Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province

Xiamen, China

Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province

Xiamen, China
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Li H.,Huaqiao University | Li H.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Gao X.,Huaqiao University | Gao X.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | And 3 more authors.
International Journal of Steel Structures | Year: 2017

Accurate numerical models are necessary to evaluate the seismic performance and load-bearing mechanism of new-type box steel bridge piers with embedded energy-dissipating shell plates under tri-directional seismic coupling action. Numerical simulations of seismic performance under six types of tri-directional seismic coupling action was conducted. The effects of this stress on the seismic performance of the new-type steel bridge piers was evaluated through analysis of damage mode, hysteresis curve, skeleton curve, stiffness and strength degradation characteristic, and energy-dissipating capacity. This study also compared the numerical analysis with experimental results in order to validate the accuracy of the proposed finite element model. Based on this model, the range of relevant parameters expanded and 88 numerical specimens were analysed for seismic performance, producing further information about the influence of thickness and curvature of the embedded shell plate, spacing of transverse stiffening ribs of the shell, axial compression ratio, and slenderness ratio. Results showed that tri-directional seismic coupling action significantly affects the specimen’s deformation capacity; the embedded shell plate effectively improves the piers’ load-carrying and deformation capacity; and the thickness of the embedded shell plate, width-to-thickness ratio of the wall plate, axial compression ratio, and slenderness ratio significantly affect the seismic performance of the new-type steel bridge piers. To promote the ease of seismic design of new-type box steel bridge piers, this study used theoretical analysis and numerical simulation to calculate equations for the minimum height of the energy-dissipating zone of the bottom embedded shell plate. Finally, formulas were also established to calculate the relevant stability bearing capacity and displacement ductility factor of the new-type steel bridge piers under tri-directional seismic coupling action in order to improve their seismic design. © 2017, Korean Society of Steel Construction and Springer-Verlag Berlin Heidelberg.


Guo Z.-X.,Huaqiao University | Guo Z.-X.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Wang L.,Huaqiao University | Wang L.,Liming Vocational University | And 5 more authors.
Construction and Building Materials | Year: 2017

This paper describes an experimental and analytical program focused on developing a strengthening technique to enhance the flexural performance of stone slabs. The technique involves the use of reinforced mortar bonded to the soffit of the stone slabs, which can be used for strengthening of stone slabs in existing structures, or manufacturing of composite stone members for new constructions. The experimental program consisted of flexural testing of strengthened stone slabs and an unstrengthened specimen serving as the benchmark. The amount of reinforcement ratio and mortar strength were varied as the test variables. An analytical model was also developed to predict the cracking and ultimate moment of strengthened stone slabs. The unstrengthened specimen failed suddenly in a brittle fashion; however, the strengthened stone slabs experienced a ductile failure mode and developed a higher flexural strength. As expected, the enhanced performance was proportional to the reinforcement ratio, but the strength of mortar affected only the cracking moment. The stone slab and the reinforced mortar layer exhibited good composite action, and no obvious interfacial failure was observed. The analytical model developed could reasonably predict the cracking and ultimate moment of stone slabs strengthened with reinforced mortar. © 2017 Elsevier Ltd


Chen L.,Huaqiao University | Chen L.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Liu J.,Huaqiao University | Liu J.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Sun J.-Q.,University of California at Merced
Journal of Applied Mechanics, Transactions ASME | Year: 2017

There has been no significant progress in developing new techniques for obtaining exact stationary probability density functions (PDFs) of nonlinear stochastic systems since the development of the method of generalized probability potential in 1990s. In this paper, a general technique is proposed for constructing approximate stationary PDF solutions of single degree of freedom (SDOF) nonlinear systems under external and parametric Gaussian white noise excitations. This technique consists of two novel components. The first one is the introduction of new trial solutions for the reduced Fokker-Planck-Kolmogorov (FPK) equation. The second one is the iterative method of weighted residuals to determine the unknown parameters in the trial solution. Numerical results of four challenging examples show that the proposed technique will converge to the exact solutions if they exist, or a highly accurate solution with a relatively low computational effort. Furthermore, the proposed technique can be extended to multi degree of freedom (MDOF) systems. © 2017 by ASME.


