In the numerical simulation of wave problems, it is often necessary to truncate the unbounded computational domain at a finite distance to reduce the requirement of computational resources. To manage this truncation, artificial boundaries are introduced, among which the Scaled Boundary Perfectly Matched Layer (SBPML) is regarded as a reliable strategy. In this paper, we implement the SBPML element into the commercial software ABAQUS using the User-Defined Elements (UEL) subroutine. The key equations of the SBPML, the procedures of meshing for the SBPML domain, and the implementation workflow of the subroutine are given in details. Four benchmark examples of wave propagation problems in unbounded domains are presented to demonstrate the accuracy and effectiveness of the proposed method. Furthermore, the application of the UEL in nonlinear seismic soil-structure interaction analysis is demonstrated by evaluating the seismic response of a five-layer alluvial basin in a homogeneous half space and an aboveground-underground integrated structure-multilayer soil system under obliquely incident earthquake waves. Using the proposed UEL, all wave propagation analyses can be directly implemented in ABAQUS with a seamless workflow. To facilitate the use of the proposed approach, the codes of the UEL are published in an open-source format.

In this study, finite element (FE) analysis of underground structure is carried out, which is subjected to the internal blast loading and the structure is surrounded with soil media. Three different methods to analyze the effect of blast loading on structure, i.e. ConWep, smooth particle hydrodynamics (SPH), and couple Eulerian-Lagrangian (CEL) are used for the simulation of blast loading using ABAQUS/Explicit (R) . Concrete damage plasticity (CDP), Mohr-Coulomb, Johnson-Cook (JC) plasticity model, Jones-Wilkins-Lee (JWL) equation of state and ideal gas are utilized for defining behavior of concrete, soil, steel, explosive and air, respectively. FE analysis is performed to compare the behavior of structure under different blast modelling methods. The effect of different explosive weights is considered to see the impact of the blast load on the structure. For parametric analysis, three explosive weights, 3kg, 5kg, and 10kg of TNT (trinitro toluene), and three concrete grades, M30, M35, and M40 are considered to see the stability of the structure. The effect of varied explosive weights and varied concrete grades is compared in terms of stress, pressure, and displacement at critical locations of the structure. The outcome of this shows that the change in explosive weight and concrete grade considerably affects the stability of the structure. As the explosive weight increases, damage to the structure increases, and with the increase in the concrete grade, the blast load resistance capacity of the structure increases. It is observed that buried part of the structure is more resistant to blast load compared to the structure visible above ground.

In modern highway construction, asphalt pavement is a widely used structural form, which is easily affected by various external conditions, among which the temperature effect is the most significant. In this paper, the cohesion model is used to simulate the structural cracks of asphalt pavement, the finite element method is used to simulate the asphalt concrete pavement model, and the temperature field simulation model of the pavement is established by using ABAQUS software, with the help of which the spatial distribution of stresses under different temperature conditions is deeply explored, and then the crack extension law during the process of temperature change is systematically investigated, and the effect of the temperature load on the degree of damage to the asphalt pavement is also studied. With the temperature change, the pavement surface layer is affected the most, and the soil base layer is affected the least. The higher the external temperature, the larger the crack expansion width inside the pavement structure, and the faster the corresponding expansion rate. The fatigue damage rate of the pavement structure is accelerated along with the increase of temperature. The research results can provide a theoretical basis for improving the high temperature performance of asphalt pavement.

