摘要
基于某水电站坝后背管实际工程,建立了坝后背管斜直段底端的局部三维有限元数值分析模型,采用混凝土塑性损伤模型模拟管道外包及坝体混凝土,并在钢管与外包混凝土之间引入摩擦接触单元模拟两者之间的接触滑移特性.根据钢管外缝隙分布特征,拟定了均匀缝隙、非均匀缝隙以及随机缝隙方案,系统研究了缝隙值的大小及分布特征对管道承载特性的影响.结果表明:管道起裂荷载与缝隙值大小呈线性关系,由初裂部位附近的缝隙量控制;管道位移最大值基本出现在腰部附近40°范围内,缝隙值分布对管道上半周尤其是管顶的变形影响最大;内水压力较大时,不同缝隙方案承载比分布规律一致且数值比较接近,钢衬与钢筋混凝土在管道腰部的承载比基本不受摩擦系数的影响.
The three-dimensional finite element model for the inclined segment of a penstock on the downstream dam surface was developed after an actual hydropower station.A concrete damage plasticity model was employed to simulate the surrounding reinforced concrete and the contact friction element was introduced to simulate the contact-sliding between the steel liner and the reinforced concrete.According to the distribution pattern of the gap between the steel liner and the concrete,three sets of schemes regarding the uniform gap,non-uniform gap and random distribution gap were established to study the influence of the gap value and distribution pattern on the bearing mechanism of the penstock systematically.The results show that the initial cracking load is linearly related to the value of the gap,controlled by the value of the gap near the initial crack.The maximum displacement of the penstock is located within 40°near the waist.The distribution of the gap has great influence on the deformation of the upper half of penstock,especially around the crown.When the inner water pressure becomes larger,the distribution laws of the bearing ratio among the three sets of gap schemes are consistent,and the distribution of values is more concentrated.The bearing ratios of the steel liner and the reinforced concrete at the waist hardly change with the friction coefficients.
作者
苏凯
杨子娟
伍鹤皋
周利
石长征
Su Kai;Yang Zijuan;Wu Hegao;Zhou Li;Shi Changzheng(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)
出处
《天津大学学报（自然科学与工程技术版）》
EI
CSCD
北大核心
2018年第9期967-976,共10页
Journal of Tianjin University：Science and Technology
基金
国家自然科学基金资助项目(51579194)
国家重点研发计划资助项目(2016YFC0401803)
中央高校基本科研业务费专项资金资助项目(2042017kf0202)~~
关键词
水电站
钢衬钢筋混凝土管道
缝隙
承载特性
hydropower station
steel-lined reinforced concrete penstock
gap
bearing mechanism
作者简介
苏凯(1977—),男,博士,副教授,suker8044@163.com.;通讯作者:伍鹤皋,wbf1988@vip.sina.com.
