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January 30,2009 Volume 2,Issue 2 Pages 114-217 Subject Area:Engineering Structures,Foundation Engineering,Civil and Architectural Engineering Construction,Basic Subject of Civil and Architectural Engineering, Engineering Mathematics, Engineering Mechanics,Civil Construction Structure |
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Title: 3D FEM numerical analysis of geotechnical engineering based on Visco-Plasticity method and Mohr-Coulomb criterion | ||||
Authors: NIU Yanning, LIANG Shouyun, SONG Shushuang, HUO Zhangli PP: 212~217 Abstract: This paper introduced a Visco-Plasticity method widely used overseas. Based on finite element method and Mohr-Coulomb criterion, it developed a procedure which could simulate the excavation process by nonlinear finite element analysis. Some problems were resolved in the research process including the effected analysis of variable system mechanics, the application of Visco-Plasticity method and the disposal of inflexion between destroyed plane and plastic potential surface of Mohr-coulomb model. The procedure was confirmed to be accurate. The paper used the reduced parameter method to analyze the slope stability, and the results were matched well with the BISHOP and MORGENSTERN by the slabbing arc method. Keywords: foundation pit; Visco-Plasticity method; Mohr-Coulomb criterion; finite element analysis |
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Title: Effects of different skew angle and span on load transverse distribution of skew girder bridge | ||||
Authors: ZHANG Xiankun, CHENG Haigen, YAO Taorong PP: 207~211 Abstract: In recent years, some project construction and design department apply the calculation method of main bridge in the calculation of skew girder bridge for convenience, which creates the project unsafety and uneconomicalness. To solve these problems, assembled skew girder bridge has been simulated used general finite element software ANSYS. Through computation and analysis, the paper discusses the effects of different skew angle and span on load transverse distribution of skew girder bridge, and obtains the changing discipline of the automobile load transverse distribution in different situation. Analysing the changing discipline, it obtains some characteristics of load transverse distribution of skew girder bridge. It has some certain reference value to the research and design of the skew girder bridge. Keywords: bridge construction; skew girder bridge; skew angle; span; load transverse distribution |
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Title: Push-over analysis of super high-rise building structure | ||||
Authors: YU Dingfu PP: 201~206 Abstract: A north tower in Shanghai is a super high-rise structure with strengthened stories, giant column and core tube,which with strengthened stories and cantilevered truss steel-concrete composite structure. Push-over analysis was applied using the program PKPM series PUSH of Chinese Academy of Building Research in this paper. The program is a three-dimensional finite element space-plastic static analysis program. Using PUSH of PKPM, the three-dimensional non-linear finite element model of the north tower in Shanghai was established and the push-over analysis was carried out. The inter-story displacement of the structure and the angle of it were obtained, the weak parts of the structure were found out, and the yield and destruction law of the components was analyzed. These have a high reference value for the analysis of the similar project. Keywords: structural engineering; plastic analysis; push-over analysis; response spectrum; seismic performance evaluation |
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Title: Optimization design for foundation pit engineering of three-in-one diaphragm wall | ||||
Authors: Guo Hongzhi PP: 195~200 Abstract: Due to the surrounding conditions, the diaphragm wall is taken as the three-in-one structure form of retaining structure, basement wall and load-bearing wall of a procuratorate building’s foundation pit, which is a new challenge for the design and construction of diaphragm wall. After the preliminary design of foundation pit is put forward in this article by using Lizheng programming software, the optimization design has been done to meet the requirement of settlement coordination, anti-permeability and some other aspects. The monitoring data in the period of excavation and construction shows that this design reduces the construction cost and is successful. Keywords: special style foundation; diaphragm wall; bearing; retaining |
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Title: The monitoring and optimum design for foundation pit support of red building segment of Yuemachang underground passage | ||||
Authors: CHI Xiuwen, ZHOU Yong PP: 192~194 Abstract: The form of foundation pit support is affected by many factors, and many projects are designed according to experience, however, the actual effect is not ideal. Combined with the changes of the surrounding environment, through accurate monitoring, the monitoring data of inclinometer tube, stress meter and water-soil pressure meter can be analyzed to optimize the design. This article puts forward the optimizing design scheme for the support of red building segment by analyzing the monitoring data of foundation pit support of Yuemachang underground passage. The scheme contains optimizing two layers of support to one layer of support, changing the way and time of support installation, and the track monitoring has been made on it. The monitoring results indicate that on the basis of ensuring safety, the optimization scheme achieves the goal of simplifying the construction procedure and saving the construction cost, it can provide a complete data reference to later construction. Keywords: geotechnical engineering; deep foundation pit support; monitoring and controlling; support optimization |
