scholarly journals Shaking Table Test of High Pier and Small Radius Curved Bridge under Multi-point Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lei Yan ◽  
Guo Li ◽  
Kang An ◽  
Kefeng Yue ◽  
Zhi Lin
Keyword(s):  
Seismic Response ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Damping Ratio ◽  
Shaking Table ◽  
Small Radius ◽  
Curved Bridge ◽  
Bridge Model ◽  
High Pier ◽  
The Impact

The non-uniform stratum and uneven surface have the complicated seismic spatial variability. The seismic response of high pier and small radius curved bridge caused by the seismic specificity of this kind of terrain has not been systematically studied. According to the multi-point excitation theory of long-span structures and the similar theory of shaking table test in model structures, a high pier with small radius curved girder bridge was used as the research object. The shaking table test of real bridge model was carried out to study the seismic response laws of this kind of bridge under multi-point excitation. The results show that the designed seismic wave expansion device can meet the test requirements. The frequency of the model structure decreases rapidly and the damping ratio increases during the whole test process. The local terrain effect amplifies the seismic response of high pier and small radius curved bridge. The seismic response of high pier and small radius curved bridge is affected by different frequency spectrum seismic waves, and there is a big difference. Based on the above results, the impact of multi-point excitation should be considered in seismic design of high pier with small radius curved bridge.

Investigation on three-directional dynamic interaction between a heavy-duty vehicle and a curved bridge

2017 ◽  
Vol 21 (5) ◽  
pp. 721-738 ◽  
Author(s):  
Shaohua Li ◽  
Jianying Ren
Keyword(s):  
Interaction Model ◽  
Element Model ◽  
Driver Model ◽  
Impact Factors ◽  
Lateral Impact ◽  
Heavy Duty ◽  
Vehicle Model ◽  
Curved Bridge ◽  
Bridge Model ◽  
The Impact

Considering the nonlinear property of suspension damping and tire stiffness, a full-vehicle model is built for a heavy-duty truck. A modified preview driver model with nonlinear time delay is inserted into the vehicle model to compute the suitable steering angle of the front wheel and to make the vehicle follow the required route. Next, the finite element model of a five-span continuous curved highway bridge is established, and the bridge’s inherent frequencies and modes are obtained. The curved bridge and the vehicle are coupled by three-directional tire forces, and a three-directional driver–vehicle–bridge interaction model is presented. The presented vehicle model and bridge model are verified by comparing with the published works. The dynamic impact factors of vertical, lateral, and torsional displacements of the bridge are calculated when a vehicle is traversing through the bridge, and the impact factors’ distributions along the bridge are analyzed. The effects of vehicle driving conditions on impact factors are also researched. It is found that the impact factor calculated from the present specification for a straight bridge is smaller than that from the three-directional driver–vehicle–bridge interaction model, and the vertical and torsional impact effects at the third span midpoint are greater than the lateral impact effect.

Shaking Table Test Study on Mid-Story Isolation Structures

2012 ◽  
Vol 446-449 ◽  
pp. 378-381
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Yu Hong Ma ◽  
Chao Yong Shen
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Lead Rubber Bearing ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with lead rubber bearing are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

scholarly journals Seismic Response of Prestressed Anchors with Frame Structure

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Shuaihua Ye ◽  
Zhuangfu Zhao
Keyword(s):  
Seismic Response ◽  
Shaking Table Test ◽  
Coupling Effect ◽  
Soil Mass ◽  
Calculation Model ◽  
Shaking Table ◽  
Frame Structure ◽  
Dynamic Calculation ◽  
Concentrated Mass ◽  
Linear Spring

Based on the equivalent mass-spring model and considering the coupling effect between creep soil and prestressed anchors, the dynamic calculation model of prestressed anchors with frame structure is established. The soil mass is expressed in the form of concentrated mass. The action of the frame structure on the soil is treated as a parallel coupling of a linear spring and a linear damper, and the free section of the anchor is treated as a linear spring. Considering the creep characteristics, the soil is regarded as a Generalized Kelvin body and the anchoring section of the anchor is regarded as an equivalent spring body, which are coupled in parallel. Considering the effect of slope height, the dynamic calculation model is solved and the seismic response is analyzed. Finally, an engineering example is used to verify the calculation method in this paper, and the results are compared with the shaking table test and numerical simulation. It shows that the calculation model proposed in this paper is safe and reasonable for the seismic design and analysis of the slope supported by prestressed anchors with frame structure.

scholarly journals Optimization and Damping Performance of a Coal-Fired Power Plant Building Equipped with Multiple Coal Bucket Dampers

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Ling-Yun Peng ◽  
Ying-Jie Kang ◽  
Zong-Rui Lai ◽  
Yu-Ke Deng
Keyword(s):  
Power Plant ◽  
Seismic Response ◽  
Optimization Design ◽  
Power Plants ◽  
Shaking Table Test ◽  
Design Method ◽  
Shaking Table ◽  
Seismic Action ◽  
Test Model ◽  
Plant Structure

A parameter optimization design method is proposed for multiple coal bucket dampers (CBDs) to reduce the seismic response of coal-fired power plants. To test the damping effect of the optimized CBDs, a 1 : 30 scale shaking table test model of a power plant structure was fabricated. A comparative testing program was conducted using three seismic excitations on a model with and without CBDs. A finite element analysis model, replicating the conditions of the shaking table test, was constructed for comparison, and the shock absorption effects of CBDs subjected to 22 groups of far-field seismic action and 28 groups of near-field seismic action were analyzed. Finally, the influence of changes in the structural period on the seismic response of the CBD-equipped structure was studied. The results indicate that the use of CBDs in a coal-fired power plant structure, based on an optimization design method for multiple-tuned mass dampers (MTMDs), results in a significant reduction in the structure displacement response, displays a certain discreteness under different excitations, and maintains a certain damping stability even as the structural period changes. Overall, the use of CBDs is a promising prospect for improving the seismic performance of coal-fired power plant structures.

scholarly journals Experimental and Numerical Studies on Sloshing Dynamics of PCS Water Tank of Nuclear Island Building

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaojun Li ◽  
Chenning Song ◽  
Guoliang Zhou ◽  
Chao Wei ◽  
Ming Lu
Keyword(s):  
Shaking Table Test ◽  
Cooling System ◽  
Damping Ratio ◽  
Time History ◽  
Hydrodynamic Pressure ◽  
Test Method ◽  
Shaking Table ◽  
Water Tank ◽  
Scaled Model ◽  
Sloshing Dynamics

Water tank is one important component of passive containment cooling system (PCS) of nuclear island building. The sloshing frequency of water is much less than structure frequency and large-amplitude sloshing occurs easily when subjected to seismic loadings. Therefore, the sloshing dynamics and fluid-structure interaction (FSI) effect of water tank should be considered when the dynamic response of nuclear island building is analyzed. A 1/16 scaled model was designed and the shaking table test was done, in which the hydrodynamic pressure time histories and attenuation data of wave height were recorded. Then the sloshing frequencies and 1st sloshing damping ratio were recognized. Moreover, modal analysis and time history analysis of numerical model were done by ADINA software. By comparing the sloshing frequencies and hydrodynamic pressures, it is proved that the test method is reasonable and the formulation of potential-based fluid elements (PBFE) can be used to simulate FSI effect of nuclear island building.

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