A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was exam...A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was examined by constructing long trenches using different slurries. The soil deformation and surface settlement induced by the excavation of the trench are found to be closely related to slurry type and excavation depth of the long trench. Increasing the bentonite concentration of the slurry has beneficial effects on stability: 1) larger particles can improve local and global stability in cases where filter cakes do not form, and 2) larger viscosity can promote filter cake formation on the walls of long trenches excavated in soft clay and enhance their stability.展开更多
It is imperative to evaluate factor of safety against basal heave failure in the design of braced deep excavation in soft clay.Based on previously published field monitoring data and finite element analyses of ground ...It is imperative to evaluate factor of safety against basal heave failure in the design of braced deep excavation in soft clay.Based on previously published field monitoring data and finite element analyses of ground settlements of deep excavation in soft clay,an assumed plastic deformation mechanism proposed here gives upper bound solutions for base stability of braced deep excavations.The proposed kinematic mechanism is optimized by the mobile depth(profile wavelength).The method takes into account the influence of strength anisotropy under plane strain conditions,the embedment of the retaining wall,and the locations of the struts.The current method is validated by comparison with published numerical study of braced excavations in Boston blue clay and two other cases of excavation failure in Taipei.The results show that the upper bound solutions obtained from this presented method is more accurate as compared with the conventional methods for basal heave failure analyses.展开更多
基金Project(41202220)supported by the National Natural Science Foundation of ChinaProject(20120022120003)supported by the Research Fund for the Doctoral Program of Higher Education,ChinaProject(2652012065)supported by the Fundamental Research Funds for the Central Universities and Beijing Higher Education Young Elite Teacher Program,China
文摘A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was examined by constructing long trenches using different slurries. The soil deformation and surface settlement induced by the excavation of the trench are found to be closely related to slurry type and excavation depth of the long trench. Increasing the bentonite concentration of the slurry has beneficial effects on stability: 1) larger particles can improve local and global stability in cases where filter cakes do not form, and 2) larger viscosity can promote filter cake formation on the walls of long trenches excavated in soft clay and enhance their stability.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.51325901)the State Key Program of National Natural Science of China(Grant No.51338009)
文摘It is imperative to evaluate factor of safety against basal heave failure in the design of braced deep excavation in soft clay.Based on previously published field monitoring data and finite element analyses of ground settlements of deep excavation in soft clay,an assumed plastic deformation mechanism proposed here gives upper bound solutions for base stability of braced deep excavations.The proposed kinematic mechanism is optimized by the mobile depth(profile wavelength).The method takes into account the influence of strength anisotropy under plane strain conditions,the embedment of the retaining wall,and the locations of the struts.The current method is validated by comparison with published numerical study of braced excavations in Boston blue clay and two other cases of excavation failure in Taipei.The results show that the upper bound solutions obtained from this presented method is more accurate as compared with the conventional methods for basal heave failure analyses.
