基于ALE、CEL法的管土垂向相互作用数值模拟对比分析
|
摘要
深海管道在自身重量、水压以及铺设的作用下会嵌入到海床的一定深度处,其中管土垂向相互作用会对管道在海底的在位稳性造成影响,选择合适的数值计算方法来处理地基土壤网格有重要意义.文中基于Lagrangian、ALE、CEL法开展了管土相互作用的数值模拟对比分析,得到管道下沉位移—抗力载荷关系曲线,与现有理论研究成果进行了对比.研究了网格尺寸大小、管道贯入速度及管道与土壤接触表面的不同粗糙度等因素对管土相互作用模拟方法的影响,通过ALE、CEL法对无量纲化参数E_u/S_u、土壤容重γ′进行了参数敏感性分析.分析结果表明:ALE、CEL法均较Lagrangian法具有更高的准确性.其中ALE法更适合接触面粗糙的情况,CEL法更适合接触面光滑的情况,并且判断出网格尺寸敏感性和贯入速度影响程度的临界点通常出现在10%～20%管径深处;当E_u/S_u的取值在400～1 000,参数对荷载位移关系几乎没有影响;当管道的贯入深度为10%管径,是判断土壤容重参数敏感性的临界位移.
Deep sea pipelines will be embedded into the seabed under the effect of self-gravity, water pressure and laying. In this case, the vertical pipe-soil interaction would have an influence on the stability of the pipeline at the bottom of the sea. It is important to choose a proper numerical method for the simulation. Three different grid algorithms of soil are implemented to investigate the vertical pipe-soil interaction in numerical simulation. The relationship of load and displacement in the process of pipeline sinking can be obtained and compared with the existing theoretical solution. In order to simulate the interaction between the pipe and soil more accurately, the effects of the soil's grid size, pipeline penetration rate and the roughness of the contact surface between pipe and soil on the simulation results of ALE and CEL are studied in details. Then, the parameter sensitivity analysis was carried out for E_u/S_u and soil bulk density by using ALE method and CEL method. The results show that the methods of ALE and CEL have higher accuracy than Lagrangian method. The ALE method is more suitable for the rough contact surface, and the CEL method is more suitable for the smooth contact surface. Moreover, the critical points of grid size sensitivity and penetration rate influence are usually located at 0.1～0.2 times of the pipe′s diameter. When the value of E_u/S_u is in the range between 400 and 1000, the parameters have little effect on the load-displacement relationship. The critical displacement to judge the sensitivity of the soil bulk density parameter is that the penetration depth of the pipe is 0.1 times the pipe diameter.
Deep sea pipelines will be embedded into the seabed under the effect of self-gravity, water pressure and laying. In this case, the vertical pipe-soil interaction would have an influence on the stability of the pipeline at the bottom of the sea. It is important to choose a proper numerical method for the simulation. Three different grid algorithms of soil are implemented to investigate the vertical pipe-soil interaction in numerical simulation. The relationship of load and displacement in the process of pipeline sinking can be obtained and compared with the existing theoretical solution. In order to simulate the interaction between the pipe and soil more accurately, the effects of the soil's grid size, pipeline penetration rate and the roughness of the contact surface between pipe and soil on the simulation results of ALE and CEL are studied in details. Then, the parameter sensitivity analysis was carried out for E_u/S_u and soil bulk density by using ALE method and CEL method. The results show that the methods of ALE and CEL have higher accuracy than Lagrangian method. The ALE method is more suitable for the rough contact surface, and the CEL method is more suitable for the smooth contact surface. Moreover, the critical points of grid size sensitivity and penetration rate influence are usually located at 0.1～0.2 times of the pipe′s diameter. When the value of E_u/S_u is in the range between 400 and 1000, the parameters have little effect on the load-displacement relationship. The critical displacement to judge the sensitivity of the soil bulk density parameter is that the penetration depth of the pipe is 0.1 times the pipe diameter.
引文
[1]郭绍曾.海底管线自沉与土体水平向抗力研究[D].天津:天津大学,2012.
[2]白玉川,杨细根,冀自青,等.波浪条件下海底管线与沙质海床间的相互作用[J].天津大学学报,2011,44(1):64-68.DOI:10.3969/j.issn.0493-2137.2011.01.012BAI Yuchuan,YANG Xigen,JI Ziqing,et al.Interaction between submarine pipelines and sand seabed under the effect of wave[J].Journal of Tianjin University,2011,44(1):64-68.DOI:10.3969/j.issn.0493-2137.2011.01.012..(in Chinese)
[3]施若苇.海底管道热屈曲及管土相互作用研究[D].杭州:浙江大学,2014.
