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On 27 January 2021, at 21:00 (UTC + 8), a shallow loess landslide occurred in Heifangtai, Yongjing County, Gansu Province, northwest of the Chinese Loess Plateau. Fortunately, the independently developed global navigation satellite system predicted the landslide 7 h in advance. Although farmland and channels were buried and destroyed, no damage has been done to the lives and houses of residents. In order to explore the triggering factors and movement process of the landslide, based on the field investigation, we collected the precipitation and temperature data more than 1 year before the landslide and comprehensively used UAV photogrammetry, numerical simulation, and laboratory test for comprehensive research. It was found that as the temperature rose and freeze–thaw cycles, changes in mechanical properties of loess and unique stratum structure were the main factors triggering the landslide. The rise in temperature led to an increase in groundwater levels, and the strength of soil decreased gradually until shear liquefaction occurred. This landslide caused a substantial topographic change, which provided conditions for slope instability in the future. The process of landslide movement can be divided into three stages: start-up stage, severe sliding stage, and deceleration stage. Simulation results show that the maximum velocity was 22 m/s, and the maximum sliding distance was 393 m. The main movement period was 40 s, and the apparent friction angle was 5°. Finally, this study provides a reliable basis for studying the dynamic process and failure mechanism of loess landslides.
Jia-Xu Kong; Jian-Qi Zhuang; Jie-Wei Zhan; Zheng-Wei Bai; Yan-Qiu Leng; Peng-Hui Ma; Jian-Bing Peng; Zuo-Peng Wang; Tian-Feng Gu; Jia-Xing Sun; Fan-Chen Zhang; Yuan-Jun Xu; Ye Wang; Jia-Qi Mu; Hong-Yu Fan. A landslide in Heifangtai, northwest of the Chinese Loess Plateau: triggered factors, movement characteristics, and failure mechanism. Landslides 2021, 1 -13.
AMA StyleJia-Xu Kong, Jian-Qi Zhuang, Jie-Wei Zhan, Zheng-Wei Bai, Yan-Qiu Leng, Peng-Hui Ma, Jian-Bing Peng, Zuo-Peng Wang, Tian-Feng Gu, Jia-Xing Sun, Fan-Chen Zhang, Yuan-Jun Xu, Ye Wang, Jia-Qi Mu, Hong-Yu Fan. A landslide in Heifangtai, northwest of the Chinese Loess Plateau: triggered factors, movement characteristics, and failure mechanism. Landslides. 2021; ():1-13.
Chicago/Turabian StyleJia-Xu Kong; Jian-Qi Zhuang; Jie-Wei Zhan; Zheng-Wei Bai; Yan-Qiu Leng; Peng-Hui Ma; Jian-Bing Peng; Zuo-Peng Wang; Tian-Feng Gu; Jia-Xing Sun; Fan-Chen Zhang; Yuan-Jun Xu; Ye Wang; Jia-Qi Mu; Hong-Yu Fan. 2021. "A landslide in Heifangtai, northwest of the Chinese Loess Plateau: triggered factors, movement characteristics, and failure mechanism." Landslides , no. : 1-13.
Landslides are widely distributed worldwide and often result in tremendous casualties and economic losses, especially in the Loess Plateau of China. Taking Wuqi County in the hinterland of the Loess Plateau as the research area, using Bayesian hyperparameters to optimize random forest and extreme gradient boosting decision trees model for landslide susceptibility mapping, and the two optimized models are compared. In addition, 14 landslide influencing factors are selected, and 734 landslides are obtained according to field investigation and reports from literals. The landslides were randomly divided into training data (70%) and validation data (30%). The hyperparameters of the random forest and extreme gradient boosting decision tree models were optimized using a Bayesian algorithm, and then the optimal hyperparameters are selected for landslide susceptibility mapping. Both models were evaluated and compared using the receiver operating characteristic curve and confusion matrix. The results show that the AUC validation data of the Bayesian optimized random forest and extreme gradient boosting decision tree model are 0.88 and 0.86, respectively, which showed an improvement of 4 and 3%, indicating that the prediction performance of the two models has been improved. However, the random forest model has a higher predictive ability than the extreme gradient boosting decision tree model. Thus, hyperparameter optimization is of great significance in the improvement of the prediction accuracy of the model. Therefore, the optimized model can generate a high-quality landslide susceptibility map.
Shibao Wang; Jianqi Zhuang; Jia Zheng; Hongyu Fan; Jiaxu Kong; Jiewei Zhan. Application of Bayesian Hyperparameter Optimized Random Forest and XGBoost Model for Landslide Susceptibility Mapping. Frontiers in Earth Science 2021, 9, 1 .
AMA StyleShibao Wang, Jianqi Zhuang, Jia Zheng, Hongyu Fan, Jiaxu Kong, Jiewei Zhan. Application of Bayesian Hyperparameter Optimized Random Forest and XGBoost Model for Landslide Susceptibility Mapping. Frontiers in Earth Science. 2021; 9 ():1.
Chicago/Turabian StyleShibao Wang; Jianqi Zhuang; Jia Zheng; Hongyu Fan; Jiaxu Kong; Jiewei Zhan. 2021. "Application of Bayesian Hyperparameter Optimized Random Forest and XGBoost Model for Landslide Susceptibility Mapping." Frontiers in Earth Science 9, no. : 1.
