钢衬壁厚对抽蓄电站围岩内水压力分担率的影响

根据实际工程需要,采用FLAC3D数值模拟软件通过改变钢衬壁厚,分析了不同设计内水压力组合条件下,钢衬、混凝土垫层和围岩的位移和变形特征及钢衬环向拉应力,研究了引水钢衬壁厚对围岩内水压力分担率的影响。结果表明,随着壁厚增大,虽可相应减少钢衬径向位移和环向拉应力,但减幅小,效果不显著;随着壁厚变小,钢衬径向位移变大,根据变形协调,有助于荷载传递,提高了围岩分担率,有利于"钢衬-垫层-围岩"联合承载;在满足抗外压稳定验算、焊接工艺和施工安装前提下,壁厚可较大幅减小。研究成果不仅有利于减少不必要的投资,还有利于降低硐室钢衬运输安装等施工难度,可供类似工程设计参考。

Influence of Wall Thickness of Steel Penstock on Sharing Ratio of Internal Pressure in Bedrock for Pumped Storage Power Station

According to the requirements of actual projects, by changing wall thickness of steel lining, numerical simulation software FLAC3D was used to analyze the stress and deformation of steel lining, concrete bed course and surrounding rock and ring tensile stress of steel lining under different combination conditions of designed inner pressure. And then the influence of wall thickness of steel penstock on sharing ratio of internal pressure in bedrock was studied. The results show that the value of circumferential tensile stress and radical displacement decreased with the increase of wall thickness of steel lining, but the trend is not remarkable, vice versa; according to the principle of deformation consistency, the thinner of the wall thickness is conducive to loading transfer and improving the sharing ratio of internal pressure in bedrock; under the premise of critical external compressive resistance of buckling, weld and transportation, the wall thickness can be reduced greatly. The results not only provide useful data for cut of unnecessary investment, decrease of construction difficulty, but also have important value for the design of similar projects.