洪水致弯曲河道挡墙稳定性衰变
|
摘要
天然河道蜿蜒曲折,河湾处环流助长紊动、引发凹岸淘蚀冲刷,导致沿河公路挡墙水毁频发。针对弯道水流运动规律,对洪水条件下弯道挡墙进行受力分析;基于挡墙稳定性分析力学模型,推导了弯曲河道挡墙稳定系数计算公式,给出挡墙基底极限冲深计算方程。通过算例验证了在河湾平缓条件下弯道洪水冲击计算的合理性,并对挡墙稳定性衰减影响因素进行分析。结果表明:洪水上涨时,在墙底未发生冲刷条件下,随着弯道处洪水对挡墙的冲击荷载增大,挡墙稳定性提高;在墙底发生冲刷条件下,挡墙稳定性降低,墙底淘蚀可能导致挡墙倾覆失稳。洪水陡落时,挡墙稳定性随挡墙前后水位差增大而降低,挡墙的抗滑稳定系数衰减速度比抗倾覆稳定系数衰减速度更快,挡墙滑移失稳可能性较大。得出的挡墙稳定系数计算方法的结果与现场情况基本吻合,可为类似沿河挡墙的设计与研究提供理论参考。
Natural rivers are curved. Bend circulation contributes to turbulence and causes erosion in concave bank, resulting in frequent flood damage on retaining wall along the river-side road. To investigate the trend of water movement at the river bend, force of retaining wall was analyzed in the condition of the flood. Based on the mechanical model of stability analysis of retaining wall, the calculating formula of the bend river retaining wall stability coefficient was deduced and calculation equation of limit punching depth under the wall was given. Shock calculation of rationality was verified in the gentle bend flood conditions and the stability of wall attenuation factors was analyzed by a numerical example. The results show that the impact load on the wall increases and the stability of wall is improved in the period of flood level rising and no erosion occurrence. However, the stability of retaining wall decreases when erosion occurs, and wall bottom scour may lead to overturning. The stability of wall decreases with the increase of water level difference between the front and back of the retaining wall, and the anti-sliding stability coefficient of the wall attenuates faster than that of the anti-overturning stability coefficient. The instability possibility of the wall is relatively high in the period of flood steeping. The calculation method and results of retaining stability coefficient are consistent with the site conditions, providing a theoretical reference for similar design and research of retaining walls along rivers.
Natural rivers are curved. Bend circulation contributes to turbulence and causes erosion in concave bank, resulting in frequent flood damage on retaining wall along the river-side road. To investigate the trend of water movement at the river bend, force of retaining wall was analyzed in the condition of the flood. Based on the mechanical model of stability analysis of retaining wall, the calculating formula of the bend river retaining wall stability coefficient was deduced and calculation equation of limit punching depth under the wall was given. Shock calculation of rationality was verified in the gentle bend flood conditions and the stability of wall attenuation factors was analyzed by a numerical example. The results show that the impact load on the wall increases and the stability of wall is improved in the period of flood level rising and no erosion occurrence. However, the stability of retaining wall decreases when erosion occurs, and wall bottom scour may lead to overturning. The stability of wall decreases with the increase of water level difference between the front and back of the retaining wall, and the anti-sliding stability coefficient of the wall attenuates faster than that of the anti-overturning stability coefficient. The instability possibility of the wall is relatively high in the period of flood steeping. The calculation method and results of retaining stability coefficient are consistent with the site conditions, providing a theoretical reference for similar design and research of retaining walls along rivers.
引文
[1]田伟平,李惠萍,高冬光.沿河路基冲刷机理与冲刷深度[J].长安大学学报(自然科学版),2002,22(4):39-42.TIAN Wei-ping,LI Hui-ping,GAO Dong-guang.Scour depth and mechanism of highway subgrade along river[J].Journal of Chang’an University(Natural Science Edition),2002,22(4):39-42.
[2]吴国雄,黄志才.沿河路基局部冲刷深度计算研究[J].中国公路学报,2005,18(4):12-15,53.WU Guo-xiong,HUANG Zhi-cai.Research on local scour depth calculation of roadbed along river[J].China Journal of Highway and Transport,2005,18(4):12-15,53.
[3]焉振,王元战.考虑软基不排水强度循环弱化的格型钢板桩防波堤动力有限元分析[J].岩土力学,2017,38(5):1454-1462.YAN Zhen,WANG Yuan-zhan.Dynamic finite element analyses of steel-sheet-pile flood bank considering post-cyclic strength degradation of soft foundations[J].Rock and Soil Mechanics,2017,38(5):1454-1462.
