Study on a Simple Self-Resetting Sliding Isolation

2011 ◽  
Vol 250-253 ◽  
pp. 2558-2561
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Yu Hong Ma ◽  
Xue Zhen Zhuang ◽  
Chao Yong Shen
Keyword(s):  
Theoretical Analysis ◽  
Shaking Table Test ◽  
Masonry Structure ◽  
Brick Masonry ◽  
Shaking Table ◽  
Isolation System ◽  
Rubber Bearing ◽  
Sliding Isolation

This paper presents a simple Self-resetting sliding isolation system, which is composed of graphite sliding device and simple rubber bearing. Theoretical analysis is carried out. Shaking table test for a typical brick masonry structure in village of China is performed on a 1:4 scale. Results show that the proposed new isolation system can achieve a favorable level of performance.

Shaking Table Test Analysis of Bottom-Business Multi-Story Masonry Structure in Small and Middle Towns in the Southward

2014 ◽  
Vol 580-583 ◽  
pp. 1463-1466
Author(s):  
Yong Duo Liang ◽  
Xun Guo ◽  
Hua Wei Yi ◽  
Yong Zhen Li ◽  
Jin Zheng Jiang
Keyword(s):  
Shaking Table Test ◽  
Masonry Structure ◽  
Shaking Table ◽  
Earthquake Simulation ◽  
Seismic Capacity ◽  
Test Analysis ◽  
Earthquake Resistant ◽  
Scale Models ◽  
Longitudinal Wall ◽  
Reduced Scale

Bottom-business multi-story masonry structure is widely used in small and middle towns in the southward in China. In the downtown of Beichuan county which affected by Wenchuan earthquake, more than 80% of this kind of building collapsed. But the Apartment of Beichuan Telecommunication Bureau behaved well earthquake resistant capacity with a moderate damage in the earthquake. The obvious difference between this building and others is the setting of winged columns in the front longitudinal wall of the first floor. For proving the influence of these members in the structure seismic capacity, the earthquake simulation shaking table test of 2 1/5 reduced scale models were designed and carried out. The models dynamic response, acceleration, displacement and strain were measured and collected, that model with winged columns behave well was testified. And the reinforcement method of balancing stiffness and increasing ductility is put forward. The results provide a foundation for the retrofitting design of the existing houses.

scholarly journals In-Plane Strengthening Effect of Prefabricated Concrete Walls on Masonry Structures: Shaking Table Test

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Weiwei Li ◽  
Weiqing Liu ◽  
Shuguang Wang ◽  
Dongsheng Du
Keyword(s):  
Shaking Table Test ◽  
Masonry Structure ◽  
Shaking Table ◽  
Strengthening Effect ◽  
Masonry Structures ◽  
Dynamic Tests ◽  
Seismic Capacity ◽  
Concrete Walls ◽  
Improvement Effect ◽  
Scaled Models

The improvement effect of a new strengthening strategy on dynamic action of masonry structure, by installing prefabricated concrete walls on the outer facades, is validated by shaking table test presented in this paper. We carried out dynamic tests of two geometrically identical five-story reduced scaled models, including an unstrengthened and a strengthened masonry model. The experimental analysis encompasses seismic performances such as cracking patterns, failure mechanisms, amplification factors of acceleration, and displacements. The results show that the strengthened masonry structure shows much more excellent seismic capacity when compared with the unstrengthened one.

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 Experimental Investigation on Semi-Active Control of Base Isolation System Using Magnetorheological Dampers for Concrete Frame Structure

2019 ◽  
Vol 9 (18) ◽  
pp. 3866 ◽  
Author(s):  
Weiqing Fu ◽  
Chunwei Zhang ◽  
Mao Li ◽  
Cunkun Duan
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Active Control ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Mr Damper ◽  
Shaking Table ◽  
Engineering Practice ◽  
Isolation System ◽  
Large Earthquakes

The traditional passive base isolation is the most widely used method in the engineering practice for structural control, however, it has the shortcoming that the optimal control frequency band is significantly limited and narrow. For the seismic isolation system designed specifically for large earthquakes, the structural acceleration response may be enlarged under small earthquakes. If the design requirements under small earthquakes are satisfied, the deformation in the isolation layer may become too large to be accepted. Occasionally, it may be destroyed under large earthquakes. In the isolation control system combined with rubber bearing and magnetorheological (MR) damper, the MR damper can provide instantaneous variable damping force to effectively control the structural response at different input magnitudes. In this paper, the control effect of semi-active control and quasi-passive control for the isolation control system is verified by the shaking table test. In regard to semi-active control, the linear quadratic regulator (LQR) classical linear optimal control algorithm by continuous control and switch control strategies are used to control the structural vibration response. Numerical simulation analysis and shaking table test results indicate that isolation control system can effectively overcome the shortcoming due to narrow optimum control band of the passive isolation system, and thus to provide optimal control for different seismic excitations in a wider frequency range. It shows that, even under super large earthquakes, the structure still exhibits the ability to maintain overall stability performance.

