Papers by Author: Lie Ping Ye

Abstract: This work is based on a typical RC frame that was closed to the epicenter and collapsed during the Wenchuan Earthquake. The seismic collapse resistance of the frame was strengthened by attached substructures, including conventional brace, buckling restrained brace (BRB) and viscous damper. Collapse fragility analysis based on incremental dynamic analysis is implemented for each strengthening scheme to compare their effects and to analyze the influence of critical parameters. The results show that the viscous damper performs better than the BRB, and the BRB performs better than the conventional brace. With the same strengthening parameters, the A-shaped bracing scheme is better than the X-shaped scheme.

Abstract: In order to guide temperature control design and construction and to guarantee the construction quality of roller compacted concrete (RCC) gravity dams in severe cold area, it is of great significance to carry out the simulation analysis of temperature and stress. The whole progress of construction and operation of Longlin RCC gravity dam in harsh climate region were simulated by using the heat of hydration analysis control function, construction stag analysis control function and the time-dependent material link of MIDAS.civil.2006. According to the construction process, the curves of temperature and the curves of stress were obtained. The locations where the crack ratio may exceed 20 were also obtained and the correct temperature control measures and the rational construction progress control system were pointed out.

Abstract: A hysteretic model of conventional steel braces consisting of 18 parameters is proposed. This model is able to simulate the hysteretic behavior of conventional steel braces accurately. The collapse-prevention strengthening effect with steel braces for a typical reinforced concrete (RC) frame that was close to the epicenter and collapsed during the Great Wenchuan Earthquake is discussed via push-over analysis and collapse fragility analysis based on incremental dynamic analysis. The result could be referred to for the seismic collapse prevention design of RC frames.

Abstract: The steel bar connection is an important and inevitable work in civil engineering. The traditional overlapped connection method usually needs to place the transversal rebars in the overlapped splicing area to restrict the splitting cracks in concrete. The steel usage and labor cost are increased. An improved splice, which is the hybrid connection of welding and overlapping, was developed for mid-diameter bars, which is easy to install and has commendable mechanical behavior. A series of reinforcing rebar splice tests with steel-concrete interaction were conducted. The failure model of hybrid connection and the ultimate strength were acquired. Based on the tests, the failure mechanism of hybrid connections was analyzed. The results show that the ultimate load of the new splice is sufficient for the engineering application and the failure model is reasonable. The hybrid connection could be used in the engineering practice.

Abstract: The experimental research on six steel plates strengthened with CFRP plates, loaded in tension, shows that their fatigue lives can be greatly increased compared with un-strengthened specimens. Linear elastic fracture mechanics (LEFM) is adopted to explain the mechanism of CFRP plates strengthening. The stress intensity factors of the steel plates are calculated with finite element method (FEM), and Paris law on crack propagation is used to predict the fatigue life of strengthened specimens. The comparison between experimental results and numerical predictions shows good agreements on the fatigue crack propagation.