引滦入津隧洞糙率两次原型观测成果综述

简介1985年5月昆明水电设计研究院科研所与引滦入津隧洞管理处合作,对引滦入津输水隧洞的水力糙率进行第一次原型观测的情况.观测结果表明,该隧洞的平均综合糙率为0 0120～0 0123.着重介绍2000年3月进行第二次糙率原型观测的情况.观测结果表明:由于15年来管理者对隧洞底板进行了多次全面的维修,使底板部分的糙率有所减小;边墙因受进口明渠侧门洞口和隧洞内维修裂缝时在边墙表面遗留了若干"补疤"造成局部阻水的影响,糙率略有增大,但全洞的平均糙率仍然保持在0 0125水平.由此证实,对于现代的混凝土衬砌输水隧洞或明渠,设计采用糙率n=0 013是完全可行的.

Summary of two times' prototype observation results of roughness coefficient for water diversion tunnel from Luanhe River to Tianjin City

The first prototype observation, performed by Branch Institute of Scientific Research of Kunming Hydroelectric Investigation, Design and Research Institute and the project management authority of the water diversion tunnel from Luanhe River to Tianjin City in May 1985, showed that the average roughness coefficient of the water diversion tunnel was within a range of 0.0120-0.0123. The second prototype observation, performed in March 2000, revealed that the roughness coefficient of the tunnel base plate decreased a little due to repeated maintenance by the project management authority, while the roughness coefficient of the tunnel side wall increased because of water flow being somewhat resisted by a number of patches left on the side wall surface for crack treatment. However, the average roughness coefficient of the whole tunnel still remained about 0.0125. So it is feasible to adopt the roughness coefficient of 0.013 in design of a concrete-lined water delivery tunnel or an open channel.