拉法山隧道工程采用拱墙铺设双层防水板中间加保温板的防水保温设计方法，为解决如何采用无钉法依次铺设“防水层+保温层+防水层”的问题，在施工现场先后试验了胶结法、吊绳吊挂法、环向钢筋固定法和防水板连接带环向张拉连接法4种铺设方法。在可行性和实用性等方面对这4种方法进行综合分析比较后，总结出防水板连接带环向张拉连接法最经济、环保，并且符合设计要求和便于现场操作。

The sandwich structure of double layers of waterproofing membranes, with one layer of thermal insulation board in between, is designed for Lafashan tunnel. 4 methods to lay the sandwich structure, including adhesion method, hanging method, circumferential rebar fixing method and connection strip tensioning method, are tried in the site. Comparison and contrast are made on these four methods. It is concluded that the connection strip tensioning method is the best method in terms of economy, environment protection, feasibility and practicability.