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Tianjin, China

Feng G.,Electronic Information Vocational Technology College | Sun S.J.,Tianjin Metro Group Co.
Applied Mechanics and Materials | Year: 2014

In the past, the semi-active control study generally is calculated based on the MATLAB numerical procedure, which can't achieve fine simulation. In this paper, to solve this problem, the finite element software ABAQUS is taken to be secondary development, a numerical simulation method of studying semi-active control is proposed. And the seismic response of a steel column is taken for the research. the numerical simulation analysis of the semi-active control is carried out. The results show that the control effect of the control method is significant, and the simulation result is clearly visible. © (2014) Trans Tech Publications, Switzerland.

Wang Y.,Shijiazhuang University | Bo H.,Tianjin Metro Group Co. | Yu B.,Shijiazhuang University
International Journal of Modelling, Identification and Control | Year: 2011

The core of the problem in urban rail transit braking is the ascertainment of the braking point and the calculation of the braking distance. In order to fix the position of the braking point when the train pulled in the station by using the simulation more accurately and rapidly, the regular braking method was improved through breaking the recursive algorithm which took time as the step length, and the new model, which can confirm the braking point and the braking distance based on the speed difference value calculated by the train running distance as the step length, is put forward in this paper. The new model solves the problems such as large calculation amount and slow computing speed in the conventional variable iteration, and it plays an active role in the traction calculation software upgrade of urban rail traffic and automatic unmanned train technology. Copyright © 2011 Inderscience Enterprises Ltd.

Sun L.-Q.,Tianjin University | Lu J.-X.,Tianjin University | Li H.,HIGH-TECH | Yan S.-W.,Tianjin University | And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015

The artificial freezing method is widely used in the urban construction of underground engineering, such as the foundation reinforcement and excavation of subway tunnels. The strength properties of artificially frozen soils are affected by many factors. Water content, temperature, salt content and other factors affect the strength of artificially frozen soils to a large degree. At present, a lot of researches on uniaxial compressive strength of artificially frozen soils has been made, but they are certainly regional. For the silty clay and clay in Tianjin area, a series of uniaxial compressive strength tests are conducted with different water and salt contents. According to the test results, the effects of water and salt contents on the strength characteristics and the "optimum water content of the artificially frozen soils" are obtained. The test results show that the dry density of the soils has little effect on the water content corresponding to the peak strength of silty clay and clay. The conclusions can be used to guide the design of engineering in Tianjin area. ©, 2015, Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering. All right reserved.

Sun L.-Q.,Tianjin Key Laboratory of Soft Soil Characteristics and Engineering Environment | Sun L.-Q.,Tianjin University | Ren Y.-X.,Tianjin University | Yan S.-W.,Tianjin University | And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015

With the development of underground engineering, the artificial freezing method has become the common techniques of underground construction. The law of the development of artificial frozen temperature field and the influence on the surrounding environment because of frost heave in the freezing process need to be further studied. The law of variation of the thermal physical parameters along with the temperature field is obtained through laboratory tests, then a numerical method considering thermal stress coupling in the process of artificial freezing is proposed and established based on an artificial frozen soil project of a connecting passage of Tianjin subway. The development law of temperature fields and the amount of frost heaving of soil during freezing process are calculated by using this method. The proposed method is proved to be feasible by comparing the calculated results with the actual data. Consequently, the proposed method can provide guidance and reference for the design and construction of artificial freezing projects. ©, 2015, Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering. All right reserved.

Liu F.,Tianjin Metro Group Co. | Xie X.,Tongji University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2014

The settlement control of adjacent building is a critical issue in foundation pit construction. The impacts of the construction of both three-axis high-pressure rotary jet grouting piles and diaphragm wall on a historical building in a subway station of Tianjin were analyzed based on the real time monitoring data, focusing on the effect of trench construction of diaphragm wall on the adjacent building settlement. The settlements in the retaining structure construction phase, the foundation pit excavation phase and the whole construction period were compared, to explore the impacts of three-axis high-pressure rotary jet grouting piles retaining structure and diaphragm wall on the building settlement. The reasons for building settlement caused by different retaining structure forms were emphatically analyzed and settlement control methods were proposed for building protection. The results obtained could provide reference to similar projects.

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