Landslide Body Research Articles

Geochemical and mineralogical analysis of low-grade metamorphic rocks and their response to shallow landslide occurrence in Central Nepal

BackgroundThe weathering intensity and geochemical properties of a rock contribute to shallow landslide occurrences. This study aims to establish the role of rock weathering in shallow slope instability in low-grade metamorphic rocks of the Lesser Himalaya region of central Nepal. The rocks of the Kuncha Formation, which consist of phyllites, metasandstones, and gritty phyllites are characterized by the formation of shallow landslides. Field characterization of the rock mass within the landslide body, along with petrographic observations, clay mineral analysis, and major bulk geochemistry were adopted to establish a relationship between rock weathering and landslide occurrence.ResultsThe landslides distributed within the Kuncha Formation in the study area are debris-related slides and falls, rock falls, and complex slides. Microscopic petrographic observation of rock from the landslide area revealed well-developed microcracks and intergranular microfractures within the weathered samples, which suggests extensive disintegration and physical alteration. Kinematic analysis of the landslide slope revealed that discontinuities and bedding planes also affected the failure of the slope. The occurrence of neo-formed clay minerals and the conversion of biotite-muscovite to vermiculite, kaolinite, and mixed-layer clays indicate chemical weathering. The CIA ranges between 71 and 80 for the rock samples and between 72 and 84 for the soil samples, signifying moderate to extreme weathering effects. The higher values of PIA and CIW reveal K-feldspar and plagioclase alteration to clay minerals by weathering and alteration. CIA-LOI plots reveal significant relationships corresponding to weathering effects.ConclusionThe transition of rock from a fresh to a moderately weathered state and the development of clay minerals and major discontinuities played a crucial role in shallow landslide occurrence. The weakened physical properties of the rock mass due to weathering coupled with unfavorable joints and fracture conditions have led to instability of the hillslopes in the study area. It was observed that one of the driving factors that drives slopes to erosion and landslides is weathering. The dominant occurrence of landslides in the weathered rock domain within the study area validates the occurrence of landslides and weathering interconnections.

Expressions of the solenovian early oligocene crisis on the northern shelf of the Eastern Paratethys

The results of regional structure studies of the Solenovian deposits of the Eastern Paratethys Early Oligocene Rupelian Stage are presented. The geological structure and paleogeographic conditions that existed in the basin during the Solenovian time were refined on the base of complex interpretation of geological and geophysical materials. A spatial picture of the Eastern Paratethys sea level drops consequences during a series of regressions in the Oligocene period is traced. Shelf areas were periodically drained, which is reflected in the erosional unconformities structure and buried river incisions. It has been established that the most significant was the regression of the Late Solenovian time with a relative sea level drop amplitude of more than 500 m. As a result, a pronounced unconformity surface complicated by river cuts was formed inside the shelf part of the Maikop seismic complex. Erosion ledges and landslide bodies formed on the slopes, and basin-fill complexes accumulated in depression parts.

Landslide displacement prediction using time series InSAR with combined LSTM and TCN: application to the Xiao Andong landslide, Yunnan Province, China

AbstractResearch on landslide displacement prediction based on interferometric synthetic aperture radar (InSAR) deformation data involves two main issues. First, InSAR can provide only one-dimensional deformation data along the satellite’s line of sight (LOS), which cannot truly reflect the deformation of the landslide body in the downward direction along the slope. Second, the use of a single prediction model does not adequately account for both long-term and local changes in landslide displacement, affecting the accuracy of the predictions. To address this, in this study, Long Short-Term Memory networks (LSTM) and temporal convolutional network (TCN) models are combined to construct a method (LSTM-TCN) of landslide displacement prediction. This method can consider the long-term and localized changes in landslide displacement. The method is first based on InSAR technology to obtain surface deformation. The deformation of the landslide is subsequently computed in the downward direction along the slope to obtain the landslide displacement time series data. Next, the LSTM-TCN is used for landslide displacement prediction. Finally, the mean absolute error (MAE), root mean square error (RMSE) and coefficient of determination (R2) are used to evaluate the performance of the model. The experiment is conducted on the Xiao Andong landslide in Anshi village, Fengqing County, Lincang City, Yunnan Province, China. The LSTM-TCN model achieves an R2 of 0.75, an RMSE of 0.43 cm, and an MAE of 0.36 cm. Compared with the individual LSTM and TCN models, the LSTM-TCN model exhibits the highest prediction accuracy and the smallest prediction error, which is closer to the true result that in the other models. These results demonstrate that the combined LSTM-TCN model effectively captures the complex features and long-term trends in landslide displacement data, significantly enhancing the accuracy of predictions.

