降低高沥青混凝土心墙拉应力的措施研究
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摘要
传统沥青混凝土心墙堆石坝中心墙和坝壳沿坝轴线方向均为直线型。心墙在水压力推动作用下产生指向下游的挠曲变形,心墙轴线伸长致使其内部产生拉应力,坝高越高,心墙产生拉裂缝的风险越大。本文基于心墙产生拉应力的机理,提出了两种新坝型(直坝曲心墙坝型和曲坝曲心墙坝型)的改善措施。借助有限元计算,研究了坝高和坝轴线长度对心墙挠曲变形和拉应力的影响,考察了新坝型的改善效果,表明坝高越高、坝轴线长度越长和岸坡坡比越大,心墙拉应力越大,新坝型对减小心墙拉应力具有良好的效果。通过施工技术、施工工期以及经济成本等方面的分析,表明新坝型可行,具有良好的应用前景。
Traditional rockfill dams with an asphalt concrete core wall is featured with a linear shape of both the core wall and dam shell. The core wall is deflected by the horizontal pushing of water pressure, and its deflection deformation and the elongation of its axis may induce tensile stress. Generally, a higher dam may have a higher risk of tensile cracks developed in its core wall. In this study, we analyze the generation mechanism of tensile stress in a core wall, and develop two new dam types as improving measures ? a straight dam with a curved core(SDCC) and a curved dam with a curved core(CDCC). Finite element analysis is used to examine the influences of dam height and dam axis length on the deflection deformation and tensile stress in the core wall and to investigate the improving effect of these two types. Results show that a greater dam height, longer dam axis, and larger bank slope ratio of a traditional dam lead to greater tensile stress in its core wall, and consequently a greater reduction in tensile stress if it is modified into either of the two suggested dam types. Analyses on construction technique, construction period, and economic cost show that the new types of rockfill dams are feasible and may have a good application prospect.
Traditional rockfill dams with an asphalt concrete core wall is featured with a linear shape of both the core wall and dam shell. The core wall is deflected by the horizontal pushing of water pressure, and its deflection deformation and the elongation of its axis may induce tensile stress. Generally, a higher dam may have a higher risk of tensile cracks developed in its core wall. In this study, we analyze the generation mechanism of tensile stress in a core wall, and develop two new dam types as improving measures ? a straight dam with a curved core(SDCC) and a curved dam with a curved core(CDCC). Finite element analysis is used to examine the influences of dam height and dam axis length on the deflection deformation and tensile stress in the core wall and to investigate the improving effect of these two types. Results show that a greater dam height, longer dam axis, and larger bank slope ratio of a traditional dam lead to greater tensile stress in its core wall, and consequently a greater reduction in tensile stress if it is modified into either of the two suggested dam types. Analyses on construction technique, construction period, and economic cost show that the new types of rockfill dams are feasible and may have a good application prospect.
引文
[1]WANG W B,H?EG K.The asphalt core embankment dam:a very competitive alternative[C]//The 1st International Symposium on Rockfill dams.Proceedings.Chengdou,2009:73-81.
[2]王为标.土石坝沥青防渗技术的应用和发展[J].水力发电学报,2004,23(6):70-74.WANG Weibiao.Development and applications of impervious asphalt concrete for embankment dams[J].Journal of Hydroelectric Engineering,2004,23(6):70-74.(in Chinese)
[3]朱晟.沥青混凝土心墙堆石坝三维地震反应分析[J].岩土力学,2008,29(11):2933-2938.ZHUN Sheng.3-D seismic response analysis of rockfill dam with asphalt concrete core[J].Rock and Soil Mechanics,2008,29(11):2933-2938.(in Chinese)
[4]LEE H J,KIM Y R.Viscoelastic constitutive model for asphalt concrete under cyclic loading[J].Journal of Engineering Mechanics,1998,124(1):32-40.
[5]AKHTARPOUR A,KHODAII A.Experimental study of asphaltic concrete dynamic properties as an impervious core in embankment dams[J].Construction&Building Materials,2013,41(2):319-334.
[6]ZHANG Y B,H?EG K,WANG W B,et al.Watertightness,cracking resistance,and self-healing of asphalt concrete used as a water barrier in dams[J].Canadian Geotechnical Journal,2013,50(3):275-287.
[7]KONGKITKUL W,MUSIKA N,TONGNUAPAD C,et al.Anisotropy in compressive strength and elastic stiffness of normal and polymer-modified asphalts[J].Soils&Foundations,2014,54(2):94-108.
