Wuhan Metro Group Co.
Wuhan Metro Group Co.
Wan M.,Hubei University |
Gu H.,Hubei University |
Zhang Z.,Wuhan Metro Group Co.
Proceedings of 2016 IEEE International Conference on Integrated Circuits and Microsystems, ICICM 2016 | Year: 2016
A new sub-1-ppm/°C curvature-compensated bandgap voltage reference (BGR) is presented in this paper. The Complementary to Absolute Temperature (CTAT) voltage component of a forward biased BJT is first well balanced with a Proportional to Absolute Temperature (PTAT) voltage, leaving only a high order logarithmic error with the form of TlnT. This residual non-linear error is corrected by a difference of two CTAT voltages with different non-linear terms through controlling the collector currents of BJTs, which can achieve an ideal non-linear compensation. All the circuits are designed in a standard 0.35-pm CMOS process. The post-simulation results show the proposed BGR achieves temperature coefficient (TC) of 0.7 ppm/°C over temperature range of-40 °C to 125 °C and power supply rejection (PSR) of-104 dB at 3.6 V power supply. The line regulation of the output reference voltage is 0.1 mV/V in the supply range of 24.5 V. The maximum dissipating current from the supply is 25.45 μA. © 2016 IEEE.
Wang Y.,Beijing Jiaotong University |
Chen W.,Beijing Jiaotong University |
Cui J.,Beijing Jiaotong University |
Xu J.,Wuhan Metro Group Co.
Modern Tunnelling Technology | Year: 2016
Given the large-scale development of metro construction, the evaluation of the safety of flexible pipelines in the upper-lying stratum is one of the key concerns, requiring evaluation before construction and interim evaluation during construction. In this paper, four cases of a single-tube tunnel and a double-tube tunnel, being parallel and perpendicular to the pipelines, respectively, are analyzed. First, the rotation angle of the pipe joints is used as a control indicator to carry out the evaluation before construction, and then the settlement of the pipelines is taken as a control indicator to carry out the interim evaluation during construction. Based on an analysis of several adverse factors, the amplifying coefficient Ki is used to revise the safety evaluation formula for flexible pipelines. Finally, the safety evaluation for a specific project case is carried out to prove that this safety evaluation method is practical and effective. © 2016, Editorial Office of "Modern Tunnelling Technology". All right reserved.
Wang G.-B.,Hubei Engineering University |
Xu H.-Q.,Wuhan Metro Group Co. |
Yu Y.-L.,Wuhan University of Technology
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013
More and more adjacent, complicated underground structures will run across each other with the further exploitation and utilization of underground space, and hence, the seismic ability of underground structures will be influenced by the adjacent underground structures. Focused on the subway tunnels between Hongshang Square Station and Zhongnan Road Station on Wuhan rail transit lines No. 2 and 4, the relevant models for different numbers of tunnels and different tunnel net distances are established, and the seismic responses of tunnels and site soils influenced by group cavities effect are analyzed. The results show that: 1) the lower tunnel can cut off the transmission of seismic waves, and therefore, it can play the function of shock absorption; 2) the existence of the upper tunnel weakens the constraining effect of surrounding soils on the adjacent tunnel, and as a result, the seismic ability of the adjacent tunnel will be reduced; 3) the group cavities have little effect on the fundamental period of soils and acceleration magnification effect; and 4) the shallow overlying soil has a significant effect on the seismic ability of tunnels and acceleration magnification effect of site soils.
Xie W.-P.,Wuhan University of Technology |
Chen Y.-M.,Wuhan University of Technology |
Yao C.-Q.,Wuhan Metro Group Ltd.
