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In the fields of structural and geotechnical engineering, improving the understanding of soil–structure interaction (SSI) effects is critical for earthquake-resistant design. Engineers and practitioners often resort to finite element (FE) software to advance this objective. Unfortunately, the availability of software equipped with boundary representation for absorbing scattered waves and ensuring consistent input ground motion prescriptions, which is necessary for accurately representing SSI effects, is currently limited. To address such limitations, the authors developed Seismo-VLAB (SVL v1.0-stable) an open-source software designed to perform SSI simulations. The methodology considers the integration of advanced techniques, including the domain decomposition method (DDM), perfectly matched layers (PMLs), and domain reduction method (DRM), in addition to parallel computing capabilities to accelerate the solution of large-scale problems. In this work, the authors provide a detailed description of the implementation for addressing SSI modeling, validate some of the SVL's features needed for such purpose, and demonstrate that the coupled DRM–PML technique is a necessary condition for accurately solving SSI problems. It is expected that SVL provides a significant contribution to the SSI research community, offering a self-contained and versatile alternative. The software's practical application in analyzing SSI and directionality effects on 3D structures under seismic loading demonstrates its capability to model real-world earthquake responses in structural engineering. [ABSTRACT FROM AUTHOR]

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Non-biodegradability of rubber tires contributes to pollution and fire hazards in the natural environment. In this study, the flexural behavior of the Rubberized Reactive Powder Concrete (RRPC) beams that contained various proportions and sizes of scrap tire rubber was investigated and compared to the flexural behavior of the regular RPC. Fresh properties, hardened properties, load-deflection relation, first crack load, ultimate load, and crack width are studied and analyzed. Mixes were made using micro steel fiber of the straight type, and they had an aspect ratio of 65. Thirteen beams were tested under two loading points (Repeated loading) with small-scale beams (1100 mm, 150 mm, 100 mm) size. The fine aggregate is replaced by 5, 10, and 15%, respectively, with crumb rubber. While replacement of silica fume was 10, 20, 30, and 50%, respectively, with very fine rubber. Also, chip rubber was added to the mixture as coarse aggregate with 5, 10, and 15%. Five tested beams were chosen as case studies to analyze and compare the results of the ABAQUS software with the experimental results. The results showed that the flexural behavior of RRPC beams that contains rubber was acceptable when compared with the flexural behavior of the RPC beam (depending on load-carrying capacity). The crack width was decreased by including waste rubber and steel fibers. There is a satisfactory agreement between the results of the numerical analysis and the results of the experimental testing. Slight ultimate load differences are targeted between the effects of the monotonic loading and the repeated loading.

Soil-rock mixture is a complex multi-phase composite geotechnical material, and its strength is determined by the physical properties of constituent multi-phase materials and their coupling mechanical response between different phases of materials. Based on the Eshelby-Mori-Tanaka equivalent inclusion average stress principle, a theoretical model of multi-scale coupled shear strength of soil-rock mixture considering the interaction effect of rock block and soil is established, and the rotational freedom reflecting the microscopic motion details of rock block is introduced. Moreover, a multi-scale coupled constitutive relationship of soil-rock mixture is derived and compiled into a multi-scale finite element program. Based on the large-scale direct shear test of soil-rock mixture, the model parameters of the multi-scale finite element method are determined, and then the multi-scale finite element program is used to simulate and predict the cross-scale deformation process of the soil-rock mixture slope. The results show that the multi-scale finite element method can effectively describe the influence of the mechanism of the micro motion characteristics of the soil-rock mixture on the macro mechanical response, and can effectively overcome the pathological mesh-dependency of the classical finite element method; the rotation displacement of the rock block is mainly concentrated within the shear zone of the slope. The maximum rotational displacement of rock blocks inside the soil-rock mixture slope is 40.7°, and the rotational displacement of rock blocks outside the shear zone is about 0°. The physical mechanism of the cross scale evolution of the shear band of the soil-rock mixture slope is that: the rotation of the rock blocks weakens the strain transmission ability between the rock block and the matrix soil, thus forming the concentration and development of the plastic strain, and finally leading to the penetration of the shear bands of the slope and the overall sliding failure.

