Shenzhen Metro Group Co.

Shenzhen, China

Shenzhen Metro Group Co.

Shenzhen, China
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PubMed | Harbin Institute of Technology, Shenzhen Metro Group Co. and Chongqing University
Type: Journal Article | Journal: Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA | Year: 2016

The aim of this study is to analyse the effect of temperature on the biodegradation and settlement properties of municipal solid waste by using bioreactors. Three kinds of controlled temperature were performed during the biodegradation test; the variation of weight, leachate and biogas production were carefully monitored. The degradation test indicated that more leachate leaked out owing to the external compression and polymer hydrolysis reaction in the aerobic phase, which could lead to the decrease of biodegradation rate in the anaerobic phase. A proper temperature range in favour of enhancing biodegradation of refuse was obtained, which ranged from 22C to 45C. Finally, an empirical equation of biodegradation ratio was proposed, which incorporated the temperature effect. In the end, the validation of this proposed model is verified, and is proved to be reasonable for predicting degradation velocity in landfills.

Sun J.,Tongji University | Sun J.,Hangzhou Fengqiang Civil Engineering Research Institute | Pan X.,Tongji University | Pan X.,Shenzhen Metro Group Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2012

A complex mechanical behavior of large squeezing deformation of tunnel weak rocks is discussed under high ground stress condition. The large squeezing deformation can be belonged to the scope of a kind of large deformation rate with slow convergence. On the basis of rheological squeezing deformation's mechanism, a nonlinear 2D visco-elastoplastic constitutive model and a 3D elasto-viscoplastic constitutive model in case of large/small deformations are proposed respectively; and the corresponding secondary development special softwares are studied. The developed material subroutines are applied to analyzing the squeezing problem which occurred in rock excavation for the Wushaoling railway tunnel project.

Qian W.J.,Southwest Petroleum University | Wu Y.F.,Shenzhen Metro Group Co. | Chen G.X.,Southwest Jiaotong University | Ouyang H.,University of Liverpool
Journal of Vibroengineering | Year: 2016

The effects of a rail vibration absorber on suppressing short pitch rail corrugation are studied. Firstly, a rail vibration field test is carried out to analyze the vibration response of the rail with and without the vibration absorbers. Secondly, based on the hypothesis that friction-induced self-excited vibration of a wheel-rail system causes rail corrugation; two finite element models of a wheel-rail system and a wheel-rail-absorber system are established and analyzed. Both sets of rail vibration test results and theoretical results show that the rail absorbers can effectively reduce the friction-induced self-excited vibration of the wheel-rail system in the frequency range of 200-800 Hz, which corresponds to frequencies of short pitch rail corrugation. This may be a main reason that the rail vibration absorber can suppress the formation of short pitch rail corrugation. © JVE INTERNATIONAL LTD.

Zhao Q.-J.,Guangzhou Metro Design and Research Institute Co. | Liu Z.-G.,Shenzhen Metro Group Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012

The anchor cable, as a mature technology, is widely applied in support of excavations and slopes in geotechnical engineering. But the cables with obvious length often bring great influence on the urban underground space after project completion, which is obvious obstruction in urban metro tunneling. The studies on the recycling pre-stressed anchor cables can provide reference for case under restricted conditions. The mechanism, technical maturity, safety reliability and economic benefits are discussed in adaptability and generalization of the recycling anchor cables. A deep excavation project of metro Line 9 in Shenzhen and other two cases are given for examples.

Liu S.-Y.,Shenzhen Metro Group Co. | Ouyang R.,Shenzhen Metro Group Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012

Because the subway is the most important infastructure in a city, effective design and construction measures of neerby deep excavations must be adopted to protect it. The rules of deformation aroused by deep excavations near the subway are gained according to case studies and practical deformation data. Based on the regional experience, the risk control technologies for deep excavations include deformation control standards of subway structure with proper safety redundancy, risk classification of deep excavations according to the possible influence level on subway, defferent technical demands according to the classification, survey technology, supervision during the construction process and the back-evaluation after the completion of excavation. The results indicate that all the nearby excavations do not disturbe the normal operation of subway.