[4]CHATTERJEE S,RANDOLPH M F,WHITE D J.The effects of penetration rate and strain softening on the vertical penetration resistance of seabed pipelines[J].Geotechnique,2012,62(7):573-582.DOI:10.1680/geot.10.P.075.
[5]WANG D,WHITE,D J,RANDOLPH M F.Large deformation finite element analysis of pipe penetration and large-amplitude lateral displacement[J].Canadian Geotechnical Journal,2010,47(8):842-856.DOI:10.1139/T09-147.
[6]HOSSAIN M K,EITAHER A,JUKES P,et al.The simulation of pipe soil interaction using coupled Eulerian Lagrangian(CEL)method[C]∥In Proceedings of the 4th International Offshore Pipeline Forum(IOPF).Houston,Texas,USA:[s.n.],2009.
[7]SHI H,SUN J,HOSSAIN K,et al.Offshore pipeline embedment in cohesive soil:a comparison between existing and cel solutions[C]∥In ASME 2011 30th International Conference on Ocean,Offshore and Arctic Engineering.Rotterdam,The Netherlands:[s.n.],2011.DOI:10.1115/OMAE2011-50230.
[8]THO K K,LEUNG C F,CHOW Y K,et al.Deep cavity flow mechanism of pipe penetration in clay[J].Canadian Geotechnical Journal,2011,49(1):59-69.DOI:10.1139/t11-088.
[9]姚震球,高慧,杨春蕾.基于滑移网格的带螺旋桨艇体尾流场数值分析方法[J].江苏科技大学学报(自然科学版),2008,22(2):15-20.DOI:10.3969/j.issn.1673-4807.2008.02.004.YAO Zhenqiu,GAO Hui,YANG Chunlei.Numerical simulation of internation between submarine and propeller based on approach of sliding mesh[J].Journal of Jiangsu University of Science and Technology(Natural Science Edition),2008,22(2):15-20.DOI:10.3969/j.issn.1673-4807.2008.02.004.(in Chinese)
[10]MURFF J D,WAGNER D A,RANDOLPH M F.Pipe penetration in cohesive soil[J].Geotechnique,1989,39(2):213-229.DOI:10.1680/geot.1989.39.2.213.
[11]AUBENY C P,SHI H,MURFF J D.Collapse loads for a cylinder embedded in trench in cohesive soil[J].International Journal of Geomechanics,2005,5(4):320-325.DOI:10.1061/(ASCE)1532-3641(2005)5:4(320).
[12]李广信.高等土力学[M].北京:清华大学出版社,2004.
[13]DAVIS E H,BOOKER J R.The effect of increasing strength with depth on the bearing capacity of clays[J].Geotechnique,1973,23(4):551-563.DOI:10.1680/geot.1973.23.4.551.
[14]刘永刚.砂土中提高筒型基础承载力的应用研究[D].天津:天津大学,2010.
[15]费康,彭劼.ABAQUS在岩土工程中的应用[M].北京:人民邮电出版社,2017.
[16]MERIFIELD R,WHITE D J,RANDOLPH M F.The ultimate undrained resistance of partially embedded pipelines[J].Geotechnique,2008,58(6):461-470.DOI:10.1680/geot.2007.00097.
[17]MERIFIELD R S,WHITE D J,RANDOLPH M F.Effect of surface heave on response of partially embedded pipelines on clay[J].Journal of Geotechnical&Geoenvironmental Engineering,2009,135(6):819-829.DOI:10.1061/(ASCE)GT.1943-5606.0000070.
[18]卿启湘,杨会,刘杰,等.基于CEL法的EPB切刀切削土体仿真分析[J].工程设计学报,2015(3):230-235.DOI:10.3785/j.issn.1006-754X.2015.03.005.QING Qixiang,YANG Hui,LIU Jie,et al.Simulation analysis on cutting soil for cutter of EPB based on CELmethod[J].Journal of Engineering Design,2015(3):230-235.DOI:10.3785/j.issn.1006-754X.2015.03.005.(in Chinese)
[19]LANGFORD T E,AUBENY C P.Large scale soil-riser model testing on high plasticity clay[C]∥The Eighteenth International Offshore and Polar Engineering Conference.Vancouver,Canada:[s.n.],2008.