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Title: Study on deformation characteristics of supporting structure of deep foundation pit and ground surface in soft soil area | ||||
Authors: ZHAO Xiang, DING Jinhai PP: 187~191 Abstract: Aiming at several deep foundation pit in the soft soil area of Hexi Nanjing, deformation characteristics of supporting structure of foundation pit and ground surface were mainly discussed. By analyzing several engineering foundation pit deformation, the characteristic of deep foundation pit deformation was discussed. By comparing the formula derivation value and measured value of the deformation of supporting structure and ground surface, the laws of ground settlement surrounding the supporting structure and the horizontal displacement of it were summarized. Due to the complexity and changefulness of the deep foundation pit, the analysis results were applied difficultly. The projects analyzed in this paper are similar projects, therefore, the analyzing results have universality in this kind of projects and a certain guiding function for subsequent projects in Hexi area of Nanjing. This is an effective way to transform theories to practical application, the approximation of calculation results has guiding significance to engineering projects. Keywords: geotechnical engineering; deep foundation pit; settlement; deformation; supporting structure |
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Title: Experimental study on soil polluted by alkali | ||||
Authors: WANG Dong, BAI Xiaohong, NIU Xiaoling, CHANG Yonghui, LIU Lijun PP: 181~186 Abstract: With the sustained rapid economic development and seriously increased man-made pollution, environmental problems have attracted more and more attention. Experimental study on physical and mechanical properties of silt polluted by alkali has theoretical and practical significance to the research of soil erosion mechanism and the adoption of regulation measures. The study on the physical and mechanical properties of silt polluted by alkaline solution of different types and concentrations has been done through the indoor simulation tests, the relationship between physical and mechanical properties and the solution has been analyzed and summarized, and chemical analysis for the solution has been determined too. The experimental results indicate that, as the solution concentration changes, the parameters of soil polluted by NaOH and NH3稨2O solution, such as mass, specific gravity of soil particles, liquid limit, plastic limit, plasticity index, coefficient of compressibility a1-2, and void ratio have changed variously. Comparison between soil samples eroded by these two kinds of solution, the former has greater impact on soil samples than the latter one. Keywords: geotechnical engineering; polluted soil; physical and mechanical properties; alkaline environment; solution erosion |
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Title: Study on velocity variation of blasting seismic wave in visco-elastic media | ||||
Authors: PANG Huandong, CHEN Shihai, DUAN Baofu, GAO Wenle PP: 175~180 Abstract: The seismic wave’s propagation rule in the standard linear solid has been studied after the charge’s initiating. An isolation model has been selected and simplified in the visco-elastic media and a minus exponent decreasing boundary condition has been imposed on one tip. By the Laplace transform method, the decreasing rule of particle displacement of seismic wave has been resolved and so does the rule of phase velocity, particle velocity in time and frequency domain respectively. The particle velocity decreases with the increasing of distance sharply. It is different to the elastic media, the latter will propagate without any attenuation. For the complexity of media, the phase velocity decreases with the frequency and the particle velocity declines according to the distance. The range of decrease varies in different distance, and so does the phase in different places and times. Considering the visco-elasticity, the propagation of the blasting seismic wave is obviously different from that in elastic stage, and the former one conforms better to the practical propagation of seismic wave. Keywords: blasting engineering; seismic wave; visco-elastic media; frequency domain |
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Title: The treatment technology of two-step quicklime adding for over-water soft-soil roadbed of expressway | ||||
Authors: YAN Changhong, CUI Dawei, XIA Wenjun, ZHENG Jun, WANG Zhi3, DONG Ping, ZHOU Xin, ZHANG Rui PP: 169~174 Abstract: In the highway construction, in order to save the cultivated area and cut down the highway cost, the over-water soft-soil at reservoir and pond has always been used for roadbed filling of expressway. For this reason, a new method of two-step quicklime adding for disposing over-water soft-soil is used for highway. This method is not only beneficial to mixing well-distributed quicklime with soft-soil, improving modified treatment efficiency, but also speeding the construction pace of highway. This paper studies the mechanism of this method. Keywords: traffic engineering; expressway; soft-soil; modified treatment; two-step quicklime adding technology |
