水流作用下粉砂海床上人工鱼礁局部冲刷的模型试验与分析
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摘要
海底条件的变化可能会加剧人工鱼礁的局部冲刷甚至产生掏空,导致人工鱼礁倾覆或掩埋,最终影响人工鱼礁的生态修复功能。为更好地了解人工鱼礁的冲刷特性,明确冲刷地形的形成机制,本研究首先采用物理模型试验的方法,对放置在粉砂底质上的人工鱼礁在不同水流条件下的局部冲刷问题进行了研究,并通过对原型流场进行数值模拟,讨论分析了水流及礁体结构特征对局部冲刷形态的影响机制。模型试验结果显示,0.11 m/s流速对试验选取的模型沙的影响不显著,礁体模型背面冲刷坑的深度仅为0.5 mm,两侧无明显冲刷坑,当流速增加到0.22和0.27 m/s时,沙床表面形成了均匀分布的沙鳞,背面冲刷坑深度分别达到1.0和1.5 mm,两侧冲刷坑的最大深度为4.5 mm,宽度分别为4.0和7.5 cm;流场数值模拟的分析结果显示,原型条件下流场、沙床剪切力和涡量的高值区和模型试验中冲刷强区存在对应关系,礁体的开孔和多柱支撑设计增大了局部冲刷强度。该研究表明,在粉砂底质条件下人工鱼礁的局部冲刷程度随流速的增加而增强,但总体冲刷不严重,未出现掏空或掩埋现象;礁体结构对局部冲刷有较大影响,因此,礁体设计与布局时应综合考虑流场效应、稳定性和冲刷形态等因素。
Artificial reefs(ARs) are an important part of marine ranching, which are installed in seabed to protect and cultivate marine life systems. After ARs are deployed, changes in seabed conditions may intensify local scouring of seabed nearby ARs and influence the stability of ARs. Therefore, it is necessary to investigate the scouring characteristics. In this study, a physical model experiment was conducted in an experimental sink to investigate the local scouring of an artificial reef at different water flow velocities, which was placed on silty sand bed. The experiment results show that the scouring response of the silty bed to the 0.11 m/s flow velocity is not significant. The depth of the scouring hole behind the reef model is 0.5 mm, and there is no obvious scouring hole on both sides. When the flow velocity increases to 0.22 and 0.27 m/s, sand scales are uniformly distributed on the surface of sand bed. The depth of the scouring hole behind is 1.0 and 1.5 mm respectively. The maximum depth of the scouring holes on both sides is 4.5 mm and the width is 4.0 cm and 7.5 cm respectively. Combined with the experiment results, the numerical simulation method was introduced to analyse the mechanism of scouring phenomenon nearby ARs. According to the simulation, the flow field, shear force and vortex distribution are similar to the scouring pattern of silty sand bed in the experiments. The numerical simulation results show that the holes in the surface and multi-legs of reef increase the flow and scouring strength. The high value area of above three parameters corresponds to the area with stronger scouring. It is concluded that the scouring strength of ARs in the silty sand bed increases with flow velocity, but it is not strong enough to influence the stability of reef model. The structure of ARs does have effects on the local scouring. Flow field, stability and scouring pattern should be taken into consideration during the design of ARs.
Artificial reefs(ARs) are an important part of marine ranching, which are installed in seabed to protect and cultivate marine life systems. After ARs are deployed, changes in seabed conditions may intensify local scouring of seabed nearby ARs and influence the stability of ARs. Therefore, it is necessary to investigate the scouring characteristics. In this study, a physical model experiment was conducted in an experimental sink to investigate the local scouring of an artificial reef at different water flow velocities, which was placed on silty sand bed. The experiment results show that the scouring response of the silty bed to the 0.11 m/s flow velocity is not significant. The depth of the scouring hole behind the reef model is 0.5 mm, and there is no obvious scouring hole on both sides. When the flow velocity increases to 0.22 and 0.27 m/s, sand scales are uniformly distributed on the surface of sand bed. The depth of the scouring hole behind is 1.0 and 1.5 mm respectively. The maximum depth of the scouring holes on both sides is 4.5 mm and the width is 4.0 cm and 7.5 cm respectively. Combined with the experiment results, the numerical simulation method was introduced to analyse the mechanism of scouring phenomenon nearby ARs. According to the simulation, the flow field, shear force and vortex distribution are similar to the scouring pattern of silty sand bed in the experiments. The numerical simulation results show that the holes in the surface and multi-legs of reef increase the flow and scouring strength. The high value area of above three parameters corresponds to the area with stronger scouring. It is concluded that the scouring strength of ARs in the silty sand bed increases with flow velocity, but it is not strong enough to influence the stability of reef model. The structure of ARs does have effects on the local scouring. Flow field, stability and scouring pattern should be taken into consideration during the design of ARs.
