深厚覆盖层上超高心墙堆石坝坝基廊道非线性开裂分析

长河坝是中国深厚覆盖层上在建的首座200 m级高的堆石坝,这类建于深厚覆盖层上的超高土石坝坝基廊道受力条件复杂,是工程成败的关键环节,国内已有类似工程出现廊道破坏尤其是廊道止水破坏导致渗漏的情况.针对这类坝型的坝基廊道安全性问题,以长河坝工程为依托进行了深入研究.采用子模型技术和混凝土非线性本构模型,详细模拟大坝真实填筑和蓄水过程,建立3维有限元模型对廊道开裂形式和破坏过程进行研究.计算分析得出了一些关于廊道裂缝的开裂范围、廊道受压屈服的范围、廊道裂缝的开裂顺序以及开裂方向等有用结论,并提出了一些合理化建议,为本工程和类似工程决策提供参考.

Nonlinear cracking analysis of foundation gallery of high core wall rockfill dam on thick overburden layer

Abstract: In order to study the safety of galleries of high core wall rockfill dams on thick overburden layer, taking the Changheba dam as a background. This kind of gallery is subjected to complicated loads. The safety of the gallery is key to the project. Some galleries of this kind have already been cracked and leaked. The leakage was always from the destruction of the watertight seal. Changheba gravelly soil core wall rockfill dam under construction is the first dam over 200m on thick overburden foundation. Numerical models were presented for the finite element analysis. Based on the sub-model method, nonlinear elastic model was used for the gallery concrete. Cracking process and failure process of the gallery was conducted. Meanwhile the actual dam construction process and reservoir impounding process were considered. Through the analytical results the crack propagation, cracking direction and breakage feature were learned. Furthermore some reasonable suggestion were given, which can be as reference to changheba project and similar project.