The Zezhang ground fissure in the Linfen Basin, China was first observed in 2004 where it damaged the infrastructure in and around the town. Field and laboratory investigations now confirm that the fissure has had a complex origin, ranging from likely recurrent fault offset with almost synchronous local sedimentation (synsedimentary), to accelerated groundwater withdrawal, soil erosion and ultimately to geomorphic expression of surface subsidence, local linear scarps and sinkholes. Trench exposures and interpretation of borehole data indicate that at least four tectonic events took place during the latest Pleistocene and Holocene generally localizing the zone of fissure expression. In contrast to other tectonic ground fissures, the ground fissures in Zezhang are highlighted with major synsedimentary characteristics. The formation mechanism of ground fissures was caused by several factors, initial and later underlying fault displacements, initial fissures with land subsidence caused by groundwater withdrawal and widening into linear sinkholes under soil erosion. The Zezhang ground fissure, its investigation techniques and the technical findings, provide a case study for assessing previously unrecognized synsedimentary fissures elsewhere.
Zhijie Jia; Jianwei Qiao; Jianbing Peng; Quanzhong Lu; Yuyun Xia; Mingdong Zang; Feiyong Wang; Junyan Zhao. Formation of ground fissures with synsedimentary characteristics: A case study in the Linfen Basin, northern China. Journal of Asian Earth Sciences 2021, 214, 104790 .
AMA StyleZhijie Jia, Jianwei Qiao, Jianbing Peng, Quanzhong Lu, Yuyun Xia, Mingdong Zang, Feiyong Wang, Junyan Zhao. Formation of ground fissures with synsedimentary characteristics: A case study in the Linfen Basin, northern China. Journal of Asian Earth Sciences. 2021; 214 ():104790.
Chicago/Turabian StyleZhijie Jia; Jianwei Qiao; Jianbing Peng; Quanzhong Lu; Yuyun Xia; Mingdong Zang; Feiyong Wang; Junyan Zhao. 2021. "Formation of ground fissures with synsedimentary characteristics: A case study in the Linfen Basin, northern China." Journal of Asian Earth Sciences 214, no. : 104790.
Loess is prone to collapse upon wetting due to its open metastable structure, which poses a considerable threat to the environment, construction processes and human life. In this study, double oedometer tests and scanning electron microscopy and mercury intrusion porosimetry analyses were conducted on loess from Yan’an to study the macroscopic and microscopic characteristics of loess wetting deformation and the underlying mechanism. The wetting collapse of loess under loading depends on the changes in different microstructure levels and elements. This collapse chain reaction is manifested by the dissipation, scattering and recombination of the cementation, deformation and reorganization of the particles, blocking of the pore channels, decrease in the dominant size and volume of unstable macropores (>14 µm) and abundant mesopores (2.5–14 µm), increase in the volume of small pores (0.05–2.5 µm), and volume contraction at the macroscale. This process is dependent on the initial water content, stress level and wetting degree. These findings can facilitate collapsible loess hazard prevention and geological engineering construction.
Jing-Jing Nan; Jian-Bing Peng; Feng-Ji Zhu; Jun-Yan Zhao; Yan-Qiu Leng. Multiscale characteristics of the wetting deformation of Malan loess in the Yan’an area, China. Journal of Mountain Science 2021, 18, 1112 -1130.
AMA StyleJing-Jing Nan, Jian-Bing Peng, Feng-Ji Zhu, Jun-Yan Zhao, Yan-Qiu Leng. Multiscale characteristics of the wetting deformation of Malan loess in the Yan’an area, China. Journal of Mountain Science. 2021; 18 (4):1112-1130.
Chicago/Turabian StyleJing-Jing Nan; Jian-Bing Peng; Feng-Ji Zhu; Jun-Yan Zhao; Yan-Qiu Leng. 2021. "Multiscale characteristics of the wetting deformation of Malan loess in the Yan’an area, China." Journal of Mountain Science 18, no. 4: 1112-1130.
The failure of landslide dams is a sudden geological disaster, and thus their formation and failure greatly threaten the security of people's lives and property. In this research, the influences of different flume gradients, dam heights, and downstream slope angles relative to the flume bed on the overtopping breaching process of noncohesive landslide dams are explored through 12 sets of model experiments. Based on these experimental results, the dam overtopping breaching can be divided into four stages: initiation, head cutting, acceleration, and riverbed rebalancing. The variation in the erosion rate (EAX and EBX) and the downstream slope angle relative to the horizontal line (Φ) exhibit clear differences in the different stages. The influences of the flume gradient, dam height, and downstream slope angle on the breaching process of landslide dams are different. In our experiments, accumulation bodies could only form in the middle and lower parts of the downstream dam face when the total height from the spillway to the flume bed was greater than 15 cm. In addition, the downstream slope angle relative to the horizontal line determined the breaching process and stage of the dam overtopping breaching. Since the dam breach evolution mode and dam overtopping breaching process were mainly affected by the dam height and downstream slope angle relative to the horizontal line, the evolution of the longitudinal section in the process of dam body failure can be divided into four modes based on our experimental results. The applicability of the widely used empirical equations for the erosion rate was assessed using the experimental data, which revealed obvious differences between the measured and calculated erosion rates. However, the erosion rate and the shear stress at the soil/water interface exhibited a good correlation in every test. Therefore, these widely used empirical equations need to be improved in future research. This preliminary research provides a basis for subsequent studies of dam breaching using models and a scientific reference for the prevention and mitigation of landslide dams.