[4]张芳枝,陈晓平.河流冲刷对堤岸渗流和变形的影响研究[J].岩土力学,2011,32(2):441-447.ZHANG Fang-zhi,CHEN Xiao-ping.Study of river scour effect on seepage flow and deformation and stability of embankments[J].Rock and Soil Mechanics,2011,32(2):441-447.
[5]刘动,陈晓平,黄井武.河流冲刷作用下人工堤岸稳定性研究[J].中山大学学报(自然科学版),2013,52(3):17-22,29.LIU Dong,CHEN Xiao-ping,HUANG Jing-wu.Study of man-made embankment stability analysis with river scour effect[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2013,52(3):17-22,29.
[6]蒋洋,柴贺军.稳定渗流条件下沿河路基挡墙主动土压力分析[J].水运工程,2008,(8):20-24.JIANG Yang,CHAI He-jun.Analysis of active earth pressure on retaining wall of riverside subgrade under steady seepage[J].Port&Waterway Engineering,2008,(8):20-24.
[7]孙即超,王光谦.冲刷致岸堤稳定的衰变[J].清华大学学报(自然科学版),2010,50(9):1346-1349.SUN Ji-chao,WANG Guang-qian.Evolution of the riverbank damage under scouring[J].Journal of Tsinghua University(Science and Technology),2010,50(9):1346-1349.
[8]王素平,李云鹏,韩冰.河道洪水水位下降对护管挡墙可靠度影响分析[J].水文地质工程地质,2014,41(3):92-97.WANG Su-ping,LI Yun-peng,HAN Bing.An analysis of the influence of declined water levels on the reliability of the pipeline protection retaining wall[J].Hydrogeology&Engineering Geology,2014,41(3):92-97.
[9]NARDI L,RINALDI M,SOLARI L.An experimental investigation on mass failures occurring in a riverbank composed of sandy gravel[J].Geomorphology,2012,163-164:56-69.
[10]EVANGELISTA S,GRECOB M,IERVOLINO M,et al.A new algorithm for bank-failure mechanisms in 2D morphodynamic models with unstructured grids[J].International Journal of Sediment Research,2015,30(4):382-391.
[11]中华人民共和国行业标准编写组.SL 379-2007水工挡土墙设计规范[S].北京:中国水利水电出版社,2007.The Professional Standards Compilation Group of People’s Republic of China.SL 379-2007 Design specification for hydraulic retaining wall[S].Beijing:China Water Power Press,2007.
[12]林继镰.水工建筑物[M].北京:中国水利水电出版社,2009:215-300.LIN Ji-yong.Hydraulic structures[M].Beijing:China Water&Power Press,2009:215-300.
[13]ROZOVSKII I L.Flow of water in bends of open channels[M].[S.l.]:[s.n.],1961.
[14]王平义.弯曲河道动力学[M].成都:成都科技大学出版社,1995.WANG Ping-yi.Curved channel dynamics[M].Chengdu:Chengdu University of Science and Technology Press,1995.
[15]张红武.弯道环流研究[R].郑州:黄委会水利科学研究所,1985.ZHANG Hong-wu.Research of circulation flow[R].Zhengzhou:Institute of Yellow River,1985.
[16]陈永宽.悬移质含沙量沿垂线分布[J].泥沙研究,1984,(1):31-39.CHEN Yong-kuan.Vertical distribution of suspended sediment concentration[J].Journal of Sediment Research,1984,(1):31-39.
[17]张红武,吕昕.弯道水力学[M].北京:水利电力出版社,1993.ZHANG Hong-wu,LüXin.Bend channel hydraulics research[M].Beijing:Water&Power Press,1993.
[18]ZIMMERMANN C,KENNEDY J F.Transverse bed slopes in curved alluvial streams[J].Journal of Hydraulics Division,ASCE,1978,104(1):33-48.
[19]AMOUDRY L O,LIU P L F.Two-dimensional,two-phase granular sediment transport model with applications to scouring downstream of an apron[J].Coastal Engineering,2009,56(7):693-702.
[20]HOFFMANS G J C M,PILARCZYK K W.Local scour downstream of hydraulic structures[J].Journal of Hydraulic Engineering,1995,121(4):326-340.
[21]陈育权.弯道水流二维数值模拟及岸线整治的水动力学方法研究[D].天津:天津大学,2007.CHEN Yu-quan.2-D Numerical simulation of bend flow and research of hydrodynamic method on renovating bank[D].Tianjin:Tianjin University,2007.
[2]吴国雄,黄志才.沿河路基局部冲刷深度计算研究[J].中国公路学报,2005,18(4):12-15,53.WU Guo-xiong,HUANG Zhi-cai.Research on local scour depth calculation of roadbed along river[J].China Journal of Highway and Transport,2005,18(4):12-15,53.
