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Cemented conglomerate accumulation is a weak and heterogeneous medium that occurs in western China. It consists mainly of argillaceous cement that loses strength rapidly upon contact with water, leading to collapse instability failure. Its deformation failure mechanism is complex and poorly understood. In this paper, the erosion failure mechanism of cemented conglomerate accumulation is investigated.

The collapse failure process after erosion of the slope foot for typical cemented conglomerate accumulation is studied based on field investigation using the particle discrete element method. And how the medium composition, slope angle and cementation degree influence the failure mode and process of the cemented conglomerate accumulation is examined.

The foot erosion of slope induces a tensile failure that typically manifests as “erosion at the foot of slope – tensile cracking at the back edge of slope top – integral collapse.” The collapse failure is more likely to occur when the cemented conglomerate accumulation has a higher rock content, a steeper slope angle or a weaker cementation degree.

A model based on rigid blocks and disk particles to simulate the cemented conglomerate accumulation is developed. It shows that the hydraulic erosion at the foot of the slope resulted in a different failure mechanism than that of general slopes. The results can inform the stability management, disaster prevention and mitigation of similar slopes.

The purpose of this study is to investigate the deformation characteristics and failure modes of the right bank slope of Xiluodu Hydropower Station after excavation.

Micro-seismic monitoring technology is applied to obtain the microfracture information and study the internal damage evolution law of the slope rock mass. A numerical model for discontinuous deformation analysis (DDA) is established to analyse the deformation characteristics and failure mode of the slope. Micro-seismic monitoring and DDA can verify and supplement each other's results in the investigation of slope failure.

The results show that the slope has a downhill displacement along the weathered zone under natural conditions; the maximum resultant displacement at the monitoring point is 380 mm. The micro-seismic events are concentrated in an area located 30–100 m horizontally away from the slope surface and at an elevation of 390–470 m. The distribution of these micro-seismic events is consistent with the location of the unloading and weathered zones; it is the same as the DDA simulation result.

The study is anticipated to be used as reference for the stability analysis of rock slopes. By combining the continuous (micro-seismic monitoring technology) and discontinuous (DDA) methods, the entire process starting from the gradual accumulation of internal rock micro-damage to the macroscopic discontinuous deformation and failure of the slope can be investigated.

This paper aims to analyze the influence of rotated anisotropy on the stability of slope, the random finite element method is used in this study.

The random field is generated by the discrete cosine transform (DCT) method, which can generate random field with different rotated angles conveniently.

Two idealized slopes are analyzed; it is observed that the rotated angle significantly affects the slope failure risk. The two examples support the conclusion that when the orientation of the layers is nearly perpendicular to the slip surface, the slope is in a relative stable condition. The results of heterogeneous slope with two clay layers demonstrate that the rotated angle of lower layer mainly controls the failure mechanism of the slope, and the rotated angle of upper layer exhibits a significant influence on the probability of slope failure.

The method for rotated anisotropy random field generation based on the DCT has a simple expression with few parameters and is convenient for implementation and practical application. The proposed method and the results obtained are useful for analyzing the stability of the heterogeneous slopes in engineering projects.

The paper aims to construct a method to simulate the relationship between the parameters of soil properties and the area of sliding mass of the true slip surface of a landslide.

The smoothed particle hydrodynamics (SPH) algorithm is used to calibrate a response surface function which is adopted to quantify the area of sliding mass of the true slip surface for each failure sample in Monte Carlo simulation. The proposed method is illustrated through a homogeneous and a heterogeneous cohesive soil slope.

The comparison of the results between the proposed method and the traditional method using the slip surface with minimum factor of safety (FS_min) to quantify the failure consequence has shown that the landslide risk tends to be attributed to a variety of risk sources, and that the use of a slip surface with FS_min to quantify the consequence of a landslide underestimates the landslide risk value. The difference of the risk value between the proposed method and the traditional method increases dramatically as the uncertainty of soil properties becomes significant.

A geotechnical engineer could use the proposed method to perform slope failure analysis.

The failure consequence of a landslide can be rationally predicted using the proposed method.

Earthworks are the embankments and cuttings that allow a railway to maintain a certain line, level and grade through the landscape. Earth embankments consist of an engineered bank of earth that carries the railway above the natural ground. A cutting is used to carry the railway through ground with a natural level above the line of the railway. Modern (post 1960s) earthworks are carefully engineered to perform well. However, many railways run on earthworks that were constructed over 100 years ago without the use of mechanised plant. The quality of construction of older earthworks was often poor compared with present-day engineering practice. Ageing of the earthwork structures, and the greater demands of heavier and faster trains and climatic change, means that earthworks suffer ultimate and serviceability failures that can present operational difficulties. Older earthworks that fail or do not perform well require maintenance and repair, and sometimes complete replacement. This chapter explores the main engineering considerations for modern earthworks, and the challenges associated with older earthworks including their modes of failure and upgrade and repair.

This paper aims to develop an effective framework which combines Bayesian optimized convolutional neural networks (BOCNN) with Monte Carlo simulation for slope reliability analysis.

The Bayesian optimization technique is firstly used to find the optimal structure of CNN based on the empirical CNN model established in a trial and error manner. The proposed methodology is illustrated through a two-layered soil slope and a cohesive slope with spatially variable soils at different scales of fluctuation.