Considering the environmental protection and infrastructure needs for solid waste recycling and improvement of soil engineering properties, a fiber-gangue composite soil consolidation material is proposed to improve the mechanical properties of expansive soils and the workability to resist freeze-thaw (FT) cycling effects. The unconfined compressive strength (UCS) of the expansive soil was measured at varying FT cycles. Then, thermal-mechanical field simulation using Advanced Simulation for Engineering and Sciences (ABAQUS) numerical simulation software was conducted to analyze the stress-strain behavior of the model and compared with the UCS test results obtained during the laboratory test. After that, the microstructural characteristics of modified soil systems after FT cycles were carried out using scanning electron microscope (SEM) mapping to obtain the reinforcement mechanism. The investigation results indicate that the UCS of the modified expansive soil (MES) not only increased after experiencing 12 FT cycles, but also demonstrated a 20.1% reduction in UCS inhibition by the improver compared to plain-expansive soil (PES). Therefore the addition of fiber-coal gangue composite effectively amends the effect of FT cycles on the UCS of expansive soil. UCS test results suggest that a reasonable 9 mm long 0.3% fiber and 20% coal gangue ratio of the composite modifier is advantageous to the soil's mechanical properties. ABAQUS numerical simulations results the UCS strength of the specimens deteriorates gradually with the increase in the number of FT cycles, which is in agreement with the laboratory measured values. From the SEM observation, the PES samples were loose and the pores increased, while the coal gangue and the fibers of the incorporated expansive soil particles formed links between them, the structure was tight, the pores and cracks were reduced, and the compactness was improved.

This study investigates the dynamic response of RC lined rectangular tunnel in soil subjected to internal blast load. For this purpose, a three-dimensional non-linear finite element model comprising of tunnel lining, reinforcement, and soil is analyzed in Abaqus/Explicit. The behaviors of soil, concrete, and steel are simulated using Drucker-Prager plasticity, concrete damaged plasticity, and Johnson-Cook (J-C) plasticity models, respectively. The effect of various grades of concrete (C30, C40, and C50) and lining thickness (300 mm, 400 mm, and 500 mm) on the dynamic response of the tunnel structure and the surrounding soil is investigated. It is observed from the results that deformations of tunnel lining increase with a decrease in the grade of concrete and decrease with an increase in lining thickness. The results suggest it is advantageous to increase the thickness of the liner for a certain grade of concrete, rather than increasing the grade of concrete for the same liner thickness for better blast response. The vulnerability of the tunnel liner is high at the roof-sidewall junction suggesting the need for better reinforcement detailing.

Various anchors are used to withstand uplift forces for offshore and onshore structures on which research is going on for almost the last six decades. In the present study, it has been attempted to obtain the responses of inclined anchors based on numerical studies. Uplift capacities of model anchor plates having dimensions of 0.025 m x 0.025 m, 0.050 m x 0.050 m, and 0.075 m x 0.075 m with embedment ratios of 1, 2, and 3 and inclination angles 30 degrees, 45 degrees, and 60 degrees with vertical, have been obtained under cyclic loading with 0.2 Hz, 0.5 Hz frequency and 0.002 m, 0.005 m amplitude. The soil bed has been made of locally available clay and the anchors are of mild steel. The numerical analysis has been carried out by ABAQUS, considering all relevant parameters of soil, plate size and inclination angle, and embedment ratio of anchor and also for different frequencies and amplitudes of loading. The variation of ultimate pullout capacity has been studied by varying these parameters. It has been observed that the ultimate capacity under pullout increases significantly with increase in the dimensions of the plate, the embedment ratio, and also the angle of inclination of the anchor with vertical.

Developing mega structures like highways and railways, bridges, and tall buildings constructed over soft clay becomes challenging for geotechnical engineers. Soft clays are considered problematic soils as they possess high compressibility and low shear strength. There are several methods for improving in situ conditions of soft clays. This research focuses on using geogrid to improve soft soil and increase its stability under loaded square footing. A model test was developed in this study for square footing resting on soft clay to investigate the effect of uniaxial geogrid to control the soil settlement and enhance its shear strength. The results of the experimental model were compared with the analytical solution using the finite element program ABAQUS, where a good agreement was found between the computed and measured data. The second objective of the research was to focus on the parameters that increase the bearing capacity of soil and hence reduce the settlement other than the parameters used in the verification case. This was achieved by conducting parametric studies using the developed numerical model. The Parametric studies focus on the role of different parameters that affect the interaction mechanism between the soil and geogrid. These parameters included the number of geogrid layers, the first geogrid location, and the geogrid length. Also, the impact of creep settlement of reinforced soft clay was considered. It was found that placing geogrid layers at depth not less than 1.3B where, the first geogrid located at distance U = 0.7 under the footing is more appropriate for improving soft clay properties. Also, the length of geogrid should be not less than 3B to be effective in reducing the consolidation settlement of the soft clay. Moreover, the geogrid layers are ineffective in reducing the settlement resulting from creep.

