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
It is important to investigate the dynamic behaviors of deep rocks near explosion cavity to reveal the mechanisms of deformations and fractures. Some improvements are carried out for Grigorian model with focuses on th...It is important to investigate the dynamic behaviors of deep rocks near explosion cavity to reveal the mechanisms of deformations and fractures. Some improvements are carried out for Grigorian model with focuses on the dilation effects and the relaxation effects of deep rocks, and the high pressure equations of states with Mie-Grüneisen form are also established. Numerical calculations of free field parameters for deep underground explosions are carried out based on the user subroutines which are compiled by means of the secondary development functions of LS-DYNA9703 D software. The histories of radial stress, radial velocity and radial displacement of rock particles are obtained, and the calculation results are compared with those of U.S. Hardhat nuclear test. It is indicated that the dynamic responses of free field for deep underground explosions are well simulated based on improved Grigorian model, and the calculation results are in good agreement with the data of U.S. Hardhat nuclear test. The peak values of particle velocities are consistent with those of test, but the waveform widths and the rising times are obviously greater than those without dilation effects. The attenuation rates of particle velocities are greater than the calculation results with classic plastic model, and they are consistent with the results of Hardhat nuclear test. The attenuation behaviors and the rising times of stress waves are well shown by introducing dilation effects and relaxation effects into the calculation model. Therefore, the defects of Grigorian model are avoided. It is also indicated that the initial stress has obvious influences on the waveforms of radial stress and the radial displacements of rock particles.展开更多
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.
基金Project(51378498)supported by the National Natural Science Foundation of ChinaProject(BK20141066)supported the Natural Science Foundation of Jiangsu Province,China+1 种基金Project(SKLGDUEK1208)supported by State Key Laboratory for Geo Mechanics and Deep Underground Engineering(China University of Mining & Technology),ChinaProject(DPMEIKF201301)supported by State Key Laboratory of Disaster Prevention & Mitigation of Explosion & Impact(PLA University of Science and Technology),China
文摘It is important to investigate the dynamic behaviors of deep rocks near explosion cavity to reveal the mechanisms of deformations and fractures. Some improvements are carried out for Grigorian model with focuses on the dilation effects and the relaxation effects of deep rocks, and the high pressure equations of states with Mie-Grüneisen form are also established. Numerical calculations of free field parameters for deep underground explosions are carried out based on the user subroutines which are compiled by means of the secondary development functions of LS-DYNA9703 D software. The histories of radial stress, radial velocity and radial displacement of rock particles are obtained, and the calculation results are compared with those of U.S. Hardhat nuclear test. It is indicated that the dynamic responses of free field for deep underground explosions are well simulated based on improved Grigorian model, and the calculation results are in good agreement with the data of U.S. Hardhat nuclear test. The peak values of particle velocities are consistent with those of test, but the waveform widths and the rising times are obviously greater than those without dilation effects. The attenuation rates of particle velocities are greater than the calculation results with classic plastic model, and they are consistent with the results of Hardhat nuclear test. The attenuation behaviors and the rising times of stress waves are well shown by introducing dilation effects and relaxation effects into the calculation model. Therefore, the defects of Grigorian model are avoided. It is also indicated that the initial stress has obvious influences on the waveforms of radial stress and the radial displacements of rock particles.
