Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network mode...Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337.展开更多
On the basis of the two dimensional finite element analysis model, the pile foundations' mechanical effect of the rigid pile composite foundation under the dynamic load was researched. Through the research, the de...On the basis of the two dimensional finite element analysis model, the pile foundations' mechanical effect of the rigid pile composite foundation under the dynamic load was researched. Through the research, the development law and deformation property of axial force of pile body, shaft resistance of pile, and cumulative settlement of pile head under vertical cyclic dynamic loads were concluded. Through the comparison and analysis of the test results of dynamic models, the test results of Poulos(1989) and cumulative settlement model of the single pile under cyclic loads were confirmed. Based on the above research, Fortran language was adopted to introduce the soil attenuation factor, the secondary development of relevant modules of ABAQUS was carried out, and the effect of soil attenuation factor on dynamic property of pile-soil was discussed further.展开更多
针对自由表面流动与弹性结构的流固耦合计算效率低、计算耗时长的问题,将流体体积法与基于结构-虚拟弹性体的快速动网格方法相结合,发展了一种适用于自由表面流动的高效流固耦合方法。使用流体体积(volume of fluid,VOF)法对流体自由表...针对自由表面流动与弹性结构的流固耦合计算效率低、计算耗时长的问题,将流体体积法与基于结构-虚拟弹性体的快速动网格方法相结合,发展了一种适用于自由表面流动的高效流固耦合方法。使用流体体积(volume of fluid,VOF)法对流体自由表面进行追踪;将流体域视为虚拟弹性体并构建结构-虚拟弹性体系统,以流固耦合界面的多相流体力为激励求解系统的动力学方程得到结构振动位移和流场网格变形;在每一个时间步内依次求解流体流动、结构变形和流场动网格,实现流固耦合计算。基于发展的方法计算了溃坝水流冲击下弹性挡板的流固耦合响应,得到了溃坝水流的自由液面和弹性挡板的运动行为,结果表明:自由液面演变和弹性挡板振动位移的计算结果与已有算法的结果吻合良好;在同等网格规模下,与已有算法相比本文方法可减少33.3%的计算时间;在水流冲击作用下,弹性挡板向冲击侧小幅弯曲。随后水流沿挡板左侧上升并形成射流,挡板向另一侧大幅弯曲。最后由于两侧流体的阻尼,挡板振幅逐渐衰减。展开更多
基金Project(51321065)supported by the Innovative Research Groups of the National Natural Science Foundation of ChinaProject(2013CB035904)supported by the National Basic Research Program of China(973 Program)Project(51439005)supported by the National Natural Science Foundation of China
文摘Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337.
基金Projects(51478178,51508181) supported by the National Natural Science Foundation of China
文摘On the basis of the two dimensional finite element analysis model, the pile foundations' mechanical effect of the rigid pile composite foundation under the dynamic load was researched. Through the research, the development law and deformation property of axial force of pile body, shaft resistance of pile, and cumulative settlement of pile head under vertical cyclic dynamic loads were concluded. Through the comparison and analysis of the test results of dynamic models, the test results of Poulos(1989) and cumulative settlement model of the single pile under cyclic loads were confirmed. Based on the above research, Fortran language was adopted to introduce the soil attenuation factor, the secondary development of relevant modules of ABAQUS was carried out, and the effect of soil attenuation factor on dynamic property of pile-soil was discussed further.
文摘针对自由表面流动与弹性结构的流固耦合计算效率低、计算耗时长的问题,将流体体积法与基于结构-虚拟弹性体的快速动网格方法相结合,发展了一种适用于自由表面流动的高效流固耦合方法。使用流体体积(volume of fluid,VOF)法对流体自由表面进行追踪;将流体域视为虚拟弹性体并构建结构-虚拟弹性体系统,以流固耦合界面的多相流体力为激励求解系统的动力学方程得到结构振动位移和流场网格变形;在每一个时间步内依次求解流体流动、结构变形和流场动网格,实现流固耦合计算。基于发展的方法计算了溃坝水流冲击下弹性挡板的流固耦合响应,得到了溃坝水流的自由液面和弹性挡板的运动行为,结果表明:自由液面演变和弹性挡板振动位移的计算结果与已有算法的结果吻合良好;在同等网格规模下,与已有算法相比本文方法可减少33.3%的计算时间;在水流冲击作用下,弹性挡板向冲击侧小幅弯曲。随后水流沿挡板左侧上升并形成射流,挡板向另一侧大幅弯曲。最后由于两侧流体的阻尼,挡板振幅逐渐衰减。
基金国家自然科学基金项目(No.51469005)广西自然科学基金项目(No.2015GXNSFAA139257+6 种基金No.2015GXNSFAA139270No.2017GXNSFAA198170)广西科技大学研究生教育创新计划项目(No.GKYC201627)supported by the National Natural Science Foundation of China(51469005)the Natural Science Foundation of Guangxi Province of China(2015GXNSFAA1392572015GXNSFAA1392702017GXNSFAA198170)the Graduate Student Education Innovation Projects of GXUST(GKYC201627)