Applied Mechanics and Materials Vols. 204-208

Abstract: By the2-D tidal flow mathematical model, Calculation and analysis of hydraulics r Characteristics of the Longkou ine LV four port rcclamaiton project;and the relationship between the fill area and the width of of longkou. Research shows that, after the completion of an embankment, with the inning area fill, Longkou velocity gradually decreases. In I, II area harbor dam is formed, When the fill range from Longkou 1km ,and the Long kou width is reduced to 50m, I, II zone Longkou maximum velocity were 1.42m /s、1.54m / s, can meet the requirements of the closure gap.when III area harbor dam formed,if the fill maximum range from Longkou 1km, then closure-gap width at least to maintain 200m; for closure-gap width below 100m, then in the north and south area at the same time need to built bank. The ebb tide duration of the Longkou greater than the flood tidal duration;during the ebb tide, flow velocity basically stable, relatively small, Longkou closure should be selected during low tide and the low tide period.

Abstract: Based on the base isolated benchmark building, the dynamic calculation methods of the seismic response were established. Through the computational analysis and comparison of the non-isolation situation and two isolation situations, the influence of the isolation effect about base isolation system stiffness, damping and the method of stiffness arrangement were demonstrated on the platform of benchmark building. The isolated benchmark building was evaluated to offer some new basis about the model used in theoretical research and isolation designed as well as alternative ways to further broaden the base isolated benchmark building.

Abstract: The lateral performance of a typical reinforced concrete external wall panel is analyzed by finite element method and the analysis results show that the reinforced concrete external wall panel has a certain strength and stiffness in its own plane. In order to rational use the strength and stiffness of the wall panel, a new type of energy dissipation connector is designed based on passive energy dissipation. The energy dissipation connector is analyzed by finite element method and the analysis results show that this energy dissipation connector has ideal hysteresis curve. The energy dissipation connector can improve the seismic behavior of main structure through rational design.

Abstract: In the state that the chimney is being used, we evaluate the seismic performance of the reinforced concrete chimney on the basis of testing the tilt, mechanical properties and chemical composition, configuration of the steel and construction measures, the lining damage, the cylinder damage, the subsidiary systems and dynamic characteristics of the chimney. The results show that: For the long-term wind action, corrosion and hot action, and lower level of construction and lower design standards, the reliability of the chimney structure can’t meet the current standards requirements, and need to take appropriate measures to be reinforced; but the seismic performance of the chimney structure can meet current standards requirements.

Abstract: The characteristics of near-fault ground motion displacements, with the obvious directivity, were analyzed. Along moving direction of the fault, displacements take on the feature of fling-step, and the large pulse is the main characteristic of displacements in the vertical moving direction of the fault. The models of near-fault ground motion with different detailed scales can be obtained by median filtering with different window length on the velocity series. Displacement spectra of the models were compared with observations from tremendous earthquakes. The results show that the highly simplified model can predict the response spectrum in very long periods, but there are distinct errors in the period range in which engineering is interested (Tp 5 sec). The refined model is necessary for very large magnitude earthquakes which include multiple rupture, and should be established according to characteristics of velocity.

Abstract: With the author and others scientific investigation on China Wenchuan Ms8.0 earthquake, China Yushu Ms7.1 earthquake and "China's active fault surveying and earthquake hazard evaluation project" relevant data results and the world requirements about project setback of active faults, etc., this paper concluded that: (1) width of Surface-Fault-Rupture is about 40m by statistics, or from the main surface rupture trace about 20m; (2) width of Surface-Fault-Rupture S and the fault vertical offset V, statistical diagrams and formulas S=8.72+9.01V; (3) Setback of the main surface trace D and buildings from damage index I, statistical diagrams and formulas I=0.7969-0.00231D; (4) based on the first three results and by the actual statistics of accuracy, we get three active fault location accuracy level of the standard i, ii, iii, respectively, the error is ± 5m, ± 25m, ± 60m, also, can give this level of standards of Surface-Fault-Rupture width to the actual engineering applications.

Abstract: Probability analysis of longitudinal horizontal nonlinear stochastic seismic response of reinforced concrete simply-supported beam bridge and continuous beam bridge are presented in this paper. Based on the degradative tri-linear resilience model, nonlinear equations of the structure are replaced by equivalent linear equations. The stochastic equivalent linear method and the decreasing order method of normal are adopted to calculate equivalent linear parameters, and then the stochastic seismic response of the structure can be analyzed by the linear of freedom system. Based on theoretical analysis and research, the analysis method of nonlinear stochastic seismic response of reinforced concrete bridge is put forward.

Abstract: Base on 8 column test data obtained under low cyclic loading test, our study group conducted a comparative study of the four categories of damage index models. Different damage index models were used to calculate the damage index of the same column, and calculation results show that the different models give quite different result on the same column damage, and corresponding conclusions of the study are presented on this basis.

Abstract: In order to accelerate the velocity and improve the accuracy of the pseudo-dynamic testing，the external displacement control method is put forward based on the hardware control. The internal displacement sensor of the actuator is invalid on control and substituted by the LVDT displacement sensor connected with the specimen. The process of the feedback displacement and command error compensation is quickly implemented by the internal closed-loop control of the actuator. Compared with the iteratively approximate load control, this method not only makes the testing velocity fast, but also enables the error between command and feedback to be “zero”. The fast pseudo-dynamic testing about a cantilever beam is carried out by applying appropriate PID parameters of the actuator. The testing result shows that although this method has rather high requirements in the control system and electro-hydraulic servo load device, and the risk to some extent, the fast response of the actuator can be firmed by applying appropriate PID control parameters. This method provides a fast testing technology for velocity-dependent structures or specimens.

Abstract: Civil experimental system consists of electric-hydraulic servo-controlled testing machine and the data logger in which the recorded data are saved. In Electro-hydraulic servo controller, a exterior trigger signal is used to remote control the data logger working, and the problem of data record synchronously is solved in on-line processing of servo testing machine and data logger, which quicken the test speed by making program calculation and command control simultaneously. The case based on digital command control for pseudo-dynamic on-line test for hybrid structure of thermal power plant is described, by which the data record simultaneously in pseudo-dynamic test achieved automatically. The research provides important reference value for the same type of on-line experiment.