To comprehensively consider the impacts of stratification, residual pore water pressure, soil nonlinearity, and boundary permeability on consolidation settlement of soft soil foundations for accurate prediction, a continuous drainage boundary condition is proposed in this study that reflects the residual pore pressure under multistage loading, and a nonlinear elastic constitutive model based on the double logarithmic model is adopted to account for the nonlinear consolidation behaviour of soils. A UMAT subroutine is developed based on the proposed boundary condition and nonlinear elastic constitutive model. Subsequently, the developed subroutine is compared with the built-in linear elastic soil constitutive model in ABAQUS and engineering examples. The application of continuous drainage boundaries in stratified foundations is analysed, as well as the influence of factors such as the loading rate and soil nonlinearity on consolidation settlement. The results indicate that, compared to the built-in model, the subroutine developed in this study can be employed to more accurately calculate the nonlinear consolidation of multilayered foundations under multistage loading. By adjusting the loading rate parameter alpha k, consolidation under different loading conditions can be predicted. Additionally, the proposed boundary condition simplifies the calculations for soft soil foundations with sand layers, providing a novel computational approach for the design of construction loading schemes and long-term settlement predictions in soft soil foundations.

Progress in jet grouting technology has been focused on the cutting-edge observer of jets, which aims to generate large columns of jet grouting and increase the activity of construction sites. Since jet grouting techniques vary from conventional grouting methods to modern techniques, they can be used in a variety of soil types and their application areas are expanding quickly. So, grouting methods have become very popular methods for subsoil strengthening. This article includes finding the physical and mechanical properties of the soil of the AL-Rashdia site, using a single-jet grouting machine and a steel model to test concrete piles and jet piles, and a double-jet grouting machine to compare the results obtained from laboratory model of one-dimensional jet grouting column pile with those of a one-dimensional concrete pile. The comparison showed that the settlement of the jet pile was smaller than that of the concrete pile and the bearing load was higher with jet columns giving a high bearing capacity comparable with the concrete pile. Shen's method is more adequate to find the ultimate bearing load and the settlement for this load. Also, the ultimate pile ratio was 115.63% for the jet column, and the ultimate pile ratio for the concrete column was 123.49%. The compressive strength of the core sample of jet columns was large which improved the bearing capacity of the foundation.

This study investigates the behavior of rockfall protection on a reinforced concrete semicircular shed against impulse excitation forces by using finite element software ABAQUS and experimental analysis on a free-fall impact test machine. There is limited field knowledge about the response of rockfall protection reinforced concrete semicircular sheds under free-fall impact. The experiments are carried out through the 0.5-m center-to-center diameter of a semicircular reinforced concrete (RC) shed which has a 1.2-m length. The shape of the impactor is cylindrical with a free-fall height of 2.4 m on a semicircular reinforced concrete shed from a free-fall impact test machine. Conventional explicit analysis in finite element software ABAQUS was employed. The concrete damaged plasticity, Johnson-Cook plasticity, and Drucker-Prager models were used to mimic the reaction behavior of concrete, reinforcement, and soil, respectively. The findings from the finite element program ABAQUS were compared to the experimental data, which were found to be in close agreement. Furthermore, the simulation was carried out on the effect of important parameters such as variation in the velocity of the impactor, lining thickness, and length of the RC shed to predict the behavior of reinforced concrete shed.