scholarly journals Experimental Study on Friction Sliding Performance of Rubber Bearings in Bridges

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yue Li ◽  
Qiqi Wu

To fully ascertain the ultimate shear failure state and the friction sliding performance of laminated rubber bearings in bridges, a series of cyclic loading tests were conducted. The energy dissipation characteristics of the laminated rubber bearings with two end plates, rubber bearings with unilateral friction sliding, and lead rubber bearing (LRB) under low-frequency cyclic loads were compared and analyzed. The results showed the following. (1) The ultimate shear deformation of the rubber bearings with two end plates could reach 300% to 400% of the rubber layer thickness. The energy dissipation capacity of the bearings was weak, and the hysteresis curves presented narrow zonal shapes. (2) The rubber bearings with unilateral friction sliding had similar energy dissipation capacities compared to the LRB. With the increase of the sliding distance, the dissipated energy continuously enlarged. The shear deformation of the bearing was no longer increased after reaching the maximum. After the test, the bearings remained in a good condition. The hysteresis curves of the load and displacement presented bilinear shapes. (3) Under the cyclic loading, the energy dissipation capacity of LRB was stable. The hysteresis curves of LRB were always fuller than the laminated rubber bearings.

2017 ◽  
Vol 11 (1) ◽  
pp. 586-597 ◽  
Author(s):  
Li Yue ◽  
Wang Kehai ◽  
Wu Qiqi

Introduction: To fully ascertain the ultimate shear failure state and friction sliding performance of laminated rubber bearings used in bridges, a series of cyclic loading tests on such laminated rubber bearings was conducted. Method: The energy dissipation characteristics of rubber bearings with two fixed end plates, rubber bearings with unilateral friction sliding and a lead rubber bearing (LRB) under a low-frequency cyclic load were compared and analyzed. Results and conclusion: The results showed that (1) the ultimate shear deformation of the rubber bearings with two fixed end plates reached 300% to 400% of the rubber layer thickness. The damage was mainly focused on the rubber layer fracture. The energy dissipation capacity of the bearings was weak, and the hysteresis curve presented a narrow zonal shape. (2) The rubber bearings with unilateral friction sliding had a similar energy dissipation capacity compared to the LRB. The maximum energy dissipation in a single cycle could reach 126% of the LRB’s maximum energy dissipation. With an increase in the sliding distance, the dissipated energy continuously increased. The shear deformation of the bearing no longer increased after reaching its maximum. After the test, the bearings remained in good condition. The hysteresis curves of load-displacement presented a bilinear shape. (3) Under cyclic loading, the energy dissipation capacity of LRBs was stable. The LRBs played an effective role in energy dissipation during loading. After the test, the LRBs nearly returned to their original condition. The hysteresis curves of LRB were always fuller than the laminated rubber bearings.


2015 ◽  
Vol 9 (1) ◽  
pp. 295-307 ◽  
Author(s):  
Edelis del V. Marquez A. ◽  
William Lobo-Q ◽  
Juan C. Vielma

A comparative study has been done to analyze the behavior of regular steel building structures of 4, 6, 8 and 10 stories, located in seismic zone 5 and soil type S1. The structures were upgraded with different brace configurations according to current Venezuelan codes. A total number of 24 numerical models were analyzed considering non-linear static and incremental dynamic analysis (IDA). The buildings were initially designed as moment resisting frames, and upgraded with six different bracing configurations: concentric braces in “X” and inverted “V”; eccentric braces inverted "V" with horizontal links, inverted “Y” and “X” with vertical links. Short length links were used to ensure a shear failure. The used methodology is based on obtaining the capacity, IDA curves, and bilinear approximations of these curves that allow the determination of yield and ultimate capacity points, in order to estimate important parameters of seismic response: overstrength and ductility; and considering these areas under the curves to estimate elastic deformation energy, energy dissipated by hysteretic damping and equivalent damping. According to the results, the cases with no brace enhancement showed the lowest lateral strength and lateral stiffness and high deformation capacity. On the other hand, the concentric bracing cases, resulted with the highest stiffness and strength and the lowest deformation capacity, therefore they have low ductility and energy dissipation capacity under seismic loading. Structures with links showed intermediate stiffness and strengths, resulting in the best performance in terms of ductility and energy dissipation capacity. The present study provides a better understanding of the benefits of eccentrically braced systems.


2020 ◽  
Vol 23 (13) ◽  
pp. 2822-2834
Author(s):  
Xian Rong ◽  
Hongwei Yang ◽  
Jianxin Zhang

This article investigated the seismic performance of a new type of precast concrete beam-to-column joint with a steel connector for easy construction. Five interior beam-to-column joints, four precast concrete specimens, and one monolithic joint were tested under reversed cyclic loading. The main variables were the embedded H-beam length, web plate or stiffening rib usage, and concrete usage in the connection part. The load–displacement hysteresis curves were recorded during the test, and the behavior was investigated based on displacement ductility, deformability, skeleton curves, stiffness degradation, and energy dissipation capacity. The results showed that the proposed beam-to-column joint with the web plate in the steel connector exhibited satisfactory behavior in terms of ductility, load capacity, and energy dissipation capacity under reversed cyclic loading, and the performance was ductile because of the yielding of the web plate. Therefore, the proposed joint with the web plate could be used in high seismic regions. The proposed joint without the web plate exhibited similar behavior to the monolithic specimen, indicating that this joint could be used in low or moderate seismic zones. Furthermore, the utilization of the web plate was vital to the performance of this system.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qiang Zhou ◽  
Lingyu Yang ◽  
Wenyang Zhao

