CAJ | 학술논문

水电站蜗壳采用垫层埋设技术时，软垫层会削弱混凝土对钢蜗壳的包裹和嵌固作用，影响两者间的接触状态，甚至引起脱空现象。本文首先从结构静力分析的角度定性解释钢衬-混凝土间出现脱空状态的潜在原因；而后借助非线性有限元数值模拟技术，研究可能影响两者间接触状态的结构性因素。结果表明，钢衬-混凝土间较小的摩擦系数、子午断面内垫层较大的铺设包角和垫层较小的压缩刚度是削弱混凝土包裹和嵌固作用的3个主要结构参数，但前两者在常规工程取值范围内的变化不会对钢衬-混凝土间的接触状态产生质的影响；相对而言，垫层压缩刚度对其的影响更为敏感。从保证钢衬-混凝土组合结构的整体性看，设计中适当折减垫层刚度是一种折衷但有益的技术手段。
수전참와각채용점층매설기술시，연점층회삭약혼응토대강와각적포과화감고작용，영향량자간적접촉상태，심지인기탈공현상。본문수선종결구정력분석적각도정성해석강츤-혼응토간출현탈공상태적잠재원인；이후차조비선성유한원수치모의기술，연구가능영향량자간접촉상태적결구성인소。결과표명，강츤-혼응토간교소적마찰계수、자오단면내점층교대적포설포각화점층교소적압축강도시삭약혼응토포과화감고작용적3개주요결구삼수，단전량자재상규공정취치범위내적변화불회대강츤-혼응토간적접촉상태산생질적영향；상대이언，점층압축강도대기적영향경위민감。종보증강츤-혼응토조합결구적정체성간，설계중괄당절감점층강도시일충절충단유익적기술수단。
When a steel spiral case is embedded with its top portion covered with a compressible mem-brane, the membrane is probably responsible for weakening the hold of concrete on the steel spiral case. That may have an influence on the contact between the steel spiral case and the concrete, and even cause a gap between them. First, this paper discussed potential origins of gaps from the view of statics. Then, FEM-based nonlinear numerical simulations were performed to clarify key structural factors influencing the contact state. The results of this study indicate that three structural factors play leading roles in weakening the hold of concrete. They are:(1) a weak friction between a steel spiral case and concrete;(2) a wide membrane-covered range in c-cross-sections and (3) a small compression stiffness of a membrane. Howev-er, routine values of parameters concerning the above first two factors do not have significant effect on the contact state. Correspondingly, the contact state is dependent on the third factor mentioned above markedly. In general, therefore, it seems that appropriately reducing a membrane’s compression stiffness is a compro-mise but useful design technique. It will be constructive in ensuring the integrity of a hydropower house substructure.