Slope Deformation Research Articles

A new forecasting method for failure time of creep landslide based on nonlinear creep behavior and new pre-warning criterion

The forecast of failure time of unstable slope and the definition of early warning threshold are very important for preventing landslide disaster and reducing its losses. Based on the monitoring curve of unstable slope deformation varying with time, the mathematical models are used to accurately describe the nonlinear creep behavior in the initial creep stage and the unstable creep stage of unstable slope and a forecasting method for creep landslide is proposed. In addition, this study examines an improved tangential angle criterion obtained by a new forecasting method. The results show that the initial creep stage of unstable slope can not be neglected for forecasting the failure time. The initial creep velocity v0 and the viscoelastic hysteresis coefficientξof the slope are determined at initial creep stage, which together control the creep process of the unstable slope. Moreover, in the secondary creep stage, there is an inverse relationship between the velocity and the critical tangential angle. According to the average velocity of the secondary creep stage, the early warning criterion of the landslide tangential angle is proposed. Combined with the forecast parameters of the unstable slope, comparative analysis of the critical tangential angle warning criterion and an improved tangential angle criterion, the early warning and forecasting system of landslide with creep characteristic is established. This system is applied to the early warning and forecasting analysis of reported soil and rock landslides cases with creep characteristics. The forecasting effect and applicability of the new method are studied in order to make it a better supplement to the early warning strategy of landslide.

Slope deformation analysis along a gravel road from Arib Gebaye to Mekdela-Amba woreda, Northern Ethiopia

Slope deformation analysis along a gravel road from Arib Gebaye to Mekdela-Amba woreda, Northern Ethiopia

Slope deformation monitoring and early identification of disasters in debris flow source area of Baini River, Dongchuan District, China

Dongchuan District is one of the most densely distributed regions of geological disasters in the world. Geological disasters such as debris flows and landslides are serious threats to the lives and property safety of local people. Slope deformation monitoring and early identification of geological disasters in debris flow source areas are of great significance for disaster prevention and reduction. In this study, the time-series Synthetic Aperture Radar Interferometry (InSAR) technique was used to detect the deformation in the source area of the Baini river debris flow. The deformation rate in the middle part of the three-sided mountain is the largest, the average deformation rate is about 30 mm/year. The deformation rate of the lower and upper part of the mountain is slightly lower, but the deformation is creeping constantly, and obvious tensile cracks faced the river valley in the upper. The production and living areas of residents in 8 villages around the debris flow source area are constantly deformed, and there are different degrees of landslide risk. This study provides a scientific basis and reference for early identification, deformation analysis, disaster prevention and mitigation of geological disasters in the Xiaojiang Basin.

Research on construction deformation prediction and disaster warning of karst slope based on mutation theory

In the study of deformation prediction and disaster warning during karst slope construction, the influencing factors and deformation law should be comprehensively considered. The layout of the deformation monitoring points of karst slope is affected by the thickness of karst overburden soil, dissolution and fragmentation degree, karst development degree, slope cracking degree, fault or weak interlayer and other factors. In this paper, the author aimed at the problem of construction deformation prediction and disaster warning of karst slope, proposed an improved model of cusp mutation by applying and optimizing the cusp mutation model, analysed the deformation trend and sudden change type of the slope, and obtained the critical control early warning value of slope deformation. Therefore, it is feasible to analyse the deformation and mutation characteristics of karstified slope by using a virtual reality-mutation model. In addition, based on the empirical formula of the slope sliding limit deformation rate and grey prediction model, the critical control warning value of slope deformation is obtained, which provides a basis to quantify the deformation index of risk evaluation. This method provides a new idea to predict karst slope construction deformation and catastrophic deformation warning and has a reference value for similar engineering examples.