Xinghua Zhu; Bangxiao Liu; Jianbing Peng; Zhifeng Zhang; Jianqi Zhuang; Weiliang Huang; Yanqiu Leng; Zhao Duan. Experimental study on the longitudinal evolution of the overtopping breaching of noncohesive landslide dams. Engineering Geology 2021, 288, 106137 .
AMA StyleXinghua Zhu, Bangxiao Liu, Jianbing Peng, Zhifeng Zhang, Jianqi Zhuang, Weiliang Huang, Yanqiu Leng, Zhao Duan. Experimental study on the longitudinal evolution of the overtopping breaching of noncohesive landslide dams. Engineering Geology. 2021; 288 ():106137.
Chicago/Turabian StyleXinghua Zhu; Bangxiao Liu; Jianbing Peng; Zhifeng Zhang; Jianqi Zhuang; Weiliang Huang; Yanqiu Leng; Zhao Duan. 2021. "Experimental study on the longitudinal evolution of the overtopping breaching of noncohesive landslide dams." Engineering Geology 288, no. : 106137.
Fatal landslides cause severe disasters to human lives and socioeconomic costs in China. In this study, the data non-seismically fatal landslides were collected between 2004 and 2016 in China. The hazard and life risk criteria of these fatal landslides were assessed, and the government's investment and ecological influencing factors for landslide prevention and mitigation were analyzed. There were more fatal landslides in Sichuan, Guizhou, Yunnan, Hunan, and Guangdong provinces. High landslide density value focused on Guizhou, Hunan, and Guangdong province had very high landslide density value, while Gansu held the biggest fatality density value as a result of a few huge fatal landslide events. The Chinese life risk evaluation criterion was higher than those in other countries because there was a greater population density in landslide-prone areas. Nevertheless, the government has invested a great deal of human and financial resources for landslide mitigation over the past 13 years. In total, 244,559 engineering projects were carried out and $15,920.89 million was spent. Thus, a total of 13,603 landslides were successfully predicted and 641,333 persons and $1,372.94 million has been saved. Additionally, the types of land use, afforestation area, and soil erosion management have a positive effect on landslides. However, a trend of reverse increase was presented in fatal landslides. This paper gives a detailed examination of the non-seismically fatal landslide hazard and proves an evaluation of the Chinese government's contribution to landslide mitigation by integrating engineering and ecological measures.
Fanyu Zhang; Jianbing Peng; Xiaowei Huang; Hengxing Lan. Hazard assessment and mitigation of non-seismically fatal landslides in China. Natural Hazards 2021, 106, 785 -804.
AMA StyleFanyu Zhang, Jianbing Peng, Xiaowei Huang, Hengxing Lan. Hazard assessment and mitigation of non-seismically fatal landslides in China. Natural Hazards. 2021; 106 (1):785-804.
Chicago/Turabian StyleFanyu Zhang; Jianbing Peng; Xiaowei Huang; Hengxing Lan. 2021. "Hazard assessment and mitigation of non-seismically fatal landslides in China." Natural Hazards 106, no. 1: 785-804.
The shear behavior of loess is closely related to its microstructural variation. Their relationship is of great significance to better understand the loess landslide mechanism. Consolidated-undrained triaxial tests were performed on natural loess from Yan'an, China, with various initial water contents under different confining pressures to investigate the shear behavior. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) tests were conducted on the specimens before and after the triaxial tests to study the variations in microstructure and pore characteristics and their relationship with the shear behavior. The triaxial tests revealed three different failure modes (shearing, homogeneous and plastic failure) and the corresponding stress-strain response of specimens depending on confining pressure level and initial water content. The cohesion decreases exponentially with increasing initial water content whereas the internal friction angle decreases slightly. This effect is closely related to the weakening effect of water on the inter-particle cementation and water-air interface in loess. The macroscopic shear behavior of loess is essentially the result of the continuous adjustment and change in its microstructure system under loading and wetting. This variation process is related to the confining pressure, initial water content and failure mode of the specimen. This condition is manifested by the softening, dispersion, disintegration and reassembly of cementations, particle movement and rearrangement, the reduction and mutual transformation of the inter-aggregate pore populations larger than 0.05 μm in diameter (macropores and abundant mesopores decrease, small pores increase), and the generation and development of cracks under certain conditions.
Jingjing Nan; Jianbing Peng; Fengji Zhu; Penghui Ma; Ru Liu; Yanqiu Leng; Zhenjiang Meng. Shear behavior and microstructural variation in loess from the Yan'an area, China. Engineering Geology 2020, 280, 105964 .
AMA StyleJingjing Nan, Jianbing Peng, Fengji Zhu, Penghui Ma, Ru Liu, Yanqiu Leng, Zhenjiang Meng. Shear behavior and microstructural variation in loess from the Yan'an area, China. Engineering Geology. 2020; 280 ():105964.
Chicago/Turabian StyleJingjing Nan; Jianbing Peng; Fengji Zhu; Penghui Ma; Ru Liu; Yanqiu Leng; Zhenjiang Meng. 2020. "Shear behavior and microstructural variation in loess from the Yan'an area, China." Engineering Geology 280, no. : 105964.
