Application of Expansion Double Spherical Seismic Isolation Bearing in Seismic Design of Continuous Girder Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1928-1934 ◽  
Author(s):  
Tian Bo Peng ◽  
Zhen Nan Wang ◽  
Xun Tao Yu ◽  
Cheng Yu Yang
Keyword(s):  
Seismic Design ◽  
Seismic Isolation ◽  
Seismic Analysis ◽  
Design Method ◽  
Longitudinal Direction ◽  
Vertical Displacement ◽  
Girder Bridges ◽  
Earthquake Effect ◽  
Continuous Girder Bridge ◽  
Girder Bridge

The double spherical seismic isolation (DSSI for short) bearing has been adopted in seismic design of several important engineering projects since developed recently. It was used generally as fixed bearings in a continuous girder bridge in these projects, and only a few fixed piers, usually just one fixed pier would transmit the horizontal earthquake action to the foundation, which is uneconomical and results in the much larger seismic risk in the longitudinal direction of a continuous girder bridge than that in the transverse direction. In order to share the earthquake effect with all the piers and avoid relative vertical displacement among all the bearings under the normal traffic conditions, a new seismic design method of continuous girder bridges is introduced. The configuration and working mechanism of two kinds of DSSI bearings used to make the new seismic design possible are introduced. It’s shown that the method is preferable for the seismic design of continuous girder bridges by a numerical seismic analysis with a four-span continuous girder bridge.

Test and Numerical Study on the Seismic Performance of A Cable Restrainer for Girder Bridges

2019 ◽  
Author(s):  
Yitong Gu ◽  
Wancheng Yuan ◽  
Xinzhi Dang
Keyword(s):  
Seismic Performance ◽  
Numerical Study ◽  
Design Method ◽  
Lateral Displacement ◽  
Static Test ◽  
Girder Bridges ◽  
Continuous Girder Bridge ◽  
Service Conditions ◽  
Girder Bridge ◽  
Parametric Analyses

<p>In China, most of the support systems applied by short/medium span bridges are elastomeric pad bearings (EPBs). This type of support system has no reliable connections between bearings and girders as well as bearings and piers, which will cause structural damages due to large lateral displacement of bearings under earthquakes. The restrainers used currently could restrict the deformation of bridges under normal service conditions and could only restrict unidirectional displacement. Considering the disadvantages of these restrainers, a new restrainer called Connected Cable Restrainer (CCR), which can be used in short/medium span bridges supported by EPBs, is developed in this paper. The design principle, basic configuration, isolation mechanism and the design method of CCR are introduced. A pseudo static test to study the seismic performance of CCR is conducted. Seismic responses of a 3-span continuous girder bridge with CCR are simulated using OpenSees platform and parametric analyses of the two main parameters, lateral restraining displacement and restraining stiffness, are also carried out. Results show that the deformation of bridges under normal service conditions would not be restrained using CCR and the displacement responses can be mitigated effectively by using CCR through parameter optimization.</p>

A new seismic design method of simply supported girder bridges for very rare ground motions in the transverse direction

2020 ◽  
pp. 002072092094059
Author(s):  
Tianbo Peng ◽  
Haoyu Zou ◽  
Lizhi Wang
Keyword(s):  
Seismic Hazard ◽  
Seismic Design ◽  
Seismic Isolation ◽  
Transverse Direction ◽  
Design Method ◽  
Safety Evaluation ◽  
Seismic Safety ◽  
Simply Supported ◽  
Girder Bridges ◽  
Seismic Design Method

In most seismic design codes, usually two seismic hazard levels are taken into account, for example, Design Earthquake and Maximum Considered Earthquake. Several disastrous earthquakes have proved that seismic safety evaluation may underestimate seismic risks, which would result in serious damage of bridge structures. Therefore, a new higher level of seismic hazard named Very Rare Ground Motion (VRGM for short) is proposed innovatively to be considered in this paper for very important bridges. A novel seismic design method of simply supported girder bridges in the transverse direction for VRGMs is proposed at first. In the proposed method, seismic isolation bearings, tension-only braces and ductile piers are combined to improve the seismic performance and meet seismic requirements of VRGMs. Taking a simply supported girder bridge as a numerical analysis example, the proposed method is compared with two bridge seismic design methods adopted in current seismic codes and its parametric analysis is conducted. It’s shown that the proposed seismic design method can combine the ductility capacities of piers and the functions of seismic isolation bearings and reduce all the concerned structural seismic responses in VRGMs effectively. This work provides an educational demonstration for engineers dealing with similar problems.