A Genetic Algorithm model, coupled with Finite Element Programming (GA-FEP), has been developed to create an optimal design for hydraulic structures to address seepage problems. While the objective function of the optimization model was to minimize the construction costs of the hydraulic structure, the main constraints were to satisfy safety factors concerning uplift pressure and exit gradient. The GA-FEP model proposed here meets the requirements of an optimal hydraulic design in two stages. Firstly, a validated numerical model coded using Finite-element Programming (FEP), was used to analyze seepage problems. This was followed by application of Genetic Algorithm (GA) and finite-element programming (FEP) to establish the optimum depth and location for cut-offs. A MATLAB programming code was used to create the link between the numerical and optimization model, creating a simulation–optimization (S–O) model. The effects of hydraulic conductivity and anisotropic ratios on the hydraulic structure design, were also investigated. The results indicate that the proposed GA-FEP model will provide a safe, efficient and economical hydraulic cut-off design. Evaluation of the model revealed acceptable agreement between expected and simulated seepage parameters pertinent to the hydraulic structure design. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

Geotechnical Engineering has developed many methods for soil improvement so far. One of these methods is the stone column method. The structure of a stone column generally refers to partial change of suitable subsurface ground through a vertical column, poor stone layers which are completely pressed. In general terms, to improve bearing capacity of problematic soft and loose soil is implemented for the resolution of many problems such as consolidation and grounding problems, to ensure filling and splitting slope stability and liquefaction that results from a dynamic load such as earthquake. In this study, stone columns method is preferred as an improvement method, and especially load transfer mechanisms and bearing capacity of floating stone column are focused. The soil model, 32 m in width and 8 m in depth, used in this study is made through Plaxis 2D finite element program. The clay having 5° internal friction angle with different cohesion coefficients ( c 10, c 15, c 20 kN/m) are used in models. In addition, stone columns used for soil improvement are modeled at different internal friction angles ( ϕ 35°, ϕ 40°, ϕ 45°) and in different s/D ranges ( s/D 2, s/D 3), stone column depths (B, 2B, 3B) and diameters ( D 600 mm, D 800 mm, D 1000 mm). In the study, maximum acceleration ( a = 1.785 m/s) was used in order to determine the seismic coefficient used. In these soil models, as maximum acceleration, maximum east-west directional acceleration value of Van Muradiye earthquake that took place in October 23, 2011 was used. As a result, it was determined that the stone column increased the bearing capacity of the soil. In addition, it is observed that the bearing capacity of soft clay soil which has been improved through stone column with both static and earthquake load effect increases as a result of increase in the diameter and depth of the stone column and decreases as a result of the increase in the ranges of stone column. In the conducted study, the bearing capacity of the soil models, which were improved with stone column without earthquake force effect, was calculated as 1.01-3.5 times more on the average, compared to the bearing capacity of the soil models without stone column. On the other hand, the bearing capacity of the soil models with stone columns, which are under the effect of earthquake force, was calculated as 1.02-3.7 times more compared to the bearing capacity of the soil models without stone column. [ABSTRACT FROM AUTHOR]

This analysis was carried out based on the smeared crack model and plasticity damage model in general finite element program ABAQUS. Comparison and analysis were made on the key factors of concrete constitutive models that have effect on the static mechanical behavior of structural members. Then the mechanical behavior of reinforced concrete members and steel-concrete composite members under monotonic loading and cyclic loading were simulated using various concrete constitutive models. Both the smeared cracking model and the plasticity damage model could accurately simulate the macroscopic response of flexural concrete members or flexural composite members subjected to monotonic load, and the smeared cracking model was more accurate in simulating the cracking behavior of concrete, applicable for analyzing the stress situation of concrete during stress-strain space constantly changing after cracking. Besides, the plasticity damage model could be adopted to simulate the stress behavior of concrete structures or composite structures under the action of cyclic load. The two models could not accurately simulate the whole process of stress behavior of concrete in two-dimensional or three-dimensional stress state. [ABSTRACT FROM AUTHOR]

In this study, the transient responses of a composite laminated plate and cylindrical shells subjected to low-velocity impacts were investigated numerically. The shear deformation theory of a doubly curved shell and von Karman’s large deflection theory were used to develop a geometrically nonlinear finite element program. It is well-known that in the case of a flat plate with fixed boundary edges, a geometrically nonlinear analysis yields larger contact forces and smaller deflections than a corresponding linear analysis. However, in the case of cylindrical shells, an opposite result was found in this study; a geometrically nonlinear analysis exhibited smaller contact forces and larger deflections than a corresponding linear analysis. The reason for this opposite result is described in this study. Conversely, with a plate and shells that have the same size, shells with a larger curvature exhibited smaller deflections and larger contact forces. The strain distribution at the bottom surface of the plate/shells using the geometrically nonlinear analysis exhibited markedly or only marginally larger tensile areas than those produced using the linear analysis. [ABSTRACT FROM AUTHOR]