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2016
In order to study the over-track building vibration impact induced by metro trains running in and out of the train depot, this paper combines two practical engineering techniques. First, we measure and analyze the train vibration load of a train depot in Wuhan and Ningbo, then comparatively analyze the results of the measured load results at the train depots and discuss the train vibration load characteristics in the train depot. Then, a sophisticated FEM model-building method based on weak vibration input yields an improvement, and its rationality has been verified by the measured results. Finally, a sophisticated FEM model of over-track buildings at the Wuhan train depot is established, and an analysis of the over-track building vibration response is calculated. Calculation results showed that the over-track building vibration induced by train load at high frequency is rich, its main frequency is near 40 Hz and the train vibration load determines the building vibration frequency distribution. The floor center of the building vibration level along the height direction is different, and the vertical vibration along the floor increases after decreasing, but the horizontal vibration level increases with the height. The research results can provide the basis for prediction, analysis and evaluation of the serviceability of over-track buildings. © 2016, Editorial Office of Journal of Vibration and Shock. All right reserved.
Wang G.-B.,Hubei Engineering University |
Chen L.,Beijing Urban Engineering Design and Research Institute Co. |
Xu H.-Q.,Wuhan Metro Group Co. |
Li P.,Wuhan University of Technology
Yantu Lixue/Rock and Soil Mechanics | Year: 2012
More and more shield tunnels will crossing each other with very short distance with the rapid development of urban rail transit construction in China. There are four tunnels crossing each other between Hongshan Square Station and Zhongnan Road Station, which are the second line and the fourth line of Wuhan rail transit. The complicated multi-tunnels were simplified as four parallel tunnels and four perpendicular tunnels with different distances according to their practical characters. Three dimensional calculation models are established and their seismic responses are analyzed, in which the following aspects are considered: amplitudes seismic waves, tunnel net distance, tunnel space position, the difference of segment stiffness and the reinforced layer between tunnels. And then, their seismic capabilities are evaluated through two aspects: structure deformation and component internal forces. The analytical results show, (1) The net distances between tunnels have little influence on tunnel seismic responses; (2) The seismic capabilities of four perpendicular tunnels is superior to that of four parallel tunnels. (3) Adjacent overlapping multi-tunnels have good seismic capabilities and can satisfy seismic requirement. The research results can provide preliminary design for relevant practical engineering in future.
Fu Z.-F.,Wuhan Metro Group Co. |
Luo X.-H.,Huazhong University of Science and Technology |
Li J.,Huazhong University of Science and Technology |
Xiong C.-H.,China Railway Siyuan Survey and Design Group Co. |
Wu X.-Y.,Wuhan Metro Group Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2011
Buckling safety factor of the design for supporting structure of foundation pit engineering is unmeasurable in the process of construction; so the different types of monitoring projects for the different safe states of foundation pit engineering are stipulated by the JGJ120-99, which is Technical Specification for Retaining and Protection of Building Foundation Excavations (in Chinese), and the GB50497-2009, which is Technical Code for Monitoring of Building Foundation Pit Engineering (in Chinese). At same time, the safety alarming value is suggested respectively. Because of the asynchronism of monitoring data and with a view to avoid the burstiness of unsafe state of working progress of pit and demand for coping behavior of different safe states, the classifying method of safe state is suggested. In light of observed data of the different monitoring projects, the generalized stability factor is defined using the theory of fuzzy mathematics by which the destination is to estimate the safe state of work progress, and safe toplimit of the generalized stability factor is given. As a real example, the developing process of generalized stability factors for different monitoring projects are analyzed based on fuzzy calculation of observed data and the priority monitoring project of security control is pointed out.
Tang F.,Wuhan Metro Group Co. |
He Y.-D.,China Railway Siyuan Survey and Design Group Co.
Journal of Railway Engineering Society | Year: 2013
Research purposes: The internal structure of the shield tunnel is an important part of tunnel engineering, affecting the shield diameter, the construction schedule and investment, especially the road -metro shield tunnel. Based on the Sanyang road Yangtze River tunnel, the mechanics characteristic, the main construction technology, methods and their advantages and disadvantages of the internal structures and the flue sheet of tunnel are analyzed and compared in the paper. Research conclusions: (1)With obvious advantages on waterproof ability, mechanicsproperty and investment, the cast-in-situ method is recommended. (2)Prefabricated arc slab flue sheet is convenient for quality control and the stress state is good under the scour and silting-up condition in the operation, the flue sheet should be prefabricated. (3)The analysis can provide theoretical evidences and references for the large road-metro shield tunnel in future.
