Papers by Author: Guo Liang Bai

Abstract: The response of a large-size cooling tower with 250m high subjected to the seismic action are investigated by both random vibration theory and response spectrum method. Shell element is taken to model the tower body, and beam element is used for the circular foundation and supporting columns. The earthquake motion input is a colored filtered white noise model and mode superposition method is adopted to analyze the random response of the large-size cooling tower. The paper presents the power spectrum density functions (PDF) and standard deviation of the displacement of the top and characteristic node, and the analysis results indicate that the results of the stationary random vibration theory and the response spectrum method are the same order of magnitude. The power spectrum density function of the bottom node stress is obviously bigger than the one at the top and the throat, and the random response of meridonal stress is dominated at the top. In addition, the peak frequency position of the power spectrum density function is different from the corresponding stress.

Abstract: As an important urban rail transit, the metro has become one of the standards to measure whether the city belongs to modern internationalized destinations or not. Though the space of subway station is relatively small, the metro comprehensive pipeline is an important part of the subway station and includes a huge variety and quantity. During the design process of metro comprehensive pipelines, pipeline collision happens frequently. On Three-Dimensional design platform based on BIM technology, pipeline design has already been mature. This paper puts forward adjustment algorithms about metro comprehensive pipeline collision and they are both flexible and easy to realize and adapt to any Three-Dimensional platform based on BIM technology

Abstract: The comprehensive pipeline is a kind of important facilities and equipment and the key to normal operation in metro station, and the certain design requirement of various pipelines’ headroom in specific spatial region need to be met. As a technology centralized upon information and based on three-dimensional mode, BIM technology can express three-dimensional model of metro comprehensive pipeline imaginatively, provide the spatial topological relations among pipelines and relevant detecting calculations. In this paper, the necessity of identification of headroom of metro comprehensive pipeline is deeply analyzed, and then the article designs identification algorithms of headroom of metro comprehensive pipeline according to BIM technology. This algorithm can detect the pipelines which not meet the design requirements of headroom on BIM platform efficiently, thus we can improve design efficiency and quality and liberate labors so that designers can be engaged in more complex design work

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.

Abstract: Two different models are set up to analyze how the connection styles influence on the seismic behavior of frame-bent structure. In the earthquake input of both directions, mode superposition response spectrum method is used to calculate the parameters of frame-bent structure such as the story shear, seismic action deformation and so on. Analyzing the difference of the parameters of both models, explaining the reasons and drawing some rules are all done in this essay.

Abstract: The uncontrollable factors such as construction errors, material inhomogeneity, etc. will inevitably lead to a certain initial imperfections. It is generally known that the stochastic initial imperfection of the structure is an important factor for affecting structural stability and bearing capacity. Since these imperfections are random in nature, this paper proposes the method mainly based on the standard orthogonal basis to expand the stochastic field, taking into account the decomposition of the stochastic initial imperfections related to structures, which is projected in the buckling mode orthogonal basis. In the end, the article by the stability analysis example shows that this method can use less random variables effectively describing the original stochastic imperfection field, and efficiently search for the most unfavorable initial imperfection distribution form in order to ensure the imperfection sensitivity structures have a higher reliability, so it can be applied to large-scale engineering structure stochastic imperfection analysis.

Abstract: For seismic design of composite frame and reinforced concrete core hybrid structures in high-rise buildings, the response spectrum method is influenced to a large extent by mode combination rules and number of combined modes. The dynamic characteristics of composite frame and concrete core hybrid structures were studied through modal analysis, natural vibration periods and mode shape of hybrid structures had calculated and analyzed, the results show that the natural vibration frequencies are near, the complete quadratic combination of mode combination rule was recommended for avoiding higher order mode shape lose in the response spectrum method. The reasonable number of combined modes for response spectrum method were studied by truncation error analysis, it is proposed that more than 20 modes are combined. The results of the time history analysis und The three dimensional finite element er three earthquake waves were compared with results of response spectrum, indicating that the maximum response of hybrid structures can be obtained under reasonable mode number.

Abstract: In order to solve the problem that traditional main building for large thermal power plant cannot satisfy seismic requirements in high-intensity area, we put forward SRC frame-RC few shear walls structure system to conduct experimental study and theoretical analysis. Based on pseudo-dynamic test of 1/7 scale model and elastic-plastic time history analysis, the deformation property and capacity for dissipation of energy, as well as the failure mechanism are analyzed. The results show that the new structure system has well seismic performance, it can satisfy seismic fortification goals in 8 intensity Ⅱ zones, but the weak positions should be given enough attentions.

Abstract: A comparative study is conducted on the seismic behaviors of three recycled aggregate concrete (RAC) frame columns under low cyclic load. The recycled aggregate replacement rate is 0%, 50%, 100% respectively. The mechanical characteristics, failure mode, hysteresis loops, ductility and consumption characteristics of frame columns with different recycled aggregate replacement rate and same axial compression ratio are analyzed in this paper comparatively. The rule characteristics between ordinary concrete and recycled aggregate concrete frame columns are found. The result indicates that failure process of recycled aggregate concrete frame columns is similar to that of ordinary concrete. The seismic behaviors of recycled aggregate concrete frame columns, including the ductility etc., still meet the related requirements of earthquake-resistance designing. So it is concluded in this paper that the recycled aggregate concrete can be applied in concrete structures. Because of its properties are certain deficiencies, some tectonic measures must be enhanced.

Abstract: For mechanical behaviors of composite frame and reinforced concrete core hybrid Structures in high-rise buildings, the three-dimension finite element models were established, modal analysis and elastic time-history analysis were finished, the cooperative work mechanism between frame and core was researched, the dynamic characteristics and seismic response of the hybrid structures under different connection type were studied. the results indicate that the stiffness characteristic of the hybrid structures should be taken between 1 to 2 so that two sub-structure can reasonably afford the internal force, the connection between frame and core bring differences in mode shape and natural vibration periods, the natural vibration periods of hinged model are greater than periods of rigid model, the mode shapes with mainly floor vibration are more likely to appear in hinged model, the connection would lead to significant changes in the deformation and distribution of inner force, the axial force of frame columns would significantly increase for the rigid connection, the shear and bending moment of frame columns would increase for the hinged connection, it was proposed that the hybrid structures should be separately analyzed with hinge model and rigid model for ensuring the frame columns have sufficient capacity of the shearing and bending both.