The particle size of loess in the Loess Plateau varies from northwest to southeast due to wind direction which is predominantly from the northwest. The clay content of loess is significantly different in the loess area of China resulting in different physical characteristics of loess and loess failure process. To determine the failure process triggered by rainfall, a series of studies were conducted via flume and triaxial tests using loess samples with different clay contents. The effects of clay on water content (WC) change, pore-water pressure (PWP) generation, and the failure process of loess slope were analyzed. The changes in WC and PWP response to the failure process of the slope at different positions were different, and the changes in the shallow layer were found to be more prominent than those at other positions. The changes in WC and PWP gradually decreased with increasing clay content. The clay in loess also plays an important role in the failure process of the loess mass, and the failure process changed from regressive overall failure to erosion-shallow sliding failure and then to erosion failure with increasing clay content. Finally, loess strength with different clay contents was tested and discussed. The strength increased and the M value decreased gradually with increasing clay content. Based on the experimental results, it was concluded that clay in loess has a significant impact on the failure process and strength of the loess mass, and the results of the current study would provide support for loess slope mitigation.
Jianqi Zhuang; Jianbing Peng; Yi Zhu. Study of the effects of clay content on loess slope failure mode and loess strength. Bulletin of Engineering Geology and the Environment 2020, 80, 1999 -2009.
AMA StyleJianqi Zhuang, Jianbing Peng, Yi Zhu. Study of the effects of clay content on loess slope failure mode and loess strength. Bulletin of Engineering Geology and the Environment. 2020; 80 (3):1999-2009.
Chicago/Turabian StyleJianqi Zhuang; Jianbing Peng; Yi Zhu. 2020. "Study of the effects of clay content on loess slope failure mode and loess strength." Bulletin of Engineering Geology and the Environment 80, no. 3: 1999-2009.
Loess is a typical soil with the characteristic of water sensitivity, and in the study of water-induced geological disasters of loess distribution areas worldwide, special attention must be paid to the influence of this sensitivity. Hence, quantitative study of the water sensitivity of loess has been a basic scientific issue of wide concern. In this study, the water sensitivity characteristics of loess in the South Jingyang Tableland of China are investigated through oedometer tests and triaxial shear tests, and the variation in the structural strength, deformation modulus, and strength parameters of intact samples with different water contents is studied. It is found that the structural yield stress, initial deformation modulus and cohesion are sensitive to the water content, i.e., decreasing in the form of a power function or an exponential function with increasing initial water content. An analysis shows that the above parameters can be used to normalize the compression curves, stress-strain curves and critical state lines of loess. According to the quantitative formula of water sensitivity in the field of petroleum exploration, a new method to assess the water sensitivity of loess by analogy is proposed, which involves the structural strength, deformation modulus and shear strength parameters in the natural and humidified states. The analysis further indicates that the water sensitivity index proposed in this paper is a reasonable, sensitive and effective way to quantify the water sensitivity of loess.
Yanqiu Leng; Jianbing Peng; Shuo Wang; Feng Lu. Development of water sensitivity index of loess from its mechanical properties. Engineering Geology 2020, 280, 105918 .
AMA StyleYanqiu Leng, Jianbing Peng, Shuo Wang, Feng Lu. Development of water sensitivity index of loess from its mechanical properties. Engineering Geology. 2020; 280 ():105918.
Chicago/Turabian StyleYanqiu Leng; Jianbing Peng; Shuo Wang; Feng Lu. 2020. "Development of water sensitivity index of loess from its mechanical properties." Engineering Geology 280, no. : 105918.
The Loess Plateau has been deemed as a landslide-prone area in northwest China because of the unique platform geomorphology and the wetting-induced loess collapse. The interactions of landslide deposit and terrace sediment have been under-explored in the literature. This lack of research has inhibited the prevention and mitigation of loess landslide. This study summarises a total of 40 loess landslides in the South Jingyang Platform, Shaanxi Province; 4 out of the 40 loess landslides are investigated in detail, with an emphasis on the geomorphology feature and the internal geometry of geology. While the sandbox experiments and the discrete element modelling primarily aimed to reproduce the kinetic process of landslide deposit falling from the platform edge and colliding with terrace sediments. The field observation distinguished three domains that represent varying degrees of interaction between the landslide deposit and the terrace sediments, namely push forward domain, shear up/out domain and original terrace sediment domain. The push forward domain is defined as an area completely contained the loess deposit, with most distinct surface upheaval, while the shear up/out domain is defined as an area that significantly interacts with the push forward domain and possesses remarkable evidence of interactions. The original terrace sediment is defined as an area that is thoroughly not disturbed by the interactions. The internal geometry change and the geomorphology features, induced by the interactions of the deposit with the sediments, are reproduced using the sandbox experiments and the discrete element modelling. The sediments shearing upwards and the occurrence of shear liquefaction are interpreted from perspectives of the velocity of deposit movement and the apparent friction angle. The results are deemed to be useful in enhancing our understanding about the interactions of the landslide deposit with the terrace sediments and countermeasures against loess flowslides in the study area in future.
Zhao Duan; Wen-Chieh Cheng; Jian-Bing Peng; Mizanur Rahman; Hao Tang. Interactions of landslide deposit with terrace sediments: Perspectives from velocity of deposit movement and apparent friction angle. Engineering Geology 2020, 280, 105913 .
AMA StyleZhao Duan, Wen-Chieh Cheng, Jian-Bing Peng, Mizanur Rahman, Hao Tang. Interactions of landslide deposit with terrace sediments: Perspectives from velocity of deposit movement and apparent friction angle. Engineering Geology. 2020; 280 ():105913.