Chen X.,Huaqiao University | Chen X.,Nanjing Southeast University | Cai Q.,Huaqiao University | Cai Q.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | And 3 more authors.
Journal of Hydrology | Year: 2016

It is well established that seismic waves disperse into higher harmonics, thereby generating waves at ultrasonic frequencies within layers. Field tests and laboratory investigations have demonstrated that ultrasonic stimulation can enhance particle release in natural systems, but the intrinsic mechanisms of ultrasonic waves are not fully comprehended. We investigated the underlying mechanics of such waves by generating increasing ultrasound stimulation upon enhanced release of trapped particles from pores. Experiments were conducted using a novel soil column apparatus that is capable of applying ultrasonic waves, controlling the confining pressures, regulating the soil column height, and controlling the temperature of the soil column. Particles with median diameters of 9.63 μm in the range of 1-35 μm were evaluated in a series of tests under three flow rates. Stimulations were applied for 60 s at power levels of 600, 1000, 1400, and 1800 W. The particle concentration in the effluent during each test was recorded. The laboratory results showed that hydrodynamic drag was the dominant force in pre-stimulation particle release. However, the flow rate was found to be constant in pre- and post-stimulation phases, and cavitation caused by ultrasound stimulation was judged to be the most likely reason for post-stimulation particle release. Furthermore, the nature of the post-stimulation particle release was distinctly different from that of the pre-stimulation release, in that an abrupt concentration change was observed in each stimulation application. These abrupt concentration changes were attributed to ultrasound stimulation, but the release concentration and the duration of particle release were controlled by the power of the ultrasound stimulation and the quantity of particles deposited in the sand. Furthermore, the release rate coefficient first decreased and then increased as the number of ultrasound stimulations increased. Two mechanisms of particle release were identified that could explain the rate change: (1) only particles deposited in the porous medium by fouling mechanisms could be released by ultrasound stimulations at power levels below a certain critical value, or (2) ultrasound stimulations at power levels above a certain critical value are sufficient to change the structure of the porous medium, producing more dead-end pore openings that allow particle flow through the porous medium. The results presented are unique in indicating that successive particle release can be induced using increasing ultrasound stimulation. © 2015 Elsevier B.V.


Peng X.,Huaqiao University | Peng X.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Shi W.,Huaqiao University | Hua C.,Huaqiao University | Hua C.,Hongyu Architectural Design Institute Co.
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2015

The world cultural heritage-Fujian earth building has often affected by the typhoon and extreme weather, and the durability of its structure has decreased continuously. Using statistical methods of soil and water loss and field test, rammed earth erosion loss rule and loss measurement formula were studied, revealing the loss mechanism of rammed earth by wind and rain erosion, rainfall infiltration wall material weakening performance, and wind driven rain hiting the walls, resulting in material particle splash erosion and denudation. And it was proved that the raindrop impact load is the direct motive erosion loss. Combined with the local meteorological data, the rammed earth annual erosion was calculated, which can be used to predict the residual life of the wall, and to provide a adaptive scientific basis for protection of Fujian earth building. ©, 2015, Editorial Department of Journal of Sichuan University. All right reserved.


Gao Y.,Huaqiao University | Gao Y.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Liu Y.,Huaqiao University | Liu Y.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | And 2 more authors.
Advances in Science and Technology of Water Resources | Year: 2016

A two-dimensional (2D) viscoelastic boundary element, VS2D2Bar, was developed based on the open source finite element package OpenSees. The applicability of the 2D viscoelastic boundary element was verified with a numerical example, and it was applied to the seismic response analysis of a gravity dam. Numerical results demonstrate that the peak dynamic response of the dam body according to the viscoelastic boundary element model greatly decreases in contrast to that obtained from the massless foundation model with fixed boundary conditions. As a result, the radiation damping effect of the infinite foundation should be considered in seismic response analysis of gravity dams. The results also show that OpenSees is applicable to the seismic response analysis of gravity dams. With a high efficiency in programming and debugging, OpenSees can be easily extended to the static and dynamic analysis of complex hydraulic structures. © 2016, Editorial Board of Advances in Science and Technology of Water Resources, Hohai University. All right reserved.


Saturated soil column experiments were conducted to determine the influences of flow direction, flow rate, and particle-size distribution characteristics on the transport and deposition of particles in saturated porous media. Two bimodal-distribution particles and one unimodal-distribution particle were employed in these studies, and soil column experiments were performed using a variety of particle-size distributions and flow conditions. In addition, a modified convection–dispersion model for particle transport and deposition was developed, considering dispersive flux on the deposition kinetics. The experimental breakthrough curves fit well with the analytical solution of the modified convection–dispersion model. Regardless of particle-size distribution, the particles’ mean velocity increases linearly with the mean interstitial fluid velocity. The particles’ mean velocity in horizontal flow is lower than that in vertical flow. Furthermore, dispersivity decreases with increasing flow rate in vertical flow. The range of the particles’ dispersivity in vertical flow is larger than that in horizontal flow. Finally, the rate of particle deposition increases with particle size. Overall, this study highlights the complicated interdependence of the effects of flow rate, flow direction, and particle-size distribution on particulate transportation and deposition. © 2014, Springer-Verlag Berlin Heidelberg.


