scholarly journals Mechanistic Investigation of Typical Loess Landslide Disasters in Ili Basin, Xinjiang, China

2021 ◽  
Vol 13 (2) ◽  
pp. 635
Author(s):  
Maoguo Zhuang ◽  
Wenwei Gao ◽  
Tianjie Zhao ◽  
Ruilin Hu ◽  
Yunjie Wei ◽  
...  
Keyword(s):  
Leading Edge ◽  
Slope Surface ◽  
Loess Landslide ◽  
Geological Investigation ◽  
Fluvial Erosion ◽  
Movement Characteristics ◽  
Mechanistic Investigation ◽  
Loess Landslides ◽  
Xinjiang Autonomous Region ◽  
Landslide Disaster

In the period from 2010 to 2018, a total of 302 geological disasters occurred in the Xinjiang Autonomous Region, China, of which 136 occurred in the Ili Basin. Compared with those in other regions, the loess landslides in the Ili Basin are strongly influenced by the seasonal freeze–thaw effect. Taking the No. 2 Piliqinghe landslide as an example and based on the field geological investigation, it was found in the present study that the main triggering factors of this landslide were the snowmelt erosion of the slope toe and meltwater infiltration into the trailing edge of the slope. The mechanism of loess landslide instability was studied using numerical simulation. The results showed that (1) the Piliqinghe landslide disaster was formed through a process composed of the local sliding of the leading edge → the creep sliding and tension cracking of the slope surface → the overall sliding stage; (2) the infiltration of snowmelt was the direct cause of the landslide formation; (3) the fluvial erosion and softening caused the soil of the slope toe to slide. The results can be used as a reference for the analysis of the disaster mechanism and movement characteristics of similar loess landslides.

Characteristic and Stability Analysis for Loess Seismic Landslide in Valley City

2012 ◽  
Vol 594-597 ◽  
pp. 1856-1863
Author(s):  
Wang Nai ◽  
Lan Min Wang ◽  
Zhong Xia Yuan ◽  
Wang Qian
Keyword(s):  
Scientific Basis ◽  
Earthquake Risk ◽  
Disaster Prevention ◽  
Loess Landslide ◽  
Loess Area ◽  
Loess Landslides ◽  
Basic Characteristics ◽  
Seismic Landslide ◽  
Landslide Disaster ◽  
Valley City

In the light of heavy seismic landslide disasters in the valley city of loess area, 104 typical loess landslides caused by the 1654 Tianshui(Ms 8.0), 1718 Tongwei(Ms 7.5) and 1920 Haiyuan(Ms 8.5) earthquakes were studied, main landslide type and basic characteristics of seismic landslide in the valley city were analyzed. The landslides in the valley city of loess area are divided into three types: homogeneous loess landslide, loess interface landslide and loess-mudstone cutting layer landslide. Through the investigation and analysis of earthquake risk, the suggestion about the 22 dangerous landslides in Tianshui is given. The study is expected to supply scientific basis for seismic landslide disaster prevention and reduction in valley city of loess area.

scholarly journals The loess landslide on 15 march 2019 in Shanxi Province, China

Landslides ◽  
2020 ◽  
Vol 17 (3) ◽  
pp. 677-686
Author(s):  
Wenhui Shi ◽  
Yanrong Li ◽  
Weiwei Zhang ◽  
Jin Liu ◽  
Shengdi He ◽  
...  
Keyword(s):  
Lessons Learned ◽  
Shanxi Province ◽  
Deep Soil ◽  
Weak Zone ◽  
Loess Landslide ◽  
Perched Water ◽  
Landslide Event ◽  
Loess Landslides ◽  
Triggering Mechanisms ◽  
Mass Volume

AbstractOn 15 March 2019, a fatal deep-seated landslide occurred at the village of Zaoling in Xiangning County of Shanxi Province, China. Extending to an area of about 120 m by 85 m, with an estimated displaced mass volume of 72,000 m3, the landslide left 20 people dead, 13 injured, and 8 buildings destroyed. There were no precursory signals prior to the event, and usual triggering mechanisms for a landslide were absent. Investigation conducted immediately after the incident revealed that the landslide was initiated in a 1.0 to 1.5-m thick-softened layer located at 40 m depth along the contact between the loess and interbedded paleosol layer. This softened layer was highly saturated due to the perched water on top of the relatively impervious paleosol layer and became a critical weak zone since the shear strength of loess is very sensitive to water content. We suggest that the perched water originated from extensive long-term unsaturated seepage of rainwater and local rapid percolation along preferential channels such as sinkholes and root network. The Zaoling landslide confirms that unlike most landslides in non-loess areas, loess landslides can occur without identifiable triggering events. They can result from gradual build up of instability due to slow (in the span of hundred years) accumulation of deep soil water. Based on the lessons learned from this landslide event, suggestions are given for the planning of urban and rural development in loess areas. Due to the fact that the process leading to the development of such a landslide is largely concealed, further research should be aimed at gaining a more thorough understanding of the mechanism of this landslide type.

