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Liu F.,Henan University of Science and Technology | Zhu H.,Tongji University | Yu N.,Shanghai Shentong Metro Group Co.
Advanced Materials Research | Year: 2011

Based on the literatures and the existent researches, the study on segment joint of prestressed concrete lining has been carried out. The analytical solution for calculating the rotational angle of the joint are deduced with the calculation assumption. So the rotating stiffness of joint is obtained. Compared with the experimental results, the numerical calculation suggests that the theoretical equations are reliable. Study shows the slip length of prestressing steel strand near the joint is one key to calculate the rotational angle and rotating stiffness of joint. The matched curve of the slip length with joint bending moment is given in the paper, which can be described by logarithmic function. When the rotational angle of the joint is calculated, the slip length could be regarded as a constant to simplify the calculation. © (2011) Trans Tech Publications. Source

Xie X.-Y.,Tongji University | Yu H.-J.,Tongji University | Wang Q.-G.,Shanghai Shentong Metro Group Co. | Wang C.,Shanghai Municipal Electric Power Company
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2014

The excavation-induced deformation of pipelines is one of the top environmental concerns for excavations in urban areas. The foundation pit at the exit to Yanggao Road Station Exit, which is part of the second stage project of Shanghai Metro line No. 9, overlies a Φ3000 mm-operating power tunnel. To prevent the possible tunnel damage due to the excessive deformation, the soils are strengthened by using the metro jet system (MJS) method, the blocks are constructed by means of the block excavation, and the FEM-based tunnel deformation prediction is adopted. In addition, a real-time tunnel deformation monitoring system consisting of static hydraulic pipes, crack meters and signal transmission equipments is also adopted. The monitoring data indicate that the soil treatment by the MJS method is an effective way for deformation control, and that the state of the tunnel can be captured by the tunnel deformation monitoring system in the very first time, which therefore enables the implementation of feed-back construction strategy. Source

Yan J.-Y.,Shanghai Shentong Metro Group Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

There will have been 13 lines with more than 500 km in length for the rail transit in Shanghai by 2012. At the same time, the urban development involves the construction of underground space that requires deep foundation pits. As a consequence, researches on the influences of deep foundation pits on the existing neighboring tunnels have become an important task. Based on the foundation pit of Wheelock Square, some protection measures which should be considered during the design and construction period for protecting metro tunnels are introduced. It may be valuable for the foundation pits more than 10 m in depth and less than 10 m in length near tunnels. Source

Liu X.,Tongji University | Zhang L.,Tongji University | Li G.,Shanghai Tunnel Engineering Co LTD | Wu H.,Shanghai Tunnel Engineering Co LTD | Zhu Y.,Shanghai Shentong Metro Group Co.
Modern Tunnelling Technology | Year: 2014

Based on a full-scale test to verify the ultimate bearing capacity of a shield tunnel reinforced with a composite cavity, a non-linear additive model that can be used to simulate the structural reinforcement of the shield tunnel is presented, in which the composite cavity and segment are defined by various materials, and the bi-directional spring unit is adopted to simulate the bonding between a non-reinforced tunnel and the composite cavity. Additionally, the effectiveness of the model is verified by means of a comparison with the results of full-scale test. Furthermore, the values of some key parameters are described and the stress on the tunnel structure and failure mechanism are presented based on the simulated results, thereby providing a reference for the reinforcement optimization of operated shield tunnels. ©, 2014, Editorial Office of "Modern Tunnelling Technology". All right reserved. Source

Ai Q.,Tongji University | Yuan Y.,Tongji University | Bi X.,Shanghai Shentong Metro Group Co.
Structure and Infrastructure Engineering | Year: 2015

Timely acquiring deformation of sectional profile is a proactive maintenance activity for ensuring the safety of tunnels. Metro tunnels, especially constructed by shield tunnelling method, are long span infrastructures need to inspect their deformations at many different positions. This is a vast amount of work if carried by traditional approaches manually. Some advanced technologies, such as terrestrial laser scanning, are also unable to carry out the work quickly and economically. However, only severe deformations that may lead to emergency action are required to be detected timely. Thus, the urgent demands for acquiring sectional profile of metro tunnel should be of fast in operation, accuracy under tolerable acceptance and competitive with cost efficient. This paper focuses on the method of acquiring sectional profile of metro tunnels by a cart equipped with charge-coupled device cameras. The geometric features of sectional profile are extracted from images by a series of algorithms based on photogrammetry. Using this method, the speed of acquisition is improved no less than 5 km/h with acceptable accuracy. An on-site application validates that this method is sufficient for screening out severe deformations in metro tunnel. © 2015 Taylor & Francis Source

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