[8]郝巨涛.国内沥青混凝土防渗技术发展中的重要问题[J].水利学报,2008,39(10):1213-1219.HAO Jutao.Important topics in development of asphalt concrete technology in China[J].Journal of Hydraulic Engineering,2008,39(10):1213-1219.(in Chinese)
[9]胡春林,胡安明,李友华.茅坪溪土石坝沥青混凝土心墙的力学特性与施工控制[J].岩石力学与工程学报,2001,20(5):742-746.HU Chunlin,HU Anming,LI Youhua.Mechanical property and construction control of the asphalt concrete core wall in Maopingxi earth-rock fill dam[J].Chinese Journal of Rock Mechanics and Engineering,2001,20(5):742-746.(in Chinese)
[10]余梁蜀,任少辉,孙振天,等.碾压式中小型沥青混凝土心墙坝施工设备与施工技术研究[J].水力发电学报,2007,26(2):70-74.YU Liangshu,REN Shaohui,SUN Zhentian,et al.Constructional equipments and technology research of rolling asphalt concrete core of minitype and mediumsized engineering[J].Journal of Hydroelectric Engineering,2007,26(2):70-74.(in Chinese)
[11]ZHONG D H,CUI B,LIU D H.Theoretical research on construction quality real-time monitoring and system integration of core rockfill dam[J].Science in China Series E:Technological Sciences,2009,52(11):3406-3412.
[12]朱晟,魏匡民,饶锡保.土石坝沥青混凝土心墙水力劈裂研究[J].水力发电学报,2013,32(11):218-222.ZHU Sheng,WEI Kuangmin,RAO Xibao.Study on hydraulic fracturing of asphalt concrete core in earth-rock dam[J].Journal of Hydroelectric Engineering,2013,32(11):218-222.(in Chinese)
[13]吴海林,彭云枫,杜晓帆,等.沥青混凝土心墙坝应力变形及水力劈裂研究[J].水力发电学报,2015,34(4):119-127.WU Hailin,PENG Yunfeng,DU Xiaofan,et al.Study on stress-deformation and hydraulic fracturing of rockfill dam with asphalt concrete core[J].Journal of Hydroelectric Engineering,2015,34(4):119-127.(in Chinese)
[14]朱晟.当前沥青混凝土防渗土石坝建设中若干问题的探讨[J].水力发电学报,2009,28(3):101-105.ZHU Sheng.Research and discussion on questions of construction of earth-rock dams with asphalt-concrete impervious layer[J].Journal of Hydroelectric Engineering,2009,28(3):101-105.(in Chinese)
[15]王为标,张应波,朱悦,等.沥青混凝土心墙石渣坝的有限元计算分析[J].水力发电学报,2010,29(4):173-178.WANG Weibiao,ZHANG Yingbo,ZHU Yue,et al.Finite element analysis of asphalt concrete core rock-debris dam[J].Journal of Hydroelectric Engineering,2010,29(4):173-178.(in Chinese)
[16]BAZIAR M H,SALEMI S,HEIDARI T.Analysis of earthquake response of an asphalt concrete core embankment dam[J].International Journal of Civil Engineering,2006,4(3):192-210.
[17]江时俊,杨具瑞,汤敏.沥青混凝土心墙与过渡层变形协调性及防渗的影响研究[J].水力发电学报,2016,35(4):98-107.JIANG Shijun,YANG Jurui,TANG Min.Deformation coordination and seepage prevention of asphalt concrete core-wall and transition layers[J].Journal of Hydroelectric Engineering,2016,35(4):98-107.(in Chinese)
[18]荣冠,朱焕春.茅坪溪土石坝沥青混凝土心墙施工期变形分析[J].水利学报,2003,34(7):115-119.RONG Guan,ZHU Huanchun.Deformation of asphalt concrete core wall of Maopingxi earth-rock dam in the stage of construction[J].Journal of Hydraulic Engineering,2003,34(7):115-119.(in Chinese)
[19]汪明元,周欣华,包承纲,等.三峡茅坪溪高沥青混凝土心墙堆石坝运行性状研究[J].岩石力学与工程学报,2007,26(7):1470-1477.WANG Mingyuan,ZHOU Xinhua,BAO Chenggang,et al.Study on Behaviors of Maopingxi high rockfill dam with asphalt concrete core of Three Gorges Project[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(7):1470-1477.(in Chinese)
[20]郦能惠,杨泽艳.中国混凝土面板堆石坝的技术进步[J].岩土工程学报,2012,34(8):1361-1368.LI Nenghui,YANG Zeyan.Technical advances in concrete face rockfill dams in China[J].Chinese Journal of Geotechnical Engineering,2012,34(8):1361-1368.(in Chinese)
