Study On Fabrication And Properties Of Inflatable Woven Fabric Used For Tunnel Flood Control

With the rapid development of society,the urban population is becoming more and more intensive.The urban traffic gradually expands from the surface space to the underground space.The subway is a major project to alleviate the traffic pressure.When the subway traffic brings convenience to people,it also brings some disasters at the same time,due to the low relief of the subway,such as floods and the spread of toxic gases.At present,the mainly defense measures of underground space for flood disaster are the setting of anti-flooding door,sand bagging and standby pump.These measures need to be handled manually,with low efficiency and effect is not good enough.Therefore,a lightweight,safety,and efficient safety inflatable woven fabric used for tunnel plugs has became a hot topic and a focus of research at home and abroad.At present,a series of researches on the inflatable woven fabric used for tunnel plugs by the U.S.research team show that the inflatable woven fabric can be applied to subway tunnels to resist the spread of floods and harmful gases.It provides a new and effective research direction for flood control and disaster prevention measures in tunnels.However,the research did not provide a reasonable program in process research and dimension design of the inflatable woven fabric.The purpose of this project is to fabricate an inflatable woven fabric used for tunnel plugs in order to achieve effective defensive function.This project will fabricate the inflatable woven fabric which meets the design requirements by exploring the fabrication of inflatable woven fabric used for tunnel plugs.Then determine the three main defensive performance indicators which are the inflatable pressure fabric,fabric strength and axial stability by the limit state design method.At last,proceeding the tunnel simulation experiment when the fabric meets the three main defensive performance indicators to verify if the inflatable woven fabric can achieve effective defense function.First of all,two methods were used to fabricate the inflatable woven fabric and then choose the more appropriate fabric fabrication method.In this project,we chose 450 D / 144 F polyester net yarns for weaving.The target fabric was a capsule-like fabric with a diameter of 6cm.The first method is variable diameter weaving method: fabricate the capsule-like inflatable woven fabric by installing trapezoidal reed and lifting platform on the semi-automatic sample loom;The second method is double weaving method: fabricate the capsule-like inflatable woven fabric on the automatic sample loom.Comparing the two fabrics after machines,we can see the advantage of the fabric of first method has good continuity in the variable diameter section,but it can not be completely sealed at both ends on the loom.The advantage of the second method is that it can be sealed on the loom,so it has good fabric strength uniformity,and the fabric has good accuracy.Therefore,this project considers that the double-layer weaving method is more suitable for the fabrication of capsule-like inflatable woven fabric.Secondly,the three main defensive performance indicators of the fabric system that the inflatable pressure,fabric strength and axial stability are designed and calculated by the limit state design method shows that when the inflation pressure over 90 kPa,the strength is greater than 1.57 N / mm and the length of the cylinder is greater than 4cm,fabric can resist the impact force of 60kPa(170N).Through testing the fabric off machine,the strength of the fabric was 21.471 N / mm,the length of the cylinder part of the capsule-like fabric is 6 cm.So,both of the strength and the axial stability meet the design requirements,and the inflation pressure is controllable.Therefore,the capsule-like inflatable woven fabric meets the main defensive performance indicators.Finally,we process the tunnel simulation test.Select the emery paper having the closed friction coefficient with the inner wall of the tunnel to simulate the inner wall of the tunnel and set up the simulated tunnel test device.Then carry out the horizontal thrust test.The test proves that the fabric can withstand the thrust of 170 N regardless the fabric is dry or completely wetted,and it keeps the relative position changeless with the inner wall of the tunnel,so that the axial stability is good.Therefore,it can be proved that the capsule-like inflatable woven fabric for tunnel plugs can achieve effective defensive function.