Chicago/Turabian StyleZhao Duan; Wen-Chieh Cheng; Jian-Bing Peng; Mizanur Rahman; Hao Tang. 2020. "Interactions of landslide deposit with terrace sediments: Perspectives from velocity of deposit movement and apparent friction angle." Engineering Geology 280, no. : 105913.
According to a previous geological investigation, high-speed and long-distance loess landslides in the South Jingyang platform in Shaanxi Province are closely related to the static liquefaction of loess. Considering the typical loess landslides in this area, isotropic consolidated undrained (ICU) triaxial tests and scanning electron microscopy analyses were conducted in this study. The main conclusions are as follows: (1) The stress-strain curves indicate strong strain softening under different confining pressures. The pore water pressure increases significantly and then remains at a high level; (2) The liquefaction potential index (LPI) shows an increasing trend followed by stabilization; the larger the LPI is, the smaller the state parameter (Ψ) is. The steady-state points of the loess are in the instability region; however, the steady-state strength is not zero; (3) Based on the ICU test results, the average pore diameter decreases; the shape ratio remains essentially unchanged; and the fractal dimension and roundness show different trends. The proportions of the macropore and mesopore decrease; that of the small pore increases slightly; and that of the micropore increases significantly; (4) The compression deformation of the highly spaced pores causes rapid strain hardening. A rapid strain softening results from the pore throat blockage at the beginning of particle rearrangement and reorganization. A stable strain softening is related to the agglomeration blocking of the reconstructed pore throat in the gradually stable stage of particle rearrangement and reorganization.
Rui-Xin Yan; Jian-Bing Peng; Jin-Yuan Zhang; Shao-Kai Wang. Static Liquefaction Capacity of Saturated Undisturbed Loess in South Jingyang Platform. Water 2020, 12, 2298 .
AMA StyleRui-Xin Yan, Jian-Bing Peng, Jin-Yuan Zhang, Shao-Kai Wang. Static Liquefaction Capacity of Saturated Undisturbed Loess in South Jingyang Platform. Water. 2020; 12 (8):2298.
Chicago/Turabian StyleRui-Xin Yan; Jian-Bing Peng; Jin-Yuan Zhang; Shao-Kai Wang. 2020. "Static Liquefaction Capacity of Saturated Undisturbed Loess in South Jingyang Platform." Water 12, no. 8: 2298.
Since the 1980s, ground fissures in the Taiyuan Basin have experienced blowouts, resulting in a significant but hidden danger to cities in the Basin. This paper describes the plane and damage characteristics of the ground fissures based on the findings of field investigations and mapping. Most ground fissures in the Basin were determined as linear with pinch-out reappearances on the surface. They were characterized by both horizontal tension with maximum widths and vertical offsets of up to 40 and 15 cm, respectively. The ground fissure strikes in the Basin were observed to be consistent with those of nearby active faults and the long-axis direction of the groundwater depression funnel. The roads and houses that lie across the fissures were determined to be the most affected by ground-fissure disasters in the Basin. The primary damage modes for the roads were vertical offset and surface collapse, whereas buildings experienced foundation failure and tensile damage. Profiles obtained through geological drilling and trench exploration further revealed obvious tension and synsedimentary characteristics of the ground fissures correlated with existing faults. Correlation analysis shows that the formation of ground fissures in Taiyuan Basin is mainly related to faults and excessive groundwater extraction. Theoretical analysis revealed that the size and activity of ground fissures in the Basin were positively correlated with four factors—the dip of faults in an area, regional tensile stress, difference between the thicknesses of aquifers on either side of a fault, and groundwater exploitation. The significant increase in ground fissure activity since the 1980s mainly reflects uncontrolled groundwater discharge. Hence, prevention of excessive groundwater exploitation in the Basin would mitigate the destructive effects of the ground fissures.
Zhijie Jia; Jianbing Peng; Quanzhong Lu; Lingchao Meng; Zhenjiang Meng; Jianwei Qiao; Feiyong Wang; Junyan Zhao. Characteristics and genesis mechanism of ground fissures in Taiyuan Basin, northern China. Engineering Geology 2020, 275, 105783 .
AMA StyleZhijie Jia, Jianbing Peng, Quanzhong Lu, Lingchao Meng, Zhenjiang Meng, Jianwei Qiao, Feiyong Wang, Junyan Zhao. Characteristics and genesis mechanism of ground fissures in Taiyuan Basin, northern China. Engineering Geology. 2020; 275 ():105783.
Chicago/Turabian StyleZhijie Jia; Jianbing Peng; Quanzhong Lu; Lingchao Meng; Zhenjiang Meng; Jianwei Qiao; Feiyong Wang; Junyan Zhao. 2020. "Characteristics and genesis mechanism of ground fissures in Taiyuan Basin, northern China." Engineering Geology 275, no. : 105783.
Loess is a type of Quaternary sediments of the wind origin in arid and semi-arid regions. This type of sediment is widely and thickly distributed in China, forming the Loess Plateau, which is the largest bulk accumulation of loess on the Earth. The Loess Plateau of China has received great attention from scientific communities, including geologists, geophysicists and engineers worldwide. Accordingly, a wealth of investigations has been undertaken on various problems arising in this area. However, some scientific questions remain relevant and unresolved. These questions mainly present in the areas of evolution and surface processes of loess landform, depositional environments of loess sediments, impacts due to Neotectonics and fault activities in loess areas, and natural and man-made geohazards. In recent years, extensive innovative studies have been carried out to further understand the above-mentioned topics. Substantial new data, theories and insights have become available. This special issue provides a timely overview on the recent case histories, theoretical advances, laboratory and field testing and state-of-art methods in the theme of loess geology and surface processes. The papers gathered in this special issue are introduced in this article.