[21]李守义,马成成,李炎隆,等.沥青混凝土心墙堆石坝的地震反应特性分析[J].水力发电学报,2013,32(6):198-202.LI Shouyi,MA Chengcheng,LI Yanlong,et al.Seismic response analysis of rockfill dam with asphaltic concrete core wall[J].Journal of Hydroelectric Engineering,2013,32(6):198-202.(in Chinese)
[22]杨超,党发宁,薛海斌,等.河谷形状对沥青混凝土心墙坝变形特性的影响[J].水利水运工程学报,2016(4):54-62.YANG Chao,DANG Faning,XUE Haibin,et al.Influences of valley topography on deformation properties of asphalt concrete core wall dam[J].Hydro-Science and Engineering,2016(4):54-62.(in Chinese)
[23]凤家骥,葛毅雄,孙兆雄.沥青混凝土应力-应变关系试验研究[J].水利学报,1987(11):56-62.FENG Jiaji,GE Yixiong,SUN Zhaoxiong.Test study on stress-strain relationship for asphalt concrete[J].Journal of Hydraulic Engineering,1987(11):56-62.(in Chinese)
[24]李国英,王禄仕,米占宽.土质心墙堆石坝应力和变形研究[J].岩土工程学报,2004,23(8):1363-1369.LI Guoying,WANG Lushi,MI Zhankuan.Research onstress-strain behavior of soil core rockfill dam[J].Chinese Journal of Geotechnical Engineering,2004,23(8):1363-1369.(in Chinese)
[2]王为标.土石坝沥青防渗技术的应用和发展[J].水力发电学报,2004,23(6):70-74.WANG Weibiao.Development and applications of impervious asphalt concrete for embankment dams[J].Journal of Hydroelectric Engineering,2004,23(6):70-74.(in Chinese)
[3]朱晟.沥青混凝土心墙堆石坝三维地震反应分析[J].岩土力学,2008,29(11):2933-2938.ZHUN Sheng.3-D seismic response analysis of rockfill dam with asphalt concrete core[J].Rock and Soil Mechanics,2008,29(11):2933-2938.(in Chinese)
[4]LEE H J,KIM Y R.Viscoelastic constitutive model for asphalt concrete under cyclic loading[J].Journal of Engineering Mechanics,1998,124(1):32-40.
[5]AKHTARPOUR A,KHODAII A.Experimental study of asphaltic concrete dynamic properties as an impervious core in embankment dams[J].Construction&Building Materials,2013,41(2):319-334.
[6]ZHANG Y B,H?EG K,WANG W B,et al.Watertightness,cracking resistance,and self-healing of asphalt concrete used as a water barrier in dams[J].Canadian Geotechnical Journal,2013,50(3):275-287.
[7]KONGKITKUL W,MUSIKA N,TONGNUAPAD C,et al.Anisotropy in compressive strength and elastic stiffness of normal and polymer-modified asphalts[J].Soils&Foundations,2014,54(2):94-108.
[8]郝巨涛.国内沥青混凝土防渗技术发展中的重要问题[J].水利学报,2008,39(10):1213-1219.HAO Jutao.Important topics in development of asphalt concrete technology in China[J].Journal of Hydraulic Engineering,2008,39(10):1213-1219.(in Chinese)
[9]胡春林,胡安明,李友华.茅坪溪土石坝沥青混凝土心墙的力学特性与施工控制[J].岩石力学与工程学报,2001,20(5):742-746.HU Chunlin,HU Anming,LI Youhua.Mechanical property and construction control of the asphalt concrete core wall in Maopingxi earth-rock fill dam[J].Chinese Journal of Rock Mechanics and Engineering,2001,20(5):742-746.(in Chinese)
[10]余梁蜀,任少辉,孙振天,等.碾压式中小型沥青混凝土心墙坝施工设备与施工技术研究[J].水力发电学报,2007,26(2):70-74.YU Liangshu,REN Shaohui,SUN Zhentian,et al.Constructional equipments and technology research of rolling asphalt concrete core of minitype and mediumsized engineering[J].Journal of Hydroelectric Engineering,2007,26(2):70-74.(in Chinese)
[11]ZHONG D H,CUI B,LIU D H.Theoretical research on construction quality real-time monitoring and system integration of core rockfill dam[J].Science in China Series E:Technological Sciences,2009,52(11):3406-3412.
