Zhang J.,Hohai University |
Zhang J.,Central South University |
Peng L.,Survey and Design Institute |
Zhu N.,Central South University |
Fang L.,Central South University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011
The bedded rocks have anisotropic and elastoplastic coupling mechanical properties. The elastic parameters of anisotropic rocks are the functions of plastic strain and loading angle. On this basis, triaxial cyclic loading and unloading tests of argillite with obviously bedded structures are designed and completed. The study results show that with the increase in plastic strain, the apparent elastic modulus decays exponentially, whereas the Poisson's ratio increases. According to this phenomenon, two empirical functions are proposed to describe the relationships of apparent elastic modulus and apparent Poisson's ratio vs. axial plastic strain and loading angle of rock specimens; and the values of related parameters are also obtained. The curved surface of apparent elastic modulus in the three-dimensional space changing with loading angle and plastic strain is drawn. The anisotropic degree of elastic modulus decreases with the development of plastic strain.
Wu W.-Q.,Nanjing Southeast University |
Yu J.-Y.,Nanjing Southeast University |
Yu J.-Y.,Survey and Design Institute
Bridge Construction | Year: 2016
To improve the design safety and service reliability of the hangers of tied arch bridge, the asymmetric parallel double hangers system was proposed for application to the bridge based on the idea of the bridge failure safety design. The Baoguo Jinsha River Bridge (a half-through rigid arch bridge with flexible tie members and with a main span of 160 m) in Panzhihua was cited as an example and the failure safety design method for the hangers of the tied arch bridge was studied. The fatigue life of the hangers of the asymmetric parallel double hangers system were predicted and analyzed, using the Palmgren-Miner linear cumulative damage theory, the finite element models for the whole bridge of the bridge with the single and/or double hanger (s) system were established, using the software ABAQUS and the stress changing laws of the remaining hangers of the bridge at the time of sudden break of the end hanger (s) were analyzed as well. The results of the analysis indicate that the sectional area differences of the double hangers will significantly influence the fatigue life differences of the hangers and will cause the two hangers to have the significantly different fatigue life. The safety of the tied arch bridge with the asymmetric parallel double hangers system is significantly higher than that of the tied arch bridge with the single hanger system and the application of the structural failure safety design theory to the design of the hangers of the bridge is feasible. © 2016, Wuhan Bridge Research Institute. All right reserved.
Zhang P.,Jilin University |
Zhang P.,Survey and Design Institute |
Chen J.,Jilin University |
Zhang L.,Jilin Institute of Architecture and Civil Engineering |
Xiao Y.,Chongqing Three Gorges University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2012
The stability of lining structure is influenced by under-excavation and over-excavation of tunnels. It is of great significance to understand the surrounding rock stress and ensure construction safety by studying the over-excavation and under-excavation rules of tunnels. Based on the multi-scale function of wavelet analysis and the statistical self-similarity between the over-excavation and under-excavation of tunnel section profile, the fractal dimensions of 47 tunnel section profiles were calculated by the wavelet analysis. According to the statistical data of joint parameters obtained by field investigation, relationship between the fractal dimension of section profile and joint parameters of tunnel surrounding rocks was analyzed. A function for evaluating the stability of tunnel surrounding rocks was established. With the increase of the fractal dimension, the stability of surrounding rocks gets worse. As the angle between the tunnel axis and joint strike and the over-excavation percentage increase, the fractal dimension of section profiles decreases. When the joint space increases from 0.25 to 0.40 m, the fractal dimension of section profile also decreases.
Jianhua H.,Survey and Design Institute |
Ruili S.,Southwest Jiaotong University
Journal of Bridge Engineering | Year: 2014
The recently completed Aizhai Bridge in the west of Hunan Province in China is a long-span suspension bridge across a deep canyon. In view of the particular problems posed by the surrounding landscape and geologic conditions, and to minimize the impact of the bridge on the natural environment, a novel pylon-girder detached suspension structure was adopted, in which there is a large difference in the span between the main cable and the stiffening girder. As part of the design process, a method for stability analysis of the combined system of pylon, anchorage, tunnel, and rock cliff was developed. In addition, to solve the problems involved in the transportation and erection of the stiffening girder of such a long-span suspension bridge in a mountainous area, a novel girder-conveying track cable method was developed. © 2014 American Society of Civil Engineers.
Chen B.,Fuzhou University |
Mu T.,Survey and Design Institute |
Chen Y.,Shenzhen Municipal Design and Research Institute Co. |
Huang J.,Fuzhou University
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2013
Steel-concrete composite structure is one of the main structures in civil engineering construction. In bridge engineering, composite members can be classified into three types according to the basic bearing behavior, i. e., composite beam, composite column and composite arch. In this paper, the main structure forms and general application of steel-concrete composite bridges in China are described; the research development and engineering application of the new composite structure types presented in recent years are focused on. The traditional steel-concrete composite bridges, such as the shaped steel-concrete slab composite girder, the PC box girder with corrugated steel webs and concrete filled steel tube arch, have been widely used and their specification system has been established by far. In the future, the application experience should be constantly summed up so as to further improve the specifications. At the same time, it is necessary to track closely the latest international trends and carry out innovative research. The research and development of new composite bridge have become very active in our country in recent years. Many new types of steel-concrete composite bridge structures were developed, such as the deck slab with stiffened scaffolding and CFST composite truss, corrugated steel web-CFST composite beam, CFST stiffened scaffolding composite columns, CFST main members with reinforced connection members composite columns and hybrid columns and steel webs (bars)-concrete arch bridge. Some of them have been used in few engineering projects, while others have not been used. In the future, it is important to strengthen their application and popularization, conduct application technology research on the engineering practice requirement, form application guide or technical standards, and make contribution to the development of the composite structures and technical progress of bridge engineering.