Rock slope failure in the Southern Carpathians (Romania): Range-wide inventory and links with long-term mountain landscape evolution

Rock slope failure (RSF) is now widely recognised as a significant contributor to the denudation of mountain ranges. Its spatial incidence can consequently be a valuable indicator of prevailing process domains, tectonic regimes and climatic variations, whether active or past. Here we provide the first systematic inventory of RSF in the Southern Carpathians, a mountain range marginally glaciated during the Pleistocene, cut by valleys up to 1.3 km deep, and displaying low-gradient summit erosion surfaces that suggest late Neogene uplift and incision of an extensive plateau. We discuss the spatial distribution of RSF in terms of process interactions and landscape evolution scenarios. Widespread metamorphic bedrock outcrops are confirmed as highly susceptible to RSF, particularly to large-scale slope deformation, but RSF also occurs on other lithologies as smaller rockslides and avalanches. Substantial spatial densities of RSF cluster around the residual, plateau-like range-top surface rims. We ascribe this to the ‘raised plateau’ features of the mountain range, where its fat, flat massifs engender greater slope stresses than would thin, serrated ones where arêtes and pyramidal peaks are gravitationally more stable. A large minority (42 %) of RSFs are spatially associated with glacial cirques and trough flanks. While these nominally qualify as paraglacial RSFs, glacial erosion may not be the main driver because the majority of RSFs occur along ridgetops and upper hillslopes in previously unglaciated fluvial contexts. Many of them thus qualify as parafluvial RSFs – i.e., occurring within a fluvial catchment but not directly generated by stream undercutting. We introduce the concept of fluvial–parafluvial and periglacial–parafluvial cycles as complementary to the recognised glacial–paraglacial cycle. All three process regimes may have prevailed concurrently or in succession, emphasising that cirque glaciation was probably not a principal agent in shrinking range-top erosion surfaces during the Quaternary. We point to post-orogenic (Neogene) tectonic uplift as the overarching driver of RSF in the Southern Carpathians, with pervasive fluvial incision keeping slopes close to failure thresholds. The role of RSF (extant and in earlier cycles) as a primary agent in perimeter scarp retreat and massif dissection here offers a ‘Transylvanian model’ of global interest whether as a comparator or a contrast for other ranges.

Remote Sensing Precursors Analysis for Giant Landslides

Monitoring and early warning systems for landslides are urgently needed worldwide to effectively reduce the losses of life and property caused by these natural disasters. Detecting the precursors of giant landslides constitutes the premise of landslide monitoring and early warning, and remote sensing is a powerful means to achieve this goal. In this work, we aim to summarize the basic types and evolutionary principles of giant landslide precursors, describe the remote sensing methods capable of identifying those precursors, and present typical cases of related sliding. Based on a review of the literature and an analysis of remote sensing imagery, the three main types of remote sensing techniques for capturing the geomorphological, geotechnical, and geoenvironmental precursors of giant landslides are optical, synthetic aperture radar (SAR), and thermal infrared methods, respectively. Time-series optical remote sensing data from medium-resolution satellites can be used to obtain abundant information on geomorphological changes, such as the extension of cracks and erosion ditches, and band algebraic analysis, image enhancement, and segmentation techniques are valuable for focusing on the locations of geomorphological landslide precursors. SAR sensors have the ability to monitor the slight slope deformation caused by unfavorable geological structures and can provide precursor information on imminent failure several days before a landslide; furthermore, persistent scatterer interferometric SAR has significant advantages in large-scale surface displacement monitoring. Thermal infrared imagery can identify landslide precursors by monitoring geoenvironmental information, especially in permafrost regions where glaciers are widely distributed; the reason may be that freeze–thaw cycles and snowmelt caused by increased temperatures affect the stability of the surface. Optical, SAR, and thermal remote sensing all exhibit unique advantages and play an essential role in the identification of giant landslide precursors. The combined application of these three remote sensing technologies to obtain the synthetic geomorphological, geotechnical, and geoenvironmental precursors of giant landslides would greatly promote the development of landslide early warning systems.

Slope Deformation Prediction Based on MT-InSAR and Fbprophet for Deep Excavation Section of South–North Water Transfer Project