scholarly journals Hydrological and mechanical properties of loess landslides under different vegetation restoration types

2021 ◽  
pp. 795-801
Author(s):  
Lei Shi ◽  
Zhongzheng Liu ◽  
Liangyan Yang
Keyword(s):  
Mechanical Properties ◽  
Soil Samples ◽  
Vegetation Restoration ◽  
Saturated Soil ◽  
Vegetation Coverage ◽  
Natural Soil ◽  
Stability Prediction ◽  
Loess Landslide ◽  
Landslide Stability ◽  
Loess Landslides

Loess landslide is a common geological disaster in northern Shaanxi, which seriously affects people's life and property safety and social and economic development. The research on vegetation restoration types and hydrological and mechanical properties of loess landslides can provide basic data support for landslide stability prediction, and further provide reference for landslide prevention and treatment. In the present study, the loess landslide point of Zhang Zi Gou in Gan Quan County, Yan’an City was taken as the research object. On the basis of the existing natural condition data, the basic physical and mechanical properties and hydrological characteristics were obtained by collecting field landslide soil samples for indoor experimental analysis. The indoor analysis shows that the landslide is mainly distributed in dry land, medium coverage and low coverage grassland, indicating that the surface vegetation coverage can affect the stability of landslide. The worse the vegetation coverage, the more landslides occur. The void ratio and porosity of landslide soil decrease with the increase of dry density. The cohesion of natural soil is obviously higher than that of saturated soil, and the internal friction angle of natural soil is slightly lower than that of saturated soil. In general, due to the influence of water content, the shear strength of natural soil samples is higher than that of saturated soil samples. Therefore, in order to improve the accuracy of prediction and early warning system, it is necessary to consider the response of hydrological and mechanical properties of loess to vegetation restoration. The results provide basic data support for the establishment of loess landslide stability prediction system and provide reference for geological disaster management. Bangladesh J. Bot. 50(3): 795-801, 2021 (September) Special

scholarly journals The Influence of Regional Freeze–Thaw Cycles on Loess Landslides: Analysis of Strength Deterioration of Loess with Changes in Pore Structure

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3047
Author(s):  
Zuyong Li ◽  
Gengshe Yang ◽  
Hui Liu
Keyword(s):  
Pore Structure ◽  
Triaxial Compression ◽  
Strength Loss ◽  
Loess Landslide ◽  
Strength Deterioration ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Loess Landslides ◽  
The Stability

The loess landslide in Gaoling District of Xi’an, Shaanxi in China is closely related to the seasonal freeze–thaw cycle, which is manifested by the destruction of pore structure and strength deterioration of the loess body under freeze–thaw conditions. In order to study the relationship between macro-strength damage and pore structure deterioration of saturated loess under freeze–thaw conditions and its influence on the stability of landslides, this paper explores the effect of freeze–thaw cycles on the strength of saturated undisturbed loess through triaxial compression test, and explores the micro-microstructure changes of saturated undisturbed loess through scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR). This is to analyze the evolution of the pore structure and strength loss evolution of saturated loess during the freeze–thaw process, and to describe the freeze–thaw damage of saturated undisturbed loess through the change of porosity and strength deterioration. Then, the internal correlation expression between the porosity change and the strength degradation is established to realize the verification analysis of the test data based on the correlation model. The research results show that: (1) As the number of freeze–thaw cycles increases, the peak strength loss rate gradually increases, and the strength deterioration of saturated loess becomes more and more obvious. (2) The freeze–thaw cycle will lead to the development of pores and cracks in the sample, accompanied by the generation of new cracks, which will cause the deterioration of the pore structure of the sample as a whole. (3) The response of strength damage and porosity deterioration of saturated undisturbed loess is roughly similar under the freeze–thaw cycle. The change in porosity can be measured to better reflect the strength deterioration of saturated loess. Therefore, the change of pore structure of undisturbed loess under freeze–thaw cycle conditions is tested by field sampling and indoor tests to reflect the phenomenon of strength deterioration, thereby analyzing the stability of loess slopes.

Engineering Loess Landslides Types and some Research Thoughts

2011 ◽  
Vol 90-93 ◽  
pp. 1291-1294
Author(s):  
Dong Qi Tang ◽  
Jian Bing Peng
Keyword(s):  
Economic Development ◽  
Water Activity ◽  
Underground Mining ◽  
Mechanical Vibration ◽  
Mining Activities ◽  
Loess Landslide ◽  
Loess Area ◽  
Vibration Effect ◽  
Loess Landslides ◽  
Main Effects

With the rapid economic development of loess area, engineering loess landslides have become a serious danger to loess area people. It is an important engineering geological problem. Through making classify narrate to the harmful of engineering loess landslides. The main effects of engineering loess landslides are divided into four types. First type is human water activity cause loess landslides. Second is load and unload activities cause the loess landslides. Third is mechanical vibration effect inducing loess landslide. Fourth, loess landslides are induced by underground mining activities. Presents the performance characteristics and take conceive of engineering loess landslides to further research advances.