Li X.,Beijing Jiaotong University | Chen X.,Shenzhen Metro Group Ltd. Co.
Journal of Construction Engineering and Management | Year: 2012

Grouting control of shield tunneling is of paramount importance to reduce settlements of existing tunnels below-passed by shield tunneling along a curved alignment and in crowded urban areas. The methodology and scheme of the grouting control of shield tunneling is illustrated taking the first Earth Pressure Balanced (EPB) shield below-crossing existing interval tunnels from Kexueguan station to Dajuyuan station of the Shenzhen metro line No. 1, for example. A combination methodology of the observational method and the predefined design method was set up to deal with parameters concerning the grouting control of shield tunneling. Some parameters of the grouting control were predefined or suggested before the below-crossing, and other parameters might be adjusted during construction on the basis of the observational method. The scheme primarily consists of preparation work before the below-crossing, automatic motoring system used in operation tunnels, simultaneous backfilling grouting and grouting directly through segment holes. For the simultaneous backfilling grouting, enough grouting was filled in the tail void with shield advance. With the help of automatic motoring system, the grouting directly through segment holes was employed in light of the measured settlements of existing tunnels. The maximum of the final measured settlements of existing tunnels is about 70% of the predefined allowable settlement of 20mm, which shows that the grouting control of shield tunneling is effective in reducing settlements of existing tunnels. The grouting practice can be used as references in similar conditions. © 2012 American Society of Civil Engineers.

Chen X.,Shenzhen Metro Group Co. | Chen X.,Shenzhen University
Applied Mechanics and Materials | Year: 2012

The mechanical properties of artificial frozen soils are the key for application of artificial ground freezing, (AGF) especially the creep characteristics of artificial frozen clay when a deep shaft is sunk by using AGF. Many catastrophic accidents took place in clay strata in deep freezing shafts past because of freezing tube breaking and flooding through ice wall caused by large creep deformation of ice wall. A new creep constitutive equation with separated variables for artificial frozen clay, after C. C. Vialov, is presented on base of testing data of most kinds of artificial frozen clay under the condition of drained system. On base of the new equation, a space-time- dependant design method, a modified C. C. Vialov's, is proposed and has been successfully used for ice wall of deep shafts all over China since 1996. Finally, the stability of ice wall for deep shafts can economically and efficiently be controlled by adjusting the variables of temperature T, un-supported height h and time elapsed t according to their sensitivity or influence. © (2012) Trans Tech Publications, Switzerland.

Song T.,Shenzhen Metro Group Co. | Chen X.,Shenzhen Metro Group Co.
Applied Mechanics and Materials | Year: 2012

The forces on TBM druing tunnelling are analyzed in detail based on the characteristics of mixed face strata. Suitable parameters of TBM are choosed according to the characteristics of the strata ahead. The studies are focused on both the acting posture of TBM and the points of the main forces. A systemic model is consequently set up, which can provide ones with analysis of TBM stability, parameter calculation and tunnelling design in mixed strata. Two cases are finally analyzed of TBM tunnelling in different mixed strata by using this model. Then some of countermeasures is given as reference for TBM tunnelling in such mixed strata in the further. © (2012) Trans Tech Publications, Switzerland.

Qi Z.,Beijing Jiaotong University | Qi Z.,Shenzhen Metro Group Co. | Li P.,Beijing Jiaotong University
Beijing Jiaotong Daxue Xuebao/Journal of Beijing Jiaotong University | Year: 2010

Based the analysis of temporal-spatial effect and settlement mechanism, apply the fuzzy cluster analysis for 1497 ground surface settlements of 24 running tunnels in Beijing subway Line 5, represent the general distinction of shallow tunnel ground surface settlements regularities of distribution and the surface settlements trough width parameter inflexion point distance, and the loss ratio of stratum, gain the relation between surface settlement trough width parameter inflexion point distance and equivalence axial depth of burial, put forward a feasible surface settlement control criterion, and control method contains the 3 classes: prewarning, alarm and extreme. Research findings supply some reference value for cognitive shallow tunnel ground surface settlements regularities of distribution and develop control standard.

Wu C.,University of Chinese Academy of Sciences | Zhang Y.,Shenzhen Metro Group Co. | Jun X.,University of Chinese Academy of Sciences
Proceedings - 2014 IEEE Workshop on Advanced Research and Technology in Industry Applications, WARTIA 2014 | Year: 2014

In the present paper, we propose a gray-level image watermarking algorithm with high capacity based on bit decomposition and spread transform. To implement this algorithm, the gray-level digital watermark image is bit decompounded into a series of binary digital images, then the cover data extracted from the original cover image are projected to multiple orthogonal directions, while a binary image is embedded in each orientations. Testing results show that that watermark can be blindly extracted using this algorithm, and its the transparency and robustness are excellent. © 2014 IEEE.

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