The construction of tunnels in soft ground leads to ground movements. In urban areas with soft soils, these movements can affect the safety of surface structures. This paper investigates the interaction between tunnelling in soft soil and adjacent piled structure. Several three-dimensional finite element analyses are performed to study the deformation of pile caps and piles during the construction of a nearby tunnel. Comparison between free field and coupled analyses is also presented. To simulate the tunnelling process and its effects on piled structures, one symmetric half of the soil medium, the tunnel boring machine, the face pressure, the final tunnel lining, the pile caps, and the piles are modelled in several construction phases. The first part of the paper describes the adopted numerical model. Then, pile cap movements as well as pile deformation and bending moments resulting from the tunnelling process are investigated. The influence of the superstructure stiffness and its gravity load level on the tunnelling-produced response of the pile foundation is also investigated. Finally, the results of coupled analyses, which include the superstructure, are compared to those obtained using the analysis of piles alone (excluding the superstructure). This comparison helps to evaluate the later type of analysis that is typically implemented in routine designs.

A recently developed technique for the digital simulation of spatially incoherent seismic ground motions is extended to include two or three spatial coordinates. This extended approach allows for four situations: (1) Simulation in the far field; (2) simulation in the near field of a small source; (3) simulation in the near field of an extended source; and (4) simulation in the near field of a limited source. In each situation, both direction‐dependent (isotropic) and direction‐dependent (anisotropic) coherency structures are accounted for. The developments proposed may facilitate the seismic analysis of structures involving foundation coupling in two or three dimensions accounting for ground motion spatial incoherence, response nonstationarity, and system nonlinearities. They can also be useful in evaluating the response of structures to other spatially variable random fields such as those of wave forces and turbulent winds.

A 3D finite element model (FEM) for predicting the distribution of lateral pressure in a square flexible walled steel silo during the filling phase was analyzed in this study. The numerical approach, developed using Abaqus software, predicts the stress state in bulk solids, as well as the pressures exerted on the silo walls. An elasto-plastic model using the Drucker–Prager criterion was employed to simulate the behavior of the granular materials. The FEM simulates the behavior of the bulk solid and its interaction with the silo’s wall and base using a surface-to-surface discretization model. The model’s predictions were validated by previous experimental measurements. The results revealed good agreement between the FEM predictions and the experimental measurements. The research confirms that the lateral pressure distribution is not uniform at any silo level. This highlights the fact that many available theories and current design codes are not accurate for flexible steel walls. As a result of the wall’s deformability, pressure regimes on the silo wall change significantly in the horizontal direction at any level. The results showed that the horizontal variations of lateral pressure change drastically with regard to wall stiffness. The FEM has been used to investigate the effect of critical parameters on wall pressure distribution, such as properties of bulk solids, wall thickness, and silo type, whether deep or flat.

As is well known, in the current design codes, the shear strength of beams is calculated based on the modified truss theory, which does not consider the effects of the flange area of T-beams. The main objective of this paper was to gain a better understanding and enhance the experimental database of the shear behavior of RC T-beams and illustrate the contribution of the flange to the shear capacity of T-beams. To accomplish this aim, a specially designed experimental program was executed, and its test results were analyzed. The main investigated variables were flange dimensions (thickness and width) and its reinforcement (longitudinal and/or vertical). Nineteen simply supported beam specimens were tested to failure under a load configuration made of two concentrated loads. Eighteen specimens had T-shaped cross-sections, while one specimen had a rectangular cross-section for comparison purposes. The items monitored during testing included the development of diagonal cracks, concrete strains, reinforcement strains, maximum loads, and deflections. Test results showed a notable increase in the shear strength of T-beams compared to rectangular beams with the same web size. For the range of variables investigated, increasing the flange thickness-to-beam depth ratio (ρ_t) from 0.3 to 0.5 increased the shear capacity by up to 54%. In addition, increasing the flange width-to-web width ratio (ρ_b) from 3 to 5 increased the shear capacity by up to 19%. It was also shown that the results of three-dimensional finite element (FE) analyses using ANSYS compared reasonably well with the test results for all specimens. Finally, based on the test and FE results, a simplified method that accounts for the contribution of the flange to shear capacity was proposed.

This research addresses the nonlinear analysis of flat bottom clinker silos that are typically used to store granular materials. Most of silos’ failure is due to the inefficiency to resist seismic forces. One of the silo failure reasons is that filled granular material is usually treated as a water pressure which is not realistic. Water pressure is linearly distributed, while granular material has a nonlinear distribution along silo height. The main investigated variables were silo width, height, reinforcement ratio, and the existence of opening in the bottom part of the silo wall. Effects of these variables on silos’ dynamic properties - modal periods and mode shapes - as well as seismic response, base shear, base overturning moment, and the least number of modes needed to satisfy mass participation of 90%, were examined. Extensive numerical analyses were conducted to examine these parameters using different types of analyses such as free vibration, response spectrum, and pushover analysis. It was found that increasing height on time-period has a great effect when compared to the effect of diameter increase. Reinforcement ratio in silo without openings has a minor effect in small diameters while it has a major effect in case of silos with large diameters.