Large Area ◽  
Break Zone

Slope stability is one of the problems of road construction which should be faced with and solve. Rainfall can reduce the shear strength of slope soil and raise the underground water level which can lead to increase slope soil pore water pressure. The influence of rainfall infiltration on slop is mainly to change the slope seepage field, increase dynamic and hydrostatic water load on the slope soil and decrease of soil shear parameters. More abundant rainfall of typhoon area could make the road slope stability more fragile. Based on Matoushan Mountain along 104 state roads in Taizhou city, Zhejiang province, slope instability disciplinarian on the condition of rainfall is studied using the method of numerical simulation in this paper. As the results, when the rainfall intensity was 0.006 m/h and continuous rain was in 24 hours, the slope surface compressive stress tends to zero which began to appear tensile stress area on the condition of self-weight. And when the rainfall intensity was 0.01 m/h and continuous rain was in 24 hours, the large area of the slope surface was tensile stress area which means to appear break zone in slope surface and likely to landslide at the same time.

scholarly journals Effects of heavy rainfall on the slope stability – A case study on Imogiri Cemetery: The graveyard complex of Mataram Royal Kings

2020 ◽  
Vol 200 ◽  
pp. 02006
Author(s):  
Shofwatul Fadilah ◽  
Djoko Luknanto
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Heavy Rainfall ◽  
Soil Mechanics ◽  
Soil Characteristics ◽  
Soil Samples ◽  
Slope Instability ◽  
Environmental Engineering ◽  
Common Cause

Rainfall is the most common cause of landslides in Indonesia. On March 17, 2019, a landslide occurred in the Imogiri Cemetery, Mataram Royal Kings Graveyard Complex. It was expected to have been triggered by heavy rainfall of 148 mm d–1 intensity. This research aims to determine the effect of rainfall on the slope stability on the landslide at the Imogiri Cemetery. The study was carried out by slope stability modelling using Geostudio software. Rainfall information and soil characteristics data obtained from testing soil samples in the Soil Mechanics Laboratory, Civil and Environmental Engineering, Universitas Gadjah Mada, were used as input on the software. The output of the analysis is the factor of safety (FS) value, defined as the ratio of the shear strength to the shear stress. Without the rains, the FS value is about 2.44, which means the slope stability is stable. After heavy rainfall, the FS value decreased to 1.209 at the end of the simulation, which indicates happen the slope instability. Based on the simulation, the FS value depends on the volume of water content and hydraulic conductivity of the soil. Result of this study shows that heavy rainfall can trigger slope instability in the Imogiri Cemetery.

scholarly journals Characteristics of ground motion and threshold values for colluvium slope displacement induced by heavy rainfall: a case study in northern Taiwan

2016 ◽  
Author(s):  
C.-J. Jeng ◽  
D.-Z. Sue
Keyword(s):  
Slope Stability ◽  
Heavy Rainfall ◽  
Slope Failure ◽  
Drainage System ◽  
Threshold Value ◽  
Slope Instability ◽  
Disaster Prevention ◽  
Strain Gages ◽  
Slope Displacement ◽  
Northern Taiwan

Abstract. The Huafan University campus is located in the Ta-Lun Shan area in northern Taiwan, which is characterized by a dip-slope covered by colluvium soil of various depths. For slope disaster prevention, a monitoring system was constructed that consisted of inclinometers, tiltmeters, crack gages, groundwater level observation wells, settlement and displacement observation marks, rebar strain gages, concrete strain gages, and rain gages. The monitoring data derived from hundreds of settlement and displacement observation marks were analyzed and compared with the displacement recorded by inclinometers. The analysis results revealed that the maximum settlement and displacement were concentrated on the areas around the Hui-Tsui, Zhi-An, and Wu-Ming Buildings and coincided with periods of heavy rainfall. The computer program STABL was applied for slope stability analysis and modeling of slope failure. For prevention of slope instability, a drainage system and tieback anchors with additional stability measures were proposed to discharge excess groundwater following rainfall. Finally, threshold value curves of rainfall based on slope displacement were proposed. The curves can be applied for predicting slope stability when typhoons are expected to bring heavy rainfall and should be significant in slope disaster prevention.

scholarly journals Infiltration, seepage and slope instability mechanisms during the 20–21 November 2000 rainstorm in Tuscany, central Italy

2006 ◽  
Vol 6 (6) ◽  
pp. 1025-1033 ◽  
Author(s):  
V. Tofani ◽  
S. Dapporto ◽  
P. Vannocci ◽  
N. Casagli
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Factor Of Safety ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Critical Time ◽  
Infiltration Rate ◽  
Slope Instability ◽  
Storm Event ◽  
Surface Boundary

Abstract. On 20–21 November 2000, a storm of high intensity, with a estimated return period of more than 100 years, triggered over 50 landslides within the province of Pistoia in Tuscany (Italy). These failures can be defined as complex earth slides- earth flows. One of the documented landslides has been investigated by modelling the ground water infiltration process, the positive and negative pore water pressure variations and the effects of these variations on slope stability during the rainfall event. Morphometric and geotechnical analyses were carried out through a series of in-situ and laboratory tests, the results of which were used as input for the modelling process. The surface infiltration rate was initially simulated using the rainfall recorded at the nearest raingauge station. Finite element seepage analysis for transient conditions were then employed to model the changes in pore water pressure during the storm event, using the computed infiltration rate as the ground surface boundary condition. Finally, the limit equilibrium slope stability method was applied to calculate the variations in the factor of safety during the event and thereby determine the critical time of instability. For the investigated site the trend of the factor of safety indicates that the critical time for failure occurs about 18 h after the storm commences, and highlights the key role played by the soil permeability and thickness in controlling the response in terms of slope instability.

scholarly journals Analysis of infiltration, seepage processes and slope instability mechanisms during the November 2000 storm event in Tuscany

2005 ◽  
Vol 2 ◽  
pp. 301-304
Author(s):  
V. Tofani ◽  
S. Dapporto ◽  
P. Vannocci ◽  
N. Casagli
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Factor Of Safety ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Critical Time ◽  
Infiltration Rate ◽  
Slope Instability ◽  
Storm Event ◽  
Surface Boundary

Abstract. On the days 20-21 November 2000, a storm of exceptional intensity triggered over 50 landslides within the province of Pistoia in Tuscany (Italy). These failures are mostly of complex type, originating as rotational or translational landslides, and transforming into flows. Two of these landslides were investigated in this paper by modelling the ground water infiltration process, the pore water pressure variations, both positive and negative, and the effects of these variations on slope stability during the rainfall event. Morphometric and geotechnical analyses were carried out for both sites through a series of in-situ and laboratory tests, the results of which were used as input for the modelling process. In a first step the surface infiltration rate was simulated using a modified Chu (1978) approach for the Green and Ampt (1911) equations in case of unsteady rainfall together with a surficial water balance. A finite element seepage analysis for transient conditions was then employed to model the changes in pore water pressure during the event, using the computed infiltration rate as the ground surface boundary condition. Finally, once again using the data from the previous step as input, the limit equilibrium Morgenstern-Price (1965) slope stability method was applied to calculate the variations in the factor of safety during the event and thereby determine the most critical time of instability. In both sites this method produced a curve for the factor of safety that indicated that the most critical time for failure occurred a few hours after the peak of rainfall.

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