Qu R.-F.,Wuhan University |
Qu R.-F.,Wuhan Metro Group Co. |
Zhou C.-B.,Wuhan University
Electronic Journal of Geotechnical Engineering | Year: 2016
The transition of Wuhan geomorphology is from denudation-accumulation mound(the third terrace) to alluvial plain(the first terrace)in general, there are several karst belts from north to south in the city and karsts is also serious development. In the construction of subway tunnel in karst development area, it is easy to cause the geological problems such as karst collapse, water inrush, mud. In order to study the influence of karst collapse on the subway tunnel and karst treatment in Wuhan, taking Hong Jian Road station -Ma Ying Road station of Wuhan subway Line 6as an example, more than 500 engineering geological sections are analyzed by Drilling Electromagnetic wave CT, borehole TV and other geophysical prospecting methods. The cavity depth, the overlying strata, the filling degree, the karst fissure and other physical characteristics have been analyzed systematically. Based on Midas-GTS finite element, the numerical model is established according to the reality, the simulation analysis of karsts collapse is done and the basic characteristics of karst collapse and its influence on the tunnel is studied. According to the simulation results and the field test results, the grouting isolation treatment technology is studied and the results show well, the research also provides a reference to establish the geological model in different regions for the study of karst treatment. © 2016 ejge.
Feng K.,Southwest Jiaotong University |
He C.,Southwest Jiaotong University |
Xia S.-L.,Wuhan Metro Group Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011
Through the analysis of the sensitive factors of effective bending rigidity ratios of shield tunnel structure, an efficient solution method based on prototype tests is proposed for the effective bending rigidity ratios. The prototype tests on segmental lining structure of Nanjing Yangtze River Shield Tunnel and Guangzhou Zhujiang River Shiziyang Shield Tunnel are carried out. The variation of η and ξ with load conditions is deduced. The results show that under the same load conditions, when the profile is larger, η becomes smaller, and meanwhile ξ becomes larger. The value of η of staggered assembling structure is larger than that of straight assembling structure. The values of ξ vary in positive and negative bending regions, and the relationship between η and ξ becomes various when using different structural types. Furthermore, the relationship between η and ξ of the two different structural types is given, and the recommended values of η and ξ of segmental lining structure using the straight assembling and the staggered assembling are proposed for 10 m and 15 m class underwater shield tunnels.
Wu X.-G.,Huazhong University of Science and Technology |
Zeng T.-M.,Wuhan Metro Group Co. |
Zhang L.-M.,Huazhong University of Science and Technology |
Song R.-X.,Huazhong University of Science and Technology
Journal of Railway Engineering Society | Year: 2013
Research purposes: Tunnel-induced pipeline damage has become a big issue, and the protection of pre-existing underground buried pipelines grows to be a public concern. Based on the impacts of metro construction on the safety of adjacent pipelines, the safety risk management standard for the existing pipelines adjacent to metro construction is studied. A systematic safety risk management system for the existing pipelines is also developed, providing supports for safety assu rance and protection of adjacent pipelines at different risk levels. Research conclusions: (1) According to the horizontal and vertical relative distances between the metro structure and the adjacent pipeline, the neighboring grade is divided into five levels (I~V); (2) To use the horizontal and vertical pipeline deformations as indicators to establish the safety control standard for the underground buried pipelines is more representative than other indicators; (3) With the deformation of the existing pipeline, usage, and its operation status taken into account, the safety risk of the tunnel-induced pipeline damage can be assessed into five different levels, namely Safe, Basic Safe, Dangerous, Basic Dangerous, and Very Dangerous. Corresponding prevention and protection measures are further proposed before and during the construction process for the adjacent pipelines according to their evaluated risk levels; (4) The proposed method is applied in one shaft foundation pit excavation project in Wuhan metro tunnel construction, and the results demonstrate the feasibility of the proposed method; (5) The research conclusions can be used in the metro tunnel construction fields by providing decision supports on the construction safety management.