Liquefaction Potential of Clayey Soils from Wenchuan Earthquake-Induced Landslides

2013 ◽  
Vol 639-640 ◽  
pp. 850-853
Author(s):  
Chuan Sheng Chen ◽  
Hong Bin Xiao
Keyword(s):  
Wenchuan Earthquake ◽  
Clayey Soil ◽  
Sandy Soils ◽  
Field Investigation ◽  
Clayey Soils ◽  
Liquefaction Potential ◽  
Ring Shear ◽  
Practical Engineering ◽  
Ring Shear Tests ◽  
Sliding Zone

It is commonly considered that liquefaction of sandy soils is the important reason for earthquake-induced landslides,but it has been reported liquefaction phenomenon can also occur in clayey soils in the recent research. In order to clarify liquefaction potential in clayey soils ,a deeper study was conducted on the basis of field investigation and a series of laboratory tests including undrained cyclic ring-shear tests on the clayey soil samples collected from the sliding zone of the Wenchuan earthquake-induced landslides. Results show that the liquefaction potential of clayey soils is lower than that of sandy soils given the same void ratio; the soil resistance to liquefaction rises with an increase in plasticity for clayey soils; It is useful to estimate the liquefaction potential of soil by means of plasticity index and the liquefaction potential of soil in practical engineering applications.

THE MECHANISM OF INITIATION AND MOTION OF THE RAPID AND LONG RUNOUT LANDSLIDES TRIGGERED BY THE 2008 WENCHUAN EARTHQUAKE

2015 ◽  
Vol 2 (3) ◽  
Author(s):  
Wang F.W ◽  
Sun P. ◽  
Cheng Q.G. ◽  
Fukuoka H.
Keyword(s):  
Wenchuan Earthquake ◽  
Disaster Mitigation ◽  
Great Earthquake ◽  
Shear Tests ◽  
Long Runout ◽  
Reconstruction Process ◽  
2008 Wenchuan Earthquake ◽  
The 2008 Wenchuan Earthquake ◽  
Ring Shear ◽  
Ring Shear Tests

The 2008 Wenchuan earthquake triggered many rapid and long runout landslides, which made great loss of property and human lives directly. It is very important to understand the mechanism of initiation and motion of the rapid and long runout landslides. In this paper, field investigations on some typical landslides are introduced at first, and then the ring shear tests for simulating the initiation and motion of the Donghekou landslide are presented in details. The real seismic wave monitored in Shifang station was applied in the simulation test for the landslide initiation, while three different conditions of water content (dry, partially saturated, and fully saturated) were applied for the samples in the simulation tests to simulate landslide motion. It was found that the valley water and groundwater played a key role in the long runout and rapid landslide motion process during the great earthquake. This makes the difference for where landslide occurred but stopped soon and where landslides moved for long distance with high speed and killed many people. For the purpose of disaster mitigation, we strongly suggest that:(a) Avoid locating village in the landslide motion path, because the same event will occur in the future; (b) Avoid locating village and people on the landslide, because the landslide will deform easily with the seismic activity; (c) The attention should also be paid for landslide and debris flow during the reconstruction process for disaster mitigation in long period. Keywords: Wenchuan Earthquake, rapid and long runout landslides, ring shear tests, initiation, motion

Physicochemical effect on shear strength characteristics of clayey soils based on ring-shear experiment

2020 ◽  
Vol 57 (12) ◽  
pp. 1820-1831
Author(s):  
Chuanqin Yao ◽  
Pan Chen ◽  
Tiantian Ma ◽  
Xiaolong Xia ◽  
Changfu Wei
Keyword(s):  
Shear Strength ◽  
Clayey Soil ◽  
Pore Solution ◽  
Solution Chemistry ◽  
Strength Characteristics ◽  
Clayey Soils ◽  
Residual Shear Strength ◽  
Pore Fluid Chemistry ◽  
Ring Shear ◽  
Physicochemical Effect

Pore fluid chemistry can significantly influence the shear strength characteristics of a clayey soil. To explore the underlying mechanisms, a series of ring shear experiments are performed on two natural clays, which represent two typical types of clayey minerals, i.e., expansive montmorillonitic clay and low-plasticity kaolinitic clay. The effects of pore solution concentrations on the shear strength of the two clays are experimentally characterized. It is shown that the shear strength of the expansive clay can be significantly influenced by the pore solution chemistry, whereas that of the low-plasticity clay proves to be relatively insensitive to it. To capture the main features of the shear strength behavior of clayey soils, the concept of intergranular stress, which is an extension of the Terzaghi’s effective stress to incorporate physicochemical effect, is introduced to interpret the experimental data. It is found that the evolution of residual shear strength can be very well characterized by using the intergranular stress, showing that the proposed intergranular stress formulation can be used alternatively to describe the stress state of clayey soils saturated with various pore solutions.

scholarly journals Rate Effects on Peak and Residual Strengths of Overconsolidated Clay in Ring Shear Tests

2021 ◽  
Author(s):  
Nguyen Thanh Duong ◽  
Motoyuki Suzuki
Keyword(s):  
Shear Strength ◽  
Residual Strength ◽  
Clayey Soil ◽  
Shear Displacement ◽  
Shear Tests ◽  
Shear Rates ◽  
Ring Shear ◽  
Wide Range ◽  
Rate Effects ◽  
Ring Shear Tests

Overconsolidated (OC) clay soil is widely distributed in landslide slopes. This soil is often fissured, jointed, contains slickensides, and is prone to sliding. Thus, the shear strength behavior of OC clayey soil is complicated and has received much attention in the literature and in practice in terms of evaluating and predicting landslide stability. However, the behavior of the shear strength of OC clayey soil at different shear rates, as seen in ring shear tests, is still only understood to a limited extent and should be examined further, especially in terms of the residual strength characteristics. In this study, a number of ring shear tests were conducted on kaolin clay at overconsolidation ratios (OCRs) ranging from 1 to 6 under different shear displacement rates in the wide range of 0.02 mm/min to 20.0 mm/min to investigate the shear behavior and rate dependency of the shear strength of OC clay. Variations in the cohesion and friction angles of OC clay under different shear rates were also examined. The results indicated that the rate effects on the peak strength of OC and normally consolidated (NC) clays are opposite at fast shear displacement rates. At the residual state, as with NC clay, the positive rate effect on the residual strength is also exhibited in OC clay, but at a lower magnitude. Regarding the shear strength parameters, the variations in the cohesion and friction angles of OC clay at different shear rates were found to be different at peak and residual states.

scholarly journals Modeling Granular Crushing in Ring Shear Tests: Experimental and Numerical Analyses

2006 ◽  
Vol 46 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Sebastian Lobo-Guerrero ◽  
Luise Vallejo
Keyword(s):  
Numerical Analyses ◽  
Shear Tests ◽  
Ring Shear ◽  
Ring Shear Tests

scholarly journals Application of large-scale ring shear tests to the analysis of tsunamigenic landslides at the Stromboli volcano, Italy

Landslides ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Daniela Boldini ◽  
Fawu Wang ◽  
Kyoji Sassa ◽  
Paolo Tommasi
Keyword(s):  
Large Scale ◽  
Stromboli Volcano ◽  
Shear Tests ◽  
Ring Shear ◽  
Ring Shear Tests
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