Remote sensing identification of shallow landslide based on improved otsu algorithm and multi feature threshold

In low-resolution remote sensing images under complex lighting conditions, there is a similarity in spectral characteristics between non-landslide areas and landslide bodies, which increases the probability of misjudgment in the identification process of shallow landslide bodies. In order to further improve the accuracy of landslide identification, a shallow landslide remote sensing identification method based on an improved Otsu algorithm and multi-feature threshold is proposed for the temporary treatment project of the Yangjunba disaster site in Leshan City. Using Retinex theory, remote sensing images are enhanced with local linear models and guided filtering; then, multi-feature scales and sliding window calculations of opening and closing transformations identify potential landslide areas, which are finally segmented using the Otsu algorithm. Through experimental verification, the method proposed in this article can clearly segment the target object and background after binary segmentation of remote sensing images. The recognition rate of shallow landslide bodies is not less than 95%, indicating that the method proposed in this article is relatively accurate in identifying shallow landslide bodies in the research area and has good application effects.

Research on an Intelligent Perception Data Collection Method

Abstract This article proposes a sensor anomaly event intelligent perception monitoring technology to address the problem of insufficient intelligent perception of landslides. This method achieves real-time dynamic monitoring of abnormal deformation in landslide disasters from deformation, accelerated deformation to instability and failure stages. This article proposes an algorithm that triggers acquisition by sensing abnormal deformation and adjusts the acquisition frequency autonomously. By embedding the algorithm into the monitoring system, real-time monitoring of abnormal event data of disaster bodies can be achieved. The system achieves low-power sleep monitoring mode by adjusting the working mode. This method provides a good real-time understanding of the dynamic evolution laws of landslide bodies and improves the effectiveness of disaster prevention and reduction.

Study of Earthquake Landslide Hazard by Defining Potential Landslide Thickness Using Excess Topography: A Case Study of the 2014 Ludian Earthquake Area, China

Influenced by the combined effects of crustal uplift and river downcutting, rivers with significant potential energy are often found in high mountain and canyon areas. Due to the active tectonic movements that these areas have experienced or are currently experiencing, geological hazards frequently occur on the mountains flanking the rivers. Therefore, evaluating the susceptibility and risk of earthquake landslides in river segments of these high mountain and canyon areas is of great importance for disaster prevention and mitigation, as well as for the safe construction and operation of hydropower stations. Currently, a major challenge in the study of landslide susceptibility and hazard is determining the thickness of potential landslide bodies. The presence of excess topography reflects the instability of the disrupted slopes, which is also a fundamental cause of landslides. This study takes the example of the Ludian earthquake in 2014, focusing on the IX and VIII intensity zones, to extract the excess topography in the study area and analyze its correlation with seismic landslides. The correlation between the critical acceleration value and the excess topography was validated using the Spearman’s rank correlation coefficient, resulting in a correlation coefficient of −0.771. This indicates a strong negative correlation between the excess topography and critical acceleration, with significant relevance. The landslide susceptibility distribution obtained by setting the potential landslide thickness based on the excess topography and proportion coefficient showed an ROC curve analysis AUC value of 0.829. This is higher than the AUC value of 0.755 for the landslide susceptibility result using a uniform potential landslide thickness of 3 m, indicating the higher model evaluation accuracy of this approach. Earthquake landslide hazard predictions for rapid post-earthquake assessments and earthquake landslide hazard zoning for pre-earthquake planning were made using actual seismic ground motion and a 2% exceedance probability in 50 years, respectively. Comparing these with the 10,559 coseismic landslides triggered by the Ludian earthquake and evaluating the seismic landslide development rate, the results were found to be consistent with reality. The improved model better reflects the control of excess topography and rock mechanics properties on the development of earthquake landslide hazards on high steep slopes. Identifying high-risk seismic landslide areas through this method and taking corresponding preventive and protective measures can help plan and construct safer hydropower and other infrastructure, thereby enhancing their disaster resistance.

