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Due to the discontinuity of soil properties in inhomogeneous slopes, the potential slip surfaces are not smooth curve surfaces, which makes great challenges for the existing rigorous theoretical methods for stability analysis of the slopes reinforced with piles under seismic conditions. By utilizing the discrete kinematically admissible failure surface to establish a non-smooth slip surface, pseudo-static approach to simulate the seismic action, and energy balance relationship considering the pile axial forces to keep the basic equilibrium principle, we derive a closed-form solution to resolve this problem. Analysis results of some examples show that the proposed method can provide more conservative pile shear forces than the existing theoretical values with a relative error of about 8% under strong earthquake. The factors such as pile parameters, slope parameters, soil properties, and seismic acceleration coefficients have important effect on the pile shear resistance. The pile shear force is nonlinearly increasing with the slope angle, horizontal seismic acceleration coefficient, and thrust application point coefficient. However, it decreases slightly with the increase of the pile spacing owing to the pile axial force, which also has an influence on the relationship between the pile location and the shear force. Soil inhomogeneity can significantly change the pile shear force, but cannot generally influence the variation pattern of the shear force with these factors. The proposed method can serve as a helpful tool for the design of piled inhomogeneous soil slopes.

To address the seismic face stability challenges encountered in urban and subsea tunnel construction, an efficient probabilistic analysis framework for shield tunnel faces under seismic conditions is proposed. Based on the upper-bound theory of limit analysis, an improved three-dimensional discrete deterministic mechanism, accounting for the heterogeneous nature of soil media, is formulated to evaluate seismic face stability. The metamodel of failure probabilistic assessments for seismic tunnel faces is constructed by integrating the sparse polynomial chaos expansion method (SPCE) with the modified pseudo-dynamic approach (MPD). The improved deterministic model is validated by comparing with published literature and numerical simulations results, and the SPCE-MPD metamodel is examined with the traditional MCS method. Based on the SPCE-MPD metamodels, the seismic effects on face failure probability and reliability index are presented and the global sensitivity analysis (GSA) is involved to reflect the influence order of seismic action parameters. Finally, the proposed approach is tested to be effective by a engineering case of the Chengdu outer ring tunnel. The results show that higher uncertainty of seismic response on face stability should be noticed in areas with intense earthquakes and variation of seismic wave velocity has the most profound influence on tunnel face stability.

The seismic performance and stability analysis of slopes are important in predicating damage and mitigating potential losses in landslide-prone areas. Fragility functions can give results of slope performance assessment that are more comprehensive and richer. This study presents a procedure of constructing seismic fragility functions for slope stability analysis with various vulnerability states based on incremental dynamic analysis (IDA). IDA is a performance-based earthquake engineering analysis based on a series of dynamic time history analyses conducted for suitable multiple-scaled seismic records. IDA not only estimates the seismic demand and capacity of systems but also provides basic data for the estimation of fragility functions. Firstly, an ensemble of seismic records meeting the requirements of specific site conditions of a slope is selected to consider the randomness of ground motion. A series of seismic stability analyses of the slope are performed to obtain the dynamic safety factor time history of the slope. Each minimum safety factor and corresponding seismic intensity measure is then extracted to develop a set of IDA curves. On the basis of IDA results, analytical seismic fragility functions of a slope are developed considering the prescribed various vulnerability states of the slope in terms of the safety factor. The failure probabilities of exceeding different specific vulnerability states for a given intensity measure of the earthquake are finally obtained.

A modified pseudo-dynamic method is introduced in the paper at first, then geometric model of seismic stability on the waterfront rock slope considering the non-linear twin shear criterion is established. Finally the influence factors on the stability of rock slope are analyzed. The conclusions are drawn that the stability of rock slope decreases as the external loading q , rock unit weight γ , horizontal seismic acceleration coefficient k h and vertical seismic acceleration coefficient k v increases, and it increases as uniaxial compressive strength σ c , the water depth h 1 and parameters of rock mass properties m i and GSI of rocks increases. These conclusions can provide great instruction significance for the future engineering design.

The escalating scarcity of disposal areas for tailings and the prevalence of abandoned conventional tailings dams necessitate innovative construction methods, leading to the emergence of hybrid tailings dams. These dams amalgamate two conventional methodologies, enabling the revitalization and reutilization of abandoned dams by enhancing the dam height. This study aims to rigorously assess the stability and responses of hybrid tailings dams, focusing on their behaviour under static and seismic conditions, through Finite Element Method (FEM) analyses. The seismic responses of six distinct hybrid tailings dams were meticulously analysed employing the equivalent linear method. Three varying earthquake motions were considered. The analyses uncovered that the upper segment of the hybrid construction profoundly impacts the response and stability of the entire dam. Nevertheless, overlaying any other hybrid method, be it downstream or centerline, over the upstream method was found to be satisfactory under low to medium seismic conditions. One noteworthy finding was the possibility of raising existing abandoned upstream method of tailings dams with critical stability issues. It is found that it is safe to use hybrid methods of construction such as downstream and centerline over exiting upstream methods of tailings construction without compromising its stability. In conclusion, our study underscores the pragmatic and sustainable potential of hybrid methods, excluding the upstream method in upper constructions, as a viable solution to address the scarcity of disposal areas. This approach not only offers a practical means to revitalize existing tailings dams but also contributes to the advancement of hybrid tailings dam construction practices.