In the operation and maintenance of the South–North Water Transfer Project, monitoring and predicting the canal slope deformation quickly and efficiently is one of the urgent problems to be solved. To predict the slope deformation of the deep excavated canal section at the head of the canal. We propose a new idea of adopting the joint prediction of MT-InSAR and Fbprophet. Firstly, MT-InSAR monitoring technology was used to invert channel deformation using 88 Sentinel-1A orbit-raising image data with a time baseline from 2017 to 2019. The time-series deformation of nine monitoring points was also extracted, and it was found that the time-series curves of the cumulative deformation of the channel slope showed fluctuations. The Fbprophet algorithm was then used to train the prediction model in Python to predict the channel slope deformation over the next 365 days. Finally, the prediction results were compared with the MT-InSAR monitoring values to analyze the prediction accuracy and applicability of the Fbprophet algorithm for the slope deformation monitoring of the South–North Water Transfer Project. The results show that: the deformation rate of the slope of the deep excavation section is in the range of 10 mm/a to 25 mm/a, the maximum accumulated deformation is about 60 mm, and the slope of the excavation canal shows a lifting phenomenon; among the nine monitoring points, the minimum and maximum predicted values of deformation using the machine learning prediction model trained in this paper were 56 mm and 73 mm, respectively; comparing the predicted and monitored values, their correlation coefficients were 0.998 at the highest and 0.988 at the lowest, and the minimum and maximum values of RMSE (RootMean Square Error) were 0.72 mm and 2.87 mm, respectively. It shows that the prediction model trained by the Fbprophet algorithm in this paper applies to the prediction of slope deformation in the deep excavation section, and our prediction results can provide a data reference for disaster prevention and the sustainable development of the South–North Water Transfer Project.

Rock slope deformation analysis of the powerhouse cut-slope at Middle Bhotekoshi Hydroelectric Project in Sindhupalchok District, Central Nepal

This paper elaborates the rock slope deformation analysis in a complex rock mass i.e., metamorphic rocks. At the powerhouse of the Middle Bhotekoshi Hydroelectric Project, Sindhupalchok, Nepal, the rock slope deformation has occurred as a result of excavation of natural rock slope turning into the cut-slope. The deformation yielded by different causes were studied and analyzed by kinematic analysis, inclinometer data combining with numerical modeling. For the study and analysis of the cut-slope, geotechnical data were collected from the existing rock types of the cut-slope. At first, the kinematic analysis was carried out by using the stereonet plot in DIPS. The core logs of investigation time were reviewed and tried to prepare the geological model of this part. The finite element method was used to analyze the stability of the rock cut-slope based on the geotechnical data. Similarly, the inclinometer recorded data were used to compare with the analyzed deformation data and tried to find out the weak zone within the cut-slope. The kinematic analysis showed that the rock slope has the least probability of failure. The result showed that there was tolerable deformation on the slope based on inclinometer data but failure was observed at PSIN-1 where the weak zone is present. The deformation at PSIN-1 was found to be in the thin ductile deformed zones where rock characteristics were different which was considered not operative for the slope stability.

Ground-Based SAR Moving Target Refocusing Based on Relative Speed for Monitoring Mine Slopes

Ground-based synthetic aperture radar (GBSAR) has the advantage of retrieving submillimeter deformation of the mine slope by using the differential interferometry technique, which is important for safe production in mining applications. However, the moving vehicle’s defocus/displaced signal will mask the SAR image of the mining area which affects the accuracy of interference phase extraction and deformation inversion. In order to remove its influence, the moving target can first be refocused and then removed. To our knowledge, there is no GBSAR moving target refocusing method currently. Hence, the refocusing method is necessary. To solve the above problem, this paper proposes a single-channel FMCW-GBSAR moving target refocusing method based on relative speed. Firstly, the FMCW-GBSAR moving target signal model is analyzed, and then the relative speed based signal model is deduced. Based on the model and GBSAR’s feature of incomplete synthetic aperture, the Range Doppler (RD) algorithm is adopted and improved to achieve refocusing using relative speed parameters. The algorithm is controlled by relative speed and squint angle; thus, the refocused target image can be obtained via searching 2D parameters. The proposed method is verified by the synthetic data, which are generated by combining NCUT FMCW GBSAR real data and simulated moving target echo.

Deformation Monitoring in Highway Slope with Square-Artificial-Marks-Based Image Processing Technology

To be able to easily and efficiently monitor the deformation characteristics of the highway slope, the author explores slope monitoring based on image processing methods. The image characteristics of highway slope deformation are studied by setting multiple square artificial marks and using image processing technology. The captured image is processed by graying, binarization, noise removal, region segmentation mark and pixel calibration, coordinate system establishment, and artificial mark coordinate point acquisition. We can calculate the coordinate value, and horizontal direction and vertical displacement deformation value of the observed artificial mark point in the image. By comparing with the observed artificial mark point coordinate value and the horizontal and vertical displacement deformation values, the result shows that the displacement point of the artificial mark point obtained by this paper’s method is consistent with the actual deformation trajectory, and the displacement deformation monitoring accuracy is 95.38%. The absolute error value of the single horizontal and vertical displacement is small. A method for monitoring the deformation of highway slope proposed in this paper can provide new ideas for solving practical engineering problems.

