Isolation design and numerical calculation of isolated rubber bearing in continuous beam bridge in high seismic intensity area

2021 ◽  
pp. 1-14
Author(s):  
Deng Pan ◽  
Tao Zhang

The stability of bridges in the face of earthquake hazards has always been the focus of construction engineering. At present, a large number of bridge construction has begun to use isolation rubber bearings to increase the seismic capacity of bridges. However, in the face of high-intensity earthquake disasters, the seismic performance of the bridge is gradually unable to meet, the main reason is the lack of relevant research on the seismic performance of the bridge in high seismic intensity area. Therefore, this study will explore the changes of the bridge in the face of high-strength earthquake, and try to use high damping rubber bearings for the isolation design of the bridge. By establishing the finite element model of continuous bridge combined with isolation rubber bearing, the numerical calculation of bridge element is carried out on this basis, and the isolation effect of isolation rubber bearing is analyzed. The results show that the compression resistance and shear resistance of the isolated rubber bearing are strong. Under the influence of different seismic waves, the maximum displacement of the bearing is 0.131 m and the maximum horizontal force is 389.6 kN, which are lower than the allowable value of the bridge, and the overall seismic performance of the bridge has been significantly improved, which can play a good theoretical support in the construction of continuous bridges in high seismic intensity areas.

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 199-206
Author(s):  
Bertha Olmos ◽  
José Jara ◽  
José Luis Fabián

This paper investigates the effects of the nonlinear behaviour of isolation pads on the seismic capacity of bridges to identify the parameters of base isolation systems that can be used to improve seismic performance of bridges. A parametric study was conducted by designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (acceleration, displacement and pier seismic forces) were evaluated for two structural models. The first model corresponded to the bridges supported on elastomeric bearings with linear elastic behaviour and the second model simulated a base isolated bridge that accounts for the nonlinear behaviour of the system. The seismic demand was represented with a group of twelve real accelerograms recorded on the subduction zone on the Pacific Coast of Mexico. The nonlinear responses under different damage scenarios for the bridges included in the presented study were estimated. These results allow determining the seismic capacity of the bridges with and without base isolation. Results show clearly the importance of considering the nonlinear behaviour on the seismic performance of bridges and the influence of base isolation on the seismic vulnerability of medium size bridges.


2013 ◽  
Vol 275-277 ◽  
pp. 1370-1373
Author(s):  
Qiu Hua Duan ◽  
Dan Dan Zeng ◽  
Lu Feng Yang

Rubber bearings are widely used in bridge structures. The aqueduct structures are water bridges, so rubber bearings are often set at the end of the aqueducts. Rubber bearing cannot solve the problems such as temperature stress and supporting inhomogeneous settlement, but also play role of isolation damping. This paper mainly studies on the effects of the water-depth with changing rubber bearing on the seismic performance of the aqueduct-water coupling structure by numerical analysis.


2011 ◽  
Vol 250-253 ◽  
pp. 3305-3308
Author(s):  
Yong Yao ◽  
Yun Peng Chu ◽  
Li Wang ◽  
Rui Zhao

Cold-formed steel structure is suitable for post-earthquake reconstruction since its good seismic performance and construction speed. Analyzing the dynamic characteristic of a two story office building by using the finite element software ANSYS. And the results show that: (1) in the time history analysis based on three types of seismic waves the lateral displacement of the structure and rotation between layers to meet the relevant specifications when confront the rare earthquake (2) Under the seismic loads, earthquake response acceleration amplification factor is smaller which indicating better seismic performance and it can be used in areas with high seismic intensity.


Author(s):  
Hao Wang ◽  
Dagen Weng

A new methodology is being introduced to address the life-cycle cost (LCC) of base-isolated large liquefied natural gas (LNG) tanks. The relationship between LCC and seismic fortification intensity is established to evaluate how much reduction of earthquake force can minimize the LCC. Each composition of LCC is analyzed including the initial cost, the isolators cost and the excepted damage cost. The isolators cost consists of the cost of lead rubber bearings and dampers. The cost of lead rubber bearings is proposed proportional to its volume and the cost of dampers is not only related to its maximum displacement but also to its tonnage. The concept of seismic intensity is being used to estimate the expected damage cost, greatly simplifying the calculation. Moreover, a tank in a LNG receiving terminal in China is employed as an example to assess its LCC in isolated and non-isolated situation respectively. The results show that the proposed method is efficient and the expected damage cost is enormously reduced because of the application of isolators, which leads to the reduction of the LCC of the tank.


Author(s):  
Naito Nobuyuki ◽  
Park Kyeonghoon ◽  
Mazda Taiji ◽  
Uno Hiroshige ◽  
Kawakami Masahide

The characteristics of the seismic bearing change depending on various factors. When an earthquake occurs, the behavior of the bridge may differ from the values expected in the structural design. The shear deformation of the seismic bearing may increase, but it is difficult to reach the fracturede formation. This paper studied the effect of the stiffness due to various dependency and durability on Lead Rubber Bearings (LRB) and the over strength of bridge piers on the bearing behavior when an earthquake occurred. As a result, if the stiffness of LRB reduces within the criteria, seismic performance can be expected safety even if the shear strain designed in the current design is greater than the allowable shear strain. The reason is that the hardening phenomenon in the high strain region of the laminated rubber bearing suppresses the displacement. Also, since the seismic bridges with over strength of the piers have come near elastic behavior when an earthquake occurs, shear strain is easy to be large.


2010 ◽  
Vol 163-167 ◽  
pp. 4008-4013
Author(s):  
Hai Biao Wang ◽  
Xun Guo ◽  
Bao Kuan Li ◽  
Hai Xu Yang

This paper focuses on the analysis of dynamic characteristics of structural systems, maximum response of acceleration and maximum inter-story displacement angle etc. so as to study the seismic performance, yielding mechanism and seismic resistance capacity of the structure under the circumstance of constructional measures of seismic intensity VII through an earthquake shake table test on a model of a six-story reinforced masonry structure with small-sized concrete hollow blocks. In view of the whole test process, the integral deformation of the reinforced masonry structural model under the influence of seismic vibration is predominantly bending deformation. While inputting different earthquake intensity, the transverse peak average of maximum input acceleration that can be sustained by the structure is lower than that of the vertical peak average. Meanwhile, transverse deformation is more severe than vertical deformation, indicating that vertical seismic resistance capacity is stronger than transverse seismic capacity. The test result shows that the effect of the constraint system consisted of ring beam, constructional column as well as horizontal tie reinforcement is quite obvious, the structure possesses comparatively strong resistance of failure under the influence of moderate and strong earthquakes, which can completely meet the requirement specified in the Seismic Codes, that is, standing erectly when it is subjected to great earthquakes in the area of seismic intensity VII. When the structure is subjected to rare earthquakes, it also possesses considerable seismic resistance capacity.


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