Deterministic approach to assess landslide susceptibility and landslide activity in the Central-Western Region of Slovakia

Quantitative assessments in landslide susceptibility evaluation are typically dominated by statistical analyses. However, this paper employs a deterministic approach to construct such maps, specifically focusing on the stability assessment of shallow landslides with slip surfaces generally not exceeding 5 m in depth at a regional scale. The study area chosen for this research is the landslide-prone region between Hlohovec and Sereď towns in the central-western part of Slovakia. Our focus is on the activation of shallow landslides, representing the youngest, third generation of landslide evolution in the area. For the stability assessment, three scenarios were considered using deterministic analysis: a scenario involving dry slopes, a scenario under partially saturated conditions, and a scenario of fully saturated slopes. This approach enables the assessment of stability conditions based on qualitative parameters derived from both field and laboratory research. The results from the deterministic analysis aid in defining different stages of activity within the landslide body. These Landslide susceptibility maps were verified directly in the field, and most landslides reactivated from 2011 to the present fell into the class with the safety factor below 1.0. In comparison with the landslide hazard map created by using bivariate statistical analysis, it was observed that 89.97% of the area is in a very high level of landslide hazard, given a safety factor below 1.0. This highlights the effectiveness of the deterministic approach in capturing the vulnerability of the region to shallow landslides.

Geofyzikální průzkum a datování sesuvu v údolí Javorné (Zlatohorská vrchovina)

The newly identified Javorná landslide (GPS 50.2506 N, 17.3099 E) is located above the Javorná settlement (Jeseník District, the Olomouc Region, Czechia) about 0.5 km southeast of Bílý kámen Mt. (612 m a. s. l.) within the Zlaté Hory Upland. The landslide was geomorphologically mapped, dated using the radiocarbon method, and geophysical measurements using electrical resistivity tomography were carried out to interpret surface and subsurface structure of the landslide. It is a rotational rockslide developed in deluvium formed by rocks of the envelope of the Desná Unit (orthoquartzites > amphibolites, gneisses), covering an area of approximately 0.11 km2 (~ 400 × 300 m). Up to three headscarps were identified, including the uppermost amphitheatre-like, which is discontinuous and not very prominent. The most significant scarp borders the landslide on the north-east all the way to its toe. Central part of the landslide is undulated, with several zones of local shallow depressions. The largest temporary water area (sap pond) documented in spring 2023 in the southern part of the landslide is ca. 10 × 5 m large. The toe of the landslide reaches in places the Javorná Stream, and it is possibly partially eroded. Frequent springs were noticed in front of the headscarp of the landslide. The resistivity profile through the landslide shows the maximal thickness of the landslide body to be 16 m in the lower part of the slope. The body of the landslide is characterized by the zone of higher resistivity values with sharp shear surface which is clearly visible from the resistivity data. Radiocarbon dating of the sedimentary fill of the intracolluvial depression determined the minimum age of the landslide to be 2760 to 3290 ± 30 years BP.

