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 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.

Effect of gas pressure on municipal solid waste landfill slope stability

2021 ◽  
pp. 0734242X2110014
Author(s):  
Shi Shu ◽  
Yuping Li ◽  
Zhenming Sun ◽  
Jianyong Shi
Keyword(s):  
Slope Stability ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Slope Failure ◽  
Gas Production ◽  
Gas Pressure ◽  
Slope Instability ◽  
Combined Effects ◽  
Environmental Disaster ◽  
Operation And Management

Slope failure in municipal solid waste (MSW) landfills is a common environmental disaster that poses serious ecological and health risks. Landfill slope stability (SS) is sensitive to leachate levels and gas pressure (GP) caused by the degradation of organic material, but the extent of these combined effects remains poorly understood. In this study, a simplified landfill GP calculation method is presented and a circular slide method that considers the combined effects of leachate and GP is established. The results show that the landfill GP is mainly affected by the gas production rate, gas conductivity of the solid waste (SW), and landfill depth. The safety factor of landfill SS is also significantly lower when GP is considered. The distribution of GP is affected by the depth of the failure circle and SW. Landfill slope instability can be explained by localized damage caused by GP breakthrough of the filled SW. This study probably provides important guidance for the design, operation, and management of MSW landfills.

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 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.

scholarly journals Physical Model Experiments on Water Infiltration and Failure Modes in Multi-Layered Slopes under Heavy Rainfall

2020 ◽  
Vol 10 (10) ◽  
pp. 3458
Author(s):  
Junfeng Tang ◽  
Uchimura Taro ◽  
Dong Huang ◽  
Jiren Xie ◽  
Shangning Tao
Keyword(s):  
Slope Stability ◽  
Heavy Rainfall ◽  
Slope Failure ◽  
Failure Modes ◽  
Lateral Flow ◽  
Flow Diversion ◽  
Water Infiltration ◽  
Capillary Barrier ◽  
Model Experiments ◽  
Layered Slope

To assess the influence of an intermediate coarse layer on the slope stability during heavy rainfall, knowledge about water movement and how slope failure occurs is important. To clarify the characteristics of water infiltration in a multi-layered slope and assess its influence on the slope failure modes, eight groups of physical slope models were investigated. It was found that the unsaturated hydraulic conductivity in the coarse layer (5.54 × 10−6 cm/s) was much lower than that of the fine layer (1.08 × 10−4 cm/s), which resulted in the capillary barrier working at a lower water content. Intermediate coarse layers embedded between finer ones may initially confine the infiltration within the overlying finer layers, delaying the infiltration and eventually inducing a lateral flow diversion in the inclined slope. Two different failure modes occurred in the model experiments: surface sliding occurred at the toe in the single-layer slope group and piping occurred at the toe in the multi-layered slope as the rainfall water accumulated, was diverted along the interface, and then broke through in the downslope direction of the intermediate coarse layer. The lateral flow diversion caused by the capillary barrier and the tilt angle may be the major factors influencing the difference of the failure modes. The result also revealed that the coarser layers may have negative effects on the slope stability.

scholarly journals The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 73
Author(s):  
Panagiotis Sitarenios ◽  
Francesca Casini
Keyword(s):  
Analytical Solution ◽  
Slope Stability ◽  
Slope Failure ◽  
Failure Modes ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Three Dimensional ◽  
Stability Limit ◽  
Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

Analysis of the Slope Stability in the Heavy Rainfall Condition

2014 ◽  
Vol 501-504 ◽  
pp. 8-11
Author(s):  
Jing Sheng Bian ◽  
Chao Sheng Bian ◽  
Zhi Ming Zhu
Keyword(s):  
Slope Stability ◽  
Heavy Rainfall ◽  
Strength Loss ◽  
Soil Parameters ◽  
Actual Situation ◽  
Earthquake Disaster ◽  
Rainfall Condition ◽  
Scene Investigation

Rainfall is one of the most important factors of the slope stability. After the "5.12" earthquake, there are a large number of loose solid produced by earthquake on the mountain, which leads to the soils strength loss in the earthquake disaster zones. and induces landslides and collapses easily in the heavy rainfall condition. The soil parameters obtained from the tests, the scene investigation of the Erman mountain landslide of Han Yuan County, the new developed control of ArcGIS to obtain intuitive landslide warning graphs have been carried out. Results show that the picture of hazard grade is consistent with the actual situation of landslide on Erman mountain. It will provide a scientific way to analyze the influence of heavy rainfall on slope stability.

scholarly journals The contribution of chestnut coppice forests on slope stability in abandoned territory: a case study

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Chiara Bassanelli ◽  
Gian Battista Bischetti ◽  
Enrico Antonio Chiaradia ◽  
Lorenzo Rossi ◽  
Chiara Vergani
Keyword(s):  
Slope Stability ◽  
Root Diameter ◽  
Slope Instability ◽  
Economic Changes ◽  
Sweet Chestnut ◽  
Forestry Practices ◽  
Short Rotation ◽  
Root Cohesion ◽  
Chestnut Coppice ◽  
High Level

Sweet chestnut has been for many centuries fundamental for the Italian mountainous economies, where this kind of forest was traditionally managed in short rotation to rapidly produce wood biomass. Due to the social and economic changes, which made such management scheme unprofitable especially on the steep and remote slopes, such practice has been mainly abandoned and most of chestnut forests became over-aged and very dense, causing an increase of localized slope instability. In this work the effect of over-aged chestnut coppice forests on shallow landslides was analysed by evaluating and comparing mechanical contribution to soil shear strength provided by root systems in differently managed chestnut stands. The study area is located in Valcuvia (Lombardy Prealps) where three different stands, one managed and the others abandoned (over 40 year aged), established on cohesionless slopes (quaternary moraine deposits) were chosen having care to select homogeneous conditions in terms of substrate, aspect and elevation. As slope steepness strongly affects forestry practices and steeper stands are more frequently abandoned, the considered stands have different terrain inclination, 30-35° in abandoned stands and 13° in the managed one. Slope stability of the three sites was evaluated by applying the infinite slope approach accounting for additional root cohesion and tree surcharge. Additional root cohesion was estimated through the Fiber Boundle Model approach by collecting roots in the field and measuring their resistance in laboratory, and by measuring root diameter and density distribution with depth by the wall technique method. The results, as expected, showed that over-aging does not affect root mechanical properties, whereas it significantly affects root distribution within the soil. In terms of slope stability, when steepness exceeds 35°, instability phenomena can be triggered by high level of soil saturation in the case of over-aged forests, whereas for less extreme cases chestnut forests, although over-aged, are able and fundamental to guarantee safe conditions.

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