Applied Mechanics and Materials Vols. 353-356

Abstract: Hidden cave is one of the most common geological hazards and the seismic prospecting method is an efficient tool to detect it. Numerical simulation method is the main method of geophysical forward modeling and plays a very important role in seismic prospecting. Gaussian beam forward modeling method combines the wave equation and the ray theory closely, and it has the advantages of high efficiency and high precision. We used Gaussian beam method to simulate the seismic wavefield of shallow hidden cave, and the results showed that the seismic numerical simulation can effectively help us design and optimize the geometry in actual field work. With the help of seismic numerical simulation, the efficiency and precision of shallow seismic prospecting will be improved significantly.

Abstract: The application of performance-based seismic design method in super high-rise building is studied in this article. The two-stage design process of a super high-rise building is introduced. On the base of proposing the performance standards and objectives of the super high-rise building under earthquake actions of different levels, optimal solution is provided after computational analyses with different softwares. Computational analyses indicate that the design could satisfy all seismic fortification requirements and seismic performance objectives of China's seismic codes in force. The performance-based design idea can provide a reference for similar projects.

Abstract: The multi-storey reinforced concrete frame structure whose frame has been added with a kind of unsymmetrical K-type friction energy dissipation brace is taken as an example in this article. The time history analysis of different angles of unsymmetrical K-type friction energy dissipation brace and symmetrical K-type friction energy dissipation brace under the rare earthquake has been done by using the finite element software SAP2000. The analysis and comparison on the seismic performance shows that symmetrical K-type friction energy dissipation brace under certain conditions. Plan layout could be more flexible by using the result obtained which could become a reference for design in days to come.

Abstract: in this paper, four single-layer masonry wall models in1/8 scale were made by a kind of special bricks on the basis of an ancient masonry pagoda structure. The models are divided into two groups by whether there is a masonry floor in a model or not. Pseudo-static test is introduced to study the seismic performance of four models with a special load control process which is suited to masonry structure. According to the test results, the horizontal bearing capacity and ductility of each masonry walls reinforced with steel straps under horizontal low cyclic loading has been sorted out. Four nonlinear restoring force models are inferred from the experimental results and phenomena under various operating conditions. And the shear capacity calculation formula of reinforced masonry wall models is fit out. The theory and experimental study show that seismic performance of the masonry pagodas strengthened with steel straps has been improved significantly.

Abstract: Earthquake damages to the tall and towering structures are usually very serious, but these dangers are often hidden. The paper uses the finite element software ANSYS to set up the overall modeling of the TC6010 tower crane which is produced by a company, and carry on the modal analysis based on it. The paper obtains the data of the displacement and the speed response of the complete machine after exerting the Ninghe Tianjin seismic wave, and has the preliminary analysis to the result. The results show that the tower crane is a low-frequency vibrating system and easy to cause the structure resonance, the crane tower may damage in the boom firstly under the action of seismic wave.

Abstract: Heat-insulating perforated brick is a new type energy-saving masonry material. In order to investigate seismic response of masonry wall with this new-type brick, a set of quasi-static full-scale cyclic tests are performed. The test results show that this brick owns a good cooperative work system between bearing layer and insulation layer, and vertical axial force is an obvious factor which affects seismic response of heat-insulating perforated brick walls. With the increase of vertical axial force, ultimate bearing capacity increases, however, ultimate displacement can be decreased. In the case of the same axial force, ultimate bearing capacity of the specimen wall with door opening is less than the one with window opening, and the ultimate displacement also is less than the one with window opening.

Abstract: In order to explore the safety performance of continuous structure bridge near fault zone, a typical three spans continuous girder bridge of highway was selected to study the structural seismic response. The finite element model of whole bridge considered the force characteristics of bearing and pile-soil interaction was constructed. Typical near-fault records were selected from the important earthquake events. Several artificial waves characterized with the soil type in bridge site were simulated and used for dynamic analysis. The seismic performance of continuous bridge was studied by nonlinear dynamic time-history method. Research results indicate that, especially large amplitude pulse effect of near-fault records for strong near-fault earthquake, will significantly enhance the seismic response of continuous girder bridge under the second seismic level (EL2) leads to structure to collapse. The fact that the near-fault effect is not considered in China existing highway bridge seismic design code will increase the destructive risk of structure.

Abstract: Blasting-induced seismic wave imposes cyclic loadings on adjacent buildings and structures with a combined loading mode of tension, compression, bending, shear and torsion, and it leads to flaking of floated coat, wall cracking, developing of original cracks, etc. This paper presents a blasting case study for the excavation of Wucun tunnel in Xiamen Success Avenue. Field monitoring and numerical calculation of a typical brick masonry structure are adopted to analyze the relationships among the maximum structural displacement, peak vibration velocity of blasting-induced foundation vibration and the change rate of crack width. On the basis of the study above, a method of calculating the safe vibrating velocity for single-layer masonry structure is proposed. Meanwhile, a suggested value of the safe vibrating velocity for single-layer masonry structure is given. All the research results can be useful for the similar construction and research.

Abstract: Considerable economic losses caused by the earthquake, while secondary disasters such as fires caused by the earthquake, the city paralyzed, long-term social unrest, especially casualty loss can not be measured by money. Isolation technology to reduce the seismic action of the superstructure of the building, so not easy to destroy buildings in the earthquake, the direct and indirect economic losses greatly reduced after the earthquake. But also can greatly reduce the loss to society.

Abstract: Vibration of continuous beam bridge is caused by explosion seismic wave in influence area. In order to provide scientific basis for seismic design and security assessment for continuous beam bridge, three-direction attenuation-amplification effect of vibration of pier-beam was analyzed. Based on blast monitoring project of South Branch Approach Bridge of Xiazhang Sea-Crossing Bridge under construction, the attenuation-amplification effect of peak vibration velocity from the bottom of the pier to the top of the box girder in the different stages were analyzed. The average attenuation-amplification coefficients of peak vibration velocity in three-direction and the one synthesized by three vectors are concluded.