Research Of Construction Technology Of Water-enriched And Small Distance And Crossed And Overlapped Subway Tunnel

With the development of chinese economy and traffic cause, Urban rail transit is playing an important role in city's development. However, While constructing tunnel,we Will inevitably have problems,which is new tunnels near the foundation or intersect the structure, the city municipal pipe network, the existing tunnel,and new tunnels. How to ensure the safety of new tunnels, and how to control ground subsidence and building settlement have become one of the problems solved. Based on this, with "Settlement control of Shenzhen Metro Line 5 which is complex formation of water-rich is shallow subway" research subjects, this paper studys on settlement control in the process of building of Shenzhen Metro Line 5 which is small spacing overlap rich water tunnel and comes the following results and conclusions:First, using the first excavation of the lower part of the tunnel, re-excavation of the upper part of the tunnel construction sequence is more favorable.Secondly, when studying on excavation Metro Line 7 impacts on Metro Line 5, the paper not only considers excavation the Metro Line 7 of the absolute value of the deformation, but also defines the overlap tunneling interaction indexη(n), to characterize on Subway Line 7 excavation impact on Subway Line 5.Thirdly, the earlier excavation following the order of the next, through research, that when small spacing overlap both up and down the tunnel construction, tunnel face distance greater than 25m, the overlap between the tunnel effect can be ignored, but the spacing over the general assembly to extend the construction period, therefore, this project subway line 5 and line 7 as the distance between the working face line 25m.Forthly, by numerical simulation, proposed overlap tunnel construction, the first hole you can not do the second lining, underwent follow-up holes can be greatly improved work efficiency, from the test section of the construction monitoring of view, this scheme is feasible. Avoided on the first hole underwent excavation threat to the security structure of the second lining, but the tunnel face closed in time.Lastly, in order to reduce the overlap of surface and tunnel construction to the impact of surrounding buildings. Used in the construction of settlement construction control technology, as a small space overlap auxiliary tunnel excavation construction method. Construction, the use of surface uplift of compensation grouting technology, around 2m Subway Line No.7 for the entire range of soil grouting, effectively reduces soil water loss caused by the settlement, in the park to the surface sinolink grouting, the formation of waterproof curtain, for reducing the surface subsidence has played a better role.