摘要
汉江雅口航运枢纽工程二期围堰是以粉细砂为主要填筑材料,并辅以土工复合材料和素混凝土板抵抗水流冲刷的过水围堰。围堰经2021年洪水过流后,过流面混凝土板出现了局部脱空、板间连接钢筋断裂等局部破坏现象,采用非线性有限元方法对过水围堰的应力-变形情况进行数值模拟,进而分析围堰局部破坏原因,提出预防措施。结果表明,在重力及水荷载共同作用下,围堰过流坝坡面不均匀沉降变形过大,致使抗冲刷混凝土板与堰体填筑料间存在不同程度的脱空,板间连接钢筋受力状态由受拉转变为受剪,局部因强度不足发生剪断破坏,最终导致混凝土板的整体性降低,抗水流冲刷能力不足。减小不均匀沉降是预防此类破坏的关键所在,为此可加强填筑碾压,提高材料的密实度,进而增强坝体的抗沉降变形能力;在混凝土板下方设置土工膜反滤,提高材料的抗渗透变形和抗水力冲刷的能力。
The phaseⅡcofferdam of the Yakou Navigation Complex project on Hanjiang River is an overflow cofferdam with silty fine sand as the main filling material,supplemented by geotextile and plain concrete slabs to resist water scouring.After the flood in 2021,the concrete slabs on the cofferdam overflow surface suffer from local failure such as local void and fracture of connecting steel bars between slabs.This paper uses the nonlinear finite element method to conduct numerical simulation of the stress and deformation of the overflow cofferdam and analyzes the causes of the local failure of the cofferdam to propose preventive measures.The results show that under the combined action of gravity and water load,the non-uniform settlement deformation of the cofferdam overflow dam slope surface is too large,resulting in varying degrees of void between the anti-scour concrete slabs and the cofferdam body filling material.The stress state of the connecting reinforcement between the slabs changes from tension to shear,and local shear failure occurs due to insufficient strength,which ultimately leads to a reduction of the integrity of the concrete slabs and insufficient anti-flow scour capacity.Reducing the non-uniform settlement is the key to preventing such failure.Therefore,it is necessary to strengthen the filling and rolling to improve the compactness of the material,thus enhancing the anti-settlement deformation capacity of the dam body.Geomembrane reverse filter is set under the concrete slabs to improve the capacity of anti-seepage deformation and anti-flow scour.
作者
查新元
童富果
李彪
ZHA Xinyuan;TONG Fuguo;LI Biao(Hubei Key Laboratory of Hydropower Engineering Construction and Management,China Three Gorges University,Yichang 443002,China;College of Water Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China)
出处
《水运工程》
北大核心
2023年第9期216-222,共7页
Port & Waterway Engineering
基金
国家自然科学基金项目(51939004)
三峡大学学位论文培优基金项目(2021SSPY014)。
关键词
过流围堰
不均匀沉降
渗透破坏
应力变形分析
非线性有限元方法
overflow cofferdam
non-uniform settlement
seepage failure
stress and deformation analysis
nonlinear finite element