Performance-Based Analysis of Coupled Support Structures and Piping Systems Subject to Seismic Loading

2015 ◽  
Author(s):  
Oreste S. Bursi ◽  
Fabrizio Paolacci ◽  
Md Shahin Reza
Keyword(s):  
Seismic Design ◽  
Seismic Analysis ◽  
Design Method ◽  
Design Guidelines ◽  
Piping System ◽  
Support Structures ◽  
Limit States ◽  
Piping Systems ◽  
Allowable Stress Design

The prevailing lack of proper and uniform seismic design guidelines for piping systems impels designers to follow standards conceived for other structures, such as buildings. The modern performance-based design approach is yet to be widely adopted for piping systems, while the allowable stress design method is still the customary practice. This paper presents a performance-based seismic analysis of petrochemical piping systems coupled with support structures through a case study. We start with a concept of performance-based analysis, followed by establishing a link between limit states and earthquake levels, exemplifying Eurocode and Italian prescriptions. A brief critical review on seismic design criteria of piping, including interactions between piping and support, is offered thereafter. Finally, to illustrate actual applications of the performance-based analysis, non-linear analyses on a realistic petrochemical piping system is performed to assess its seismic performance.

Study on Vehicle-Bridge Coupling Vibration of Equal Span Girder Bridge of Different Span Number

2013 ◽  
Vol 540 ◽  
pp. 63-68
Author(s):  
Wei Zhao Li ◽  
Zong Lin Wang ◽  
Hang Sun ◽  
Yan Li
Keyword(s):  
Surface Roughness ◽  
Influencing Factor ◽  
Dynamic Responses ◽  
Box Girder Bridges ◽  
Coupling Vibration ◽  
Average Value ◽  
Girder Bridges ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Traveling Speed

The vehicle-bridge coupling vibration of girder bridge has been widely investigated. But most of previous work focused on the influencing factor of the vibration, such as traveling speed of vehicle, deck surface roughness and vehicle-bridge frequency ratio etc. Taking the box girder bridges of different span number with 20m single span length for example, applying the separated iterative method to multi-sample analysis the vehicle-bridge coupling vibration. The study considered the influence of the vehicle, traveling speed and the random deck surface roughness and then took the average value of the sample to discuss the influence of the span number on the dynamic responses. Results show that the continuous girder form can effectively decrease the dynamic responses of the equal span girder bridge than the simple-supported form. But the influence of the span number on the responses of equal span continuous girder bridge is not obvious.

The Design of Performance-Based Seismic Analysis of Main Power Plant of the Conventional Island

2011 ◽  
Vol 243-249 ◽  
pp. 3992-3996
Author(s):  
Gui Xuan Wang ◽  
Jie Zhao ◽  
Zhen Liu ◽  
Yang Zheng
Keyword(s):  
Power Plant ◽  
Seismic Design ◽  
Nuclear Power ◽  
Seismic Analysis ◽  
Design Method ◽  
Development Trend ◽  
Design Procedures ◽  
New Development ◽  
Practical Engineering ◽  
Performance Based Seismic Design

The performance-based design is a new development trend of seismic design. It is a breakthrough of the seismic design procedures. Based on the existing performance design method and some documents provided performance objective, computing and seismic structural measures, the performance-based seismic design is applied to the special structure of conventional island of the nuclear power plant. The performance-based seismic design is proved to be feasible according to a practical engineering case, as well the performance-based seismic design is needed to be further improved.

Revisiting arching in deck slabs

1996 ◽  
Vol 23 (4) ◽  
pp. 973-981 ◽  
Author(s):  
Baidar Bakht
Keyword(s):  
Design Method ◽  
Field Tests ◽  
Scale Model ◽  
Girder Bridges ◽  
Transverse Arch ◽  
Deck Slabs ◽  
Arching Action ◽  
Girder Bridge ◽  
Concrete Deck ◽  
Deck Slab

