钢筋混凝土顶管穿堤施工三维数值分析
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摘要
钢筋混凝土顶管施工技术广泛应用于排水管道、电力管道等城市基础设施建设,当其需要长距离穿越江河底部时,会面临上覆土层厚度变化显著、江底水头压力大和江边环境影响敏感等问题。本文结合上海白龙港南线输送干线大直径顶管穿越黄浦江段工程,建立了综合考虑上覆土层变化及江底水头压力的数值模型。采用模拟顶管机头迎面压力和管土摩擦作用的方法进行分析评估,研究了顶管端面压力、减阻泥浆模量、管土摩阻力及减阻效果等参数对地层土体变形与施工状况的影响,探讨了下穿江堤对堤坝桩基变形的影响。结果表明,由于上覆土厚度变化及水压力作用,顶管端面压力应小于机头中心土体自重应力;提高泥浆模量,降低摩擦系数,可减小顶管上方土体和结构的沉降。
The reinforced concrete pipe jacking technology is widely used in the construction of urban infrastructure such as drainage pipes and power pipes. It would face several problems such as significant changes in the thickness of the overburden layer, high water pressure at the bottom of the river and the sensitive environmental impact of the riverside during long distance jacking at the bottom of river. Combined with the large-diameter pipe jacking of the main line of the Shanghai Bailonggang South Line crossing the Huangpu River section, a numerical model which comprehensively consider the overburden changes and the pressure at the bottom of the river was established. The effects of parameters such as excavation face support pressure, drag reduction mud modulus, pipe friction and drag reduction on the soil deformation and construction conditions of the stratum,were studied and the influence of the lower river embankment on the deformation of the dam foundation were discussed with the method of simulating the head pressure and pipe friction of the pipe jacking head. The research showed that due to the thickness variation of the overlying soil and the water pressure, the supporting pressure of the excavation face should be less than the self-weight stress of the excavated body at the center of the head and the settlement of the soil and structure above the top pipe could be reduced by increasing the mud modulus and reducing the friction coefficient.
The reinforced concrete pipe jacking technology is widely used in the construction of urban infrastructure such as drainage pipes and power pipes. It would face several problems such as significant changes in the thickness of the overburden layer, high water pressure at the bottom of the river and the sensitive environmental impact of the riverside during long distance jacking at the bottom of river. Combined with the large-diameter pipe jacking of the main line of the Shanghai Bailonggang South Line crossing the Huangpu River section, a numerical model which comprehensively consider the overburden changes and the pressure at the bottom of the river was established. The effects of parameters such as excavation face support pressure, drag reduction mud modulus, pipe friction and drag reduction on the soil deformation and construction conditions of the stratum,were studied and the influence of the lower river embankment on the deformation of the dam foundation were discussed with the method of simulating the head pressure and pipe friction of the pipe jacking head. The research showed that due to the thickness variation of the overlying soil and the water pressure, the supporting pressure of the excavation face should be less than the self-weight stress of the excavated body at the center of the head and the settlement of the soil and structure above the top pipe could be reduced by increasing the mud modulus and reducing the friction coefficient.
引文
[1] Peck R B. Deep excavations and tunneling in softground[C]//Proceeding of 7th International Conferenceon Soil Mechanics and Foundation Engineering. Mexico City:State of the Art Report,1969:225-290
[2] Attewell P B, Woodman J P. Predicting the dynamics of ground settlement and its derivatives caused by tunnelingin soil[J].Ground Engineering, 1982, 15(8):13-20
[3] Sagaseta C. Analysis of undrained soil deformation due to ground loss[J]. Geotechnique, 1987, 37(3):301-320
[4] Loganathan N, Poulos HG. Analytical prediction for tunneling-induced ground movement in clays[J]. Journal of Geotechnical und Geoenvironmental Engineering, 1998, 124(9):846-856
[5]黄宏伟,胡昕.顶管施工力学效应的数值模拟分析[J].岩石力学与工程学报,2003, 22(3):400-406Huang Hongwei, Hu Xin. 3D numerical analysis on construction mechanics effect of pipe-jacking[J]. Chinese Journal of RockMechanics and Engineering, 2003, 22(3):400-406