Assessing Many Image Processing Products Retrieved from Sentinel-2 Data to Monitor Shallow Landslides in Agricultural Environments

Remote images are useful tools for detecting and monitoring landslides, including shallow landslides in agricultural environments. However, the use of non-commercial satellite images to detect the latter is limited because their spatial resolution is often comparable to or greater than landslide sizes, and the spectral characteristics of the pixels within the landslide body (LPs) are often comparable to those of the surrounding pixels (SPs). The buried archaeological remains are also often characterized by sizes that are comparable to image spatial resolutions and the spectral characteristics of the pixels overlying them (OBARPs) are often comparable to those of the pixels surrounding them (SBARPs). Despite these limitations, satellite images have been used successfully to detect many buried archaeological remains since the late 19th century. In this research context, some methodologies, which examined the values of OBARPs and SBARPs, were developed to rank images according to their capability to detect them. Based on these previous works, this paper presents an updated methodology to detect shallow landslides in agricultural environments. Sentinel-2 and Google Earth (GE) images were utilized to test and validate the methodology. The landslides were mapped using GE images acquired simultaneously or nearly simultaneously with the Sentinel-2 data. A total of 52 reference data were identified by monitoring 14 landslides over time. Since remote sensing indices are widely used to detect landslides, 20 indices were retrieved from Sentinel-2 images to evaluate their capability to detect shallow landslides. The frequency distributions of LPs and SPs were examined, and their differences were evaluated. The results demonstrated that each index could detect shallow landslides with sizes comparable to or smaller than the spatial resolution of Sentinel-2 data. However, the overall accuracy values of the indices varied from 1 to 0.56 and two indices (SAVI and RDVI) achieved overall accuracy values equal to 1. Therefore, to effectively distinguish areas where shallow landslides are present from those where they are absent, it is recommended to apply the methodology to many image processing products. In conclusion, given the significant impact of these landslides on agricultural activity and surrounding infrastructures, this methodology provides a valuable tool for detecting and monitoring landslide presence in such environments.

Physical Model Test of Deformation Self-Adaptive Mechanism of Landslide Mass

Reservoir impoundment induces a large amount of cumulative deformation of landslide body, leading to damage to the geological environment. Due to many yearly cycles of reservoir water fluctuation, the cumulative deformation of landslides tends to be stable, showing a self-adaptive deformation phenomenon. The study of the self-adaptive deformation mechanism is very important for evaluating landslide stability and achieving the safe operation of hydropower stations. To study the mechanism of self-adaptive deformation, two sets of physical models were used to monitor the groundwater, earth pressure, and cumulative deformation of landslide under periodic fluctuations of the reservoir water level. The results showed that the soil consolidation compaction, release of sliding stress, and increase in permeability are the three main factors of the self-adaptive deformation of landslide accumulation. The overall permeability decreased first and then increased, the front permeability increased greatly, and the middle and rear permeability decreased. The main factors that affected the permeability change were deformation and seepage force.

Deformation Characteristics and Activation Dynamics of the Xiaomojiu Landslide in the Upper Jinsha River Basin Revealed by Multi-Track InSAR Analysis

The upper Jinsha River, located in a high-mountain gorge with complex geological features, is highly prone to large-scale landslides, which could result in the formation of dammed lakes. Analyzing the movement characteristics of the typical Xiaomojiu landslide in this area contributes to a better understanding of the dynamics of landslides in the region, which is of great significance for landslide risk prediction and analysis. True displacement data on the surface of landslides are crucial for understanding the morphological changes in landslides, providing fundamental parameters for dynamic analysis and risk assessment. This study proposes a method for calculating the actual deformation of landslide bodies based on multi-track Interferometric Synthetic Aperture Radar (InSAR) deformation data. It iteratively solves for the optimal true deformation vector of the landslide on a per-pixel basis under a least-squares constraint based on the assumption of consistent displacement direction among adjacent points on the landslide surface. Using multi-track Sentinel data from 2017 to 2023, the line of sight (LOS) accumulative de-formation of the Xiaomojiu landslide was obtained, with a maximum LOS deformation of −126 mm/year. The true surface displacement of the Xiaomojiu landslide after activation was calculated using LOS deformation. The development of two rotational sub-slipping zones on the landslide body is inferred based on the distribution of actual displacements along the central profile line. Analysis of temporal changes in water body area data revealed that the Xiaomojiu landslide was activated after a barrier lake event and continuously moved due to the influence of higher water levels’ in the river channel. In conclusion, the proposed method can be applied to calculate the true surface displacement of landslides with complex mechanisms for analyzing the movement status of landslide bodies. Furthermore, the spatiotemporal analysis of the Xiaomojiu landslide characteristics can support analyzing the mechanisms of similar landslides in the Jinsha River Basin.

