Finite Elements Analysis Techniques of Ve ssel Collision with Cable-Stayed Bridge
Author: Ashraf R. Sayed and Walid A. Attia | Size: 1.3 MB | Format:PDF | Quality:Unspecified | Publisher: Life Science Journal, 2012;9(2) | Year: 2012 | pages: 12
Abstract: Vessel collision design for bridges crossing navigable waterways is an important consideration since it significantly affects the total cost of bridges. Economical design requires appropriate determination of impact loads imparted to bridge piers. While the collision force is dynamic in nature, current provisions for bridge design are based on static approximations of structural behavior and limited experimental data, it prescribed by current bridge design specifications (Method II probabilistic approach as outlined in " the AASHTO Guide Specifications for
Vessel Collision Design of Highway Bridges"). Collision force and structural deformations predicted by the static and the dynamic analysis techniques are compared for vessel collisions of varying mass (DWT) and Velocity.This
research is concerned with the effect of vessel impact forces on long span cable-stayed bridge. The Contact-Stiffness Approach was applied to determine the maximum impact force of a vessel collision as a function of the vessel velocity, and the deadweight tonnage of the vessel. Impact force is applied to the tower of bridge at the point above water level. A comparative study was conducted to investigate the effect of vessel impact force on Tatara cablestayed bridges, with a center span of 890 m, cases of loading with different values of the vessel velocity, and deadweight tonnage of the vessel were studied for Static and dynamic Analysis finite element bridge Structure usingANSYS program. Results from such comparisons indicate that, dynamic analysis technique are preferable. For more severe collision conditions, the use of equivalent static force for design purposes is acceptable
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
Seismic Retrofit of a Cable-S tayed Bridge with Passive Control Techniques: A Comp arative Investigation through Non-Linear Dynamic Analyses
Author: M.D. Martínez-Rodrigo ; A. Filiatrault | Size: 536 KB | Format:PDF | Quality:Unspecified | Publisher: Department. of Civil, Structural and Environmental Engineering, State University of New York at Buffalo, USA | Year: 2012 | pages: 10
The present contribution deals with the seismic performance of an existing cable-stayed steel bridge. The structure experienced damage during the Saguenay earthquake in 1988 needing structural rehabilitation. As an alternative, in this study the retrofit of the structure with different passive supplemental damping and seismic isolation systems is proposed and evaluated in order to achieve an admissible performance of the bridge under a set of seismic events of different magnitudes including near field records. To this end a Finite Element numerical planar model is implemented and the bridge response is obtained trough non-linear dynamic analyses. Strength degradation capabilities are included in the model allowing the occurrence of brittle failure when certain levels of ductility are exceeded in the members. The major improvement in the overall response of the bridge is shown
and conclusions regarding the most appropriate retrofit alternative for the particular case are derived.
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
It is shown that current design methods are inadequate to prevent progressive collapse. Definitions for the terms collapse resistance and robustness are proposed. An approach for designing against progressive collapse is suggested and a set of corresponding design criteria is presented. These include requirements, design objectives, design strategies, and verification procedures. In addition to the better-known design methods providing specific local resistance or alternate load paths, an approach based on isolation by compartmentalization is presented and discussed. It is found that the terms continuity, redundancy, and robustness should be carefully distinguished. The general concepts and findings presented here are applied to bridges.
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
This paper describes the seismic performance verification and retrofit method examination of a cable-stayed bridge in the Sakitama Bridge. First, the input earthquake motion was specified for use in both the target seismic performance and the bridge verification, while the parts and members of the latter were verified by seismic response analysis. The main tower and caisson foundation that were difficult to evaluate were verified by a nonlinear finite element analysis. Based on the verification results, regions requiring a seismic retrofit were identified, and the retrofit methods were examined.
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
The prevailing Italian and Greek methodologies for seismic risk assessment are used herein to construct loss scenarios for the building stock
of a small city (Potenza, Southern Italy). The inventory of buildings of interest is obtained from a survey carried out after the 1990 earthquake that
struck Potenza and its hinterland, subsequently updated in 1999. About 12,000 buildings were surveyed in Potenza, using the Italian first level
survey form for damage and vulnerability evaluation. In the Italian methodology, a hybrid technique is set up to evaluate vulnerability, combining
an analysis of building typologies with expert judgement. The probabilistic distribution of damage is evaluated by assigning Damage Probability
Matrices (DPMs) from the literature. Besides the vulnerability classes A, B and C of the MSK-scale, the class D of the anti-seismic buildings
is considered and the relevant DPM is defined. Damage and economic loss scenarios relevant to dwelling buildings are constructed for three
reference earthquakes. Next, the hybrid methodology for seismic vulnerability assessment of reinforced concrete (R/C) and masonry buildings
developed at the University of Thessaloniki (Greece) is applied to the same building stock. The methodology combines available statistical data of
damage collected after past earthquakes with a systematic nonlinear analysis of various “model buildings”, representative of several vulnerability
classes. Similarities, as well as discrepancies, between the two methods are discussed in the light of the obtained results, and possible sources for
the discrepancies are suggested
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
![[Image: info.png]](http://postgen.civilea.com/icon/info.png){kind=icon}
![[Image: download.png]](http://postgen.civilea.com/icon/download.png){kind=icon}
![[Image: 74204242505854264743.jpg]](https://pic.civilea.com/images/74204242505854264743.jpg)
![[Image: 91779771682941293440.jpg]](https://pic.civilea.com/images/91779771682941293440.jpg)