Masonry structures are widely used in developing countries due to their low cost and simple construction, especially in remote areas, where there are a large number of houses without seismic measures. These buildings are prone to collapse and cause a lot of casualties, even under the action of small earthquakes. For the reinforcement of this structure, a cheap, effective, and easy-to-construct reinforcement method is urgently needed. Therefore, this article studies the reinforcement method of polypropylene bands (PP-bands). We have carried out low-frequency cyclic loading tests for two PP-band reinforced masonry walls and two compared masonry walls. We mainly studied the influence of PP-band and different compressive strengths of plastering mortar on the masonry wall’s seismic capacity. The seismic indicators mainly studied in this article include ultimate bearing capacity, energy dissipation capacity, stiffness degradation, and hysteresis characteristics. The experimental results show that the PP-band can greatly enhance the seismic capacity of the masonry wall. The ultimate bearing capacity, energy dissipation capacity, and displacement ductility of the PP-band reinforced wall are increased by 38%–48%, 22%–47%, and 138%–226%.


2016 ◽  
Vol 16 (01) ◽  
pp. 1640015 ◽  
Author(s):  
Yun Tian Wu ◽  
Yu Shan Fu ◽  
Chong-Ming Dai

A new type of partially steel tubed concrete (PSTC) column is proposed that is suitable to be used in new high rise reinforced concrete (RC) buildings. Three exterior joint specimens consisting of RC beams and PSTC columns and two exterior RC joint specimens were designed and tested under high axial load and cyclic loading to investigate the joint behavior in terms of failure pattern, hysteresis response, deformation, energy dissipation capacity and degradation of strength and stiffness. Test results indicate that the PSTC column can benefit the performance of the joint in terms of strength, ductility and energy dissipation capacity and can partly compensate for the unfavorable effect induced by slab. The strong column–weak beam mechanism can also be ensured in RC beam to PSTC column joint.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Cong-Thuat Dang ◽  
Ngoc-Hieu Dinh

Several retrofitting methods for reinforced concrete (RC) beam-column joints in old buildings without seismic details were developed. Four half-scale RC exterior beam-column joints were fabricated and tested under cyclic loading simulating earthquake excitation. The control specimen was designed to fail in joint shear. Two practical retrofitting strategies were applied to the control specimen which consider the architectural characteristic in real buildings, including steel jacketing and haunch retrofit solution. The structural performance of the test specimens was investigated in terms of various factors including damage and failure, load-drift relationship, ductility, dissipated energy, and strain profiles of longitudinal reinforcement. Experimental results confirmed that the proposed retrofit methods were shown to enhance the seismic capacity of the joints in terms of the strength, deformation capacity, and energy dissipation capacity while the shear deformation in the panel zone significantly reduced in comparison with the control specimen.


2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Haian Liang ◽  
Hao Zeng ◽  
Kaiwei Cao ◽  
Chao Liu ◽  
Xinjun Cheng

In order to study the cumulative damage and failure characteristics of long spiral belled pile under horizontal cyclic loading of offshore wind and waves, a series of indoor experiments on single piles under horizontal cyclic load were carried out. The cycle times as well as load amplitude at the same frequency were considered during the horizontal pseudo-static cyclic tests. On the basis of the distribution of pile deflection, bending moment, and Earth pressure around the pile, the pile-soil interaction was comprehensively discussed. The cumulative energy dissipation characteristics were introduced to describe the damage of test piles. Meanwhile, the effects of load amplitude and cycle times on the cumulative damage of long spiral belled piles were discussed. A power function model for energy dissipation coefficient prediction under multi-stage cyclic load was proposed. The results show that the horizontal peak bearing capacity of long spiral belled pile is increased by 57.2% and 40.4%, respectively, as compared with the straight pile and belled pile under the same conditions. The horizontal displacement mainly occurs at the upper part of the pile. Under the condition of limited cyclic times, the load amplitude has more significant effect on the bearing characteristics of the long spiral belled pile. In contrast to the straight pile and belled pile, the long spiral belled pile has better energy dissipation capacity, and the rank of the energy dissipation capacity of these three piles is long spiral belled pile > belled pile > straight pile. The power function model can well reflect the cumulative damage characteristics of long spiral belled pile under horizontal cyclic loading, and there is a good linear relationship between power function model parameters and load amplitude. The energy dissipation coefficient of long spiral belled pile with diverse cycle times at different mechanical stages of test pile is analysed. Then, the recommended power function model parameters according to different failure stages are proposed. The verification example indicates that the prediction results are close to the measured values with a calculation error of 22%. The prediction model can provide a certain reference for the application of long spiral belled pile in marine structures.


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