At present, associated flow rule of traditional plastic theory is adopted in the slip line field theory and upper bound method of geotechnical materials. So the stress characteristic line conforms to the velocity line...At present, associated flow rule of traditional plastic theory is adopted in the slip line field theory and upper bound method of geotechnical materials. So the stress characteristic line conforms to the velocity line. It is proved that geotechnical materials do not abide by the associated flow rule. It is impossible for the stress characteristic line to conform to the velocity line. Generalized plastic mechanics theoretically proved that plastic potential surface intersects the Mohr-Coulomb yield surface with an angle, so that the velocity line must be studied by non-associated flow rule. According to limit analysis theory, the theory of slip line field is put forward in this paper, and then the ultimate beating capacity of strip footing is obtained based on the associated flow rule and the non-associated flow nile individually. These two results are identical since the ultimate bearing capacity is independent of flow role. On the contrary, the velocity fields of associated and non-associated flow rules are different which shows the velocity field based on the associat- ed flow rule is incorrect.展开更多
Moral generalism and particularism are two positions in meta-ethics which have different views regarding the relation between moral thought and principles. By accepting this relationship, generalists emphasize the nec...Moral generalism and particularism are two positions in meta-ethics which have different views regarding the relation between moral thought and principles. By accepting this relationship, generalists emphasize the necessity of principles in decision making process, and claim that the rationality of moral thought depends on the provision of a suitable supply ofmoral principles. In contrast, particularists have rejected, or at least doubted, the existence of moral principles, and believe that the rationality of moral thought depends on recognizing special features of a case and relevant conditions. This is why, unlike generalists, they use case study method rather than syllogism in decision making process and moral judgment. Consequently, to support their view, particularists commonly resort to holism in the theory of reasons, while atomism is in support of generalism. To evaluate these two attitudes, this study surveys some arguments that particularists and generalists proposed to justify their view and criticize the rival＇s one, and also explains their positions concerning the epistemological and metaphysical role of moral principles and reasons. Finally, after evaluating their claims, the importance of both approaches in meta-ethics is stressed.展开更多
The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They ...The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They develop the machinery of K-theory wrong-way maps in the context of orbifolds and use it to relate the quantization commutes with reduction phenomenon to Bott periodicity and the K-theory formulation of the Weyl character formula.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
文摘At present, associated flow rule of traditional plastic theory is adopted in the slip line field theory and upper bound method of geotechnical materials. So the stress characteristic line conforms to the velocity line. It is proved that geotechnical materials do not abide by the associated flow rule. It is impossible for the stress characteristic line to conform to the velocity line. Generalized plastic mechanics theoretically proved that plastic potential surface intersects the Mohr-Coulomb yield surface with an angle, so that the velocity line must be studied by non-associated flow rule. According to limit analysis theory, the theory of slip line field is put forward in this paper, and then the ultimate beating capacity of strip footing is obtained based on the associated flow rule and the non-associated flow nile individually. These two results are identical since the ultimate bearing capacity is independent of flow role. On the contrary, the velocity fields of associated and non-associated flow rules are different which shows the velocity field based on the associat- ed flow rule is incorrect.
文摘Moral generalism and particularism are two positions in meta-ethics which have different views regarding the relation between moral thought and principles. By accepting this relationship, generalists emphasize the necessity of principles in decision making process, and claim that the rationality of moral thought depends on the provision of a suitable supply ofmoral principles. In contrast, particularists have rejected, or at least doubted, the existence of moral principles, and believe that the rationality of moral thought depends on recognizing special features of a case and relevant conditions. This is why, unlike generalists, they use case study method rather than syllogism in decision making process and moral judgment. Consequently, to support their view, particularists commonly resort to holism in the theory of reasons, while atomism is in support of generalism. To evaluate these two attitudes, this study surveys some arguments that particularists and generalists proposed to justify their view and criticize the rival＇s one, and also explains their positions concerning the epistemological and metaphysical role of moral principles and reasons. Finally, after evaluating their claims, the importance of both approaches in meta-ethics is stressed.
文摘The authors examine the quantization commutes with reduction phenomenon for Hamiltonian actions of compact Lie groups on closed symplectic manifolds from the point of view of topological K-theory and K-homology. They develop the machinery of K-theory wrong-way maps in the context of orbifolds and use it to relate the quantization commutes with reduction phenomenon to Bott periodicity and the K-theory formulation of the Weyl character formula.
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.
