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Zhang J.-Y.,Shanghai JiaoTong University | Zhang J.-Y.,Sichuan Institute of Building Research | Chen L.-Z.,Shanghai JiaoTong University | Zhu J.,University of Nebraska at Omaha
Soil Dynamics and Earthquake Engineering | Year: 2016

This paper presents theoretical analysis of the parallel seismic (PS) method for evaluating existing piles using the flexural mode wave exited by a horizontal impact on the lateral surface of a pile. A simplified theoretical model of the flexural wave for PS method was established to elaborate the theoretical basis. A correction factor was then obtained and proposed to correct the pile depth obtained from the PS method, thus providing a more accurate estimation. A three dimension (3-D) finite element (FE) model was developed and the existence of the flexural waves on branch F(1, 1) in the pile shaft has been verified. Two time domain methods were used to calculate the flexural wave velocity in the pile. One was based on the pile tip reflection signal using a model where pile head reflection was minimized, and another method used the slope of the upper fitted line in the PS test. The flexural wave velocities from both methods match well with the predicted flexural wave group velocity determined from the dispersion curve of a 1-rod embedded in the soil. The accuracy in estimation of pile tip depth is improved by applying the correction factor. A series of parametric studies were carried out to demonstrate the effectiveness of using flexural wave for PS test and the correction factor proposed in this study. © 2016 Elsevier Ltd.

Gao J.,Southwest Jiaotong University | Wang Z.,Southwest Jiaotong University | Pan Y.,Southwest Jiaotong University | Ge Q.,Sichuan Institute of Building Research
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2016

Strong earthquake has adverse impact on the petrochemical steel structures of refinery and lead to large economic losses and serious secondary disasters. We studied a reformer reactor of a large refinery, built the finite element model and set viscous dampers to reduce the seismic risk of petrochemical structures based on their characteristics. Then we analyzed the influence factors, including location, quantity and the damping parameters of the viscous dampers. The results show that the inter-story force and inter-story displacement angle of the floor where the viscous damper was setted decrease significantly, and the damping effect with setting viscous damper in the bottom is greater than that in the middle and upper part. Besides, the inter-story force and inter-story displacement angle decrease when the number of viscous damper increases, but the decrease amplitude reduces gradually. In addition, the influence of damping coefficient on the damping effect of the petrochemical steel structure is greater than that of the damping index. So the damping coefficient should be given priority to consider in the structure design for better seismic performance. © 2016, China National Publications Import and Export (Group) Corporation. All right reserved.

Wu Z.-J.,Sichuan Institute of Building Research | Zhang J.-J.,Southwest Jiaotong University | Wang Z.-J.,Southwest Jiaotong University | Wu X.-X.,Southwest Jiaotong University
Zhendong Gongcheng Xuebao/Journal of Vibration Engineering | Year: 2015

The defect had been overcome in this paper that there was only the differential time can been considered in the traditional inconsistent excitation input. The wavelet decomposition and reconstruction method was used to build a series of spatial similarity coupling waves in this paper, which can simulate the mutation of local site conditions in the natural ground motion, just because of the characteristics that the harmonic content and the order can be adjusted. So it made a way to meet all kinds of various site conditions about inconsistency input. On the other hand, the wave coupling similarity was been combined with the dynamic response of the underground pipeline structure for the first time, then a series of rule been obtained when the internal force of pipeline structure changing with the similarity of coupled waves, through this large scale shaking table test. The results show that it had a significant influence on the internal force response values, the coupling wave similarity between the two adjacent particles in the pipeline structure. Finally, a series of important rule had been obtained in this inconsistency motivation test. © 2015, Nanjing University of Aeronautics an Astronautics. All right reserved.

Tian L.,Shandong University | Ma R.,Shandong University | Wang W.,Dalian University of Technology | Wang L.,Sichuan Institute of Building Research
Open Civil Engineering Journal | Year: 2013

Collapses of power transmission towers had usually taken place in previous large earthquake. The collapse process of a power transmission tower under earthquake excitation is studied in this paper. Using international finite element software ABAQUS, the three-dimensional finite element model of the power transmission tower is created based on a practical engineering. Three typical seismic records are selected. The progress collapse processes of the power transmission tower under different seismic excitations are simulated using the nonlinear time history method. The collapse paths and failure positions of the power transmission tower are obtained under different seismic excitations. The results can provide reference for seismic design of power transmission tower which can prevent the collapse of the power transmission tower. © Tian et al.

Qin S.,Chongqing University | He D.,Chongqing University | Chen P.,Chongqing University | Zhang P.,Sichuan Institute of Building Research
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2016

Based on the present situation of masonry structure and the development of housing industrialization, We proposed an invonative unbonded post-tensioned precast concrete composite wall to develop a new structure form in the low-rise civil construction. We studied two specimens with various levels of pre-stressing were studied experimentally by the quasi-static test system to investigate the seismic behavior of the composite wall and obtained the seismic behavior indexes of corresponding specimens. The results show that the walls have better bearing capacity and good ductility. They could meet the application requirements of the low-rise building in eight-intensity area and be used as an alternative of masonry load-bearing wall structure. We also presented some suggestions about the structure forms of the compostie wall. © 2016, China National Publications Import and Export (Group) Corporation. All right reserved.