引文
[1]郑延璇,梁振林,关长涛,等.三种叠放形式的圆管型人工鱼礁流场效应数值模拟与PIV试验研究[J].海洋与湖沼, 2014, 45(1):11-19.Zheng Y X, Liang Z L, Guan C T, et al. Numerical simulation and experimental study on flow field of artificial reefs in three tube-stacking layouts[J].Oceanologia et Limnologia Sinica, 2014, 45(1):11-19(in Chinese).
[2]邵万骏,刘长根,聂红涛,等.人工鱼礁的水动力学特性及流场效应分析[J].水动力学研究与进展, 2014,29(5):580-585.Shao W J, Liu C G, Nie H T, et al. Analysis of hydrodynamic characteristics and flow field around artificial reefs[J]. Chinese Journal of Hydrodynamics,2014, 29(5):580-585(in Chinese).
[3]赵林,邓超,于振江,等.组合式金字塔型人工鱼礁水动力学分析[J].渔业现代化, 2018, 45(6):53-59.Zhao L, Deng C, Yu Z J, et al. Hydrodynamic analysis of combined pyramidal artificial reef[J]. Fishery Modernization, 2018, 45(6):53-59(in Chinese).
[4]张伟,李纯厚,贾晓平,等.大亚湾混凝土鱼礁和铁质鱼礁附着生物群落结构的季节变化[J].南方水产科学,2015, 11(1):9-17.Zhang W, Li C H, Jia X P, et al. Seasonal variation of biofouling communities on concrete and steel reefs in Daya Bay[J]. South China Fisheries Science, 2015,11(1):9-17(in Chinese).
[5]李磊,陈栋,彭建新,等. 3种人工鱼礁模型对黑棘鲷的诱集效果研究[J].海洋渔业, 2018, 40(5):625-631.Li L, Chen D, Peng J X, et al. On the attractive effects of three artificial reef models for Sparus macrocephlus[J].Marine Fisheries, 2018, 40(5):625-631(in Chinese).
[6]杨进,李纯厚,贾晓平,等.大亚湾杨梅坑人工鱼礁区生态系统健康评价[J].生态科学, 2011, 30(4):399-405,410.Yang J, Li C H, Jia X P, et al. Ecosystem health assessment of artificial reef area in the Yangmei Delve of Daya Bay[J]. Ecological Science, 2011, 30(4):399-405, 410(in Chinese).
[7]吴忠鑫,张秀梅,张磊,等.基于Ecopath模型的荣成俚岛人工鱼礁区生态系统结构和功能评价[J].应用生态学报, 2012, 23(10):2878-2886.Wu Z X, Zhang X M, Zhang L, et al. Structure and function of Lidao artificial reef ecosystem in Rongcheng of Shandong Province, East China:an evaluation based on Ecopath model[J]. Chinese Journal of Applied Ecology, 2012, 23(10):2878-2886(in Chinese).
[8]尹增强,章守宇.东海区资源保护型人工鱼礁经济效果评价[J].资源科学, 2009, 31(12):2183-2191.Yin Z Q, Zhang S Y. A preliminary study on the economic impact evaluation of the protective artificial reef in the east China Sea on the basis of financial indices[J]. Resources Science, 2009, 31(12):2183-2191(in Chinese).
[9]欧荣昌.人工鱼礁工程行为与箱网锚碇装置之研究[D].高雄,中国:国立中山大学, 2002:149-154.Ou R C. Engineering behavior of artificial benthic habitats and analysis and design of anchoring devices for farming cages[D]. Gaoxiong, China:National Sun YatSen University, 2002:149-154(in Chinese).
[10]赖明贤.台湾西南海域人工鱼礁礁体工程行为分析[D].高雄,中国:国立中山大学, 2000:42-46.Lai M X. The engineering behavior of artificial reefs off southwestern coast of Taiwan[D]. Gaoxiong, China:National Sun Yat-Sen University, 2000:42-46(in Chinese).
[11]李欣雨.人工鱼礁在波浪作用下的流场效应及其局部冲刷数值模拟[D].天津:天津大学, 2016:42-48.Li X Y. Numerical simulation on wave-affected flow field and local scour of artificial reefs[D]. Tianjin:Tianjin University, 2016:42-48(in Chinese).
