小直径污水盾构隧道抗渗防腐措施及防腐内衬的选用

Anti-Corrosion Measures for Small Diameter Sewage Shield Tunnel and Selection of Anti-Corrosion Lining

市政管网隧道采用盾构法施工存在隧道耐久性难以保证、防腐方法尚不明确的问题,针对洪武路污水盾构隧道研究了污水盾构隧道的渗漏模式和机理、三元乙丙橡胶的应力松弛规律、内衬防腐方法的选用以及防腐内衬材料的比选.研究表明:小直径盾构隧道在运行过程中容易产生密封垫耐久性降低、管片环纵缝张开、钢筋混凝土锈蚀等情况导致水压大于接触面应力,从而发生隧道渗漏等病害,有必要采取防腐内衬降低渗漏风险;目前常用的防腐内衬中,封堵缝+内喷涂抗渗防腐材料以其对过流断面影响小、防腐抗渗性能强、工期短等优点成为一种具有应用前景的方法;内喷涂材料中MMA+瓷釉涂料的各项性能均能满足施工要求,具有应用推广价值.

Aiming at the tunnel durability and anti-corrosion method in the construction of municipal pipe network tunnel by shield method,the leakage mode and mechanism of the sewage shield tunnel,the stress relaxation law of EPDM,the selection of anti-corrosion method of the lining and the comparison and selection of anti-corrosion lining materials are studied.The research results show that during the operation of small-diameter shield tunnel,the durability of the sealing gasket is easily reduced with the opened longitudinal joint of the segment ring and rust-eaten concrete,which results the tunnel leakage and other diseases occur due to a high water pressure greater than the contact surface stress.Thus it is necessary to take anti-corrosion lining to reduce the risk of air leakage.In the current common anti-corrosion lining,the sealing joint plus internal spraying anti-seepage and anti-corrosion materials are used to prevent the leakage.The advantages of small flow section influence,strong anti-corrosion and anti-seepage performance,short construction period and so on become a method with application prospect.The performance of MMA plus enamel coating in the internal spraying material can meet the construction requirements,which has application and promotion value.