[2]白玉川,杨细根,冀自青,等.波浪条件下海底管线与沙质海床间的相互作用[J].天津大学学报,2011,44(1):64-68.DOI:10.3969/j.issn.0493-2137.2011.01.012BAI Yuchuan,YANG Xigen,JI Ziqing,et al.Interaction between submarine pipelines and sand seabed under the effect of wave[J].Journal of Tianjin University,2011,44(1):64-68.DOI:10.3969/j.issn.0493-2137.2011.01.012..(in Chinese)
[3]施若苇.海底管道热屈曲及管土相互作用研究[D].杭州:浙江大学,2014.
[4]CHATTERJEE S,RANDOLPH M F,WHITE D J.The effects of penetration rate and strain softening on the vertical penetration resistance of seabed pipelines[J].Geotechnique,2012,62(7):573-582.DOI:10.1680/geot.10.P.075.
[5]WANG D,WHITE,D J,RANDOLPH M F.Large deformation finite element analysis of pipe penetration and large-amplitude lateral displacement[J].Canadian Geotechnical Journal,2010,47(8):842-856.DOI:10.1139/T09-147.
[6]HOSSAIN M K,EITAHER A,JUKES P,et al.The simulation of pipe soil interaction using coupled Eulerian Lagrangian(CEL)method[C]∥In Proceedings of the 4th International Offshore Pipeline Forum(IOPF).Houston,Texas,USA:[s.n.],2009.
[7]SHI H,SUN J,HOSSAIN K,et al.Offshore pipeline embedment in cohesive soil:a comparison between existing and cel solutions[C]∥In ASME 2011 30th International Conference on Ocean,Offshore and Arctic Engineering.Rotterdam,The Netherlands:[s.n.],2011.DOI:10.1115/OMAE2011-50230.
[8]THO K K,LEUNG C F,CHOW Y K,et al.Deep cavity flow mechanism of pipe penetration in clay[J].Canadian Geotechnical Journal,2011,49(1):59-69.DOI:10.1139/t11-088.
[9]姚震球,高慧,杨春蕾.基于滑移网格的带螺旋桨艇体尾流场数值分析方法[J].江苏科技大学学报(自然科学版),2008,22(2):15-20.DOI:10.3969/j.issn.1673-4807.2008.02.004.YAO Zhenqiu,GAO Hui,YANG Chunlei.Numerical simulation of internation between submarine and propeller based on approach of sliding mesh[J].Journal of Jiangsu University of Science and Technology(Natural Science Edition),2008,22(2):15-20.DOI:10.3969/j.issn.1673-4807.2008.02.004.(in Chinese)
[10]MURFF J D,WAGNER D A,RANDOLPH M F.Pipe penetration in cohesive soil[J].Geotechnique,1989,39(2):213-229.DOI:10.1680/geot.1989.39.2.213.
[11]AUBENY C P,SHI H,MURFF J D.Collapse loads for a cylinder embedded in trench in cohesive soil[J].International Journal of Geomechanics,2005,5(4):320-325.DOI:10.1061/(ASCE)1532-3641(2005)5:4(320).
[12]李广信.高等土力学[M].北京:清华大学出版社,2004.
[13]DAVIS E H,BOOKER J R.The effect of increasing strength with depth on the bearing capacity of clays[J].Geotechnique,1973,23(4):551-563.DOI:10.1680/geot.1973.23.4.551.
[14]刘永刚.砂土中提高筒型基础承载力的应用研究[D].天津:天津大学,2010.
[15]费康,彭劼.ABAQUS在岩土工程中的应用[M].北京:人民邮电出版社,2017.
[16]MERIFIELD R,WHITE D J,RANDOLPH M F.The ultimate undrained resistance of partially embedded pipelines[J].Geotechnique,2008,58(6):461-470.DOI:10.1680/geot.2007.00097.
[17]MERIFIELD R S,WHITE D J,RANDOLPH M F.Effect of surface heave on response of partially embedded pipelines on clay[J].Journal of Geotechnical&Geoenvironmental Engineering,2009,135(6):819-829.DOI:10.1061/(ASCE)GT.1943-5606.0000070.
[18]卿启湘,杨会,刘杰,等.基于CEL法的EPB切刀切削土体仿真分析[J].工程设计学报,2015(3):230-235.DOI:10.3785/j.issn.1006-754X.2015.03.005.QING Qixiang,YANG Hui,LIU Jie,et al.Simulation analysis on cutting soil for cutter of EPB based on CELmethod[J].Journal of Engineering Design,2015(3):230-235.DOI:10.3785/j.issn.1006-754X.2015.03.005.(in Chinese)
[19]LANGFORD T E,AUBENY C P.Large scale soil-riser model testing on high plasticity clay[C]∥The Eighteenth International Offshore and Polar Engineering Conference.Vancouver,Canada:[s.n.],2008.