Yanrong Li; Shengdi He; Jianbing Peng; Qiang Xu; Adnan Aydin; Yongxin Xu. Loess Geology and Surface Processes: An Introductory Note. Journal of Asian Earth Sciences 2020, 200, 104477 .
AMA StyleYanrong Li, Shengdi He, Jianbing Peng, Qiang Xu, Adnan Aydin, Yongxin Xu. Loess Geology and Surface Processes: An Introductory Note. Journal of Asian Earth Sciences. 2020; 200 ():104477.
Chicago/Turabian StyleYanrong Li; Shengdi He; Jianbing Peng; Qiang Xu; Adnan Aydin; Yongxin Xu. 2020. "Loess Geology and Surface Processes: An Introductory Note." Journal of Asian Earth Sciences 200, no. : 104477.
The Fenwei Graben System is an important extensional fault-depression zone, which is the tectonic boundary between the Ordos Block and the South China Block and the North China Block. The graben system presents an “S” shape, with a total length of 1200 km and a width of 30–60 km and an overall strike of NNE. Due to complex tectonic background and active faults, nearly 612 ground fissures develop in these basins, and more than 90% of these ground fissures are tectonic fissures, which are closely associated with fault activities. To reveal the plane symbiotic phenomena, profile symbiotic modes and symbiotic mechanism between tectonic fissures and faults in the Fenwei Graben System, the developmental characteristics were investigated in detail by surveying, mapping, trenching and drilling in the study area. The main conclusions are as follows. (1) The tectonic fissures of the Fenwei Graben System are mainly distributed along the margin faults of basins, the boundary faults between blocks and the hidden faults within blocks, causing serious damages to farmlands, houses and roads. The symbiosis between these fissures and faults is obvious on the surface. (2) The profile symbiotic morphology includes vertical extension type, syncline and anticline “y” type, and stepped type. (3) The symbiotic mechanisms include vertical growth, lateral rupture and clustery derivation. (4) The activities of underlying faults give impetus to the formation and expansion of tectonic fissures. The exposure of the fissures makes underlying faults continue to develop in the form of surface fractures.
Feiyong Wang; Shouzhong Xun; Jianbing Peng; Qiangbing Huang; Quanzhong Lu; Zhenjiang Meng; Jianwei Qiao; Yang Liu; Zhijie Jia; Junyan Zhao. A study of the symbiotic relationship between tectonic fissures and faults in the Fenwei Graben System, China. Environmental Earth Sciences 2020, 79, 1 -14.
AMA StyleFeiyong Wang, Shouzhong Xun, Jianbing Peng, Qiangbing Huang, Quanzhong Lu, Zhenjiang Meng, Jianwei Qiao, Yang Liu, Zhijie Jia, Junyan Zhao. A study of the symbiotic relationship between tectonic fissures and faults in the Fenwei Graben System, China. Environmental Earth Sciences. 2020; 79 (10):1-14.
Chicago/Turabian StyleFeiyong Wang; Shouzhong Xun; Jianbing Peng; Qiangbing Huang; Quanzhong Lu; Zhenjiang Meng; Jianwei Qiao; Yang Liu; Zhijie Jia; Junyan Zhao. 2020. "A study of the symbiotic relationship between tectonic fissures and faults in the Fenwei Graben System, China." Environmental Earth Sciences 79, no. 10: 1-14.
The failure of a landslide dam is a sudden geo-hazard, which can significantly threatens the lives and property of local residents. In this study, 11 experiments were designed to reproduce the failure process of landslide dams with different grain size distributions and hydrodynamic conditions. In order to fully consider the influence of seepage on the stability of landslide dams with different textural properties, the inflow discharge was small in these tests. By analyzing the experimental data, we found that the textural properties plays a key role in the failure modes and process of landslide dams. The eleven tests produced five different results: the landslide dam in experiment 1 and 8 remained stable; the landslide dam in experiment 2 partially failed; in experiments 3–6, the dams failed due to overtopping and erosion, while in experiment 7, the dam failed due to overtopping and soil collapse; in experiment 9–11, the dams failed due to piping, overtopping and erosion. In addition, the evolution of the outflow discharge and density also varied for the different textural properties of the dam materials. Based on the experimental results, the landslide dam materials were classified as coarse-matrix controlled, medium particle controlled, fine-matrix controlled, and balanced composition. The failure modes and process as well as the evolution characteristics of the outflow discharge and flow density were all summarized, providing a scientific reference for disaster prevention and mitigation research of landslide dams.
Xinghua Zhu; Jianbing Peng; Bangxiao Liu; Cheng Jiang; Jian Guo. Influence of textural properties on the failure mode and process of landslide dams. Engineering Geology 2020, 271, 105613 .
AMA StyleXinghua Zhu, Jianbing Peng, Bangxiao Liu, Cheng Jiang, Jian Guo. Influence of textural properties on the failure mode and process of landslide dams. Engineering Geology. 2020; 271 ():105613.
Chicago/Turabian StyleXinghua Zhu; Jianbing Peng; Bangxiao Liu; Cheng Jiang; Jian Guo. 2020. "Influence of textural properties on the failure mode and process of landslide dams." Engineering Geology 271, no. : 105613.