[12]王兆印,张新玉.水库粘性淤积物泄空冲刷的模型试验研究[J].泥沙研究, 1989(2):62-68.Wang Z Y, Zhang X Y. Model test study on venting of viscous sludge in reservoir[J]. Journal of Sediment Research, 1989(2):62-68(in Chinese).
[13]李文杰,杨胜发,李斌强,等.基于原型沙的三峡库区细颗粒泥沙冲淤模型试验研究[J].泥沙研究, 2016(3):17-23.Li W J, Yang S F, Li B Q, et al. Physical model study on fine sediment transport in the Three Gorges Reservoir based on prototype sand[J]. Journal of Sediment Research, 2016(3):17-23(in Chinese).
[14]汪求顺.近岸海床细泥沙输移及冲刷防护研究[D].大连:大连理工大学, 2015:83-87.Wang Q S. Study of fine sediment tranport and scour protection in coastal waters[D]. Dalian:Dalian University of Technology, 2015:83-87(in Chinese).
[15]Khosronejad A, Kang S, Sotiropoulos F. Experimental and computational investigation of local scour around bridge piers[J]. Advances in Water Resources, 2012, 37:73-85.
[16]Burkow M, Griebel M. A full three dimensional numerical simulation of the sediment transport and the scouring at a rectangular obstacle[J]. Computers&Fluids, 2016, 125:1-10.
[17]于春洁,吴非,王丽勤.水下生产设施基础冲刷模型试验与数值模拟分析[J].中国海上油气, 2017, 29(4):145-151.Yu C J, Wu F, Wang L Q. Test with a scour model and numerical simulation on the foundation of subsea production systems[J]. China Offshore Oil and Gas,2017, 29(4):145-151(in Chinese).
[18]窦国仁.全沙模型相似律及设计实例[J].水利水运科技情报, 1977(3):1-20.Dou G R. A similarity theory concerning the design of total sediment transport models with reference to a particular project[J]. Hydro-Science Information,1977(3):1-20(in Chinese).
[19]中华人民共和国交通运输部. JTS/T 231-2-2010海岸与河口潮流泥沙模拟技术规程[S].北京:人民交通出版社, 2010.Ministry of Transport of the People's Republic of China.JTS/T 231-2-2010 Technical regulation of modelling for tidal current and sediment on coast and estuary[S].Beijing:China Communications Press(in Chinese).
[20]刘青泉.床面附近泥沙运动的力学特性[J].应用基础与工程科学学报, 1997, 5(1):56-66.Liu Q Q. The mechanics properties of sediment movement in layers close to the bed[J]. Journal of Basic Science and Engineering, 1997, 5(1):56-66(in Chinese).
[21]孔令双,曹祖德,顾峰峰,等.淤泥质河床冲淤分析计算[J].浙江水利科技, 2014(5):52-56.Kong L S, Cao Z D, Gu F F, et al. Study on the erosion and deposition of the muddy sea bed[J]. Zhejiang Hydrotechnics, 2014(5):52-56(in Chinese).
[22]吴建,刘德飞,拾兵.可实现k-ε模型在人工鱼礁流场分析中的模拟研究[J].中国水运, 2013, 13(1):99-100.Wu J, Liu D F, Shi B. Simulation study of k-εmodel in artificial fish reef flow field analysis[J]. China Water Transport, 2013, 13(1):99-100(in Chinese).
[23]张丛丽,喻国良,谢锦波.单向流定床床面上水平管道周围流场与切应力分布特性[J].海洋科学, 2009,33(3):27-30.Zhang C L, Yu G L, Xie J B. The characteristics of the shear stress and flow field around a pipeline on fixed-bed with different gap-ratios in unidirectional flows[J].Marine Sciences, 2009, 33(3):27-30(in Chinese).
[24]孙宁松,孙永福,宋玉鹏.海洋平台桩基冲刷及影响因素分析[J].海岸工程, 2004, 23(4):38-44.Sun N S, Sun Y F, Song Y P. Scour around pile foundation of offshore platform and analysis of affecting factors[J]. Coastal Engineering, 2004, 23(4):38-44(in Chinese).
[25]崔勇,关长涛,万荣,等.布设间距对人工鱼礁流场效应影响的数值模拟[J].海洋湖沼通报, 2011, 11(2):59-65.Cui Y, Guan C T, Wan R, et al. Numerical simulation on influence of disposal space on effects of flow field around artificial reefs[J]. Transactions of Oceanology and Limnology, 2011, 11(2):59-65(in Chinese).