Abstract Seismic slope stability analysis at regional scale (e.g., landslide hazard mapping, infrastructure slope management) is essential in areas that are susceptible to earthquake. Analytical infinite slope model is well suited and widely used for regional analyses which involve hundreds and thousands of slopes. Use of infinite slope model implicitly assumes shallow translational failure mechanism. However, earthquake can also cause deep rotational failure, which is more destructive and should also be considered. This study aims to develop closed-form solutions that can be efficiently used for seismic slope stability analysis at regional scale considering deep rotational failure mechanism. The existing research is critically reviewed first, and their shortcomings are identified. In contrast to the conventional “two-step” approach, a more efficient and versatile “one-step” approach is proposed in this study. The “one-step” approach can be used to calculate factor of safety for pseudo-static analysis and yield coefficient for displacement-based seismic analysis. To consider the effects of uncertainty from soil properties and seismic loading, the “one-step” approach is further extended for probabilistic analysis and application is demonstrated through a case study. The efficiency and versatility of the proposed “one-step” approach make it well suited for regional seismic slope stability analysis.

This study developed a finite-element lower-bound procedure to investigate seismic slope stability in homogeneous and non-homogeneous soils. In order to account for dynamic earthquake inputs, horizontal and vertical accelerations are expressed by the pseudo-dynamic approach, in the form of sinusoidal functions. Within the framework of lower-bound theory, the seismic slope stability analysis is transformed to a linear programming problem subjected to: stress equilibrium, stress discontinuity, stress boundary and yield conditions. An interior-point algorithm implemented into MATLAB was adopted to seek optimal lower-bound solutions of slope bearing capacity and safety factor. The proposed procedure for lower-bound analysis of seismic slope stability was validated by comparing the slope safety factor obtained from different approaches including limit equilibrium and Abaqus. A nonuniform soil slope with linearly varied and layered soil strength parameters and non-associated flow rule are considered, and the corresponding effects on seismic slope stability are discussed. The true solution of safety factor to seismic slope stability is well assessed by rigorous lower and upper bounds with the discrepancy no greater than 4.5%.

In order to investigate the failure effect of seismic fault and the slope stability under seismic damages along highways, the spatial distributions of earthquakes previously occurred in engineering research areas was qualitatively analyzed. Afterwards, the study put forward a seismic fault model along highways to analyze its kinematic characteristics. On this basis, by using ABAQUS finite element program, the seismic response of the selected representative cutting slope of highways in seismic damage areas was calculated. The displacement field output from the programs was used to analyze the displacement change in the top of the slope while the acceleration obtained from program was applied for calculating the coefficient of acceleration distribution. By substituting the stress field output by the dynamic finite element analysis software into the genetic algorithm (GA) program compiled by using MATLAB, the time interval curve of safety factors of the slope was calculated and critical slip surfaces can be intelligently searched. By doing so, the change law of safety factors with the change in acceleration of seismic waves and the value range of safety factors of the envelop diagram of slip surface can be obtained.

Slope stability is one of the most important issues of geotechnical engineering. Significant slope failures (landslides), which result from earthquakes, can cause considerable losses of life and property. Hence, it is required that a slope keeps its stability under the effect of earthquake forces. This study includes the numerical analysis (pseudo-static) of slopes improved with stone columns under the effect of earthquake force. In the analysis conducted using the finite element program, the safety factor was determined by performing the safety analysis of the slopes modeled (different s/D (2, 2.5, 3) ratios, c/(γ.H) (0.19, 0.14, etc.) ratios, and slope angles (β: 20°, 25°)) without the effect of earthquake force and under the effect of earthquake force. As a result of this study, it was observed that the slopes improved with stone columns had a higher factor of safety compared to the slopes without stone columns both under the effect of earthquake force and without the effect of earthquake force. In the study, the safety factor of the slopes improved with stone columns under the effect of earthquake force increased up to 1.24 times in comparison with the slopes not improved with stone columns. Furthermore, under the effect of earthquake force, a 22.50% decrease was observed in the horizontal displacement of the slope model supported with stone columns compared to the slopes without stone columns. The study determined that the stability of clay slopes reinforced with stone columns under the effect of earthquake force increased. In light of the data obtained from this study, it is thought that it may be important in terms of creating preliminary information in land applications that require quick and economical solutions. Moreover, it is thought that the study will shed light on other studies to be carried out since it is a basic study on the numerical investigation of finite clay slopes reinforced with stone columns under the effect of earthquake force (pseudo-static).

For thousands of years, engineers have been grappling with slope instability as an issue in geotechnical and geological engineering. Earthquake loading has a great impact in slope stability. The present study is to investigate the impact of various soil properties and slope geometry on FOS in the presence as well as in the absence of seismic loading. Here, pseudo-static methods are used to analyses seismic slope stability under earthquake loading. From parametric studies, present work concluded that the FOS values start to decline drastically with earthquake impact. Moreover, various prediction models have been developed using Multiple Linear Regression (MLR) & Multiple Non-Linear Regression (MNLR) considering all the data. The input data of slope stability estimation consists of the values of soil parameter, slope parameter and earthquake loading parameters. As an output, MLR and MNLR predict FOS values as a function of these parameters. The model is then checked by comparing the results to another ten actual situations. It was found that the predicted FOS using MNLR gives satisfactory results.