A set of widely developed ground fissures within the Datong Basin, northern China, have inflicted serious damage to farm fields, roads, houses, and building foundations in Datong City. Such emergence of large-scale ground fissures is rare in urban areas. The formation mechanisms of these features were therefore investigated in detail through surveying, mapping, trenching, drilling, and geophysical prospecting. The 11 fissures in Datong City are located on the hanging wall of the Kouquan fault (part of regional horst and graben terrain), and run approximately parallel, with a dominant strike of NE34°–70° and a maximum length of 5.5 km. These structures occur in clear zones with similar directions and lateral distributions on the surface. They possess evident synsedimentary fault characteristics, including y-shaped, trapezoidal, and traction structures in their profiles. The synergistic action of different tectonic factors and groundwater exploitation is responsible for fissure formation. Under the influences of regional tensile stress, upper mantle uplift, and fault block movement, activity along local faults created hidden fracture systems within the hanging wall. The over-exploitation of groundwater in the region subsequently accelerated fracture growth, and varying vertical compressibility of the strata on both sides of the local fault resulted in uneven subsidence on the surface, generating tensile zones and promoting the appearance of fissures at the edges of settlement funnels.
Feiyong Wang; Jianbing Peng; Zhixin Chen; Qingliang Wang; Zhenjiang Meng; Jianwei Qiao; Junyan Zhao. Development characteristics and mechanisms of damage-causing urban ground fissures in Datong City, China. Engineering Geology 2020, 271, 105605 .
AMA StyleFeiyong Wang, Jianbing Peng, Zhixin Chen, Qingliang Wang, Zhenjiang Meng, Jianwei Qiao, Junyan Zhao. Development characteristics and mechanisms of damage-causing urban ground fissures in Datong City, China. Engineering Geology. 2020; 271 ():105605.
Chicago/Turabian StyleFeiyong Wang; Jianbing Peng; Zhixin Chen; Qingliang Wang; Zhenjiang Meng; Jianwei Qiao; Junyan Zhao. 2020. "Development characteristics and mechanisms of damage-causing urban ground fissures in Datong City, China." Engineering Geology 271, no. : 105605.
The ground fissure of Shuanghuaishu in Shaanxi Province, China, is a tectonic ground fissure developed in the northern Loess Plateau of the Weihe Basin. Remarkably, it exhibits multiple activities under heavy rainfall conditions. To explore how heavy rainfall infiltration can induce ground fissures to reactivate, we conducted an in situ large-scale water immersion test on the ground fissure zone. Through measurement of soil moisture content and observation of subsidence and deformation of surface and soil layers at different depths before and after water immersion, we determined the variation law of soil moisture content and the humidification deformation of the ground fissure zone after rain infiltration. Results show that ground fissures destroy the structure of soil layers and form a certain width of influence zone, which allows surface water to seep through the fissure zone into the deep soil below the relative aquifuge. After water immersion, the deformation of the soil in the ground fissure zone is obviously larger than that in the non-fracture zone, the influence zone width of hanging wall of the ground fissure is larger than that of the footwall, and the influence range on the upper soil layer is larger than that on the lower soil layer.
Quanzhong Lu; Yang Liu; Jianbing Peng; Liang Li; Wen Fan; Nina Liu; Kai Sun; Rendao Liu. Immersion test of loess in ground fissures in Shuanghuaishu, Shaanxi Province, China. Bulletin of Engineering Geology and the Environment 2020, 79, 2299 -2312.
AMA StyleQuanzhong Lu, Yang Liu, Jianbing Peng, Liang Li, Wen Fan, Nina Liu, Kai Sun, Rendao Liu. Immersion test of loess in ground fissures in Shuanghuaishu, Shaanxi Province, China. Bulletin of Engineering Geology and the Environment. 2020; 79 (5):2299-2312.
Chicago/Turabian StyleQuanzhong Lu; Yang Liu; Jianbing Peng; Liang Li; Wen Fan; Nina Liu; Kai Sun; Rendao Liu. 2020. "Immersion test of loess in ground fissures in Shuanghuaishu, Shaanxi Province, China." Bulletin of Engineering Geology and the Environment 79, no. 5: 2299-2312.
In this study, 5002 ground fissures in more than 1500 localities across 22 provinces in China are investigated and mapped to reveal their spatial distribution. The distribution of these ground fissures in China exhibits six regular patterns – assemblages in North China, syngenesis in extensional basins, clustering along fault zones, distributing along geomorphic boundaries, developed on the edge of subsidence areas, and clustering in large and medium-sized cities. Combined with regional GPS, numerical simulations, physical model test and In-SAR monitoring, the generative processes of ground fissures are analyzed and discussed in relationship to four mechanisms: (1) deep dynamic tectonism controls on the location of ground fissures, (2) intracontinental dynamic tectonism resulting in ground fissure assemblages, (3) fault stress inducing formation of ground fissures, and (4) groundwater overmining resulting in the reactivation and expansion of ground fissures. The geological environment is thus responsible for the establishment and appearance of ground fissure. More importantly, ground fissure propagation in China is the result of the synergistic effects of internal geological dynamic (including in deep tectonism, intracontinental tectoniim, and fault movement) coupled with anthropomorphic stress. This genetic model can be summarized as one that is tectonically controlled, stress-driven, and affected by regional hydrodynamic.
