带加劲环地面式钢衬钢筋混凝土管道取消伸缩节研究
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摘要
以某水电站带加劲环地面式钢衬钢筋混凝土管道为例,建立三维有限元模型,在分析其承载特性的基础上,论证了取消伸缩节的可行性。结果表明,在正常运行工况下,钢管以环向受拉为主;考虑温度变化后,环向应力基本不变,而轴向拉应力在温升作用下减小,在温降作用下增大;设伸缩节后,伸缩节附近钢管轴向应力的减小使其等效应力反而增大,且由于加劲环的约束和钢管与混凝土之间的摩擦作用,钢管并不随温度变化而自由伸缩,伸缩节起不到减小温度应力和适应不均匀沉降的作用,因此对于带加劲环的地面式钢衬钢筋混凝土管道建议不设伸缩节。
Combined with a ground based steel-lined reinforced concrete penstock with stiffening ring of a hydropower station,this paper demonstrates the feasibility of canceling expansion joint on the basis of analyzing the bearing behavior by three-dimensional finite element method.The research shows that under normal operating conditions,the steel pipe is dominated by circumferential tensile stress.Considering the temperature variation,the circumferential stress basically remains unchanged;however,the axial tensile stress decreases under the temperature rise,and increases under the temperature fall.After installing expansion joint,the decrease of the axial stress of the steel pipe near the expansion joint makes the equivalent stress increase;furthermore,due to the constraint of stiffening ring and the frictional effects between the steel penstock and the concrete,the steel penstock can not stretch freely with the temperature variation;at the same time,the expansion joint can not reduce the temperature stress and adapt to the uneven settlement.So,it is recommended to cancel the expansion joint for ground based steel-lined reinforced concrete penstock with stiffening ring.
Combined with a ground based steel-lined reinforced concrete penstock with stiffening ring of a hydropower station,this paper demonstrates the feasibility of canceling expansion joint on the basis of analyzing the bearing behavior by three-dimensional finite element method.The research shows that under normal operating conditions,the steel pipe is dominated by circumferential tensile stress.Considering the temperature variation,the circumferential stress basically remains unchanged;however,the axial tensile stress decreases under the temperature rise,and increases under the temperature fall.After installing expansion joint,the decrease of the axial stress of the steel pipe near the expansion joint makes the equivalent stress increase;furthermore,due to the constraint of stiffening ring and the frictional effects between the steel penstock and the concrete,the steel penstock can not stretch freely with the temperature variation;at the same time,the expansion joint can not reduce the temperature stress and adapt to the uneven settlement.So,it is recommended to cancel the expansion joint for ground based steel-lined reinforced concrete penstock with stiffening ring.
引文
[1]吴海林,杨威妮,张伟.水电站压力管道取消伸缩节研究进展[J].三峡大学学报:自然科学版,2009,31(3):1-6.
[2]林绍忠,刘宁.三峡工程水电站厂坝间压力钢管取消伸缩节研究[J].水利学报,2003(2):1-5.
[3]申艳,伍鹤皋,蒋逵超,等.紫坪铺水利枢纽引水系统取消厂前伸缩节研究[J].中国农村水利水电,2004(6):72-74.
[4]刘东常,涂祝明,孙健,等.龙开口水电站厂坝间压力钢管取消伸缩节研究[C]//第六届全国水电站压力管道学术论文集.北京:中国水利水电出版社,2006,348-351.
[5]杨经会,冯建武,刘曜,等.地面式钢衬钢筋混凝土管道温度作用机理与取消伸缩节研究[C]//第八届全国水电站压力管道学术论文集.北京:中国水利水电出版社,2014,89-96.
[6]袁文娜,伍鹤皋,樊熠玮,等.摩擦系数对水电站垫层蜗壳结构特性的影响[J].中国农村水利水电,2014(4):155-158.
[2]林绍忠,刘宁.三峡工程水电站厂坝间压力钢管取消伸缩节研究[J].水利学报,2003(2):1-5.
[3]申艳,伍鹤皋,蒋逵超,等.紫坪铺水利枢纽引水系统取消厂前伸缩节研究[J].中国农村水利水电,2004(6):72-74.
[4]刘东常,涂祝明,孙健,等.龙开口水电站厂坝间压力钢管取消伸缩节研究[C]//第六届全国水电站压力管道学术论文集.北京:中国水利水电出版社,2006,348-351.
[5]杨经会,冯建武,刘曜,等.地面式钢衬钢筋混凝土管道温度作用机理与取消伸缩节研究[C]//第八届全国水电站压力管道学术论文集.北京:中国水利水电出版社,2014,89-96.
[6]袁文娜,伍鹤皋,樊熠玮,等.摩擦系数对水电站垫层蜗壳结构特性的影响[J].中国农村水利水电,2014(4):155-158.