摘要
高拱坝的横缝、诱导缝以及坝体裂缝对大坝变形及应力状态影响重大。由于这些缝,尤其是坝体裂缝的受力特性复杂,采用常规的接触单元无法准确模拟其实际效应。本文提出一种新的复合接触单元,将接触元件隐含在薄层混凝土单元中,通过动态调整接触元件的刚度系数,可有效地模拟缝的形成过程、开合效应及灌浆作用,它具有概念简单,计算时保持有限元网格不变,易于数值实现等优点。结合算例分析,对接触元件刚度和单元厚度等影响计算效率的因素进行敏感性研究,并提出相应的推荐取值范围。最后,将该复合接触单元应用于小湾高拱坝仿真分析,通过计算与监测结果对比,验证了所提单元模型的准确性和有效性。
Deformation and stress of a high arch dam are greatly influenced by its artificial or natural cracks, such as transverse joints, induced joints and temperature cracks. The mechanical features of these cracks, especially temperature cracks, are too complicated to be simulated with conventional contact elements. This paper puts forth a composite contact element, in which a contact component can be inserted into a thin concrete element. The concept of this new element is simple and easy to implement numerically, and it supports use of regular finite element meshes in computation. The formation and grouting effects of cracks can be effectively simulated by dynamically adjusting the stiffness coefficient of contact component. The recommended values of stiffness coefficient and thickness of the thin concrete element are presented with sensitivity analysis for a numerical example. The proposed method has been applied to Xiaowan high arch dam, and comparison of computations with in-situ data shows its accuracy and effectiveness.
出处
《水力发电学报》
EI
CSCD
北大核心
2012年第5期216-222,共7页
Journal of Hydroelectric Engineering
基金
武汉大学博士研究生科研自主基金(NO.20102060101000058)
关键词
水工结构
仿真分析
复合接触单元
高拱坝
有限单元法
hydraulic structures
simulation
composite contact element
high arch dam
finiteelement method