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Title: Enhancing the flexural and bearing resistance of concrete pavement partially substituted with fly ash using polypropylene fibers | ||||
Authors: MANDULA, HATTORI Kunio, OGATA Hidehiko, GUO Shiwen, GOYAL AJAY, ANWAR A M PP: 163~168 Abstract: Recently, flexible fiber reinforced concrete has been involved in many practical fields in China as a new building material. Flexible fiber reinforced concrete has many benefits over the ordinary concrete. This paper shows field and experimental work for pavement fly ash concrete incorporating polypropylene fibers with different percentage (0, 0.5% and 1.0%) in volume. Different parameters are considered in the current work, such as flexure strength, bending toughness index, post-crack strength, as well as measuring the depression resulting from the abrasion test. The results show the adequacy of using polypropylene fibers to improve the overall performance of the road pavements. It is recommended to make use of the current results to extend the use of polypropylene fibers in road construction. It is also thought that the overall cost will be less than other means of reinforcement to obtain the same performance. Keywords: building materials; polypropylene fiber; parement fly ash concrete; flexure strength; bending toughness index; abrasion resistance |
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Title: The investigation and analysis of peasant workers’ safety during construction | ||||
Authors: ZHAO Degang, XU Feng, YAO Yirui PP: 158~162 Abstract: This paper surveys 11 construction sites of Minhang Campus of Shanghai Jiao Tong University using the questionnaire survey and interview methods. After analyzing the status of peasant workers in terms of education, supervision, work fencing, regulation, rewards and punishment measures, work environment and living conditions, this paper concludes that the safety consciousness of peasant workers is very low due to their weak education background and insufficient professional training. The survey also reveals that with the increase of working age and abundance of construction experience, the safety consciousness of peasant workers becomes lower instead. Finally, this paper suggests that the safety consciousness of all peasant workers should be enhanced, and the education measures of construction enterprises should be improved. Keywords: construction; construction safety; peasant workers; questionnaire study |
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Title: An optimum calculation method about grading index of soft rock filling | ||||
Authors: WANG Yonghe, LI Jichao, QING Qixiang PP: 146~149 Abstract: Through the particle analysis tests of coarse grained soft rock fillings, the test data were fit by polynomial equations. Comparing with the traditional manual drawing method, this paper introduces a new way, through analyzing the test data, to process curve fitting and gradual iteration by means of the Excel software on the base of the least square method and the Newton iteration method. This way can calculate exactly nonuniformity coefficient Cu and curvature coefficient Cc of soft rock filling in order to ascertain the rationality of filling’s gradation. It is proved that the relationship between grain size and accumulate percent is fit to the cubic polynomial. The way to deal with it based on the least square method and the Newton iteration method is simple and effective, and can be popularized and applied in the processing of test data. Keywords: civil engineering; curve fitting; least square method; Newton iteration method; nonuniformity coefficient; curvature coefficient |
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Title: Analysis of internal force of flat hinged arc toe | ||||
Authors: WANG Xigang, ZHANG Bin PP: 141~145 Abstract: This paper proposes the theory of flat hinged arc which is between the non-hinged and dual-hinged arc. When arc toe crazes, non-hinged arc merely loads bending moment and dual-hinged arc axial forces, flat hinged arc bears the both actions. Therefore, it should be analyzed by theory of flat hinged arc and calculated by iterative procedure. Stone arch bridge servicing for some sections cracking or man-made after a joint, still keep the normal work of the status. Based on the basic theory and corresponding calculation method, arch-hinged theory used to carry out the structural analysis of stone arch bridge, and increase the loaded capability of the bridge. The results close to the actual state of the force, and use iterative methods to calculate arch foot. This service has the practical significance of stone arch bridge on the bearing capacity of a certain assessment. Keywords: bridge engineering; flat hinged arc; iterative procedure; eccentricity moment Wk; arc toe; rotational angle |
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Title: Multiple random equivalent plane truss model for numerical test | ||||
