无纺布对海底隧道衬砌防水作用的试验研究

Test study of waterproof effect of nonwoven fabrics on subsea tunnel lining

采用无纺布作为防水层中的垫层,是国内外隧道工程中结构外层防水常用的措施,但对于无纺布如何改善隧道衬砌背后水压力分布及结构应力分布却一直缺乏相应研究。依托厦门翔安海底隧道,对不同防排水方式(即全封堵、堵排结合及排放方式)的隧道衬砌无纺布作用进行研究,采用相似模型试验方法,模型试验的比例尺为1:38.88,试验台架可同时施加土压力和水压力。通过模型试验得出结论:无论在全封堵条件还是限排条件下,无纺布均起到很好的集水、附水的作用,加强了水在衬砌四周的流动性、相互补给性,使衬砌周围的水压分布更为均匀,并且改善了衬砌结构周边的应力环境。

As a common waterproof material used in tunnel construction,nonwoven fabrics are widely used as a cushion in the waterproof layer.But the water pressure and structure stress distribution mechanism after using it hasn’t been studied thoroughly.Through the research of Xiang’an subsea tunnel,the effect of nonwoven fabrics has been studied with different proof-drainage patterns;i.e.whole block,block combined with drainage and drainage modes.The primary research method adopted is simulated model test with proportional scale of 1：38.88.Its test apparatus can apply both soil pressure and water pressure at the same time.According to the model test,the conclusion is as follow： under whether whole block or limited drainage condition,nonwoven fabrics have a good function of water collection and absorption;the nonwoven fabrics can strengthen the water fluxility and complementarity around the lining to make the water pressure distribution on it more well and also improve the stress condition around the lining structure.