Stability Analysis of Loess Landslides Induced by Irrigation

2014 ◽  
Vol 716-717 ◽  
pp. 395-399 ◽  
Author(s):  
Zhao Duan ◽  
Zi Guang He ◽  
Hong Zhou Lin
Keyword(s):  
Stability Analysis ◽  
Groundwater Level ◽  
Shaanxi Province ◽  
Dynamic Equations ◽  
Safety Factors ◽  
Loess Landslide ◽  
Shearing Strength ◽  
Loess Landslides ◽  
The Stability ◽  
Sliding Force

This passage picks up the case of the loess landslide in Zhangcunwan, Jingyang county, Shaanxi province for the research of the formation mechanism and stability analysis of loess under the condition of irrigation, which raises the dynamic equations of loess landslides induced by irrigation,and applies the equations into the case in the landslide in zhangcunwan. Besides,the passage has given the trajectory equations in the landslide in Zhangcunwan and verifies, as a consequence ,the results can be calculated accurately and it generally tallies with the actual one. The internal soil anti-shearing strength and the safety factors will decrease when the groundwater level rises 1m per case till the stabilizing force decreases by the soil sliding force when the whole slope if in the state of limited equilibrium.As the contents of irrigation rising continuously of the water level, the anti-shearing strength will be outdone by the shearing strength and this shall bring about the loss of the stability of the slope..

Statistical Analysis of Excavation Model of the Loess Landslide Developmental Characteristics

2015 ◽  
Vol 744-746 ◽  
pp. 601-605 ◽  
Author(s):  
Dong Qi Tang ◽  
Jiang Bing Peng
Keyword(s):  
Trailing Edge ◽  
Loess Landslide ◽  
Zonal Distribution ◽  
Malan Loess ◽  
Distribution Features ◽  
Loess Landslides ◽  
Rapid Excavation ◽  
Developmental Characteristics ◽  
The Impact ◽  
Wild Goose

In recent years, with the increasing of excavation activity, caused the landslide more and more increasing, the landslide occurred gradually aroused public concern. For typical loess landslides caused by excavation, respectively from the distribution features of the landslide, landslide characteristics after wall, slope high on the impact of landslides and landslides trailing edge fracture characteristics were analyzed. Statistics show that the engineering loess landslides in the distribution respectively are selectivity of landform, strata of selectivity and zonal distribution. The excavation methods are rapid excavation and “eating” excavation. Landslide back wall angle is between 60-80°. The height of the scarp is between 3-20m, controlled by the thickness of the Malan loess. The slope high is more than 60m, with the increase of height. The risk of slide is higher. Trailing edge crack development is “wild goose feather” type and “bilateral ears” type. It provides conditions for trailing edge of evolution.

Lvliang Typical Loess Landslide Mechanism and Characteristics

2011 ◽  
Vol 90-93 ◽  
pp. 1313-1317 ◽  
Author(s):  
Dong Qi Tang ◽  
Jian Bing Peng ◽  
Qi Yao Wang ◽  
Ji Shan Xu
Keyword(s):  
Scientific Basis ◽  
Economic Activities ◽  
Loess Landslide ◽  
Main Research ◽  
Loess Area ◽  
Landslide Mechanism ◽  
Geological Disasters ◽  
Loess Landslides

The loess area ecology environment is very fragile, happening various geological disasters, loess landslides is one of the most mainly the geological disasters in loess area. Lvliang region loess hilly develops common, with the human economic activities increasing, inducing a lot of loess landslides. Taking typical loess landslides as the main research object, the loess landslides of Lvliang region from two aspects of characteristics and mechanism are analyzed. It is considered that the main types of the loess landslides are located within the layer of loess. Landslide is controlled by topography and lithology, landslide mechanism is induced by human economic activities. Through research for the region loess landslides hazard prevention provide the scientific basis.

The Physical and Mechanic Properties of the Loess Landslide

2012 ◽  
Vol 446-449 ◽  
pp. 3003-3006
Author(s):  
Li Hua Li ◽  
Meng Dang ◽  
Heng Lin Xiao ◽  
Hui Ming Tang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Water Content ◽  
Maximum Shear Stress ◽  
Friction Angle ◽  
Dry Density ◽  
Disaster Prevention ◽  
Loess Landslide ◽  
Landslide Disaster

The loess landslide in BaDong city, HuBei province China suffers great losses, which is an extremely typical landslide disaster. Variation in water level in the Yangtse River and rainfall has enormous influence on the loess landslide disaster. Some tests on loess have been done, which mainly include water content influence on shear strength of the loess, the relation between water content and dry density etc. The results have shown that When the water content average increasing with 3%, the cohesive strength reduces with 57%，49%，54% respectively and the internal friction angle average reduces 43%. The bigger the water content, the bigger the shear displacement at the same imposed load. When water content average increases with 3%, the corresponding maximum shear stress reduces with 50%, which may be in favor of loess landslide disaster prevention.

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