[26]赵静,王世澎,袁振宇,等.坐底式平台基础冲刷的模型试验研究[C]//第二十五届全国水动力学研讨会暨第十二届全国水动力学学术会议文集(上册).舟山:中国力学学会, 2013:547-554.Zhao J, Wang S P, Yuan Z Y, et al. Study on scour experiment of bottom-supported platform[C]//Proceedings of the 25th National Conference on Hydrodynamics&12th National Congress on Hydrodynamics. 2013:547-554(in Chinese).
[2]邵万骏,刘长根,聂红涛,等.人工鱼礁的水动力学特性及流场效应分析[J].水动力学研究与进展, 2014,29(5):580-585.Shao W J, Liu C G, Nie H T, et al. Analysis of hydrodynamic characteristics and flow field around artificial reefs[J]. Chinese Journal of Hydrodynamics,2014, 29(5):580-585(in Chinese).
[3]赵林,邓超,于振江,等.组合式金字塔型人工鱼礁水动力学分析[J].渔业现代化, 2018, 45(6):53-59.Zhao L, Deng C, Yu Z J, et al. Hydrodynamic analysis of combined pyramidal artificial reef[J]. Fishery Modernization, 2018, 45(6):53-59(in Chinese).
[4]张伟,李纯厚,贾晓平,等.大亚湾混凝土鱼礁和铁质鱼礁附着生物群落结构的季节变化[J].南方水产科学,2015, 11(1):9-17.Zhang W, Li C H, Jia X P, et al. Seasonal variation of biofouling communities on concrete and steel reefs in Daya Bay[J]. South China Fisheries Science, 2015,11(1):9-17(in Chinese).
[5]李磊,陈栋,彭建新,等. 3种人工鱼礁模型对黑棘鲷的诱集效果研究[J].海洋渔业, 2018, 40(5):625-631.Li L, Chen D, Peng J X, et al. On the attractive effects of three artificial reef models for Sparus macrocephlus[J].Marine Fisheries, 2018, 40(5):625-631(in Chinese).
[6]杨进,李纯厚,贾晓平,等.大亚湾杨梅坑人工鱼礁区生态系统健康评价[J].生态科学, 2011, 30(4):399-405,410.Yang J, Li C H, Jia X P, et al. Ecosystem health assessment of artificial reef area in the Yangmei Delve of Daya Bay[J]. Ecological Science, 2011, 30(4):399-405, 410(in Chinese).
[7]吴忠鑫,张秀梅,张磊,等.基于Ecopath模型的荣成俚岛人工鱼礁区生态系统结构和功能评价[J].应用生态学报, 2012, 23(10):2878-2886.Wu Z X, Zhang X M, Zhang L, et al. Structure and function of Lidao artificial reef ecosystem in Rongcheng of Shandong Province, East China:an evaluation based on Ecopath model[J]. Chinese Journal of Applied Ecology, 2012, 23(10):2878-2886(in Chinese).
[8]尹增强,章守宇.东海区资源保护型人工鱼礁经济效果评价[J].资源科学, 2009, 31(12):2183-2191.Yin Z Q, Zhang S Y. A preliminary study on the economic impact evaluation of the protective artificial reef in the east China Sea on the basis of financial indices[J]. Resources Science, 2009, 31(12):2183-2191(in Chinese).
[9]欧荣昌.人工鱼礁工程行为与箱网锚碇装置之研究[D].高雄,中国:国立中山大学, 2002:149-154.Ou R C. Engineering behavior of artificial benthic habitats and analysis and design of anchoring devices for farming cages[D]. Gaoxiong, China:National Sun YatSen University, 2002:149-154(in Chinese).
[10]赖明贤.台湾西南海域人工鱼礁礁体工程行为分析[D].高雄,中国:国立中山大学, 2000:42-46.Lai M X. The engineering behavior of artificial reefs off southwestern coast of Taiwan[D]. Gaoxiong, China:National Sun Yat-Sen University, 2000:42-46(in Chinese).
[11]李欣雨.人工鱼礁在波浪作用下的流场效应及其局部冲刷数值模拟[D].天津:天津大学, 2016:42-48.Li X Y. Numerical simulation on wave-affected flow field and local scour of artificial reefs[D]. Tianjin:Tianjin University, 2016:42-48(in Chinese).
[12]王兆印,张新玉.水库粘性淤积物泄空冲刷的模型试验研究[J].泥沙研究, 1989(2):62-68.Wang Z Y, Zhang X Y. Model test study on venting of viscous sludge in reservoir[J]. Journal of Sediment Research, 1989(2):62-68(in Chinese).
