一、科学试验的目的: 南桠河三级电站高压钢岔管主管直径大(直径3.5米),承受水头高(包括动水压力合计为390米水头),其H.D值达1365。过去国内一般采用外加强三梁式岔管,该结构缺点是体型庞大,费钢材很多,且大型加强梁在锻造、切削、焊接、运输及退火等方面工 First, the purpose of scientific experiments: Nanfanghe III power plant high-pressure steel bifurcation tube diameter (3.5 meters in diameter), to withstand head high (including hydrodynamic pressure total of 390 meters head), the H.D value of 1365. In the past, the general use of external enhanced three-beam bifurcation, the disadvantage of this structure is large size, a lot of fee steel, and large-scale strengthening beam in forging, cutting, welding, transportation and annealing and so on