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A rig for experimenting the dynamic behaviour of masonry arches
Published in Koen Van Balen, Els Verstrynge, Structural Analysis of Historical Constructions: Anamnesis, Diagnosis, Therapy, Controls, 2016
4.4 Shaking table The shaking table has two axis of motion (x and y), allowing arbitrary motion in an horizontal plane. The table uses two ball screws linear actuators to transform the rotation of the motors in linear motion. The pitch per revolution of the actuator screws is 6.35 mm. The maximum amplitude of displacement is about 35 mm in both directions (±17.5 mm). This is not much and this is maybe the biggest limitation of the current design. But - as budget was limited - the table was also purchased second-hand and choice was limited. Considering that the table is meant to test small-scale models, the capacity is actually not very different from what many full-scale earthquake shaking table are capable of (Lisbon (P): ±175 mm, Bristol (UK): ±150 mm, Saclay (F): ±125 mm, ...). The implications of this limitation are discussed in 6.2. Over-travel of the table is prohibited by four optical sensors which stop the motor offending a displacement limit. As the encoders are incremental and not absolute, they are also used to return the table automatically to a zero or home position. The table top is currently 450 mm × 350 mm.
Research of earthquake engineering in Hong Kong: current status and future challenge
Published in B.F. Spencer, Y.X. Hu, Earthquake Engineering Frontiers in the New Millennium, 2017
Y.L. Xu, J.M. Ko, K.T. Chau, S.S. Lam, Y.L. Wong
In 1991, Geological Society of Hong Kong held an international conference on seismicity in Eastern Asia to address aspects of seismicity, tectonic geology, seismic hazards and earthquake countermeasures together with Guangdong Seismiological Society. The Hong Kong Geotechnical Control Office also published a report entitled “Review of Earthquake Data for the Hong Kong Region” at the same year to provide data on historical earthquakes within 300 km of Hong Kong (GCO, 1991). In 1996, an inter-departmental Working Group was set up by the Buildings Department of Hong Kong to examine the likely effects of earthquakes on buildings in Hong Kong. A one day seminar on earthquake resisting structures was accordingly organized by the Hong Kong Institution of Engineers, Structural Division. More recently, an international workshop on earthquake engineering for regions of moderate seismicity was jointly organized by the three universities in Hong Kong and the Mid-America Earthquake Centre, USA, in 1998. In parallel to these activities, several special projects have been generated and undertaken by different departments in Hong Kong to investigate the seismic problems special to Hong Kong conditions. A number of research projects have been initiated and undertaken in several universities in Hong Kong to have in-depth understanding of various aspects in earthquake engineering. A large simulated earthquake-shaking table has been also set up in The Hong Kong Polytechnic University. The following is only a summary and an overview of earthquake engineering studies in Hong Kong. Although work on earthquake engineering in Hong Kong is relatively recent, the departments and researchers involved spread so widely that it is beyond our capability in a limited time to review all the relevant work in Hong Kong and to cover all relevant information in this paper.
Inverse problems in engineering
Published in Jamshid Ghaboussi, Soft Computing in Engineering, 2018
The example is the neurocontrol of structures subjected to earthquake ground motion. The experimental setup is shown in Figure 4.16. The structure is a three-story single span steel frame setup on an earthquake shaking table. An actuator on the ground floor is connected to a cable system that applies the control force to the first floor. The objective is for the actuator to apply a force in the first floor to reduce the overall motion of the structure caused by the earthquake ground motion. The control system determines the magnitude to control force.
Effect of Non-Uniform Vertical Excitations on Vertical Pounding Phenomenon in Continuous-Deck Curved Box Girder RC Bridges Subjected to Near-Source Earthquakes
Published in Journal of Earthquake Engineering, 2022
S. Tamaddon, M. Hosseini, A. Vasseghi
According to the findings, the present method can calculate the lateral displacement and torsion of deck for bridges with various central curve angles and non-uniform vertical seismic excitation under the effect of the k-th vertical pounding. It was repeatedly observed in the previous earthquakes that the deck of curved bridges has fallen off the rubber bearings or piers. The equations derived focusing on the pounding phenomenon and the responses obtained by the method presented in this paper can be employed to evaluate the curved bridges’ vulnerability. However, to scrutinize the dynamic behavior resulting from the structural dynamics equations with reality, more details can be monitored in the earthquake shaking table test.
Research on the Overstrength Performance of Lateral Force-Resisting System of Guangzhou West Tower Based on Story Overturning Moment
Published in Journal of Earthquake Engineering, 2023
Yuhong Ling, Haopeng Zhang, Jing Zhou
In order to analyze the reason why the model structure sustains relatively minor damage after encountering a series of earthquake of intensity 7 ~ 9 in the simulated earthquake shaking table test, the seismic demand and the seismic capacity of the GZTP structure are obtained by analyzing the numerical analysis results and the test results of the model structure. The seismic demand is determined by the elastic seismic spectrum analysis based on the SCD spectrum and the elastic dynamic time history analysis based on the SCE records under earthquake of various intensities. The seismic capacity is determined by nonlinear incremental dynamic time history analysis of the elastic-plastic GZTP structure.