[13]李文杰,杨胜发,李斌强,等.基于原型沙的三峡库区细颗粒泥沙冲淤模型试验研究[J].泥沙研究, 2016(3):17-23.Li W J, Yang S F, Li B Q, et al. Physical model study on fine sediment transport in the Three Gorges Reservoir based on prototype sand[J]. Journal of Sediment Research, 2016(3):17-23(in Chinese).
[14]汪求顺.近岸海床细泥沙输移及冲刷防护研究[D].大连:大连理工大学, 2015:83-87.Wang Q S. Study of fine sediment tranport and scour protection in coastal waters[D]. Dalian:Dalian University of Technology, 2015:83-87(in Chinese).
[15]Khosronejad A, Kang S, Sotiropoulos F. Experimental and computational investigation of local scour around bridge piers[J]. Advances in Water Resources, 2012, 37:73-85.
[16]Burkow M, Griebel M. A full three dimensional numerical simulation of the sediment transport and the scouring at a rectangular obstacle[J]. Computers&Fluids, 2016, 125:1-10.
[17]于春洁,吴非,王丽勤.水下生产设施基础冲刷模型试验与数值模拟分析[J].中国海上油气, 2017, 29(4):145-151.Yu C J, Wu F, Wang L Q. Test with a scour model and numerical simulation on the foundation of subsea production systems[J]. China Offshore Oil and Gas,2017, 29(4):145-151(in Chinese).
[18]窦国仁.全沙模型相似律及设计实例[J].水利水运科技情报, 1977(3):1-20.Dou G R. A similarity theory concerning the design of total sediment transport models with reference to a particular project[J]. Hydro-Science Information,1977(3):1-20(in Chinese).
[19]中华人民共和国交通运输部. JTS/T 231-2-2010海岸与河口潮流泥沙模拟技术规程[S].北京:人民交通出版社, 2010.Ministry of Transport of the People's Republic of China.JTS/T 231-2-2010 Technical regulation of modelling for tidal current and sediment on coast and estuary[S].Beijing:China Communications Press(in Chinese).
[20]刘青泉.床面附近泥沙运动的力学特性[J].应用基础与工程科学学报, 1997, 5(1):56-66.Liu Q Q. The mechanics properties of sediment movement in layers close to the bed[J]. Journal of Basic Science and Engineering, 1997, 5(1):56-66(in Chinese).
[21]孔令双,曹祖德,顾峰峰,等.淤泥质河床冲淤分析计算[J].浙江水利科技, 2014(5):52-56.Kong L S, Cao Z D, Gu F F, et al. Study on the erosion and deposition of the muddy sea bed[J]. Zhejiang Hydrotechnics, 2014(5):52-56(in Chinese).
[22]吴建,刘德飞,拾兵.可实现k-ε模型在人工鱼礁流场分析中的模拟研究[J].中国水运, 2013, 13(1):99-100.Wu J, Liu D F, Shi B. Simulation study of k-εmodel in artificial fish reef flow field analysis[J]. China Water Transport, 2013, 13(1):99-100(in Chinese).
[23]张丛丽,喻国良,谢锦波.单向流定床床面上水平管道周围流场与切应力分布特性[J].海洋科学, 2009,33(3):27-30.Zhang C L, Yu G L, Xie J B. The characteristics of the shear stress and flow field around a pipeline on fixed-bed with different gap-ratios in unidirectional flows[J].Marine Sciences, 2009, 33(3):27-30(in Chinese).
[24]孙宁松,孙永福,宋玉鹏.海洋平台桩基冲刷及影响因素分析[J].海岸工程, 2004, 23(4):38-44.Sun N S, Sun Y F, Song Y P. Scour around pile foundation of offshore platform and analysis of affecting factors[J]. Coastal Engineering, 2004, 23(4):38-44(in Chinese).
[25]崔勇,关长涛,万荣,等.布设间距对人工鱼礁流场效应影响的数值模拟[J].海洋湖沼通报, 2011, 11(2):59-65.Cui Y, Guan C T, Wan R, et al. Numerical simulation on influence of disposal space on effects of flow field around artificial reefs[J]. Transactions of Oceanology and Limnology, 2011, 11(2):59-65(in Chinese).
[26]赵静,王世澎,袁振宇,等.坐底式平台基础冲刷的模型试验研究[C]//第二十五届全国水动力学研讨会暨第十二届全国水动力学学术会议文集(上册).舟山:中国力学学会, 2013:547-554.Zhao J, Wang S P, Yuan Z Y, et al. Study on scour experiment of bottom-supported platform[C]//Proceedings of the 25th National Conference on Hydrodynamics&12th National Congress on Hydrodynamics. 2013:547-554(in Chinese).