【摘要】 中国某300m级高拱坝在河段覆盖层之下存在一条基岩深槽,这使得该拱坝设计面临2种选择:对深槽进行基础回填混凝土处理;或者采用大开挖方式,将坝底高程设计在基岩深槽底部高程。该文建立了该高拱坝基础回填和基础大开挖2种设计方案的三维有限元模型,并基于变形加固理论,分析了2种方案在正常工况和超载下的位移、应力情况及塑性区扩展规律,并以不平衡力和塑性余能范数为评价标准,评价了2种方案的整体安全性。结果表明:2种方案在超载能力和整体稳定性上均达到要求,基础回填方案在坝体位移、应力及整体安全等方面优于大开挖方案。更多还原

【Abstract】 The riverbed bedrock of a 300-m-high arch dam has a deep groove so the arch dam design must choose between filling this groove with concrete or excavating to the bottom of the groove.3-D finite element models were developed for the concrete backfilling scheme and the deep excavation scheme.Deformation reinforcement theory(DRT)was then used to analyze the dam displacement,stresses and plastic zone extensions for both normal and overloaded conditions.The global stabilities of both schemes were evaluated based on the unbalanced force and the plastic complementary energy.The results show that both design schemes meet the requirements for the overloading capacity and global stability with the concrete backfilling scheme somewhat better than the deep excavation scheme in terms of the displacement,stresses and global stability of the arch dam.更多还原