Abstract: To deliver the badly need medical services for the victims, major regional hospitals are expected to remain operational after an earthquake. In order to provide continuing services, these hospitals not only have to secure the structural safety of the buildings, but need to ensure the functionality of essential equipments. In this study, a finite element analysis was performed on equipments attached in a series of reference buildings to examine the structural demand of hospital equipments during an earthquake. It was found out that the current code provides a good estimation for equipment with a short period of vibration. For those with longer periods, however, the component amplification factor should be obtained from the design spectrum.
Abstract: In this paper, a simplified analytical method is developed for the axial harmonic response of totally and partially embedded pile groups in homogeneous and layered soil deposits. Based on BDWF model, finite element sub-structure method is used to setup the dynamic model of cap-pile groups which can precisely simulate kinetic interaction and inertial interaction. A comprehensive parameter study focuses on the influence of caps’ elastic modulus and mass density on pile groups’ dynamic response, and then points out the limition of rigid cap in practical design. An approximate solution is finally presented for the internal forces distributed on pile heads due to pile-to-pile interaction. The solution of above approach was compared with that of traditional simplified model (rigid and massless cap solution) in simulating an in-site experiment and dynamics response of partially embedded pile groups for offshore wind farm.
Abstract: The objective of this research is to determine factor of safety for various cut slopes under the influence of earthquake activity. Finite element method was used to generate initial static stress condition and run dynamic analyses of the cut slopes. Factor of safety was then calculated using limit equilibrium method. Both sand and clay were analyzed in this study. The results show that steep slopes with initial safety factor of 1.5 are capable to sustain earthquake magnitude of 0.25g due to high shear strength of the soil. However, slopes with friction angle less than 21º for sand and cohesion value less than 38 kPa for clay are not stable. This shows that earthquake loading should be considered in the design of cut slopes in Malaysia.
Abstract: In this study, the seismic behavior of the main tower building of Beijing Yintai Center is presented with regard to the dynamic characteristics analysis and seismic response analysis. Firstly, by means of three-dimensional finite element analysis software, the dynamic properties and seismic responses under frequent earthquake action of the structure are obtained, respectively. It can be seen that the structure has a rational arrangement for structural elements and has a good seismic behavior. Then, the seismic behavior of the structure is studied through the dynamic elasto-plastic analysis method and static elasto-plastic analysis method under rare earthquake. Analysis results of both analysis methods show that the behavior of the structure accords with the earthquake performance objectives and the structure would not collapse under the rare earthquake action.
Abstract: The bridge buffeting response is a type of response varying with the time, space and frequency, in this paper, the bridge buffeting response analysis method based on Proper Orthogonal Decomposition (POD) and aeroelastic coupling is proposed, which can consider the contribution of effective turbulence on the bridge buffeting response. To test the proposed technique, a cable-stayed bridge is used to compare current analysis with the results using the traditional buffeting simulation method.
Abstract: The vibration frequency and vibration mode of a Geiger dome are studied first in this paper. Then the influence of the prestress and the externalload to the frequency and the way to change the vibration modes are discussed. At last, the response to the earthquake and the comparison of the aseismatic behavior between before and after adding the stability cables are studied. The results of the paper are believed to provide a meaning help in the preliminary design of cable domes.
Abstract: The recent development of Doppler radar sensor has allowed to study the typhoon wind structure more accuracy and systematic. In order to obtain more wind data near typhoon eye-wall, vehicular Doppler radar emerge as the times require. Based on two typhoon observed results carried out by vehicular Doppler radar in category A terrain, firstly the 10min mean wind profiles under 1000m height in different regions of typhoon were analyzed. The typhoon mean wind speeds increase a logarithmic law with height at nearly lower two hundred meters in all regions of typhoons. Using the power law to fit wind profiles, the exponential index α in pre-eye-wall region is greater than it in post-eye-wall region, and it decreases with increasing the mean wind speed. Secondly, based on analyzing the relationship between mean wind speed and wind ratio, the calculation formula for nominal gradient height were established in category A terrain. Finally introducing the probability method to study the mean wind profile, the exponential index α was established in category A terrain.
Abstract: Through establishing single material point model of base isolation system and two material points model of story isolation system in vertical earthquake, the isolation effect of base and story isolation system in vertical earthquake are studied. Results show that two kinds of isolation systems cannot effectively keep apart the vertical seismic action, and the effect is amplified on the contrary, especially the position of isolation layers in story structures affect the amplification effect. Compared with the base and story isolation structures, while using the same isolation device, the former is better than the latter in isolating vertical seismic action.
Abstract: A new masonry system has been developed to improve the seismic behaviour of RC frame with masonry panels. In this system dry-stack masonry panels are built with masonry units capable of sliding in-plane of a panel. These masonry panels have reduced in-plane stiffness but increased frictional energy dissipation capacity compared with the traditional masonry panels. Under seismic or wind loads these panels do not detrimentally interfere with natural RC frame response but rather positively contribute to it mainly by increasing dumping. A cyclic test has been performed to evaluate the behaviour of this masonry system. Test results demonstrate that the new system can improve the seismic behaviour of RC frame structures with masonry panels.
Abstract: In this paper, three typical bedrock long-period seismic waves and two commonly used waves were selected for three dimensional seismic responses parallel computation of a valley topography site under uniform excitation and traveling wave excitation. The equivalent-linear analysis method was used in simulation of soil’s non-linear properties. Computation results showed that horizontal acceleration response increase and vertical acceleration response decrease under long-period seismic wave excitation compared with those under commonly used waves excitation. When considering wave traveling effect, the horizontal acceleration response decrease and the vertical acceleration response increase. The conclusions are useful for relevant engineering projects. Parallel computation was also performed to raise computational efficiency.