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Changsha, China

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.

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.

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.

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.

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.

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