Fiber element-based nonlinear analysis of concrete bridge piers with consideration of permanent displacement

Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near- fault ground shaking. In this research, the influence of distributed plasticity modeling parameters using both force-based and displacement-based fiber elements in the prediction of internal forces obtained from the nonlinear static analysis is studied. Having chosen suitable type and size of elements and number of integration points, the authors take the next step by investigating the influence of material behavioral model employed for the prediction of permanent deformations in the nonlinear dynamic analysis. The result shows that the choice of element type and size, number of integration points, modification of cyclic concrete behavior model and reloading strain of concrete significantly influence the fidelity of fiber element method for the prediction of permanent deformations

A novel index for damage detection of deck and dynamic behavior of horizontally curved bridges under moving load

The purpose of this paper is to evaluate the responses of horizontally curved bridges that are affected by vehicles load. The effect of vehicles dynamic loads on bridges is influenced by factors such as geometric characteristics of structures and moving loads specifications. To consider the effect of dynamic loads in design of bridges, static load increases with a coefficient which is called “impact factor” in Design Codes. In this paper, by examining the effect of curvature of deck and the speed of vehicles which are passing along the bridge on the dynamic response of bridge, set of new equations for DAF is presented. For this purpose, dynamic analysis is performed for seven bridges with different radius of curvature under the influence of AASHTO truck. In the case study models, it can be seen that the separation of impact factor into two different coefficients; support reaction and displacement responses make bridge design more economical and safer. Reduction of the curvature radius decreases dynamic amplification factor (both coefficients). To identify the possible damages of the examined bridges in the early stages of the advent a new index is presented. This index can predict the damages due to moving vehicles

Proposed Cyclic Loading Protocol of Moment-Resisting Connections for Soft Soil Sites

Extended Abstract In earthquake engineering, experimentation may have a variety of objectives and may utilize different testing techniques, ranging from field to laboratory experimentation, dynamic to quasi-static experimentation, and two to threedimensional experimentatio