Study on the Suitability of Seismic Isolation Technologies for Rural Buildings

2013 ◽  
Vol 353-356 ◽  
pp. 2221-2227
Author(s):  
Guang Hui Zhang
Keyword(s):  
Friction Coefficient ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Economic Conditions ◽  
Difficulty Level ◽  
Earthquake Disaster ◽  
Sliding Isolation ◽  
Rural Buildings ◽  
Collapse Ratio

Rural buildings are subject to the most serious damage and the highest collapse ratio in earthquake disaster. It is urgent at present to develop seismic isolation technologies applicable to rural buildings under current rural economic conditions of China. Through comparing the existing domestic seismic isolation technologies in respects of the acquisition difficulty level, price and friction coefficient of material and the placement of sliding material, and analyzing the result of simulated shaking table test respectively with the gravel foundation isolation technology and the gravel sliding isolation technology, this paper points out matters needing attention during the development of seismic isolation technologies for rural buildings.

Shaking table test on building in masonry structure with construction waste recycled brick

2014 ◽  
Vol 11 (4) ◽  
pp. 357-364
Author(s):  
Hui Su ◽  
Jian Wang ◽  
Xinpei Jiang ◽  
Yang Tan
Keyword(s):  
Seismic Behavior ◽  
Shaking Table Test ◽  
Concrete Block ◽  
Masonry Structure ◽  
Recycled Aggregate Concrete ◽  
Shaking Table ◽  
Recycled Aggregate ◽  
Test Results ◽  
Scaled Model ◽  
Construction Waste

Based on the shake table test on "tie column-ring beam-cast-in-place slab" construction waste recycled brick masonry structure, a 1/3 scaled model of 4 stories is tested to analyze the seismic behavior of the multi-storey masonry structure. The test is conducted with EL-Centro seismic wave, Taft wave and artificial wave to simulate the damages observed and the seismic response under different earthquake levels. On the basis of test results, the seismic performance of the model is good and the overall structure could satisfy seismic fortification requirements in the region of intensity 8. At the same time, there was no obvious difference between this masonry structure and recycled aggregate concrete block masonry structure. The lintel of the door and window damage seriously. The base damages more easily than the superstructure. Masonry structure with construction waste recycled brick can satisfy the requirement of the masonry structure buildings in eight degree of aseismatic design area.

Seismic Performance of Guideway Sliding Isolator with Gap Springs for Precision Machinery

2008 ◽  
Vol 11 (5) ◽  
pp. 511-524
Author(s):  
George C. Yao ◽  
Wen-Chun Huang ◽  
Fan-Ru Lin
Keyword(s):  
Shaking Table Test ◽  
Model Simulation ◽  
Shaking Table ◽  
Viscous Damping ◽  
Far Field ◽  
Seismic Excitations ◽  
Isolation System ◽  
Near Fault ◽  
Seismic Motion ◽  
Nonlinear Performance

The performance of gap springs in a guideway sliding isolator (GSI) system developed to protect precision machinery against seismic motion has been studied. A spring is initially distanced from the system by a gap, causing the isolation system to exhibit nonlinear performance once the gap is closed, reducing the chance of resonance. A full-scale shaking table test of a 22-ton specimen and a numerical model simulation in SAP2000 have been performed. The study shows that springs possessing the appropriate gaps are more effective in controlling relative displacements than is a pure friction system. The optimal gap for a system subjected to far-field earthquakes was found to be 5mm. In addition, supplemental viscous damping of less than 15% of the critical damping had no significant effect on the GSI system far-field seismic response, but it did reduce the relative displacements of the system for near-fault seismic excitations.

Discussion on Masonry Structure Model Mechanical Property Test

2012 ◽  
Vol 238 ◽  
pp. 659-662 ◽  
Author(s):  
Gong Lian Chen ◽  
Lin Jun Si
Keyword(s):  
Shaking Table Test ◽  
Mechanical Test ◽  
Dynamic Test ◽  
Masonry Structure ◽  
Shaking Table ◽  
Structure Model ◽  
Loading Test ◽  
Mixture Ratio ◽  
Static Test ◽  
Masonry Material

The problems in the mechanical test of masonry structure model were discussed in this paper, including the masonry material, similar relationship, shaking table test device, judgment of wall cracking and number of cycles in pseudo-static loading test. The conclusions are: (1) for the masonry material mechanical test, usually the size decreased the strength increased, but if the laying method and appropriate adjustments in the process of the test mixture ratio, the size effect can be greatly reduced; (2) In the dynamic test of the masonry structure, for the gravity distortion model, the common way is the external prestressing method, but in this method the tension force is not constant, which is differ from the actual situation; (3) The wall cracking can be judged when the main tension crack of the wall appeared; (4) The loading cycle in the pseudo-static test of masonry wall would be twice.

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