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Wu F.-Z.,China Railway Tunnel Group Co. | Fu Z.,China Railway Tunnel Stock Co.
Journal of Railway Engineering Society | Year: 2014

Research purposes: Tongzhai tunnel entrance was affected by the same high stress, and other geological factors carbonaceous slate role in the early stages to I18 steel support parameters based support, the construction of large deformation occurs, arch distortion, shotcrete off, seriously affecting construction safety and progress.This paper is finding solutions to large deformation method to provide a reference for the subsequent construction. Research conclusions: (1)In the stress deformation by the engineering test, take the anti - supporting measures, adhere to the "strong first and optimization late" principle, support in place at a time, so as to control the deformation. (2) Soft surrounding rock after excavation is timely supported, enclosing to ring as soon as possible, and timely radial grouting to effectively strengthen loose rock, improve the surrounding rock properties, reduce rock pressure effected on the supporting structure, the support and surrounding rock stress system has formed, to restrain the deformation of tunnel. (3) Reduce the times of the excavation, set the inverted arch as early as possible, control the initial support closing time strictly. (4) The control measures of deformation of tunnel carbonaceous slate can provide reference for similar engineering.

Peng Z.,China Railway Tunnel Stock Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

Subsurface excavation tunnel at Punan section of phase I project of Xiamen airport road is a shallow-buried, large-span and soft rock tunnel, the surrounding construction environment is complex. Building #34 is a key protection object during tunnel traverses buildings. According to the structures, foundation rocks and surrounding environment of building #34, the ground tracking grouting method is adopted to protect buildings during construction by systematically analyzing the reliabilities and operabilities of various building protection schemes. The sleeve valve pipe grouting is adopted for building #34 according to grouting test results of buildings #104, #105.Monitoring points of building subsidence and crack development have been set in order to control the subsidence and crack development of building #34 and guide the construction timely. Monitoring results show that grouting uplift can control houses subsidence effectively. Finally, the total subsidence value of each monitoring point is controlled within 25 mm; the differential subsidence of each monitoring point is controlled within 1‰. The building #34 structures are in control state when tunnel traverses. Therefore, the grouting uplifting is a very important method to protect existing buildings traversed by tunnel. This study results will provide some references for similar tunnel projects.

Liu K.,Wuhan University of Technology | Dong J.,Xilingol Pledge Qiantu Traffic Design Co. | Liu R.,China Railway Tunnel Stock Co. | Zheng L.,Xilingol Pledge Taibus County Road Maintenance Work Area
Key Engineering Materials | Year: 2014

As the asphalt pavement has excellent road performance, in the past decade, modified asphalt has more and more applications in highway. In this paper, an anti-rut agent was used as a modifier to add into base asphalt and its effects on the property of the asphalt were investigated. A shear blender was used to ensure the anti-rut agent equally distributed. The conventional physical properties test and Dynamic Shear Rheometer (DSR) test were used to evaluate the properties of the asphalt. The results showed that the softening point and rutting parameter increases significantly, the ductility and penetration decrease due to the introduction of the anti-rut agent. Besides, the result of fatigue test showed that excess anti-rut agent may lead a deterioration in the fatigue life. © (2014) Trans Tech Publications.

Teng J.,Huazhong University of Science and Technology | Wu X.,Huazhong University of Science and Technology | Qin Y.,Huazhong University of Science and Technology | Hou T.,China Railway Tunnel Stock Co. | Zhang L.,Huazhong University of Science and Technology
Engineering Economist | Year: 2015

Reducing energy and resource consumption as well as emissions by building projects are important goals in sustainable development of modern society. In this article, a method based on the concept of life-cycle ecological footprint is proposed to assess the efficiency of the incremental cost brought about by eco-footprint saving measures taken in building projects. This method is then utilized to provide guidelines for school building decision makers to select design plans with higher ecological and financial efficiency. In this method, a set of eco-footprint models is developed to compute the efficiency of incremental cost. Two indices are presented and adopted for assessing the life-cycle incremental cost-efficiency of eco-footprint-saving measures: the life-cycle eco-efficiency index and financial efficiency index for per unit incremental cost. The procedure for applying this method to assessing projects aimed at improving the efficiency of building energy consumption is also introduced. A case study of a school building in China is used to demonstrate the features of this method and the advantages of adopting the method. The results show that this method helps to identify inefficient design plans and provide an effective tool for decision making. Copyright © 2015 Institute of Industrial Engineers

Ye X.-W.,Hong Kong Polytechnic University | Ye X.-W.,Zhejiang University | Ding P.,Hong Kong Polytechnic University | Ding P.,Xiamen University | And 4 more authors.
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2013

In order to grasp the temperature and strain fields of frozen soils during freezing construction of the metro-tunnel cross-passage, a method for real-time monitoring of freezing construction using fiber Bragg grating (FBG) sensing technology is proposed. Under the condition of low temperature and high humidity, FBG sensors have the advantages in terms of accuracy, sensitivity and stability in comparison with the traditional electrical sensors. In this connection, the design scheme and installation method of a novel freezing monitoring device integrated with FBG sensors is addressed. FBG sensors are deployed in freezing monitoring holes at both sides of the frozen soil wall of the cross passage to timely monitor the temperature and strain of the frozen soils in the process of freezing construction. The original temperature and strain monitoring data are analyzed based on the FBG sensing principle by use of the wavelet transform de-noising approach. The distribution pattern of the temperature and strain of the frozen soils in thickness and depth directions are recognized, which will provide a basis for further digesting the formation and expansion mechanism of frozen soil walls.

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