Gao L.,Sichuan Institute of Building Research | Xue J.,Xi'an University of Architecture and Technology | Wang J.,Sichuan Institute of Building Research
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2015

Finite element software ABAQUS was used to analyze the nonlinear performances of steel reinforced recycled concrete frame infilled with recycled concrete blocks. The simulation results agreed with the experimental results and the rationality of the finite element model was proved. Parametric analysis of the structure was carried out, in which the recycled concrete strength, yield strength of steel in frame columns, axial compression ratio, masonry strength and aspect ratios of the infilled wall were considered as analytical parameters. The results indicate that the horizontal load-bearing capacity of the structure is improved with the increment of recycled concrete strength and yield strength of steel in frame columns, but there is no significant effect on the elastic stiffness and the ductility. With the increment of the axial compression ratio, the load-bearing capacity increases before decreasing, the elastic stiffness changes a little and the ductility decreases. With the increment of the masonry strength and aspect ratio of the infilling wall, the ductility decreases while the horizontal load-bearing capacity and the elastic stiffness increase obviously. ©, 2015, Science Press. All right reserved.

Gao L.,Sichuan Institute of Building Research | Xue J.-Y.,Xi'an University of Architecture and Technology | Wang J.-L.,Sichuan Institute of Building Research
Gongcheng Lixue/Engineering Mechanics | Year: 2016

Based on the experimental study on seven 1/2.5-scaled model of one-bay and one-story steel reinforced recycled concrete frames infilled with recycled concrete blocks under low cyclic reversed loading, the effects of infilled walls' arrangement, masonry material, the vertical spacing of tie bar, axial compression ratio, and the ratio of width to height of infilled wall on seismic behaviors were analyzed. The typical final failure mode, load-displacement curves, load carrying capacity and displacement ductility were also analyzed. The results indicate that the failure mechanism is the beam-hinged mechanism, and the higher filling rate of infilled wall can reduce the damage degree of the whole structure. With the increment of the filling rate of infilled wall, the increase will happen for the infilled blocks strength, the axial compression ratio and the number of tie bar, loading carrying capacity and initial stiffness. The mean value of displacement ductility is 6.26, which shows the strong capacity of resisting collapse. Based on the experimental results, a four segments restoring force model for the structure was proposed, and can provide theoretical foundation for the nonlinear seismic analysis of a steel reinforced recycled concrete frame infilled with recycled concrete blocks. © 2016, Engineering Mechanics Press. All right reserved.

Ma J.,Sichuan Institute of Building Research | He K.,Sichuan Institute of Building Research
Advances in Intelligent Systems and Computing | Year: 2015

This paper developed a new method named as MPG/FEM method which is constructed by coupling the meshfree poly-cell Galerkin method (MPG) with the finite element method (FEM) for the analysis of elasticity problems. The present MPG/FEM method synthesizes the advantages of both FEM and MPG. MPG/FEM method not only simplifies the implementation of essential boundary conditions like FEM, but also inherits good accuracy from MPG. The numerical tests in the present work demonstrate that the results obtained by MPG/FEM method show an excellent agreement with the theoretical results. The coupled method is very accurate and has a promising potential for the analyses of more complicated elasticity problems. © Springer-Verlag Berlin Heidelberg 2015.

Xu Y.,University of Sichuan | Xiong F.,University of Sichuan | Wu T.,Sichuan Institute of Building Research
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2015

The results of reanalyzing the testing method of sintered brick mortar rebound show that the carbonation depth has slight influence on the mortar rebound. Based on the results and analysis performed by Origin8.0, a sintered brick mortar rebound curve was shown between Standard mortar test block strength and mortar rebound value without considering the carbonation depth. © 2015, China National Publications Import and Export (Group) Corporation. All right reserved.

Ge Q.-Z.,Sichuan Institute of Building Research | Ge Q.-Z.,Tongji University | Weng D.-G.,Tongji University | Zhang R.-F.,Tongji University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2016

Whole process of aircraft's crashing into an extra-large liquefied natural gas (LNG) storage tank was simulated using a numerical method. The LS-DYNA program was used to build the SPH model of a F-15 fighter considering the interaction of tank, LNG, and insulating layer. The plane's material model and parameters were chosen and analyzed. Based on Riera method, the comparison between the crash load obtained with the numerical method and that with the theoretical method was made to prove the reliability and practicability of the SPH model of a F-15 fighter. The analysis results revealed that the impact energy absorbed by the outer tank increases with increase in impact angle, so the vertical impact is the worst impact angle; the height of the aircraft impact position affects the response of the tank little; when the aircraft impact speed is 215 m/s, the tank is destroyed seriously; if the speed reduces to 160 m/s, the stress of the inner tank material approaches the maximum value, so 160 m/s can be taken as the maximum impact speed using the current design method. © 2016, Editorial Office of Journal of Vibration and Shock. All right reserved.

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