摘要
准确预测抽水蓄能电站面板堆石坝在频繁水位波动下的应力变形特性,对大坝安全至关重要。在广义塑性理论框架下,本文提出了一个改进本构模型GP_WHU,并开发了本构模型子程序。进行了单元体试验的有限元验证,GP_WHU模型可以较好地反映堆石料在三轴剪切和低频多周次循环加卸载路径下的应力变形响应。以贺州抽水蓄能电站的上水库面板堆石坝为例,采用GP_WHU模型进行了大坝填筑、初次蓄水和频繁水位波动情况下坝体和面板的应力变形分析。初次蓄水导致上游坝坡附近区域发生明显的位移增量和主应力方向偏转,位移增量最大值出现在约1/3坝高处。频繁水位波动作用下,上游坝坡水位变幅区底部附近的坝体出现明显的累积位移,沉降增量最大值约占填筑完工期坝体沉降的3%~9%。随着水位波动次数的增加,坝体与面板的变形和应力逐渐增大,并在波动次数达100次后趋于稳定。研究可为面板堆石坝在设计和运维过程中充分考量频繁水位波动作用提供关键计算依据。
Accurate prediction of the stress-deformation behavior of a concrete-faced rockfill dam(CFRD)under frequent reservoir stage fluctuations is critical to ensuring the safety of the pumped-storage power station.This study develops an improved constitutive model,GP_WHU,in the framework of the generalized plasticity theory,and demonstrates the application of a corresponding user module.We conduct triaxial tests on representative volume elements(RVE),and use the measurements to validate the model's performance,verifying its capability of effectively capturing the stress-strain response of rockfill materials under triaxial shear,single loading and unloading,and low-frequency multi-cycle loading and unloading conditions.We apply this new model in a case study of an upper reservoir CFRD under construction for a pumped-storage power station in Hezhou,and conduct numerical simulation of dam filling,initial impoundment,and stress-strain response under cyclic reservoir stage fluctuations.Results show the initial impoundment caused significant displacement increment and principal stress direction deviation in the upstream slope area,with the maximum displacement increment occurring at roughly one-third of the dam height from the bottom.And under cyclic hydrodynamic loading,significant cumulative displacement occurred in the dam body near the bottom of the upstream slope in the water level fluctuation zone,and the maximum settlement increment accounted for roughly 3%to 9%of the settlement at the end of construction.As the cycling number increased,both deformation and stress in the dam body and face slabs gradually incresaed but tended to stabilize after around 100 cycles.The study provides key computational support for a full consideration of the effect of frequent reservoir stage fluctuations in the design and operation of CFRD.
作者
胡锦方
马刚
杨启贵
汪泾周
熊堃
HU Jinfang;MA Gang;YANG Qigui;WANG Jingzhou;XIONG Kun(Institute of Water Engineering Sciences,Wuhan University,Wuhan 430072,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Ministry of Education,Wuhan University,Wuhan 430072,China;Changjiang Institute of Survey,Planning,Design and Research,Wuhan 430010,China;Changjiang Survey,Planning,Design and Research Company Limited,Wuhan 430010,China)
出处
《水力发电学报》
北大核心
2025年第12期84-99,共16页
Journal of Hydroelectric Engineering
基金
国家自然科学基金项目(52322907,U23B20149)
中国电建科技项目(DJ-ZDXM-2022-01)。
关键词
面板堆石坝
蓄水过程
频繁水位波动
本构模型
数值模拟
concrete-faced rockfill dam(CFRD)
impounding process
frequent water level fluctuation
constitutive model
numerical simulation
