盾构隧道承插式接头管片防水性能试验研究

Experimental Study on Waterproof Performance of Shield Tunnel Segment With Socket Joint

国内正在尝试采用一种新型接头——承插式接头来实现管片之间的连接,这种接头可满足快速拼装要求,但其防水性能却未曾验证。为保障承插式接头管片在推广应用过程中的防水性能,有必要对承插式接头的管片接缝防水性能开展研究,为新型管片扩展应用提供理论依据。以南京江心洲污水收集系统二通道建设工程(穿越夹江段)为实例,通过开展接缝密封垫压缩性能试验、管片接头防水性能试验、管片纵缝拼装滑动试验研究承插式接头管片接缝的防水性能,为工程项目方案提供可行性参考依据。各项试验研究结果表明:1)纵缝EPDM密封垫完全压密需要的压缩力较小,可以符合承插式接头纵缝拼装特性;2)纵缝双道密封垫在滑动拼装过程中有脱落挤出的风险,进行润滑处理可以有效地降低摩擦力;3)内外道EPDM密封垫在设计的极限张错量工况下,防水能力在0.9 MPa以上,可以满足设计防水要求。

A novel type of socket joint is being used to realize the connection between segments in China,which can meet the requirements of rapid assembly,but its waterproof performance has not been verified.Thus,to guarantee the waterproof performance of segment with socket joint,a waterproof test is conducted on the segment with socket joint applied in the second channel of the Jiangxinzhou sewage collection system in Nanjing,China,is conducted in terms of compression performance test of sealing gasket,waterproof performance test of segment joint,and sliding test of segment longitudinal joint assembly,so as to provide theoretical guidance for expansion and application of segment with socket joint.The results of various tests show the following:(1)The compression force required for the complete compaction of ethylene-propylene-diene monomer(EPDM)gaskets for longitudinal joints is small,which can meet the assembly characteristics of longitudinal joints of socket joint.(2)The double sealing gaskets of the longitudinal joint would fall and extrudes during sliding assembly process,which can be avoid by lubrication treatment.(3)The waterproof capacity of the inner and outer EPDM gaskets is more than 0.9 MPa under the designed limit tension displacement condition,which can meet the design waterproof requirements.