黄河小浪底水利枢纽工程排沙洞混凝土衬砌采用了双层双圈环锚无粘结预应力新技术，文中对其洞内试验段的预应力钢筋和测试元件布置，以及洞内无粘结预应力混凝土施工工艺做了概括总结．结合从开始浇筑混凝土到预应力钢筋张拉锚固结束的全过程中对衬砌混凝土和普通钢筋的应力及洞径变化等实测资料，分析了混凝土温度收缩应力变化和衬砌混凝土预压应力分布规律，论述了洞内试验段衬砌混凝土裂缝的成因，提出了优化混凝土配合比、加强施工温控的改进建议． The Yellow River Xiaolangdi Water Conservancy Project of sand drainage tunnel concrete lining with a double double ring ring anchor unbonded prestressed new technology, the article of its experimental section of the cave prestressed steel and test element arrangement, as well as the hole without prestressed cement Concrete construction process done a summary. Based on the measured data of the changes of the stress and the diameter of the lining concrete and ordinary steel in the whole process from the beginning of pouring the concrete to the end of the prestressing tensioning and anchoring, the temperature shrinkage stress of the concrete and the prestressed stress distribution of the lining concrete are analyzed. The cause of the crack in the lining concrete in the test section of the tunnel was put forward. Suggestions for improving the mix proportion of concrete and strengthening the temperature control in construction were put forward.