Dynamic modeling of minimum mass of pore-gas for triggering landslide in stable gentle soil slope

This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes. A stable gentle soil slope model is constructed with a dry cement powder core, a saturated clay middle layer, and a dry sand upper layer. The test injects H2O2 solution into the cement core to produce new pore-gas. The model test includes three identical H2O2 injections. The small mass of generated oxygen gas (0.07% of slope soil mass and landslide body) from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide. Meanwhile, despite the first injection causing leak paths in the clay layer, the generated small mass of gas from the second and third injections can further trigger the landslide. A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated. The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H2O2 solution in cement powder. The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07% of the landslide body. Furthermore, the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.

Mechanically Controlled Landslide Deformation

AbstractMany landslide models assume a fully deformable body without any resistance against deformation. However, in reality, landslide bodies can display negligible to large deformation during motion. Examples for limited deformation include the prehistoric giant landslides of Flims and Köfels, or the Vajont landslide of 1963, where the structure of rock largely remained intact and the slides did not evolve into rock avalanches. Here, we propose a novel mechanical model for the controlled deformation of landslides. The model is based on the principle of material strength or resistance and includes a user‐specified function that reflects the mechanisms (internal friction, cohesion, viscosity, and yield strength) that act against the deformation induced by the free‐surface or the hydraulic pressure gradient of the landslide. This controls the landslide deformation and, in turn, also the motion and run‐out, and offers a unique possibility to describe the landslide motion ranging from a fully non‐deformable body sliding along the mountain slope to a completely fluidized motion without any resistance against the force associated with the free‐surface pressure gradient. The latter is the situation often considered for the motion of granular flows such as avalanches of snow or rock, or debris flows. The former can play a substantial role in the dynamics, however, has not yet been considered in mass flow simulations, severely limiting the applicability of those models. We demonstrate the performance of the new model and its applicability, also with the advanced open‐source computational mass flow simulation tool r.avaflow.

Research and application of a flexible measuring array for deep displacement of landslides

Abstract. The multidimensional and multi-sliding surface measurement of deep-seated displacement on landslides poses a significant technical challenge in landslide monitoring and early warning. The fixed-borehole inclinometer serves as an important measurement method based on drilling for this purpose. In this study, a novel flexible measurement array for deep-seated landslide displacement and its installation and measurement processes were developed, enabling higher accuracy in full-hole multidimensional deformation measurement. The measurement array consists of individual measurement probes as basic units, connected in series through coaxial cables and high-pressure rubber hoses, forming a flexible measurement array. Each probe is equipped with acceleration and magnetic field sensors, allowing for the measurement of borehole inclination and azimuth angles and providing a more comprehensive understanding of the deformation of deep-seated landslides. This flexible measurement array resolves the limitations of traditional fixed inclinometers, such as limited probe quantity or inaccurate installation positions that fail to reflect the deformation trend of the landslide body. Moreover, it eliminates the need for auxiliary installation accessories like pulleys and inclinometer pipes, simplifying the mechanical structure and installation process, which represents an advancement in methodology and an improvement in measurement techniques. This array provides a more comprehensive and improved monitoring tool for disaster prevention and mitigation, thereby enhancing the level of geological hazard monitoring and early warning technology.

