Extended end-plate (EP) bolted connections are widely used in steel structures as moment-resisting connections. Most of these connections are semi-rigid or in other words flexible. The paper aims to study the behavior of such connections under the effect of column top-side cyclic loading using the finite element (FE) method. For semi-rigid connections, it is very vital to determine the moment-rotation relationship as well as the connection stiffness. These beam-column connections have been parametrically studied, the effect of joint type, shear forces, diameter of bolt, thickness of end-plate, and end-plate style were studied. Parametric studies show that the panel zone shear force is the key factor and has a significant effect on the connection stiffness. Finally, based on the component method, the stiffness of the bending component is improved, and the initial stiffness calculation model of the connection under column top-side cyclic loadings is established. The results show that the calculation model is in good agreement with the finite element analyses, and this proves that the calculation model proposed in this study could act as a reference method.

Based on numerical shape functions and the structural stressing state theory, the mechanical properties of the curved prestressed concrete box girder (CPCBG) bridge model under different loading cases are presented. First, the generalized strain energy density (GSED) obtained from the measured strain data is used to represent the stressing state pattern of the structure; then, the stressing state of the concrete section is analyzed by plotting the strain and stress fields of the bridge model. The stressing state pattern and strain fields of the CPCBG are shown to reveal its mechanical properties. In addition, the measured concrete strain data are interpolated by the non-sample point interpolation (NPI) method. The strain and stress fields of the bridge model have been plotted to analyze the stressing state of the concrete cross-section. The internal forces in the concrete sections are calculated by using interpolated strains. Finally, the torsional effects are simulated by measuring the displacements to show the torsional behavior of the cross-section. The analysis and comparison of the internal force and strain fields reveal the common and different mechanical properties of the bridge model. The results of the analysis of the curved bridge model provide a reference for the future rational design of bridge projects.

In urban areas, it is common to construct underground structure nearby existing buildings. To investigate the impact of excavation construction on the adjacent existing buildings and surrounding soil, eight parallel scale model tests that considered the process of cut and cover construction are carried out with two kinds of the diameter of support piles, two kinds of the adjacent structure, and two kinds of the relative horizontal distance from the excavation in the laboratory. And, the variations of horizontal and vertical displacements of adjacent buildings and the soil pressure surrounding the excavation and the foundations of existing buildings with different parameters are presented and discussed. Then, the experimental data and the results of eight prototype finite element models are compared and analyzed.

This study investigated the flexural behavior of concrete one-way slabs reinforced with CFRP grids as longitudinal reinforcement, employing both experimental and finite element (FE) methods. A total of eight concrete one-way slabs were tested, including one with a steel grid and seven with CFRP grids. The test variables considered were concrete strength grade, grid size, and concrete cover thickness. The experimental results revealed that the CFRP grid-reinforced slabs underwent significant deformation without failure. Concrete strength grade was found to significantly influence the cracking load, with an increase of 64.1% observed when the grade was raised from C20 to C40. Reducing the cover thickness proved most effective in enhancing serviceability load capacity, yielding a 44.9% increase when the cover was reduced from 30 mm to 10 mm. Additionally, a finite element model was developed and validated against the experimental results, showing good agreement.

Excessive vibration of temporary grandstand by the crowd has lateral rhythmic motions, which attracted increasing attention in the recent years. This paper focuses on experiments where a temporary grandstand occupied by 20 participants is oscillated by a shaking table with a series of random waves and the crowd-induced rhythmic swaying motions at lateral direction, respectively. The dynamic forces that were induced by participants who have swayed at 0.51.8Hz are recorded by a tri-axial human biomechanics force plate. A new relationship between the annoyance rate and structural acceleration at logarithmic coordinate is investigated and proposed, and the swaying load model is given. Based on these experimental results, a simplified three-degree-of-freedom lumped dynamic model of the joint humanstructure system is reinterpreted. Afterwards, combined with a feasible range of crowd/structural dynamic parameters, a series of interaction models are analyzed, the vibration dose value (VDV) of the structure is obtained and discussed, and the notable parameters for interaction model are predicted. The experimental results show that the lateral serviceability limit is 1.29m/s^1.75 and the upper boundary is 2.32m/s^1.75. The dynamic response of model indicated that the VDV of structure will be decreased with increasing the mass of static crowd and damping ratio of the dynamic crowd. The max response of the model is α0.6, f₂=1.8Hz or α>0.6, f₂=1.5Hz or f₁=2.53.5Hz. It may be used as a reference value in vibration safety and serviceability assessment of TDGs, to estimate realistically the vibration response on the occasions when the crowds are swaying.