In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergon...In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.展开更多
This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shea...This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shear localization, there is a direct relation between segmentation and alloy strength （hardness） that is related to the alloying elements and constitutive phases. For instance, alpha brass is successfully processed by ECAP at room temperature, but alpha/beta brasses fail even at a temperature of 350 °C. Finite element simulation of cracking and segmentation was performed using DEFORMTM to investigate the influence of different parameters on segmentation. The results confirm that friction and processing speed have narrow effects on attaining a perfect billet. However, employing back pressure could be reliably used to diminish shear localization, billet cracking, segmentation, and damage. Moreover, diminishing the flow localization using back pressure leads to uniform material flow and the billet homogeneity increases by 36.1%, when back pressure increases from 0 to 600 MPa.展开更多
文摘In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.
基金financial support and providing research facilities used in this work
文摘This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shear localization, there is a direct relation between segmentation and alloy strength （hardness） that is related to the alloying elements and constitutive phases. For instance, alpha brass is successfully processed by ECAP at room temperature, but alpha/beta brasses fail even at a temperature of 350 °C. Finite element simulation of cracking and segmentation was performed using DEFORMTM to investigate the influence of different parameters on segmentation. The results confirm that friction and processing speed have narrow effects on attaining a perfect billet. However, employing back pressure could be reliably used to diminish shear localization, billet cracking, segmentation, and damage. Moreover, diminishing the flow localization using back pressure leads to uniform material flow and the billet homogeneity increases by 36.1%, when back pressure increases from 0 to 600 MPa.