Determinations of the early warning threshold for creep landslides and their applications

<p indent="0mm">The accuracy of the threshold is very important for early warning of slopes. However, the existing slope failure threshold criteria are insufficiently accurate and have limited applicability. This paper proposes three dimensionless parameters based on slope deformation displacement, velocity, and acceleration and statistically analyzes 80 slope deformation monitoring examples. The second-order dimensionless failure threshold is obtained using probability and statistics theory. The dimensionless threshold is applied in the early warning analysis of landslide #2 in Jiangxi Province’s copper mine. The results show that (1) the “two-sample heteroscedasticity t-test” method shows that the dimensionless parameters in the failure case are significantly greater than the dimensionless parameters in the non-failure case; (2) a dimensionless threshold can eliminate the influence of vector parameters, which are physical in nature; (3) the “ROC curve” approach is used to validate the reliability and accuracy of the dimensionless threshold model, and it is theoretically explained that the prediction accuracy of the dimensionless threshold of acceleration is relatively the highest; (4) in this situation, the corresponding warning time of the three dimensionless thresholds is not the same, with the secondary dimensionless threshold of acceleration having the earliest time.

Research on the protection of expansive soil slopes under heavy rainfall by anchor-reinforced vegetation systems

An anchor-reinforced vegetation system (ARVS) is a new type of flexible slope protection system. ARVSs are composed of vegetation, anchors and high-performance turf reinforcement mats (HPTRMs) and can maintain the stability of expansive soil slopes while producing superior ecological effects. Through in situ comprehensive monitoring and comparative analyses, we systematically discuss the impact of heavy rainfall on ARVS-protected expansive soil slopes during the local wet season in Nanning. The results show that during the local wet season, the soil temperature and water content in vegetation-covered areas are lower than those in bare areas. The soil temperatures in different areas on the expansive soil slopes decrease with increasing depth. The ARVSs significantly affected the regulation of water transport and soil temperature, which limited soil deformation in different directions. The subsequent heavy rainfall would cause greater deformation of the expansive soil slope when less antecedent rainfall fell. Low-intensity and long-duration heavy rainfall events have greater negative impacts on expansive soil slopes than high-intensity and short-duration rainfall events. Under the action of severe rainfall-evaporation, expansive soil slopes protected by ARVSs can maintain stability.

Deformation and Failure Process of Slope Caused by Underground Mining: A Case Study of Pusa Collapse in Nayong County, Guizhou Province, China

Pusa village is located in the karst mountain area of Nayong County, Guizhou Province, China. Laoyingyan mountain rock is gently dipping, the upper part consists of hard rock formations, and the lower part is made up of soft rock composed of 3 coal seams. On August 28, 2017, a massive landslide occurred in this area, resulting in 82,3000 m3 of debris, which resulted in significant casualties and brought up the malaise in society. In this paper, the geological conditions and long-term mining activities in the study area are analyzed by field investigation. The base friction tests and numerical models are used to simulate and analyze the failure and deformation process of Pusa collapse to accommodate the research on the deformation and failure mechanism of the slope and provide better prevention and treatment suggestions. The results show that the Pusa collapse can mainly be attributed to unique geological conditions, underground mining activities, and the topography of the slope. The intensified mining activities promoted the development of fractures and cracks in the slope, resulting in unstable upper slopes. The failure process of the Pusa collapse can be summarized into four-stage: the development of goaves roof deformation, the crest of the slope cracks, intensification of deformation, and occurrence of collapse. The upper slope with high strength rock developed crack-toppling failure. Meanwhile, the upper slope with low strength rock developed subside-crack-sliding failure, and those two failures together contributed to the mechanism of Pusa collapse. Slope deformation and failure mechanism can be summarized as subside-crack-toppling-shear sliding type.

