压力隧洞衬砌后张预应力计算

Post-tensioned prestress computation for lining concrete of pressure tunnel

清江隔河岩电站引水隧洞是我国首例采用后张预应力衬砌的地下工程 ,采用洞挖施工 ,贴壁衬砌 ,后张预应力作业在洞内进行。针对这些特点 ,为满足工程要求 ,设计时曾对预应力锚索在衬砌中的布置、曲线锚索预应力计算方法、锚索锚固过程预应力分布 ,以及混凝土衬砌环预应力估算等作了研究 ,并进行了仿真结构模型试验。

The intake tunnel of Geheyan hydropower plant is the first case in China,of which the lining concrete prestress was post-tensioned.After tunnel excavation and concrete lining,the post-tensioning operation was carried out in tunnels.In the light of these characteristics,the research was carried out on a series of technical issues in the process of design,such as deployment of prestressed anchor cable in lining concrete,prestress computation method about curvilinear anchor cable,stress distribution in stretching process of anchor cable,stress estimation of circular lining concrete etc.,and at last emulated structural model test was carried out.These research achievements have been applied in Geheyan hydropower project and later engineering practices.This paper gives summarization of related computation method about post-tensioned prestress for pressure tunnel lining concrete,expecting this technology is further spread and applied in future.