Electrical Resistivity Tomography (ERT) Investigation for Landslides: Case Study in the Hunan Province, China

Electrical resistivity tomography is a non-destructive and efficient geophysical exploration method that can effectively reveal the geological structure and sliding surface characteristics inside landslide bodies. This is crucial for analyzing the stability of landslides and managing associated risks. This study focuses on the Lijiazu landslide in Zhuzhou City, Hunan Province, employing the electrical resistivity tomography method to detect effectively the surrounding area of the landslide. The resistivity data of the deep strata were obtained, and the corresponding geophysical characteristics are inverted. At the same time, combined with the existing drilling data, the electrical structure of the landslide body is discussed in detail. The inversion results reveal significant vertical variations in the landslide body’s resistivity, reflecting changes in rock and soil physical properties. Combined with geological data analysis, it can be concluded that the sliding surface is located in the sandy shale formation. Meanwhile, by integrating various geological data, we can conclude that the landslide is currently in a creeping stage. During the rainy season, with rainfall infiltration, the landslide will further develop, posing a risk of instability. It should be promptly addressed through appropriate remediation measures. Finally, based on the results of two-dimensional inversion, this article constructs a three-dimensional surface morphology of the landslide body, which can more intuitively compare and observe the internal structure and material composition of the landslide body. This also serves as a foundation for the subsequent management and stability assessment of landslides, while also paving the way for exploring new perspectives on the formation mechanisms and theories of landslides.

Comparison of anomalies in the VLF spectrum of the natural electromagnetic field with data from the seismometer in a landslide-affected area

The data from a permanent monitoring station, based on a sound card as an AD/DA converter and a magnetic loop antenna for continuous recording of electromagnetic field intensities in the Very Low Frequency (VLF) range, were recorded and compared with data from a seismic station based on Raspberry Pi located in a landslide-affected area. The stations operated 24/7 and were placed in a room below ground level. Correlations were observed between seismic signals in the frequency spectrum from 0.1 Hz to 10 Hz (some extending beyond 20 Hz) and anomalies in the electromagnetic field in the VLF range. These anomalies are likely associated with micro-fracturing, piezo-electromagnetic, and triboelectric phenomena within the landslide body, producing relatively weak VLF emissions and a faint seismic signal. A single-component 4.5 Hz 395 Ohm vertical Racotech RGI-20DX geophone with electronic extension to lower frequencies (< 1 Hz) was used with a sampling rate of 100 sps (samples per second). VLF emissions cover almost the entire spectrum from 6 kHz with a peak at 14 kHz to 18 kHz. The received spectrum was divided into following sections: VLF band 4 kHz – 6 kHz; 6 kHz – 8 kHz; 8 kHz – 10 kHz; 10 kHz – 12 kHz; 12 kHz – 14 kHz; 14 kHz – 16 kHz; 16 kHz – 18 kHz. Simultaneously, there were changes in these sections analysed and compared with the seismic record within the same time interval.

Numerical Simulation of Rainfall‐induced Xianchi Reservoir Landslide in Yunyang, Chongqing, China

AbstractA calamitous landslide happened at 22:00 on September 1, 2014 in the Yunyang area of Chongqing City, southwest China, enforcing the evacuation of 508 people and damaging 23 buildings. The landslide volume comprised 1.44 million m3 of material in the source area and 0.4 million m3 of shoveled material. The debris flow runout extended 400 m vertically and 1600 m horizontally. The Xianchi reservoir landslide event has been investigated as follows: (1) samples collected from the main body of landslide were carried out using GCTS ring shear apparatus; (2) the parameters of shear and pore water pressure have been measured; and (3) the post‐failure characteristics of landslide have been analyzed using the numerical simulation method. The excess pore‐water pressure and erosion in the motion path are considered to be the key reasons for the long‐runout motion and the scale‐up of landslides, such as that at Xianchi, were caused by the heavy rainfall. The aim of this paper is to acquired numerical parameters and the basic resistance model, which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere.