Criteria for ultimate aseismic capacity of high rockfill dam

<p indent="0mm">The ultimate aseismic capacity is important to evaluate the seismic safety of a rockfill dam. However, no specification in China explicitly stipulates the criteria for the ultimate aseismic capacity of a rockfill dam. Existing evaluation factors and their indices to represent earthquake-induced damage to rockfill dams are not unified, and there is a problem with the safety degrees obtained by the indexes of different evaluation factors not being coordinated. In this study, a large number of systematic analyses of overall elastic-plastic deformation and slip deformation of high rockfill dams (height &gt; <sc>200 m)</sc> under earthquake are performed in addition to a comparative study of measured engineering analysis. Based on the above studies, four basic principles for determining the criteria for the ultimate aseismic capacity of a high rockfill dam are proposed: strictly following the mapping relationship between the relative settlement ratio of dam crest and the damage degree of dams under earthquake, ensuring that the dam can not be a collapse in extreme earthquakes, taking the relative settlement ratio of dam crest as the key control evaluation factor, and ensuring the coordination of different evaluation factors such as the relative settlement ratio of dam crest and the slip deformation of dam slope. Finally, the criteria for the ultimate aseismic capacity of a high concrete face rockfill dam and a core-wall rockfill dam under earthquake conditions are proposed. The findings of the study could provide an important standard basis for determining the ultimate aseismic capacity of a high rockfill dam.

Fill‐and‐Spill, Tilt‐and‐Repeat (FaSTaR) cycles: Stratigraphic evolution above a dynamic submarine stepped slope

AbstractThe classic fill‐and‐spill model is widely applied to interpret topographic controls on depositional architecture and facies distributions in slope successions with complicated topography. However, this model implies a constant topographic configuration over the lifespan of a turbidite system. In contrast, the impact on patterns of erosion and deposition above dynamic slopes whose topographic configuration varies spatially over time remains poorly investigated. Here, using high‐resolution 3D seismic reflection data and more than 100 wells from a 40 km long stepped slope system (Campos Basin, offshore Brazil), we document the evolution of a sand‐prone turbidite system active during the Oligocene–Miocene transition. This turbidite system was influenced by vertical and lateral deformation, and we propose a new stratigraphic model to explain the resultant depositional architecture. Two depocentres were identified as steps, with channels on the proximal step, and channel–lobe complexes on the distal step, bounded by sediment bypass‐dominated ramps. Lateral stepping of channels on the proximal step, and oblique stacking of the down‐dip lobe complexes, each cut by through‐going channels, indicate multiple fill‐and‐spill cycles. A persistent north‐east‐ward stepping and thickening on the steps are interpreted to reflect lateral tilting of the seafloor driven by salt tectonics. The dynamic substrate prevented the establishment of a single long‐lived conduit across the proximal step, as recorded in systems with fixed topographic configurations. The filling of through‐going channels with mud at the end of each cycle suggests waxing‐to‐waning sediment supply cycles and periods of sand starvation when the lateral tilting dominated and drove avulsion of the feeder channels towards topographic lows. This study demonstrates that subtle dynamic slope deformation punctuated by discrete sediment supply cycles results in complex stratigraphic patterns with multiple phases, and multiple entry and exit points. Repeated cycles of fill‐and‐spill, tilt‐and‐repeat are likely to be present in other stepped slope systems.

Shallow Failure of Weak Slopes in Bayan Obo West Mine.

The slope stability of large open-pit mines has always been a concern and the analysis of large-scale slope landslides is a focus. However, shallow failure in soft rock slopes also has a serious impact on safe production. The northern slope of Baiyunebo West Mine has many shallow landslides in the final slope, resulting in damage of the maintenance channel of the belt transportation system, which has a serious impact on the safety of production. In order to reduce the shallow failure in weak rock slope, it is necessary to analyze the behavior and characteristics of shallow failure in weak rock. Firstly, the mechanical parameters of the intact rock were obtained by using the exploration data; secondly, through the analysis of blasting-damage range, the distribution characteristics of fractures after the failure of weak rock were obtained. Finally, through theoretical analysis, numerical simulation, surface displacement monitoring and on-site shallow-failure case analysis, the deformation and characteristics of shallow failure of weak rock slope in West Mine were obtained. It was found that the mechanical parameters of rock mass strength on the surface of weak rock slope and the original rock were quite different after mining disturbance. The mode of failure of shallow weak rock slope in the West Mine was creep-cracking; the numerical modelling analysis was carried out by using the assignment method of shallow lithology weakening and gradual change, which is more in line with the deformation characteristics of weak rock slope in West Mine. The lower deformation of the soft rock slope in West Mine is 3–5 times that of the upper deformation. The research results are helpful to understand the influence of blasting on the stability of soft rock slope. At present, West Mine has started to adjust blasting parameters according to the research results, so as to reduce the excessive damage of blasting to rock mass, so the stability of the slope is improved.

