田湾核电站安全壳预应力张拉技术

PRE-TENSIONING TECHNOLOGY FOR THE SAFE SHELL OF TIANWAN NUCLEAR POWER PLANT

田湾核电站安全壳预应力实际张拉力达11.2MN,为国内最大吨位预应力,钢束最长为178.42m,属超长预应力钢束。锚具部件的安装包括竖向钢束、水平钢束。简体墙和穹顶水平钢束初步张拉采用等应力张拉,主张拉采用C1500F千斤顶。张拉结束后,锚固夹片并将荷载传递至锚块上,检查滑动量后二次紧固。筒体墙竖向钢束采用两端同时张拉方式,张拉程序与水平预应力张拉相同,通过控制千斤顶压力及测量延伸率、夹片拉入值进行预应力张拉质量控制。

Pre-tensioning actually exerted on the safe shell of Tianwan Nuclear Power Plant reaches 11.2 MN, the largest pre-stress at home; and the longest steel restraint is 178.42M, a super-long pre-stressed restraint. Erected anchor components include vertical restraint and horizontal restraint. The preliminary tensioning of the horizontal restraints of dome and cylinder wall is made with equal stress while the principal tensioning is executed with C1500F jack. After tensioning, fix the clamp with anchor so as to transfer loads to the anchor, and then retighten it after checking the sliding movement. The vertical restraint of the cylinder wall is tensioned from both ends simultaneously in a sequence same as that for the horizontal pre-tensioning. By controlling jack pressure and measuring elongation percentage as well as tensioning value of the clamp, pre-tensioning quality is controlled.