prestressed reinforcing steel 基本例句 预应力筋 The methods are suggested to determine the tensile steps and the tensile forces of prestressed strands for decreasing the secondary bending moment along the axial of the penstock.提出了预应力筋束分步张拉施工与荷载控制方法，以减小管壁混凝土的轴向次弯矩。