Papers by Author: Jun Wu Dai

Abstract: The seismic damage of nonstructural system is severely, and has affect escaped from building and rescue. Suspending system is the typical one of the nonstructural system. This paper investigated the seismic damage of suspending system in Lushan earthquake. Suspending system of many buildings are failure, especially for the hospital and gymnasium which is used for disadvantaged group and rescue. Moreover, design of suspending systerm is lack of industrial standards, so much attention should be paid.

Abstract: This paper introduces the seismic damage of nonstructural system under severe earthquake at home and abroad. Then seismic research on nonstructural system is little, and that does not match to severe damage, especially the nonstructural system cost high proportions of total price. Damage of nonstructural system has affected people in the life and property safety in the earthquake. Moreover, the paper pays more attention to ceiling system under seismic.

Abstract: Framed-Ground Floor Structure for short which has serious seismic damage and high collapsed rate, is the unreasonable structure system. The experiences is 1. The shear wall can be increased to improve stiffness of weak layer. And designer should try to arrange the walls equably. 2. In order to avoid stiffness mutation, stiffness ratio between ground frame and transition layer can be adjusted. 3. Collapse resistant design of Framed-Ground Floor Structures should be emphasized. Then seismic response analysis is conducted by ANSYS. And the seismic response is little, and strength damage or stable damage do not occur for the little acceleration peak. Along with the increasing acceleration peak, The bigger horizontal displacement leads to damage of Framed-Ground Floor Structures. Moreover, the damage is in advance as the increasing acceleration peak.

Abstract: Multi-story Masonry Building with R. C. Frames on Ground Floor (Framed-Ground Floor Structure for short) which has serious seismic damage and high collapsed rate, is the unreasonable structure system. However, the structure system not be abolished for economic reason. Collapse types of that are divided into collapse of ground floor, collapse of transition layer, global collapse. And seismic damage is also serious for frame column and shear wall. Experiences are obtained from above seismic damage, and the following aspects should be taken into account in the future. 1. The shear wall can be increased to improve stiffness of weak layer. And designer should try to arrange the walls equably. 2. In order to avoid stiffness mutation, stiffness ratio between ground frame and transition layer can be adjusted. 3. Collapse resistant design of Framed-Ground Floor Structures should be emphasized.

Abstract: Power system related to the people's livelihood is an important lifeline and its rapid post-earthquake rehabilitation and reconstruction is particularly important. Considering the importance of power system, cost estimation method of post-earthquake rehabilitation of power system is proposed. Based on the direct economic losses of power system, post-earthquake rehabilitation cost is given by index of the post-earthquake adjustment factor which is put forward according to post-earthquake rehabilitation cost and direct economic losses of power system in “5.12” Wenchuan earthquake. Cost estimation method of post-earthquake rehabilitation of power system could provide good suggestions for post-earthquake rehabilitation work.

Abstract: Many RC frame structures were severely damaged or collapsed in some layer. The phenomenon was significantly different from the expected failure mode in seismic design code. This paper comprehensively sums up the earthquake characteristics of masonry infilled RC frame structures. Based on an investigation of a masonry infilled RC frame structure damaged in the earthquake area, conduct the research on frail-layer caused by infill walls uneven decorated. On the hypothesis of keeping the main load-bearing component invariant, two models were considered, i. e. frame with floor slab, and frame with both floor slab and infill wall. Furthermore, divide them into groups of the bottom, the middle and the top frail-layer to discuss by changing the arrange of infill wall. Time history analyses using three-dimensional sophisticated finite element method were conducted. The major findings are: 1)infill walls may significantly alter the failure mechanism of the RC frames. 2)controlling the initial interlayers lateral stiffness ratio in a reasonable range is an effective method to avoid frail-layer damage. These findings suggest that the effects of infill wall should be considered in seismic design, keep the initial interlayers lateral stiffness ratio less than the paper suggested, and the structural elasto-plastic analysis model should take slabs and infill walls into account.

Abstract: FE models of both the single-layer Kiewitt reticulated domes and the impactor were developed incorporating ANSYS/LS-DYNA. Three failure modes for Kiewitt reticulated dome under impact load are discerned. Moreover, Global collapse of structure belongs to the progressive collapse, and is the most serious failure. After this, stress of members, velocity and strain energy of each component are introduced to display the progressive process of collapse. It shows that the dome does not defend impact load as a whole. Each component of structure is impacted and dented in turn. And the collapse enlarges from impact zone to the supports of dome. Furthermore, collapse relates to energy transform among kinetic energy, stain energy and potential energy of structure. Moreover, collapse will continue, if initial kinetic energy and release of potential energy of structure exceed the strain needed.