Papers by Keyword: Rare Earthquake

Abstract: Based on the finite element model of slope, the stability of sand slope are studied. The results show that The pore water pressure shows increase trend, while the excess pore water pressure shows decreasing trend with the increase of the water depth. With the increase of the the water depth, safety factor of slope calculated by quasi static reduces to 0.193 from 2.366, which reduces 12.26times. The minimum safety factor calculated by dynamic time history is less than that by quasi static method, which shows that there is some limitations of the quasi static method.Without considering the groundwater, the destruction of slope is mainly the circular shearing damage through the slope toe, while the destruction is not yet through the slope toe, but from a point on the front of slope.

Abstract: Based on the finite element model of slope, the stability and dynamic response of sand slope are studied. The results show that with the increase of groundwater, the maximum horizontal displacement of slope shows increasing trend, and reach maximum horizontal displacement on the top of the slope, and the displacement under near-field earthquake is greater than that under far-field earthquake. The accelerations with groundwater are less than that without groundwater, which shows that the existence of groundwater damps vibration. Without considering the groundwater, the destruction of slope is mainly the circular shearing damage through the slope toe, while the destruction is not yet through the slope toe, but from a point on the front of slope.

Abstract: In order to study the seismic response of slope under the effect of seismic load, a numerical model was established by ANSYS program. It was mainly analyzed the dynamic responses of slope under the effect of both general earthquake and rare one. The results indicate that under general earthquake, slope deforms a little, there is small stress within slope, and small tensile stress on the top of slope; under rare earthquake, slope deforms greatly, slope surface has large displacement, and there is larger tensile strain on the slope top. At the same time, stress concentration effects expand further within slope and slope toe. Consequently, with regard to slopes in higher fortification intensity area, some steps should be taken to strengthen slope in order to improve slope seismic stability.

Abstract: With vigorous development of hydroelectric source in west China, the anti-seismic security issue of dam engineering attracted particular attention. This paper presented the principle of dynamic time-history analysis method and established the model with the assistance of finite element method and combined with practical engineering for further analysis on the dynamic response of displacement and stress of dam’s dynamic time-history analysis to the time history. According to the result, it is feasible and necessary to apply the dynamic time-history analysis method to study the anti-seismic performance of the dam. Furthermore, it pointed out the weak part of the dam in anti-seismic function as well as the area concentrated with critical stress, providing reference for future anti-seismic engineering and shock resistance.

Abstract: High-rise building with podium is a common seen architecture style in China. Nowadays more designers inclined not to separate the main and podium, but this would lead to the eccentric between the center of mass of the tower and base, which may exceed the code requirement when the ratio of offsetting is larger than 20% and cause complicated seismic response. This paper takes an eccentric high-rise frame-shear wall structure of single tower as example, analyze the inelastic performance of this structure under rare earthquake by Pushover method, and point out the weak parts of the position by the distribution and development of plastic hinges.Draw the structure inelastic response indicators in the rare case of earthquakes, and point out the weak parts of the structure of the distribution and development of plastic hinge (region), put forward reasonable proposals for optimizing the structure design.

Abstract: .In this paper, seismic behaviors of the frame-shear wall structure, which are composed of the concrete filled steel tubular (CFST) column, have been studied. Dynamic behaviors and earthquake responses of the CFST under rare earthquake are analyzed. Comparing the calculation results, the earthquake resistant behavior of the CFST structure has been appraised synthetically, which may be referential for structural design.

Abstract: With the complex high-rise and extra-high buildings construction, dynamic characteristics of these structures are more and more paying close attention and researching. At the same time, the dynamic response of high-rise building with complicated structure system is always a hot and difficult research, and it is going to be further developed on the research of dynamic features, displacement and internal force. Selecting a complicated systematical structure of a city, using finite element to establish the model and inputting rare earthquake wave, this paper carried out an analysis on the natural vibration characteristics, relative storey displacement and maximum shear of the structure by applying dynamic elastoplastic time history analysis method, drawing the conclusion that the structure design is safe and putting forward the corresponding improvement measures.

Abstract: Unseating prevention devices(UPD) are used to prevent relative great displacement between supper-structure and sub-structure, and to protect the super-structure falling down from piers as the support loss capacity. Unseating prevention devices are the ultimate security installment in the collapse-proof system when the highway bridges encounter rare earthquake or unexpected earthquake. Based on the relational design standards at home and abroad, the paper is emphasis on the time-history analysis for structure with cable-unseating prevention devices under rare earthquake. The analysis results obtained show that the collapse-proof effectiveness of unseating prevention devices and the variation law of collapse-proof changing with cable length and design displacement value. What’s more, under rare seismic, the rational unseating prevention devices can ensure the ultimate security of the structure, increase the integrity and anti-pushing rigidity of the structure, and make the seismic load to be well-distributed among the piers. As a result, the unseating prevention devices can effectively avoid girder falling in strong seismic, achieving no collapsing in strong seismic.

Abstract: The analysis on earthquake response of one multi-tower isolation structure with an enlarged base in rare earthquake and aftershocks was carried out using elastic time history analysis method. It includes the damping effect of structure, plastic deformation of members and plastic hinges distribution in structure. The results show that isolation structure comes to plastic state under rare earthquake lighter, vertical elements remain flexible under earthquake aftershocks, the plastic hinges on horizontal members are deepen, but the structure can meet the requirement while it is renovated. Plastic hinges first appear in the bottom of structure, then they gradually develop upwards, Plastic hinges are generated at the ends of beams, but not occur in columns and walls. The displacement of structure under rare earthquake is mainly concentrated on isolation layer and it can take energy consumption by large displacement.