Effect of the Water-Air Coupling on the Stability of Rainfall-Induced Landslides Using a Coupled Infiltration and Hydromechanical Model

The water and air flow in soil pores in response to rainfall infiltration is an important factor affecting the stability of rainfall-induced landslides. The objective of this paper is to investigate the effect of water-air flow on the deformation and stability of rainfall-induced landslides based on a coupled infiltration and hydromechanical model. The model is formulated by the water and air flow equation, the mechanical equilibrium, and porosity equations. The rainfall infiltration is introduced as a flux boundary, which is determined according to the comparison of the infiltration capacity and rainfall intensity. The numerical model and solution approach are validated by simulating the Liakopoulos drainage test and a rainfall infiltration experiment with satisfactory results. Taking the Tanjiawan landslide as a case study, the water and air flow in response to rainfall infiltration and its effect on deformation and stability are examined. The results show that the pore air is gradually trapped and compressed due to rainwater infiltration. The entrapped air has a slowing effect on the rainfall infiltration and a pushing-out effect on the front sliding body, which is an important driving force for the evolution of the slope deformation and stability due to rainfall infiltration.

Was the deep-seated gravitational slope deformation enhanced by an earthquake? Evidence from shaking table tests

Was the deep-seated gravitational slope deformation enhanced by an earthquake? Evidence from shaking table tests

Research on stability of steep bank slope and reserved thin-walled rock cofferdam during excavation of intake foundation pit

The intake of water diversion project is generally located on the bank slope above the large reservoir or deep water area of a river. Due to the influence of water level change and hydraulic action, the rock mass of bank slope is seriously weathered and broken, leading that the rock mass has low strength and is easy to collapse or landslide. In this paper, the water intake engineering of the long-distance diversion project in central Shanxi Province is selected as the research object. The multi-point displacement meter is used to monitor the slope deformation after anchorage and concrete retaining wall support. Based on the FLAC3D V6.0 software, the numerical simulation of the excavation process of the steep reinforced river bank slope is carried out, and the long-term deformation of the slope is predicted. The excavation scheme of retaining outer thin-walled rock wall as water cofferdam is proposed. The excavation process of foundation pit, which is supported with concrete-filled steel tubular pile reinforcing cofferdam and concrete supporting beam, is simulated. It is found that the upper part of the steep slope supported by anchor cable and concrete retaining wall is stable, and the large deformation and plastic failure of the water-retaining thin rock wall are mainly affected by the disturbance of foundation pit excavation. The concrete-filled steel tubular pile support avoids the collapse of the reserved thin-walled cofferdam, and the horizontal beam in the foundation pit improves the stress state of the external wall of the foundation pit. The research results of this paper reveal the evolution mechanism of rock mass deformation and failure during excavation of foundation pit on steep bank slope, and provide guidance for excavation and support of foundation pit for similar bank slope.

Field Investigation and Dynamic Process Simulation: A Case Study of Rock Avalanche in Pusa Village, Nayong County, Guizhou Province, China

This paper geologically analyzed and numerically simulated the rock avalanche which happened in Pusa Village, Zhangjiawan Town, Nayong County, Guizhou Province, China on 28 August 2017, with approximately 5 × 10 m3 of failure mass. The features, dynamic process and evolution mechanism of the Pusa avalanche, based on the detailed field geological survey, UAV photography and monitoring video, was analyzed in detail, and the numerical model was established to simulate the initiation-movement-accumulation process. The results show that the rock avalanche originated basically from the limestone and siltstone of Yelong Formation, Triassic which extend approximately horizontally and possess developed dissolution and subsidence. The joints within such strata have progressively evolved into fissure belt and subsidence belt resulting from long-term weathering, and the steep joints parallel to slope surface were developed due to the tectonic and unloading actions. The slope deformed and fractured because of long-term gravity and weathering actions, and meanwhile the rainstorm and mining activity accelerated the deformation of slope, which finally resulted in the overall instability of slope. The in-depth analysis to the generation and disaster-induced mechanism of Pusa avalanche is of great importance to the prevention of such accidents.