The size of training data suite, T, has a significant influence on the performance of trained CNN. In general, a trained CNN with larger T tends to have higher coefficient of determination (R²) and smaller root mean square error (RMSE). The artificial neural networks (ANN) and response surface method (RSM) can provide comparable results to CNN models for the slope reliability where only two random variables are involved whereas a significant discrepancy between the slope failure probability (P_f) by RSM and that predicted by CNN has been observed for slope with spatially variable soils. The RSM cannot fully capture the complicated relationship between the factor of safety (FS) and spatially variable soils in an effective and efficient manner. The trained CNN at a smaller the scale of fluctuation (λ) exhibits a fairly good performance in predicting the P_f for spatially variable soils at higher λ with a maximum percentage error not more than 10%. The BOCNN has a larger R² and a smaller RMSE than empirical CNN and it can provide results fairly equivalent to a direct Monte Carlo Simulation and therefore serves a promising tool for slope reliability analysis within spatially variable soils.

A geotechnical engineer could use the proposed method to perform slope reliability analysis.

Slope reliability can be efficiently and accurately analyzed by the proposed framework.

The purpose of this paper is to propose a novel combined finite-discrete element method (FDEM), based on the cohesive zone model, for simulating rockslide problems at the laboratory scale.

The combined FDEM is realized using ABAQUS/Explicit. The rock mass is represented as a collection of elastic bulk elements glued by cohesive elements with zero thickness. To reproduce the tensile and shear micro-fractures in rock material, the Mohr-Coulomb model with tension cut-off is employed as the damage initiation criterion of cohesive elements. Three simulated laboratory tests are considered to verify the capability of combined FDEM in reproducing the mechanical behavior of rock masses. Three slope models with different joint inclinations are taken to illustrate the application of the combined FDEM to rockslide simulation.

The results show that the joint inclination is an important factor for inducing the progressive failure behavior. With a low joint inclination, the slope failure process is observed to be a collapse mode. As the joint inclination becomes higher, the failure mode changes to sliding and the steady time of rock blocks is shortened. Moreover, the runout distance and post-failure slope angle decrease as the joint inclination increases.

These studies indicate that the combined FDEM performed within ABAQUS can simulate slope stability problems for research purposes and is useful for studying the slope failure mechanism comprehensively.

This study is an attempt to estimate the influence of the presence of cavities on the stability of slopes in earth dams under rapid drawdown conditions. The purpose of this paper is to study the influence of different factors, such as the diameter and location of cavities, in addition to their existence effects.

A series of finite element simulation models were developed using PLAXIS 2D finite element software to analyse the stability of slopes in earth dams while considering various effects from cavities in the subsoil under rapid drawdown conditions.

The results indicated that the presence of cavities and an increase in the diameter of cavities decreased the stability of the upstream face dramatically for all examined locations in a horizontal direction; however, this effect was less on the downstream side. The results also showed that variations in the location of cavities in the horizontal direction have a greater effect on the stability than those in the vertical direction. The results revealed that increasing shear strength parameters of embankment does not reduce the influence of cavities on stability when those cavities are in critical locations.

A numerical model has been developed to simulate the effects of cavities on the stability of slopes in water-retaining structures/earth dams. The stability of earth dam slopes on upstream and downstream sides under rapid drawdown conditions considering various cavity effects, including their existence, diameter and location, were numerically analysed.

The purpose of this paper is to present a finite‐element analysis of the initiation of a slope failure in a small‐scale laboratory test due to pore pressure variation. To this aim, a fully coupled multiphase model for saturated/partially saturated solid porous materials based on porous media mechanics is used.

The slope is described as a three‐phase deforming porous continuum where heat, water and gas flow are taken into account. The gas phase is modelled as an ideal gas composed of dry air and water vapour. Phase changes of water, heat transfer through conduction and convection and latent heat transfer are considered. The independent variables are: solid displacements, capillary pressure, gas pressure and temperature. The effective stress state is limited by Drucker‐Prager yield surface for the sake of simplicity. Small strains and quasi‐static loading conditions are assumed.

The paper shows that the multiphase modelling is able to capture the main experimental observations such as the local failure zone at the onset of slope failure and the outflow appeared in that zone. It also allows understanding of the triggering mechanisms of the failure zone.

This work can be considered as a step towards a further development of a suitable numerical model for the simulation of non‐isothermal geo‐environmental engineering problems.

The multiphysics approach looks promising for the analysis of the onset of landslides, provided that the constitutive models for the multiphase porous media in saturated/unsaturated conditions and the related mechanical and hydraulic properties are described with sufficient accuracy.

Elasto‐plastic thermo‐hydro‐mechanical modelling of the initiation of slope failure subjected to variation in pore pressure boundary condition.

The purpose of this paper is to attempt to generate a better, systematic and scientific understanding of the basic reasons behind slope instability to help in developing the basic principles of landslide hazard zonation, monitoring and forecasting of landslide hazards for better and more effective landslide hazard mitigation and management.

The study is based on extensive field observations and intensive reviews of literature from secondary sources.

Mass movements especially landslides as they are known to common man are a recurring natural phenomenon and are an integral part of any geological/geomorphological circle of landform development through sequential development of slopes in any elevated region and especially in young fold mountain chains.

The paper presents a valuable insight into the basic reasons behind a landslide to spread awareness, to educate and sensitize people towards better and effective landslide hazard mitigation and thereby ensure people's participation in disaster management. It also aims to initiate and encourage research in the field of landslide management.

Landslides occur frequently and without any appreciable warning as such causing havoc and often insurmountable damage to life and property but despite their uncertainty, their causative factors and indicators of slope instability are very well known to an extent that the magnitude of these events, susceptible areas, the timing of such events and their potential impact can be studied, analyzed and evaluated on the basis of past occurrences and existing knowledge to mitigate their impact. The real value of the present study is to minimize losses due to landslides through better knowledge and enhanced levels of understanding of the phenomenon and its management by simply avoiding those particular reasons that could lead to slope instability problems.