Zhang Z.,China Railway Fifth Survey and Design Institute Group Co.
Modern Tunnelling Technology
During metro construction, the problems arising from the excavation of mined tunnels passing existing structures have drawn more and more attention. Based on the construction of the Daguanying station of the Beijing metro line 7 and the principles of stratum-structure interaction, this paper simulates the construction of a mined tunnel passing 4 small existing pilot headings and analyzes the influences of the construction on the deformation, stress of the pilot headings, surface settlement, and nearby pipelines. It is concluded that the construction creates an obvious disturbance of the existing structures and after the reinforcement of the passing sections, the deformation of the pilot headings, stress concentration on both sides, and surface settlement are well controlled. Source
Lu Y.-J.,China Railway Fifth Survey and Design Institute Group Co.
Tiedao Xuebao/Journal of the China Railway Society
Soil filling above an existing shallow-buried tunnel probably leads to deformation of tunnel lining and reduction of the safety factor and even leads to destroying of tunnel lining and detriment to traffic safety. The filling project of a planned park to be executed above the Changqiangling Tunnel of the Yangpingguan-Ankang Railway was taken as an example. Selecting some typical sections, the influence of different filling thicknesses on the existing shallow-buried tunnel was analyzed numerically and the allowable filling thickness was determined.The research results indicate as follows: Filling above the existing shallow-buried tunnel causes monolithic lining settlement and basically symmetrical lining settlement on both left and right sides and produces gradually reduced displacements from vault to invert of the tunnel; the post-filling safety factors of the monolithic lining are decreased but by a not-large magnitude, however, the safety factors of the abutment and vauet become so low as to cause cracks possibly to occur; the displacement at the vault increases almost linearly with increasing of the filling thickness, so the allowable filling thickness should be sets as 0.3H~0.4H(H representing the covering depth of the existing tunnel) to control displacements; by analyzing a number of sections, the curve of allowable filling is obtained for the fill zone, then filling within the range of this curve and adoption of corresponding engineering measures can insure the operation safety of the existing tunnel. The proposed method is simple, easy to execute and accurate in meeting engineering requirements, so it can be used to guide engineering practice and provide reference to similar engineering projects. Source
Dou J.,Construction Headquarters of the Fugu Coal Dedicated Railway Line |
Chen D.,China Railway Fifth Survey and Design Institute Group Co.
Modern Tunnelling Technology
In light of the clearance intrusion of the primary support in the Sujiawan tunnel, this paper determines relevant parameters for controlling support deformation based on checking the support structure and secondary lining with MIDAS-GTS software and analyzing the geological conditions of the tunnel body. Reasonable countermeasures are proposed after the analysis of required construction technologies, including strengthening geological surveys of the top of the tunnel's central line, improving the drainage system, enhancing the support system with an increased reserved deformation allowance, and intensifying tunnel monitoring and measurements. ©, 2014, Editorial Office of "Modern Tunnelling Technology". All right reserved. Source
Wan Y.,China Railway Fifth Survey and Design Institute Group Co.
Gaoya Dianqi/High Voltage Apparatus
For the "four-Electricity" integration of High-Speed Railway, this paper briefly describes the status and problem of the current SCADA system, presents a solution of SCADA system based on cloud computing, and introduces the basic concept of Hadoop platform, discusses in detail Hadoop-based design and technology roadmap for the large-scale, wide-area, distributed SCADA system, and provides a useful exploration on design method. Source
Liu J.,China Railway Fifth Survey and Design Institute Group Co.
Journal of Railway Engineering Society
Research purposes: Combined with construction of a (48+4×80+48)m rigid frame-continuous girder bridge in a high seismic intensity area, the effects of applying the fluid viscous damper, lock-up device, double spherical seismic isolation bearing and shock absorber to the long multi-span rigid frame-continuous girder bridge are analyzed and compared respectively, and the main parameters that affect to the effect of seismic isolation design are discussed to provide the basis for the reasonable selection of seismic isolation measures. Research conclusions: (1) It is necessary to make the seismic design for the long multi-span rigid frame-continuous girder bridge in a high seismic intensity area because the seismic response to the rigid frame pier is rather big. (2) The analysis results show that the four seismic isolation measures of using the fluid viscous damper, lock-up device, double spherical seismic isolation bearing and shock absorber have their own advantages and disadvantages. The first two measures are only available for the bridge in longitudinal direction. The latter two measures are available for the bridge in both longitudinal direction and in transverse direction. (3) Reasonably selecting seismic isolation measure and its main parameters is very important to the seismic design of long multi-span rigid frame-continuous girder bridges in a high seismic intensity area. (4) The research results can be used in guiding for seismic design of bridge. Source