内水压力作用下加劲环对压力钢管外围混凝土应力的影响

Effect of Stiffener Ring on the Stress of Steel Penstock＇s Outer Concrete under Inner Pressure

通过有限元分析，从加劲环厚度、高度及设置问距三方面，探究内水压力作用下加劲环式压力钢管外围混凝土环向应力的变化规律。计算表明，加劲环厚度越大，外围混凝土环向应力呈锯齿形波动．力Ⅱ劲环高度越大，外围混凝土环向应力越小；加劲环间距越大，外围混凝土环向应力呈先增大后减小的趋势。另外，从内水压力、钢管厚度及压力钢管半径三方面，研究有无加劲环时外围混凝土环向应力差的变化规律。计算表明，内水压力、钢管厚度及压力管道半径越大，加劲环对外围混凝土环向应力影响越大；相比无加劲环时，加劲环的设置使得外围混凝土环向应力有所增大，但幅度有限。

Through FEM,the regular of the hoop stress of outer concrete of steel penstock with stiffener ring under inner pressure has been studied in the aspects of the width, height and distance of stiffener ring. The results indicate the hoop stress presents sawtooth variation with wi der stiffener ring. The hoop stress is increasingly less with higher stiffener ring. The hoop stress increases firstly, decreases at last with longer distance of stiffener ring. In addition, the regular of the hoop stress difference of outer concrete when existing stiffener ring or not to steel pen stock has been researched in the aspects of inner pressure, width and radius of steel penstock. The results indicate that the higher pressure, the wider steel penstock and the bigger radius it is, the stiffener ring can impose greater effect on hoop stress of outer concrete, Compared with no stiffener ring, the hoop stress of outer concrete increases when stiffener rings are set, but the increasing extent is limited.