[6]闫治国,朱合华,李向阳,等.顶管同步顶进工作井稳定性三维数值分析[J].岩土工程学报,2005, 27(8):891-896Yan Zhiguo, Zhu Hehua, Li Xiangyang, et al. 3D-FEM analysis on stability of shaft with conduit jacked synchronously in two directions[J]. Chinese Journal of Geotechnical Engineering,2005,27(8):891-896
[7]冯海宁,龚晓南,徐日庆.顶管施工环境影响的有限元计算分析[J].岩土力学与工程学报,2004, 23(7):1158-1162Feng Haining, Gong Xiaonan, Xu Riqing. Finite element analysis of influence of pipe-jacking construction on environments[J].Chinese Journal of Rock Mechanics and Engineering, 2004, 23(7):1158-1162
[8]陈展,刘飞,魏畅毅.顶管施工对地铁轨道变形影响的数值分析[J].北京建筑大学学报,2015, 31(4):13-23Chen Chen, Liu Fei, Wei Changyi. Numerical Analysis of Pipe Jacking Construction Impact on the Subway Rails[J]. Journal of Beijing University of Civil Engineering and Architecture, 2015,31(4):13-23
[9]刘波,章定文,刘松玉,等.大断面顶管通道近接穿越下覆既有地铁隧道数值模拟与现场试验[J].岩石力学与工程学报,2017, 36(11):2850-2860Liu Bo, Zhang Dingwen, Liu Songyu, et al. Numerical simulation and field monitoring on a large cross-section pipe-jacking underpass traversing existing metro tunnels[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(11):2850-2860
[10]岳兵,郑全兴,曾天兵.长距离大口径钢管斜顶管施工的难点及解决措施[J].中国给水排水,2012, 28(22):143-146Yue Bing, Zheng Quanxing, Zeng Tianbing. Problems and Solutions for Inclined Jacking Construction of Long-distance Large-diameter Steel Pipes[J]. China Water&Wastewater, 2012, 28(22):143-146
[11]王晏.丹阳市长江黄岗取水口江中延伸工程设计要点[J].中国给水排水,2012, 28(4):46-48Wang Yan. Design Key Points of River Extension Project for Huanggung Water Intake at Danyang Section of Yangtze River[J]. China Water&Wastewater, 2012, 28(4):46-48
[12]颜建平.大直径越江顶管管道抬升的施工模拟及分析[J].特种结构,2017, 34(5):13-16Yan Jianping. Numerical Simulation and Analysis of Large Pipe Uplifting in Jacking[J]. Special Structures, 2017, 34(5):13-16
[2] Attewell P B, Woodman J P. Predicting the dynamics of ground settlement and its derivatives caused by tunnelingin soil[J].Ground Engineering, 1982, 15(8):13-20
[3] Sagaseta C. Analysis of undrained soil deformation due to ground loss[J]. Geotechnique, 1987, 37(3):301-320
[4] Loganathan N, Poulos HG. Analytical prediction for tunneling-induced ground movement in clays[J]. Journal of Geotechnical und Geoenvironmental Engineering, 1998, 124(9):846-856
[5]黄宏伟,胡昕.顶管施工力学效应的数值模拟分析[J].岩石力学与工程学报,2003, 22(3):400-406Huang Hongwei, Hu Xin. 3D numerical analysis on construction mechanics effect of pipe-jacking[J]. Chinese Journal of RockMechanics and Engineering, 2003, 22(3):400-406
[6]闫治国,朱合华,李向阳,等.顶管同步顶进工作井稳定性三维数值分析[J].岩土工程学报,2005, 27(8):891-896Yan Zhiguo, Zhu Hehua, Li Xiangyang, et al. 3D-FEM analysis on stability of shaft with conduit jacked synchronously in two directions[J]. Chinese Journal of Geotechnical Engineering,2005,27(8):891-896
[7]冯海宁,龚晓南,徐日庆.顶管施工环境影响的有限元计算分析[J].岩土力学与工程学报,2004, 23(7):1158-1162Feng Haining, Gong Xiaonan, Xu Riqing. Finite element analysis of influence of pipe-jacking construction on environments[J].Chinese Journal of Rock Mechanics and Engineering, 2004, 23(7):1158-1162
[8]陈展,刘飞,魏畅毅.顶管施工对地铁轨道变形影响的数值分析[J].北京建筑大学学报,2015, 31(4):13-23Chen Chen, Liu Fei, Wei Changyi. Numerical Analysis of Pipe Jacking Construction Impact on the Subway Rails[J]. Journal of Beijing University of Civil Engineering and Architecture, 2015,31(4):13-23
[9]刘波,章定文,刘松玉,等.大断面顶管通道近接穿越下覆既有地铁隧道数值模拟与现场试验[J].岩石力学与工程学报,2017, 36(11):2850-2860Liu Bo, Zhang Dingwen, Liu Songyu, et al. Numerical simulation and field monitoring on a large cross-section pipe-jacking underpass traversing existing metro tunnels[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(11):2850-2860
[10]岳兵,郑全兴,曾天兵.长距离大口径钢管斜顶管施工的难点及解决措施[J].中国给水排水,2012, 28(22):143-146Yue Bing, Zheng Quanxing, Zeng Tianbing. Problems and Solutions for Inclined Jacking Construction of Long-distance Large-diameter Steel Pipes[J]. China Water&Wastewater, 2012, 28(22):143-146
[11]王晏.丹阳市长江黄岗取水口江中延伸工程设计要点[J].中国给水排水,2012, 28(4):46-48Wang Yan. Design Key Points of River Extension Project for Huanggung Water Intake at Danyang Section of Yangtze River[J]. China Water&Wastewater, 2012, 28(4):46-48
[12]颜建平.大直径越江顶管管道抬升的施工模拟及分析[J].特种结构,2017, 34(5):13-16Yan Jianping. Numerical Simulation and Analysis of Large Pipe Uplifting in Jacking[J]. Special Structures, 2017, 34(5):13-16