[3]焉振,王元战.考虑软基不排水强度循环弱化的格型钢板桩防波堤动力有限元分析[J].岩土力学,2017,38(5):1454-1462.YAN Zhen,WANG Yuan-zhan.Dynamic finite element analyses of steel-sheet-pile flood bank considering post-cyclic strength degradation of soft foundations[J].Rock and Soil Mechanics,2017,38(5):1454-1462.
[4]张芳枝,陈晓平.河流冲刷对堤岸渗流和变形的影响研究[J].岩土力学,2011,32(2):441-447.ZHANG Fang-zhi,CHEN Xiao-ping.Study of river scour effect on seepage flow and deformation and stability of embankments[J].Rock and Soil Mechanics,2011,32(2):441-447.
[5]刘动,陈晓平,黄井武.河流冲刷作用下人工堤岸稳定性研究[J].中山大学学报(自然科学版),2013,52(3):17-22,29.LIU Dong,CHEN Xiao-ping,HUANG Jing-wu.Study of man-made embankment stability analysis with river scour effect[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2013,52(3):17-22,29.
[6]蒋洋,柴贺军.稳定渗流条件下沿河路基挡墙主动土压力分析[J].水运工程,2008,(8):20-24.JIANG Yang,CHAI He-jun.Analysis of active earth pressure on retaining wall of riverside subgrade under steady seepage[J].Port&Waterway Engineering,2008,(8):20-24.
[7]孙即超,王光谦.冲刷致岸堤稳定的衰变[J].清华大学学报(自然科学版),2010,50(9):1346-1349.SUN Ji-chao,WANG Guang-qian.Evolution of the riverbank damage under scouring[J].Journal of Tsinghua University(Science and Technology),2010,50(9):1346-1349.
[8]王素平,李云鹏,韩冰.河道洪水水位下降对护管挡墙可靠度影响分析[J].水文地质工程地质,2014,41(3):92-97.WANG Su-ping,LI Yun-peng,HAN Bing.An analysis of the influence of declined water levels on the reliability of the pipeline protection retaining wall[J].Hydrogeology&Engineering Geology,2014,41(3):92-97.
[9]NARDI L,RINALDI M,SOLARI L.An experimental investigation on mass failures occurring in a riverbank composed of sandy gravel[J].Geomorphology,2012,163-164:56-69.
[10]EVANGELISTA S,GRECOB M,IERVOLINO M,et al.A new algorithm for bank-failure mechanisms in 2D morphodynamic models with unstructured grids[J].International Journal of Sediment Research,2015,30(4):382-391.
[11]中华人民共和国行业标准编写组.SL 379-2007水工挡土墙设计规范[S].北京:中国水利水电出版社,2007.The Professional Standards Compilation Group of People’s Republic of China.SL 379-2007 Design specification for hydraulic retaining wall[S].Beijing:China Water Power Press,2007.
[12]林继镰.水工建筑物[M].北京:中国水利水电出版社,2009:215-300.LIN Ji-yong.Hydraulic structures[M].Beijing:China Water&Power Press,2009:215-300.
[13]ROZOVSKII I L.Flow of water in bends of open channels[M].[S.l.]:[s.n.],1961.
[14]王平义.弯曲河道动力学[M].成都:成都科技大学出版社,1995.WANG Ping-yi.Curved channel dynamics[M].Chengdu:Chengdu University of Science and Technology Press,1995.
[15]张红武.弯道环流研究[R].郑州:黄委会水利科学研究所,1985.ZHANG Hong-wu.Research of circulation flow[R].Zhengzhou:Institute of Yellow River,1985.
[16]陈永宽.悬移质含沙量沿垂线分布[J].泥沙研究,1984,(1):31-39.CHEN Yong-kuan.Vertical distribution of suspended sediment concentration[J].Journal of Sediment Research,1984,(1):31-39.
[17]张红武,吕昕.弯道水力学[M].北京:水利电力出版社,1993.ZHANG Hong-wu,LüXin.Bend channel hydraulics research[M].Beijing:Water&Power Press,1993.
[18]ZIMMERMANN C,KENNEDY J F.Transverse bed slopes in curved alluvial streams[J].Journal of Hydraulics Division,ASCE,1978,104(1):33-48.
[19]AMOUDRY L O,LIU P L F.Two-dimensional,two-phase granular sediment transport model with applications to scouring downstream of an apron[J].Coastal Engineering,2009,56(7):693-702.
[20]HOFFMANS G J C M,PILARCZYK K W.Local scour downstream of hydraulic structures[J].Journal of Hydraulic Engineering,1995,121(4):326-340.
[21]陈育权.弯道水流二维数值模拟及岸线整治的水动力学方法研究[D].天津:天津大学,2007.CHEN Yu-quan.2-D Numerical simulation of bend flow and research of hydrodynamic method on renovating bank[D].Tianjin:Tianjin University,2007.