考虑水力劈裂效应的重力坝坝踵裂缝稳定分析
|
摘要
混凝土重力坝坝踵开裂是重力坝常见的现象,由于高坝缝内存在较高的扬压力,水压的劈裂作用有可能驱使裂缝进一步扩展,严重影响坝体的安全性。基于大型有限元分析软件,建立重力坝数值分析模型,人为在坝踵附近设置不同深度的裂缝,分析不同位置、不同裂缝深度、不同缝内水压分布作用下裂缝的稳定性,以分析水力劈裂效应。研究结果表明,坝踵附近裂缝多处于压剪复合断裂模式,但在缝内高水压作用下,有可能变为拉剪复合断裂,也极易失稳扩展;随着裂缝长度的增加,水力劈裂效应愈加显著。
Cracking at concrete gravity dam heel is a common phenomenon.Due to hydraulic fracturing of uplift in the crack,the crack at dam heel would expand and influence the dam′s safety seriously.A numerical analysis model for gravity dam is built using finite element software.By the assumption of cracks at dam heel,the stability of dam heel crack is studied considering different crack location,crack depth and water pressure distribution type in cracks.The results show that the cracks at dam heel belong to compression-shear mixed fracturing type,however,it would be changed into tension-shear mixed fracturing type and easily expand due to high water pressure in crack;the hydraulic fracturing effect gets stronger with the increment of crack length and water pressure.
Cracking at concrete gravity dam heel is a common phenomenon.Due to hydraulic fracturing of uplift in the crack,the crack at dam heel would expand and influence the dam′s safety seriously.A numerical analysis model for gravity dam is built using finite element software.By the assumption of cracks at dam heel,the stability of dam heel crack is studied considering different crack location,crack depth and water pressure distribution type in cracks.The results show that the cracks at dam heel belong to compression-shear mixed fracturing type,however,it would be changed into tension-shear mixed fracturing type and easily expand due to high water pressure in crack;the hydraulic fracturing effect gets stronger with the increment of crack length and water pressure.
引文
[1]中华人民共和国水利部.SL319-2005混凝土重力坝设计规范[S].北京:中国水利水电出版社:2005.
[2]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2000,24(6):14-17.
[3]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2001,25(1):4-6.
[4]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2001,25(2):1-3.
[5]贾金生,李新宇,郑璀莹.特高重力坝高压水劈裂影响的初步研究[J].水利学报,2006,37(12):1 509-1 515.
[6]黄耀英,胡群革.砼坝裂缝稳定性分析[J].浙江水利水电专科学校校报,2002,14(4):1-4.
[7]李宗利,刘霞,周宁娜.高混凝土重力坝坝踵开裂对坝体静力学性能影响研究[J].水力发电,2009,35(4):84-87.
[8]Rene T,Lotfi G.Formu lation of hydrodynam ic pressure in cracks dueto earthquakes in concrete dam s[J].Earthquake Engineering andStructural Dynam ics,1994,23(7):699-715.
[9]胡良明,李宗坤,周鸿钧.重力坝坝踵界面裂缝的地震断裂分析[J].郑州大学学报(工学版),2002,23(3):101-103.
[10]丁遂栋.断裂力学[M].北京:机械工业出版社,1997.
[2]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2000,24(6):14-17.
[3]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2001,25(1):4-6.
[4]王志远.重力坝的实测坝踵应力及原因分析[J].大坝观测与土工测试,2001,25(2):1-3.
[5]贾金生,李新宇,郑璀莹.特高重力坝高压水劈裂影响的初步研究[J].水利学报,2006,37(12):1 509-1 515.
[6]黄耀英,胡群革.砼坝裂缝稳定性分析[J].浙江水利水电专科学校校报,2002,14(4):1-4.
[7]李宗利,刘霞,周宁娜.高混凝土重力坝坝踵开裂对坝体静力学性能影响研究[J].水力发电,2009,35(4):84-87.
[8]Rene T,Lotfi G.Formu lation of hydrodynam ic pressure in cracks dueto earthquakes in concrete dam s[J].Earthquake Engineering andStructural Dynam ics,1994,23(7):699-715.
[9]胡良明,李宗坤,周鸿钧.重力坝坝踵界面裂缝的地震断裂分析[J].郑州大学学报(工学版),2002,23(3):101-103.
[10]丁遂栋.断裂力学[M].北京:机械工业出版社,1997.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心