Разработка математической модели поверхностного трансляционного оползня с дёрном на прямых склонах горных территорий при выпадении атмосферных осадков

Introduction. An analysis of existing studies shows that surface translational landslides on grassy slopes, along with other hazards, contribute to soil erosion and harm grazing lands. The formation of a landslide body is based on the stress-strain state of a sod and its subsequent destruction when liquid precipitation falls on the slope. The most accurate method for studying such a landslide process is mathematical modeling. The fundamental disadvantages of all existing mathematical models in this area is an incomplete system of equations that describe the stress-strain state of a surface layer of a slope during precipitation. Materials and methods. This study uses a mathematical modeling methodology based on theory of generalized functions. Results and discussion. The developed mathematical model is reduced to a system of partial differential equations. This system describes the stress-strain state of a sod, caused by the external stress field and the stress field of the swelling. The study of this system of equations and the resulting final expressions showed that the superposition of these stress fields leads to a weak bending of a potential landslide body. Separation of this body from the slope occurs under the influence of general stretching, leading to its destruction. As a result, it turns into a lumpy, loose landslide body that moves down the slope. Conclusion. The mechanism of a surface translational landslide with a sod on straight slopes of mountain territories during atmospheric precipitation has been revealed. According to this mechanism: 1) the external stress field forms a potential landslide body; 2) under the influence of the liquid precipitation, the stress field of the swelling is formed. The superposition of these stress fields leads to a movement of the landslide over a short distance. Suggestions for practical application and direction of future research. The research results can be used to prevent landslides with a sod on straight slopes of mountainous territories during precipitation. Further research directions should be related to an improvement of mathematical models of the stress-strain state of a sod under different slope topography.

Method for identifying the main factors controlling landslides based on a particle coupling algorithm simulating the ultimate state of a gas pipeline

To determine the ultimate load of buried gas pipelines under different working conditions under landslide action and provide a quick decision-making tool for landslide risk management, a pipe–soil coupling model is established based on smoothed particle hydrodynamics and the finite element method. The double elastic slope criterion and fault tree analysis method are used to perform limit and failure analyses on the pipelines. The research results indicate that pipeline stress and strain during oblique crossing are positively correlated with the crossing angle. The upper section of the pipeline exhibits tensile bending, whereas the lower section exhibits compressive bending. Local stress is concentrated at the elbows at both ends of the pipeline during longitudinal crossing, which is similar to the force applied during oblique crossing. The ultimate pipeline bearing capacity is negatively correlated with its burial depth and pressure. There is a positive correlation between the distance from the pipeline to the rear edge of the landslide and the width of the landslide. There is also an optimal value for the moisture content of landslides. Fault tree analysis reveals that, to prevent pipeline failure under the action of landslides, priority should be given to determining a reasonable pipeline laying method, reducing the moisture content of the sliding body, controlling the thickness and width of the landslide body, controlling the displacement and inclination angle of the sliding body, timely eliminating soil and soil pressure, and avoiding the failure of drainage systems and support facilities. Based on the research results, we propose a method that can preliminarily identify the main control factors affecting pipeline integrity. This method provides a reference for studying and developing engineering mitigation measures, identification procedures, and operation guidance documents for geological disaster risks for pipelines crossing landslide sections.

Identification of sliding surface using electrical-resistivity tomography for landslide mitigation: A case study of the Cibitung Landslide

Landslide mitigation efforts require a knowledge of the geometry and depth of the sliding surface present in a landslide body. Electrical resistivity tomography is the most common geophysical method used in landslide investigation. This paper presents the results of a series of electrical resistivity tomography surveys performed using a dipole-dipole array configuration to identify the sliding surfaces within a landslide body located in the Cibitung landslide area. The ERT images parallel the landslide body suggest that the sliding surface located below the crown is characterized by a bedrock layer with very low resistivity values. This bedrock layer continues down-slope at a maximum depth of 9 m below the ground surface. In contrast, the landslide body is characterized by a higher resistivity value. Based on the interpretation of the ERT images, the landslide involved a non-circular deep sliding surface. The results of this study have been used, in combination with the geotechnical drilling data, to construct the landslide cross-section necessary to analyze landslide stability and subsequently to recommend a landslide stabilization measure.