The arching action in concrete deck slabs of girder bridges is generally recognized and is utilized by the Ontario Highway Bridge Design Code, and some other codes, to specify an empirical design method which leads to considerable savings in the amount of reinforcement. Despite this general recognition, there are some aspects of the arching action that are yet to be explored. To the knowledge of the author, all reported laboratory and field tests on deck slabs exploring its arching action under applied loads have been conducted by measuring strains in the bottom transverse reinforcement midway between the girders. Based on the results of tests on a full-scale model of a deck slab, it has been confirmed in this note that the transverse bottom reinforcement in the deck slab acts as a tie to the internal transverse arch in the slab. Because of embedment in concrete, the force in this reinforcement is the smallest midway between the girders, and not the largest as would be the case if the slab were in pure bending. Key words: arching in slabs, deck slabs, girder bridge, punching shear, steel-free deck slabs.

Seismic Analysis of Underground Structures

2006 ◽  
Vol 1 (3) ◽  
pp. 378-389 ◽  
Author(s):  
Kazuhiko Kawashima ◽  
Keyword(s):  
Seismic Design ◽  
Seismic Behavior ◽  
Seismic Isolation ◽  
Seismic Analysis ◽  
Soft Ground ◽  
Underground Structures ◽  
Deformation Method ◽  
Seismic Deformation

A review on the seismic behavior and design of underground structures in soft ground is described focusing on the development of equivalent static seismic design called the seismic deformation method. Seismic isolation of underground structures is also presented.

Development of Seismic Design Method for Free Standing Rack

2013 ◽  
Author(s):  
Akihisa Iwasaki ◽  
Yoshitsugu Nekomoto ◽  
Hideyuki Morita ◽  
Katsuhiko Taniguchi ◽  
Daisaku Okuno ◽  
...  
Keyword(s):  
Seismic Design ◽  
Seismic Analysis ◽  
Design Method ◽  
Spent Fuel ◽  
Free Standing ◽  
Highly Nonlinear ◽  
Spent Fuel Pool ◽  
Vibration Tests ◽  
Seismic Design Method ◽  
Complex Phenomena

For high earthquake resistance and ease of installation, free standing racks which are not anchored to the pool floor or walls has been adopted in many countries. Under the earthquake, the response of the free standing rack is highly nonlinear and involves a complex combination of motions (sliding, rocking, twisting, and turning) and impacts between the fuel assemblies and the fuel cell walls, rack-to-rack, and the pit floor and the rack pedestals. To obtain an accurate simulation of the free standing rack, the seismic analysis requires careful considerations of these complex phenomena (sliding, rocking, twisting, and turning), fluid coupling effects and frictional effects. The important evaluation items while applying the free standing rack to the actual nuclear plants are maximum sliding displacement of the rack, maximum rocking displacement and maximum leg load under earthquake. When the sliding displacement increases, the rack may collide against the spent fuel pool wall. In addition, the free standing rack should not exhibit tilt sufficient to cause to the rack to overturn. The vibration tests were conducted in order to predict the rack behavior under earthquake, and the analysis method was validated by comparison to tests results. Furthermore, we developed the seismic design method to obtain the margin of safety for free standing rack.

The Reliability Study of LRB Continuous Girder Bridges Subject to Seismic Excitation

2010 ◽  
Vol 29-32 ◽  
pp. 209-214
Author(s):  
Wen Jing Liu ◽  
Li Li ◽  
Kun Ye
Keyword(s):  
Base Isolation ◽  
Guangdong Province ◽  
Seismic Excitation ◽  
Reliability Study ◽  
Girder Bridges ◽  
Continuous Girder Bridge ◽  
Study Case ◽  
Girder Bridge ◽  
First Time ◽  
Isolation Performance

LRB base isolation technology is different from the traditional continuous girder structure system, and shows good isolation performances. However, because fixed piers were canceled and all bearings were LRB, it is often considered that the reliability of structure might be reduced. Therefore, the reliability of LRB continuous girder bridges subject to seismic excitation was systematically studied from different indicators for the first time in this paper, the world's first double traffic double deck isolated continuous girder bridge – Dongjiang double-layer-pier isolated approach bridge in Dongguan of Guangdong province was adopted as study case. The results shows that, when the effect of pile-soil interaction is considered, LRB system still has a very good isolation performance; pounding subjected to seismic must be analyzed; dynamic stability needs checking when higher piers and larger earthquake displacement. Generally speaking, the reliability of LRB continuous girder bridges subject to seismic excitation won’t be reduced.

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