The seismic performances of the large-span prestressed concrete frame structure of bunker bay of thermal power plant under different intensity level was investigated by shaking table tests.A 1/8 microconcrete nonfull ...The seismic performances of the large-span prestressed concrete frame structure of bunker bay of thermal power plant under different intensity level was investigated by shaking table tests.A 1/8 microconcrete nonfull weight scaled model was designed according to the prototype structure and the conditions of laboratory.Three kinds of scaled ground motion accelerations were employed as seismic excitations.White noise was input in the structure through each seismic wave applied.The experimental results indicate that the structure is safe to endure seven degree intensity as required in Chinese codes.The natural vibration frequency of the structure is decreasing with the increasing of the seismic intensity,the natural vibration frequency of the structure decreases by about 24.5%,and the structural stiffness reduces by nearly 44% in seven degree intensity of seldom occurred earthquake.The damage at the top of column in the first floor is the most serious,the weak part of the structure is at the first floor,and the strong beam/weak column phenomenon appeared obviously,so this kind of large-span prestressed concrete frame should not be used in a high intensity district.展开更多
A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed.The frame and soil are closely contacted in the role of prestressed anchors and they cannot be se...A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed.The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope.The lateral displacement of frame and soil is nearly in phase.The movement characteristic satisfies the theory of elastic foundation beam.The frame is treated with elastic foundation beam in this model.The influence of prestressed anchors is simplified as linear spring and damped system related with velocity.Under the condition of horizontal earthquake excitation,the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration.This method is applied to a case record for illustration of its capability,in order to verify the method,3D nonlinear FEM(ADINA)is used to analyze the seismic performance of this case,the comparative results show that the design and the analysis are safe and credible by using the proposed method.The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.展开更多
基金Supported by the National Natural Science Foundation of China (50878172)the Scientific Research Foundation for the Returned Overseas Chinese Scholars of Ministry of Education of China (20083j0012)
文摘The seismic performances of the large-span prestressed concrete frame structure of bunker bay of thermal power plant under different intensity level was investigated by shaking table tests.A 1/8 microconcrete nonfull weight scaled model was designed according to the prototype structure and the conditions of laboratory.Three kinds of scaled ground motion accelerations were employed as seismic excitations.White noise was input in the structure through each seismic wave applied.The experimental results indicate that the structure is safe to endure seven degree intensity as required in Chinese codes.The natural vibration frequency of the structure is decreasing with the increasing of the seismic intensity,the natural vibration frequency of the structure decreases by about 24.5%,and the structural stiffness reduces by nearly 44% in seven degree intensity of seldom occurred earthquake.The damage at the top of column in the first floor is the most serious,the weak part of the structure is at the first floor,and the strong beam/weak column phenomenon appeared obviously,so this kind of large-span prestressed concrete frame should not be used in a high intensity district.
基金supported by the National Natural Science Foundation of China(Grant No.50978129)the Gansu Provincial Science and Technology Foundation of China(Grant No.2GS064-A52-040)Scientific-research Development Foundation of Lanzhou University of Technology(Grant No.BS04200901)
文摘A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed.The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope.The lateral displacement of frame and soil is nearly in phase.The movement characteristic satisfies the theory of elastic foundation beam.The frame is treated with elastic foundation beam in this model.The influence of prestressed anchors is simplified as linear spring and damped system related with velocity.Under the condition of horizontal earthquake excitation,the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration.This method is applied to a case record for illustration of its capability,in order to verify the method,3D nonlinear FEM(ADINA)is used to analyze the seismic performance of this case,the comparative results show that the design and the analysis are safe and credible by using the proposed method.The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.