Jianbing Peng; Jianwei Qiao; Xiaohan Sun; Quanzhong Lu; Jianguo Zheng; Zhenjiang Meng; Jishan Xu; Feiyong Wang; Junyan Zhao. Distribution and generative mechanisms of ground fissures in China. Journal of Asian Earth Sciences 2019, 191, 104218 .
AMA StyleJianbing Peng, Jianwei Qiao, Xiaohan Sun, Quanzhong Lu, Jianguo Zheng, Zhenjiang Meng, Jishan Xu, Feiyong Wang, Junyan Zhao. Distribution and generative mechanisms of ground fissures in China. Journal of Asian Earth Sciences. 2019; 191 ():104218.
Chicago/Turabian StyleJianbing Peng; Jianwei Qiao; Xiaohan Sun; Quanzhong Lu; Jianguo Zheng; Zhenjiang Meng; Jishan Xu; Feiyong Wang; Junyan Zhao. 2019. "Distribution and generative mechanisms of ground fissures in China." Journal of Asian Earth Sciences 191, no. : 104218.
Loess often has poor engineering properties due to its loose accumulation and strong collapsibility. Therefore, improvement of the soil is necessary to meet the needs of engineering. In the current work, the improvement effect of sodium alginate added in different proportions to loess was studied. Limited water content test and particle size grading test were conducted to study the effect of sodium alginate on the basic physical parameters of soil. In addition, unconfined compressive strength test (UCS) and consolidated undrained test (CU) were used to analyze the changes in the mechanical properties of the soil after improvement. Additionally, permeation and disintegration tests were used to study the change in the soil’s water stability. What’s more, the microscopic mechanism of sodium alginate improved loess was also proposed based on the results of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that sodium alginate not only can change the liquid-plastic limit and particle size gradation of loess but also improve the strength, shear parameters, and water stability of loess. SEM and XRD studies revealed that sodium alginate changed the microstructure of the loess, formed a colloidal material to encapsulate the soil particles, filled the pores between soil particles, and caused aggregation of the clay material in the soil to form larger particle size via flocculation. These results show that sodium alginate can be used as a more environmental friendly and sustainable additive to replace the traditional soil stabilization additives, such as cement or lime to stabilize loess.
Yong Zhao; Jianqi Zhuang; Ying Wang; Yanjun Jia; Pengyao Niu; Kecheng Jia. Improvement of loess characteristics using sodium alginate. Bulletin of Engineering Geology and the Environment 2019, 79, 1879 -1891.
AMA StyleYong Zhao, Jianqi Zhuang, Ying Wang, Yanjun Jia, Pengyao Niu, Kecheng Jia. Improvement of loess characteristics using sodium alginate. Bulletin of Engineering Geology and the Environment. 2019; 79 (4):1879-1891.
Chicago/Turabian StyleYong Zhao; Jianqi Zhuang; Ying Wang; Yanjun Jia; Pengyao Niu; Kecheng Jia. 2019. "Improvement of loess characteristics using sodium alginate." Bulletin of Engineering Geology and the Environment 79, no. 4: 1879-1891.
The most serious earth fissure disasters in China occur in the Fenwei basin. Since the late 1950s, earth fissure disasters have widely occurred in the Weihe, Yuncheng, Linfen, Taiyuan, and Datong sub-basins in the Fenwei basin, and such disaster has increased progressively in recent years. The current paper summarizes the characteristics of earth fissures in the Fenwei basin. Earth fissures usually occur in an extensional faulted basin, along an active fault zone, and within an area of land subsidence. Earth fissures often have a similar trend, with many branches that intermittently appear along their strike. The main and secondary earth fissures at a shallow depth form rupture belts of different widths, but they merge into a single shear belt and stay connected with the underlying active fault. The throw of two blocks increases with depth along a sedimentary fault. Earth fissures usually show the characteristic of three-dimensional movement. Vertical dislocation is the primary aspect of earth fissure movement. The horizontal tension is smaller and the horizontal twist is the smallest, which is consistent with the movement pattern of underlying active faults. Earth fissures have exhibited activity three or four times since the late Pleistocene. In the past half-century, earth fissures formed during four or five periods of peak activity were influenced strongly by groundwater fluctuation. Our research also indicates that cluster formation of earth fissures is polygenetic and results from a combination of tectonic and human activities. Earth fissures are driven by deep tectonic motions beneath the basin and are controlled by the local tectonic stress of the local fault zones. One of the most important factors contributing to earth fissure formation is groundwater overexploitation. This paper provides a scientific basis for proposed administrative means, mitigation measures and engineering solutions in the field of engineering geology.
Jianbing Peng; Xiaohan Sun; Quanzhong Lu; Lingchao Meng; Hongqian He; Jianwei Qiao; Feiyong Wang. Characteristics and mechanisms for origin of earth fissures in Fenwei basin, China. Engineering Geology 2019, 266, 105445 .
AMA StyleJianbing Peng, Xiaohan Sun, Quanzhong Lu, Lingchao Meng, Hongqian He, Jianwei Qiao, Feiyong Wang. Characteristics and mechanisms for origin of earth fissures in Fenwei basin, China. Engineering Geology. 2019; 266 ():105445.
Chicago/Turabian StyleJianbing Peng; Xiaohan Sun; Quanzhong Lu; Lingchao Meng; Hongqian He; Jianwei Qiao; Feiyong Wang. 2019. "Characteristics and mechanisms for origin of earth fissures in Fenwei basin, China." Engineering Geology 266, no. : 105445.