[12]朱晟,魏匡民,饶锡保.土石坝沥青混凝土心墙水力劈裂研究[J].水力发电学报,2013,32(11):218-222.ZHU Sheng,WEI Kuangmin,RAO Xibao.Study on hydraulic fracturing of asphalt concrete core in earth-rock dam[J].Journal of Hydroelectric Engineering,2013,32(11):218-222.(in Chinese)
[13]吴海林,彭云枫,杜晓帆,等.沥青混凝土心墙坝应力变形及水力劈裂研究[J].水力发电学报,2015,34(4):119-127.WU Hailin,PENG Yunfeng,DU Xiaofan,et al.Study on stress-deformation and hydraulic fracturing of rockfill dam with asphalt concrete core[J].Journal of Hydroelectric Engineering,2015,34(4):119-127.(in Chinese)
[14]朱晟.当前沥青混凝土防渗土石坝建设中若干问题的探讨[J].水力发电学报,2009,28(3):101-105.ZHU Sheng.Research and discussion on questions of construction of earth-rock dams with asphalt-concrete impervious layer[J].Journal of Hydroelectric Engineering,2009,28(3):101-105.(in Chinese)
[15]王为标,张应波,朱悦,等.沥青混凝土心墙石渣坝的有限元计算分析[J].水力发电学报,2010,29(4):173-178.WANG Weibiao,ZHANG Yingbo,ZHU Yue,et al.Finite element analysis of asphalt concrete core rock-debris dam[J].Journal of Hydroelectric Engineering,2010,29(4):173-178.(in Chinese)
[16]BAZIAR M H,SALEMI S,HEIDARI T.Analysis of earthquake response of an asphalt concrete core embankment dam[J].International Journal of Civil Engineering,2006,4(3):192-210.
[17]江时俊,杨具瑞,汤敏.沥青混凝土心墙与过渡层变形协调性及防渗的影响研究[J].水力发电学报,2016,35(4):98-107.JIANG Shijun,YANG Jurui,TANG Min.Deformation coordination and seepage prevention of asphalt concrete core-wall and transition layers[J].Journal of Hydroelectric Engineering,2016,35(4):98-107.(in Chinese)
[18]荣冠,朱焕春.茅坪溪土石坝沥青混凝土心墙施工期变形分析[J].水利学报,2003,34(7):115-119.RONG Guan,ZHU Huanchun.Deformation of asphalt concrete core wall of Maopingxi earth-rock dam in the stage of construction[J].Journal of Hydraulic Engineering,2003,34(7):115-119.(in Chinese)
[19]汪明元,周欣华,包承纲,等.三峡茅坪溪高沥青混凝土心墙堆石坝运行性状研究[J].岩石力学与工程学报,2007,26(7):1470-1477.WANG Mingyuan,ZHOU Xinhua,BAO Chenggang,et al.Study on Behaviors of Maopingxi high rockfill dam with asphalt concrete core of Three Gorges Project[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(7):1470-1477.(in Chinese)
[20]郦能惠,杨泽艳.中国混凝土面板堆石坝的技术进步[J].岩土工程学报,2012,34(8):1361-1368.LI Nenghui,YANG Zeyan.Technical advances in concrete face rockfill dams in China[J].Chinese Journal of Geotechnical Engineering,2012,34(8):1361-1368.(in Chinese)
[21]李守义,马成成,李炎隆,等.沥青混凝土心墙堆石坝的地震反应特性分析[J].水力发电学报,2013,32(6):198-202.LI Shouyi,MA Chengcheng,LI Yanlong,et al.Seismic response analysis of rockfill dam with asphaltic concrete core wall[J].Journal of Hydroelectric Engineering,2013,32(6):198-202.(in Chinese)
[22]杨超,党发宁,薛海斌,等.河谷形状对沥青混凝土心墙坝变形特性的影响[J].水利水运工程学报,2016(4):54-62.YANG Chao,DANG Faning,XUE Haibin,et al.Influences of valley topography on deformation properties of asphalt concrete core wall dam[J].Hydro-Science and Engineering,2016(4):54-62.(in Chinese)
[23]凤家骥,葛毅雄,孙兆雄.沥青混凝土应力-应变关系试验研究[J].水利学报,1987(11):56-62.FENG Jiaji,GE Yixiong,SUN Zhaoxiong.Test study on stress-strain relationship for asphalt concrete[J].Journal of Hydraulic Engineering,1987(11):56-62.(in Chinese)
[24]李国英,王禄仕,米占宽.土质心墙堆石坝应力和变形研究[J].岩土工程学报,2004,23(8):1363-1369.LI Guoying,WANG Lushi,MI Zhankuan.Research onstress-strain behavior of soil core rockfill dam[J].Chinese Journal of Geotechnical Engineering,2004,23(8):1363-1369.(in Chinese)