Li H.,Huaqiao University | Li H.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Luo Y.,Tongji University | Li D.,Hefei Administrative Bureau of Key Engineering Project | Ding D.,China Wuzhou Engineering Design Group Co.
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2015

The degradation characteristics of stiffness and strength, load-displacement curves, failure shape and stress distribution of 16 steel box columns and 85 numerical calculated members were investigated. The interactive mechanism between local buckling and overall instability of steel box beam-columns under cyclically lateral loading was also discussed. Based on the regressive results of experimental and numerical data, the formula of stability bearing capacity of steel box beam-columns under cyclically lateral loading was fitted. The results show that when the axial compression ratio of steel box column is less than 0.1 or the maximum slenderness ratio is less than 40, the local buckling of plate has dominated effect on the mechanical behavior of steel box columns. The width-to-thickness ratio of web plate has main effect on the ductility and the degradation characteristics of stiffness and strength of the columns. While the axial compression ratio of steel box column is more than 0.2 and the maximum slenderness ratio is more than 80, the overall instability has dominated effect on the mechanical behavior of steel box columns. The effects of axial compression ratio and slenderness ratio on the mechanical behavior of the columns are both conspicuous. ©, 2015, Central South University of Technology. All right reserved.


Liu Y.,Huaqiao University | Liu Y.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Guo Z.-X.,Huaqiao University | Guo Z.-X.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | And 2 more authors.
Gongcheng Lixue/Engineering Mechanics | Year: 2015

Five prefabricated RC columns linked at the middle region and two monolithically casted RC columns were tested under axial compression loads to investigate the influence of linkage site curing time on the axial compression performance of specimens at different stages of construction. The results indicate that obvious differences in axial compression performance for prefabricated RC columns exist at different construction stages. The axial strength of the prefabricated RC column without casting concrete at the linkage site is 46.2% that of the monolithically casted RC columns. After concrete is cast, the axial strength of prefabricated RC columns increases with the increase of curing time for the linkage site. When the curing time for the linkage site is 28 days, the axial strength of the specimen is 87.9% that of the monolithically casted RC columns. Due to the pressure exerted at the cone-shaped cross section of the upper columns, the linkage site of the prefabricated RC columns expanded laterally, which gave rise to the confinement of the concrete by the stirrups. The failure modes of the specimens show distinct plastic characteristics compared with those of the monolithically casted RC columns. The mechanical analysis of axial compression for prefabricated RC columns was carried out and a calculation method for axial strength is proposed. Calculated results show good agreement with test results. This paper can be referenced for the engineering practice of prefabricated RC structures. © 2015, Engineering Mechanics Press. All right reserved.


Hou W.,Huaqiao University | Hou W.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province | Shi Q.-X.,Xi'an University of Architecture and Technology | Guo Z.-X.,Huaqiao University | Guo Z.-X.,Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province
Gongcheng Lixue/Engineering Mechanics | Year: 2013

In order to study the failure mechanism and seismic performance of reinforced concrete core walls under different parameters, the concrete core walls under static horizontal loads are simulated using nonlinear analysis and performance assessment program PERFORM-3D. The validity and accuracy of an elastic-plastic model is verified by the comparison between the analytical predictions and test results. On this basis, the parameters on the seismic behavior of reinforced concrete core walls are analyzed, including the effects of axial compression ratio, coupling beam span-depth ratio, coupling beam longitudinal reinforcement rate and height to width ratio. According to the calculation results, the bearing capacity of concrete core walls is improved with the increase of the axial compression ratio. However, when the value of a test axial compression ratio reaches 0.5, bearing capacities are reduced. Deformation capacity reduces with the increase of axial compression ratio. With the increase of height to width ratio, the bearing capacity of concrete core walls is reduced but the deformation capacity is improved significantly. Moreover, the failure mode of core walls with different high aspect ratios is changed. With the increase of coupling beam stiffness, the bearing capacity of core walls increases while ductility deformation capacity reduces seriously. In addition, based on the elastic-plastic damage analysis of a core walls model, the damage development order and component yield situation of core walls are obtained.

Loading Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province collaborators
Loading Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province collaborators