临海隧道新型止水带研究

Study on New Water Stop for Near Sea Tunnel

为了解决传统止水带无法满足隧道特定环境下防水要求的问题,以止水带拉断判断标准和拉脱判断标准为理论基础,分析了止水带防水失效机理;结合临海隧道工程特点,在传统止水带基础上,提出了新型可排水止水带结构形式。对传统止水带进行了抗拉、抗剪等力学分析;通过在传统止水带三元乙丙橡胶材料中添加不同比例的硫酸钡和石墨,进行了材料耐盐酸和耐硫酸试验,测试拉伸强度、扯断伸长率、撕裂强度等物理力学性能,比较了添加不同组分硫酸钡和石墨材料测试数据。结果表明:通过降低止水带附近水压,可以减小其所受拉应力,提高止水带安全性;传统止水带满足安全使用要求,添加质量分数5%的石墨后的新型止水带材料耐化学腐蚀性能最好,且满足相关技术要求。

In order to solve the problems that traditional water stop fails to meet the waterproof requirement of tunnel in certain condition,based on judgment standards of tensile failure and pulling off of it,the waterproof failure mechanism of water stop was analyzed;according to the characteristics of the near sea tunnel engineering,a new type structure form of drainable water stop was proposed based on traditional water stop.Mechanical analyses of tension and shear on the traditional water stop were carried out;by adding different proportions of barium sulfate and graphite in ethylene-propylene-diene monomer（EPDM）material of traditional water stop,resistance tests on hydrochloric acid and sulfuric acid of water stop materials were conducted to test its tensile strength,tensile elongation,tear strength and other physical and mechanical properties,and the test data of barium sulfate and graphite materials with different compositions were compared.The results show that by reducing the water pressure near water stop,its tensile stress can be reduced and the safety of the water stop can be improved;the traditional water stop meets the requirements for safe use,and resistance performance on chemical corrosion of newwater stop by adding 5% mass fraction of graphite is the best,which also meets the relevant technical requirements.