Authors: YUAN Fang, DIAO Ke PP: 134~140 Abstract: A numerical approach based on multiple random equivalent plane truss model (MRETM-2D) is developed to simulating the fracture process of heterogeneous brittle material, such as concrete, geological materials and so on. Heterogeneous brittle material, having micro cracks and voids, is inhomogeneous. Generally a large number of computational elements have to be created to simulate those cracks and voids in common numerical test. This would be a time-consuming task and limit the application of this method. By using a large number of connections rather than computational elements, MRETM-2D gives a new method to describe micro cracks, voids and their heterogeneity in any scale level. The results of numerical uniaxial tensile and compression test show that MRETM-2D can satisfactorily simulate the breakage process and analyze the deformation and mechanical properties of heterogeneous brittle material. Keywords: engineering mechanics; multiple random equivalent plan truss model; numerical simulation test; heterogeneous brittle material; cellular automata |
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Title: Finite element analysis for simulated seismic behavior test of the joint with batter piles in pile-wharf | ||||
Authors: LONG Binghuang, LI Wengui PP: 123~133 Abstract: A test scheme on seismic behavior of a new joint with batter piles is proposed and the test is simulated under cyclic loading with nonlinear finite element analysis in the paper. Hysteretic curve, skeleton curve, ductility coefficient, secant stiffness and dissipation capacity of the joint are described. The influences of the web reinforcement ratio of pile cap, strength of concrete, axial load ratio and reinforcement ratio in the core of piles on seismic behavior of the joint are discussed too. Analytical results show that the web reinforcement ratio of pile cap and strength of concrete are important to the ductility and dissipation capacity of the joint, and axial load ratio is important to the bearing capacity, stiffness, ductility and dissipation capacity of the joint. Certain reinforcement distribution in the core of piles can improve the ductility and dissipation capacity of the joint, but by giving the requirement quantity of reinforcement, enhancing the reinforcement ratio in the core of piles has little influence on the ductility and dissipation capacity of the joint. Several conclusions have reference value for seismic test of the joint under cyclic loading. Keywords: structure design; pile-wharf; batter piles joint; nonlinear; finite element analysis |
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Title: A techno-economic scheme evaluation about the condensing heat recovery of air source heat pump | ||||
Authors: GAO Gang, GAO Yafeng, CUI Wenying PP: 120~122 Abstract: Recently, building energy-efficient becomes more important than anytime before in our country. And the independent humiture control & solution desiccant air-conditioning system as the new air-condition appreciates more people’s attention. In this system, whether provides massive inexpensive heats for the need of solution regeneration is of the most importance, and also decides whether this system obtains large-scale application. Based on the temperature and humidity control air-conditioning system, this paper proposes the concrete scheme which recyclies the heat dissipation of the condenser part of air cooled heat pump unit to regenerate solution and proves the energy-saving effect. 15 percent energy is saved in the regenerator and remarkable energy-saving effect is obtained. Keywords: heating, gas supply, ventilation and air conditioning engineering; liquid desiccant; heat recovery; condensing heat; energy saving |
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Title: Analysis on thermodynamic properties of liquid desiccant in liquid desiccant air conditioning system | ||||
Authors: YI Xiaoqin, LIU Xiaohua, JIANG Yi PP: 114~119 Abstract: LiBr, LiCl and CaCl2 are three kinds of liquid desiccant which are widely used in liquid desiccant air conditioning system at present. For those desiccants, surface vapor pressure, solubility boundary, specific thermal capacity, density and viscosity are the most important properties which affect the performance of liquid desiccant air conditioning system. This paper summarizes experimental data and calculation formulations of the three kinds of desiccants based on the review of a lot of literature. Furthermore, the paper also analyzes the impact of thermal properties of the three salt solutions on performance of liquid desiccant air conditioning system. In a comprehensive view, compared with the other two solutions, CaCl2 solution is easier to crystallize, which results in a limited handled air state range, smaller specific thermal capacity which brings on evident temperature rise in dehumidification process, and larger density and viscosity, so the performance of CaCl2 solution is worse than that of LiCl and LiBr solution in liquid desiccant air conditioning system. For LiCl and LiBr solution, when dehumidification load is the same, desired concentration of LiCl is less than that of LiBr, and when solutions absorb equal moisture, temperature rise in LiCl solution is less than that in LiBr solution, so dehumidification ability of LiCl solution is more stable. In density and viscosity, each of the two solutions has its strong points. In a word, LiCl and LiBr solution are two kinds of suitable liquid desiccant for liquid desiccant air conditioning system. Keywords: heating, gas supply, ventilation and air conditioning engineering; liquid desiccant; surface vapor pressure; solubility boundary; specific thermal capacity |
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