As a novel type of foundation in beach and shallow sea, the bucket structure is especially suitable for complex conditions such as soft clay ground and the worse types of sea environments. In this paper, the bearing c...As a novel type of foundation in beach and shallow sea, the bucket structure is especially suitable for complex conditions such as soft clay ground and the worse types of sea environments. In this paper, the bearing capacity of a multi-bucket structure is studied by experiments with a single bucket and four-bucket foundation in a saturated sand layer. Based on the experimental data and numerical analysis results, the bearing capacity behavior and the bucket group effect are compared and analyzed. Furthermore, some influential factors, such as the soil type, the ratio of length to diameter L/D, the ratio of the bucket spacing to the bucket diameter S/D, and the bucket number are introduced and their effects on the multi-bucket structural capacity are investigated. The vertical static capacity adjustment factor is introduced to evaluate the bucket group effects of the multi-bucket foundation.展开更多
Glacier-lake outburst debris flow(GLODF),unique in high altitude mountains where modern glacier is active,is significantly large in its scale of time and space,and strong in power of destroy.Following the world's ...Glacier-lake outburst debris flow(GLODF),unique in high altitude mountains where modern glacier is active,is significantly large in its scale of time and space,and strong in power of destroy.Following the world's becoming warmer,GLODF frequency gradually rises.In late years,quantitative estimation methodologies has been put into use of mass GLODF estimations.To improve former methodologies,this article suggests that the glacier(or the massif)on the trailing edge and the moraine dam are the two major systems providing independent glacier lake outburst possibilities.Bucket Effect exists in GLODF issues.Therefore focusing on the relatively unstable one of the above two provides better accuracy in estimation on GLODF possibility.Thus,this article summarizes method of presort through specific GLODF evaluation.展开更多
针对锚线斜拉作用下吸力筒与砂土相互作用的微观特征仍不清楚这一问题,采用离散元(discrete element method,简称DEM)-有限元(finite element method,简称FEM)耦合数值方法,从宏观到微观角度分析系泊点深度对吸力筒基础抗拔性能的影响...针对锚线斜拉作用下吸力筒与砂土相互作用的微观特征仍不清楚这一问题,采用离散元(discrete element method,简称DEM)-有限元(finite element method,简称FEM)耦合数值方法,从宏观到微观角度分析系泊点深度对吸力筒基础抗拔性能的影响。在建模中,采用FEM中有限元网格来模拟吸力筒,采用DEM中颗粒来模拟吸力筒周围砂土,并通过控制滚轴运动来模拟锚线的拉作用。结果表明:吸力筒的拉力-位移曲线存在峰值拉力,且与不同系泊点深度下吸力筒运动模式有密切关系;吸力筒旋转方向、拔出位移的反转临界系泊深度点位于吸力筒从顶部往下h=66.7%深度附近(即吸力筒深度的2/3处,h为系泊深度)。此外,从颗粒尺度分析了土体变形及破坏行为,最终确定了吸力筒-颗粒土相互作用的破坏模式。研究结果表明,忽略锚线的系泊点深度将会导致误判吸力筒的承载能力及与土体的破坏模式。展开更多
The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance ...The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance the attraction of agricultural regions and establish more effective connections between rural and urban areas by properly developing eco-agricultural sightseeing and organizing satellite sustainable agricultural villages into an urban peripheral network.Dajidian Sustainable Agricultural Village in Baoding City,Hebei Province was taken for an example to elaborate the overall design concepts,and analyze the strategies for planning the village as an integrated system,including social,ecological and economic dimensions,which are specifically demonstrated as:the development of sustainable agriculture,the establishment of diversified circulation system,the independence of energy utilization,the soundness of public service system,the improvement of agricultural villages as communities.Through studying the planning of sustainable agricultural villages,this research aimed at realizing the sustainable development of overall environment system in both cities and rural areas,and guiding the improvement of the new countryside construction.展开更多
文摘As a novel type of foundation in beach and shallow sea, the bucket structure is especially suitable for complex conditions such as soft clay ground and the worse types of sea environments. In this paper, the bearing capacity of a multi-bucket structure is studied by experiments with a single bucket and four-bucket foundation in a saturated sand layer. Based on the experimental data and numerical analysis results, the bearing capacity behavior and the bucket group effect are compared and analyzed. Furthermore, some influential factors, such as the soil type, the ratio of length to diameter L/D, the ratio of the bucket spacing to the bucket diameter S/D, and the bucket number are introduced and their effects on the multi-bucket structural capacity are investigated. The vertical static capacity adjustment factor is introduced to evaluate the bucket group effects of the multi-bucket foundation.
文摘Glacier-lake outburst debris flow(GLODF),unique in high altitude mountains where modern glacier is active,is significantly large in its scale of time and space,and strong in power of destroy.Following the world's becoming warmer,GLODF frequency gradually rises.In late years,quantitative estimation methodologies has been put into use of mass GLODF estimations.To improve former methodologies,this article suggests that the glacier(or the massif)on the trailing edge and the moraine dam are the two major systems providing independent glacier lake outburst possibilities.Bucket Effect exists in GLODF issues.Therefore focusing on the relatively unstable one of the above two provides better accuracy in estimation on GLODF possibility.Thus,this article summarizes method of presort through specific GLODF evaluation.
文摘针对锚线斜拉作用下吸力筒与砂土相互作用的微观特征仍不清楚这一问题,采用离散元(discrete element method,简称DEM)-有限元(finite element method,简称FEM)耦合数值方法,从宏观到微观角度分析系泊点深度对吸力筒基础抗拔性能的影响。在建模中,采用FEM中有限元网格来模拟吸力筒,采用DEM中颗粒来模拟吸力筒周围砂土,并通过控制滚轴运动来模拟锚线的拉作用。结果表明:吸力筒的拉力-位移曲线存在峰值拉力,且与不同系泊点深度下吸力筒运动模式有密切关系;吸力筒旋转方向、拔出位移的反转临界系泊深度点位于吸力筒从顶部往下h=66.7%深度附近(即吸力筒深度的2/3处,h为系泊深度)。此外,从颗粒尺度分析了土体变形及破坏行为,最终确定了吸力筒-颗粒土相互作用的破坏模式。研究结果表明,忽略锚线的系泊点深度将会导致误判吸力筒的承载能力及与土体的破坏模式。
基金Supported by the Key Project of National Scientific and Technological Supporting Program of the "Eleventh Five-year Plan"(2008BAJ08B04-10)Scientific and Technological Program of the Ministry of Construc-tion(2009-K5-1)Soft Science Research Program of Tianjin Municipal Construction Committee(2008Soft-36)~~
文摘The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance the attraction of agricultural regions and establish more effective connections between rural and urban areas by properly developing eco-agricultural sightseeing and organizing satellite sustainable agricultural villages into an urban peripheral network.Dajidian Sustainable Agricultural Village in Baoding City,Hebei Province was taken for an example to elaborate the overall design concepts,and analyze the strategies for planning the village as an integrated system,including social,ecological and economic dimensions,which are specifically demonstrated as:the development of sustainable agriculture,the establishment of diversified circulation system,the independence of energy utilization,the soundness of public service system,the improvement of agricultural villages as communities.Through studying the planning of sustainable agricultural villages,this research aimed at realizing the sustainable development of overall environment system in both cities and rural areas,and guiding the improvement of the new countryside construction.
