The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plas...The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and considerable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the "barrier" and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.展开更多
For the Guanshui Road Station tunnel project of Guiyang Metro Line 2,the wind pavilion group was moved out of the main tunnel to reduce the number of openings in the main tunnel,and the wind pavilion group was excavat...For the Guanshui Road Station tunnel project of Guiyang Metro Line 2,the wind pavilion group was moved out of the main tunnel to reduce the number of openings in the main tunnel,and the wind pavilion group was excavated in a triangular configuration at the entrance of the main tunnel.Based on the finite element software ABAQUS,a three-dimensional model is established to study the influence of different triangular-distribution tunnels excavation schemes on the surface settlement and tunnel stability.The objective of this study is to reveal the change rules of surface settlement,deformation and force in the support structures and the surrounding rock and identify the best excavation scheme for this tunnel configuration.Results show that to control the surface settlement and the deformation of the support structures,the optimal excavation sequence involves excavating the upper fresh air exhaust tunnel before the lower running tunnel.To control the stress of the support structures,the optimal excavation involves excavating the lower running tunnel before the upper fresh air exhaust tunnel.In this project,the most reasonable excavation sequence of the tunnel is from top to bottom.The most reasonable thickness of tunnel penetration is 5 m.展开更多
路面病害自动化检测是实现道路智慧化管养的关键技术之一,针对路面病害图像中病害目标占比小、不同类型病害尺度差异大、背景环境复杂等特性,基于YOLOv8架构,提出聚焦形状特征的路面病害检测算法FSF-YOLO(focusing on shape features YO...路面病害自动化检测是实现道路智慧化管养的关键技术之一,针对路面病害图像中病害目标占比小、不同类型病害尺度差异大、背景环境复杂等特性,基于YOLOv8架构,提出聚焦形状特征的路面病害检测算法FSF-YOLO(focusing on shape features YOLO)。构建一种无信息丢失的加强特征提取模块,通过保留多维度空间特征信息,增强骨干网络对低分辨率图像和细小病害目标的特征提取能力;引入可形变注意力特征融合模块,利用病害细长形状特征拓展目标识别区域,提高模型对于长距离病害目标的特征表达能力;运用分组卷积空间金字塔池化模块,强化不同尺寸病害目标特征识别;采用轻量级共享卷积检测头,减少网络参数量和计算量。实验结果表明,提出的方法对不同类别的路面病害目标均获得了较好的效果,在RDD2022数据集上的平均精度达到67.3%,与原算法相比提升了5.3个百分点,整体性能优于其他路面病害检测算法。展开更多
基金Project(50378036) supported by the National Natural Science Foundation of China
文摘The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and considerable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the "barrier" and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.
基金Projects(B200204032,2019B07914)supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(51878667,51678571,51808193)supported by the National Natural Science Foundation of China。
文摘For the Guanshui Road Station tunnel project of Guiyang Metro Line 2,the wind pavilion group was moved out of the main tunnel to reduce the number of openings in the main tunnel,and the wind pavilion group was excavated in a triangular configuration at the entrance of the main tunnel.Based on the finite element software ABAQUS,a three-dimensional model is established to study the influence of different triangular-distribution tunnels excavation schemes on the surface settlement and tunnel stability.The objective of this study is to reveal the change rules of surface settlement,deformation and force in the support structures and the surrounding rock and identify the best excavation scheme for this tunnel configuration.Results show that to control the surface settlement and the deformation of the support structures,the optimal excavation sequence involves excavating the upper fresh air exhaust tunnel before the lower running tunnel.To control the stress of the support structures,the optimal excavation involves excavating the lower running tunnel before the upper fresh air exhaust tunnel.In this project,the most reasonable excavation sequence of the tunnel is from top to bottom.The most reasonable thickness of tunnel penetration is 5 m.
文摘路面病害自动化检测是实现道路智慧化管养的关键技术之一,针对路面病害图像中病害目标占比小、不同类型病害尺度差异大、背景环境复杂等特性,基于YOLOv8架构,提出聚焦形状特征的路面病害检测算法FSF-YOLO(focusing on shape features YOLO)。构建一种无信息丢失的加强特征提取模块,通过保留多维度空间特征信息,增强骨干网络对低分辨率图像和细小病害目标的特征提取能力;引入可形变注意力特征融合模块,利用病害细长形状特征拓展目标识别区域,提高模型对于长距离病害目标的特征表达能力;运用分组卷积空间金字塔池化模块,强化不同尺寸病害目标特征识别;采用轻量级共享卷积检测头,减少网络参数量和计算量。实验结果表明,提出的方法对不同类别的路面病害目标均获得了较好的效果,在RDD2022数据集上的平均精度达到67.3%,与原算法相比提升了5.3个百分点,整体性能优于其他路面病害检测算法。
