In welded-contact boundary conditions, some stress components are not required to be continuous across the boundary between two elastic half-spaces. The purpose of this note is to study the modifications in the stress...In welded-contact boundary conditions, some stress components are not required to be continuous across the boundary between two elastic half-spaces. The purpose of this note is to study the modifications in the stress field of a long inclined strike-slip, dip-slip or tensile fault caused by the welded-contact boundary conditions across the interface between two elastic half-spaces. The Poisson’s ratios of the two half-spaces do not appear in the stress field of a strike-slip fault. In the case of a dip-slip fault, the Poisson’s ratio of the half-space in which the fault lies, has a significant influence on the stress field across the interface. However, for a tensile fault, the modification in the stress field is significantly affected by the Poisson’s ratios of both the half-spaces.展开更多
The solution of static deformation of two homogeneous, isotropic, and perfectly elastic half-spaces in welded contact due to a long dip-slip fault with uniform slip is well known. The aim of the present article is to ...The solution of static deformation of two homogeneous, isotropic, and perfectly elastic half-spaces in welded contact due to a long dip-slip fault with uniform slip is well known. The aim of the present article is to obtain the static deformation of two homogeneous, isotropic, and perfectly elastic half-spaces in welded contact due to nonuniform slip along a long dip-slip fault. The fault is vertical and lies entirely in the lower half-space, extending up to the interface. Four slip profiles are considered： lin- ear, parabolic, elliptic, and cubic. Closed-form expressions for the elastic residual field have been ob- tained for the different slip profiles. The displacement field due to four nonuniform slip profiles is com- pared with the displacement field due to uniform slip. For comparison, we have assumed the source potency for different slip profiles to be the same, which is achieved by taking the fault slip at the inter- face constant and varying the fault width. It is found that the displacement field varies significantly at the fault width rather than at the interface. Moreover, uniform slip along the fault makes the edges singular. This singularity at the lower edge is not present in the case of nonuniform slip along a long dip-slip fault.展开更多
Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situate...Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situated in an elastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving associated boundary value problem with the help of integral transformation and Green’s function method and a suitable numerical methods is used for computation. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.展开更多
Abstract The Nansha ultra-crust layer-block is confined by ultra-crustal boundary faults of distinctive features, bordering the Kangtai-Shuangzi-Xiongnan extensional faulted zone on the north, the Baxian-Baram-Yoca-Cu...Abstract The Nansha ultra-crust layer-block is confined by ultra-crustal boundary faults of distinctive features, bordering the Kangtai-Shuangzi-Xiongnan extensional faulted zone on the north, the Baxian-Baram-Yoca-Cuyo nappe faulted zone on the south, the Wan'an-Natuna strike-slip tensional faulted zone on the west and the Mondoro-Panay strike-slip compressive faulted zone on the east. These faults take the top of the Nansha asthenosphere as their common detachmental surface. The Cenozoic dynamic process of the ultra-crust layer-block can be divided into four stages: K2-E21, during which the northern boundary faults extended, this ultra-crust layer-block was separated from the South China-Indosinian continental margin, the Palaeo-South China Sea subducted southwards and the Sibu accretion wedge was formed; E22-E31, during which the Southwest sub-sea basin extended and orogeny was active due to the collision of the Sibu accretion wedge; E32-N11, during which the central sub-sea basin extended, the Miri accretion wedge was formed and “A-type” subduction of the southern margin of the north Balawan occurred; N12-the present, during which large-scale thrusting and napping of the boundary faults in the south and mountain-building have taken place and the South China Sea stopped its extension.展开更多
文摘In welded-contact boundary conditions, some stress components are not required to be continuous across the boundary between two elastic half-spaces. The purpose of this note is to study the modifications in the stress field of a long inclined strike-slip, dip-slip or tensile fault caused by the welded-contact boundary conditions across the interface between two elastic half-spaces. The Poisson’s ratios of the two half-spaces do not appear in the stress field of a strike-slip fault. In the case of a dip-slip fault, the Poisson’s ratio of the half-space in which the fault lies, has a significant influence on the stress field across the interface. However, for a tensile fault, the modification in the stress field is significantly affected by the Poisson’s ratios of both the half-spaces.
基金supported by the Major Research Project and Junior Research Fellowship from the University Grant Commission,New Delhi
文摘The solution of static deformation of two homogeneous, isotropic, and perfectly elastic half-spaces in welded contact due to a long dip-slip fault with uniform slip is well known. The aim of the present article is to obtain the static deformation of two homogeneous, isotropic, and perfectly elastic half-spaces in welded contact due to nonuniform slip along a long dip-slip fault. The fault is vertical and lies entirely in the lower half-space, extending up to the interface. Four slip profiles are considered： lin- ear, parabolic, elliptic, and cubic. Closed-form expressions for the elastic residual field have been ob- tained for the different slip profiles. The displacement field due to four nonuniform slip profiles is com- pared with the displacement field due to uniform slip. For comparison, we have assumed the source potency for different slip profiles to be the same, which is achieved by taking the fault slip at the inter- face constant and varying the fault width. It is found that the displacement field varies significantly at the fault width rather than at the interface. Moreover, uniform slip along the fault makes the edges singular. This singularity at the lower edge is not present in the case of nonuniform slip along a long dip-slip fault.
文摘Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situated in an elastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving associated boundary value problem with the help of integral transformation and Green’s function method and a suitable numerical methods is used for computation. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.
文摘Abstract The Nansha ultra-crust layer-block is confined by ultra-crustal boundary faults of distinctive features, bordering the Kangtai-Shuangzi-Xiongnan extensional faulted zone on the north, the Baxian-Baram-Yoca-Cuyo nappe faulted zone on the south, the Wan'an-Natuna strike-slip tensional faulted zone on the west and the Mondoro-Panay strike-slip compressive faulted zone on the east. These faults take the top of the Nansha asthenosphere as their common detachmental surface. The Cenozoic dynamic process of the ultra-crust layer-block can be divided into four stages: K2-E21, during which the northern boundary faults extended, this ultra-crust layer-block was separated from the South China-Indosinian continental margin, the Palaeo-South China Sea subducted southwards and the Sibu accretion wedge was formed; E22-E31, during which the Southwest sub-sea basin extended and orogeny was active due to the collision of the Sibu accretion wedge; E32-N11, during which the central sub-sea basin extended, the Miri accretion wedge was formed and “A-type” subduction of the southern margin of the north Balawan occurred; N12-the present, during which large-scale thrusting and napping of the boundary faults in the south and mountain-building have taken place and the South China Sea stopped its extension.