Shao X.-D.,Hunan University |
Chen Z.-X.,Survey and Design Institute |
Jin X.-Q.,Hunan University |
Zhan X.-F.,Hunan University
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2010
In order to eliminate the randomness of cracks, equidistant pre-compaction seams were introduced into reinforced approach pavement of jointless bridge. Then a scale model test was conducted. In the model, mechanical behavior of the reinforced approach pavement suffered from temperature falling was simulated. At the same time, based on concrete bonding-sliding theory, calculated formulas of crack width for the reinforced approach pavement under longitudinal loads were derived. Comparisons between the scale model test results and the results given by the derived formulas show that the two kinds of results agree well with each other. It means that the cracks can develop well under certain principle, meanwhile, the reinforced approach pavement can absorb deformation effectively. Hence, the derived formulas can be applied to the process of the design of reinforced approach pavement implanted with pre-compaction seams in jointless bridges.
Zhou X.,Central South University of forestry and Technology |
Luan J.,Survey and Design Institute |
Zhang D.,Central South University of forestry and Technology
Advanced Materials Research | Year: 2013
With the wide applications of post-tensioned concrete structures, the grouting conditions of tendon ducts are paid more attentions. In order to accurately assess the internal grouting quality of the grouted tendon ducts and certainly guarantee the lifetime of prestressed concrete structures Ground Penetrating Radar (GPR), which is a kind of nondestructive testing (NDT) method, has been applied to inspect and evaluate qualitatively and quantitatively on the grouting defects, respectively. A series of in-house tests were carried out for simulating the defects of tendon ducts by foams with different sizes. The results show that the GPR technic was one of the optimal methods for inspecting the internal grouting quality of grouted tendon ducts for post-tensioned concrete structures. © (2013) Trans Tech Publications, Switzerland.
Cheng G.,Survey and Design Institute |
Chen G.,Survey and Design Institute Co.
Modern Tunnelling Technology | Year: 2013
Based on the actual construction of the Shizishi tunnel on the Lijiang to Panzhihua highway, which crosses over the Xinzhuang railway tunnel, the cracking and spalling of the lining in the railway tunnel was comprehensively analyzed through numerical simulation and observed phenomena. It was determined that the main factor of the newly-built highway tunnel's effects on the existing railway tunnel was blasting vibration, especially within the section with poorer quality. The reinforcement measures taken regarding the existing railway tunnel and treatment measures used for the newly-built highway tunnel are presented in this paper as a preliminary reference for similar projects.
Wang Y.,China Railway Major Bridge Reconnaissance and Design Institute Co. |
Zhong N.,Chongqing Expressway Group Co. |
Zhuang W.,Survey and Design Institute |
Zheng X.,Survey and Design Institute
Proceedings of the Institution of Civil Engineers: Bridge Engineering | Year: 2014
The Guanyinyan Yangtze River Bridge is the key structure on the second ring highway of Chongqing City, southwest of China. The bridge is a cable-stayed bridge with a main span of 436 m. The main girder is a steel-concrete composite girder with a total width of 36?2 m. The final design solutionwas based on an extensive comparison of proposals. Themain bridge was constructed using the balanced cantilever method. This paper presents the challenges in design and static analysis of the bridge, including the detailed design, global static analysis, local finite element model analysis, the determination of the allowable maximum thickness of steel plate against fatigue and brittle fracture induced by low temperature.
Zhang Q.,Yangtze River Scientific Research Institute |
Hu J.,Survey and Design Institute |
Chen G.,Hunan Jishou Chadong Highway Construction and Development Co. |
Liao J.,Survey and Design Institute |
And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2012
Due to both the distance between constructions and the distance between construction and high-steep slope are quite small, grasping the stability of foundation rock and mutual effects between constructions accurately is crucial to the feasibility of design scheme. Four key problems concerning stability of foundation rock of Aizhai suspension bridge are summarized. Comprehensive approaches to investigate the bridge foundation rock masses are introduced, as well as main geological defects, the stability analysis and monitoring results of foundation rock masses during construction stage. The geological conditions exposed during excavation, stability analysis and monitoring results show that comprehensive survey approaches are indispensable to fully understand the geological conditions of rock masses. The stability problems of Aizhai suspension bridge focus on the high-steep slopes of two banks. Design load never causes significant deformations; and mutual effects between constructions are not obvious. The stability of rock foundations can be guaranteed if the high-steep slopes are reinforced appropriately. The tower-beam-separation design and the arrangement of constructions are feasible. The studies of foundation rock stability give support to the innovation in structural design. Tunnel-type anchorage can generate very huge pull-resistance capability caused by gripping effect from surrounding rock masses. Because the tunnel-type anchorages used in large suspension bridges at home and abroad are limited, and the researches on rock mechanics problems of surrounding rock masses of tunnel-type anchorage are not deep enough, the bearing capacity of tunnel-type anchorage may be seriously underestimated.