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| Research on the Anti - alkaline Test of Embedded - channel in Lining Segment in Shield Tunnel |
| JIN Shi - he，YAN Song - hong，LIANG Qing - guo |
| (Lanzhou Jiaotong University，Lanzhou，Gansu 730070，China) |
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Abstract Research purposes ： Embedded - channels of shield segment have been widely used abroad because of its easy to use，environmental，elegance，and no injury to segment structure，no influence on the useful life of tlie segment when electromechanical installation in subway. The prelude of embedded - channels application in domestic is also pulled open gradually because of its advantages while our country has entered the peak of the metro construction. But our country has not yet to establish a national standard of embedded - channels. The test - method of embedded - channel is not perfect， can only refer to the railway standard. Our country has a vast territory， and the concrete alkalinity is diferent in diferent regions. It is necessary and urgentto study on embedded - channels alkaline and to establish national technical standards. This paper takes Lanzhou subway engineering as the example， studies on anti - alkaline test of embedded - channels of shield segment. Research conclusions ：( 1) In the processes of shield segment construction，the insulating layer of embedded - channels will be softened and cause insulation failure under concrete alkaline environment. Then， the aluminum and zinc elements of multi - element co - penetration will react and produce about 2 liter of hydrogen under concrete alkaline environment. There is no any space in the surface of embedded - channels，trapping by concrete in gravity. Hydrogen was compressed and enough pressure was created to break through the 250 mm thick of concrete trapping, and they are insufficient of concrete compactn;s anti - permeability ability because of hydrogen hotels. ( 2 ) The evaluating index is set up by research test of embedded - channels anti - alkaline. ( 3 ) The ability of embedded - channel anti - alkaline has been enhanced obviously after spray neutral epoxy resin in surface of embedded - channel which was successfully applied to shield segment construction in Lanzhou metro project. (4) The research achievements are mainly applied to the field of shield segment design and construction ; can also be applied to the field of high speed railway or building construction using embedded - channel.
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Received: 28 January 2016
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2016, Vol. 33 
