This paper deals with the bearing capacity determination of strip footing on a rock mass in hilly area by considering the influence of inclined and eccentric loading. Applying the generalized HoekBrown failure criteri...This paper deals with the bearing capacity determination of strip footing on a rock mass in hilly area by considering the influence of inclined and eccentric loading. Applying the generalized HoekBrown failure criterion, the failure behavior of the rock mass is modeled with the help of the power cone programming in the lower bound finite element limit analysis framework. Using bearing capacity factor(Ns), the change in bearing capacity of the strip footing due to the occurrence of eccentrically inclined loading is presented. The variations of the magnitude of Ns are obtained by examining the effects of the Hoek-Brown rock mass strength parameters(uniaxial compressive strength(sci), disturbance factor(D), rock parameter(mi), and Geological Strength Index(GSI)) in the presence of different magnitudes of eccentricity(e) and inclination angle(λ) with respect to the vertical plane, and presented as design charts. Both the inclined loading modes, i.e., inclination towards the center of strip footing(+λ) and inclination away from the center of strip footing(-λ), are adopted to perform the investigation. In addition, the correlation between the input parameters and the corresponding output is developed by utilizing the artificial neural network(ANN). Additionally, from sensitivity analysis, it is observed that inclination angle(λ) is the most sensitive parameter. For practicing engineers, the obtained design equation and design charts can be beneficial to understand the bearing capacity variation in the existence of eccentrically inclined loading in mountain areas.展开更多
Properties of wall pressure beneath a transitional hypersonic boundary layer over a 7°half-angle blunt cone at angle of attack 6°are studied by Direct Numerical Simulation.The wall pressure has two distinct ...Properties of wall pressure beneath a transitional hypersonic boundary layer over a 7°half-angle blunt cone at angle of attack 6°are studied by Direct Numerical Simulation.The wall pressure has two distinct frequency peaks.The low-frequency peak with f≈10−50 kHz is very likely the unsteady crossflow mode based on its convection direction,i.e.along the axial direction and towards the windward symmetry ray.Highfrequency peaks are roughly proportional to the local boundary layer thickness.Along the trajectories of stationary crossflow vortices,the location of intense high-frequency wall pressure moves from the bottom of trough where the boundary layer is thin to the bottom of shoulder where the boundary layer is thick.By comparing the pressure field with that inside a high-speed transitional swept-wing boundary layer dominated by the z-type secondary crossflow mode,we found that the high-frequency signal originates from the Mack mode and evolves into the secondary crossflow instability.展开更多
基金supported by Centre for Development of Advanced Computing (CDAC), Pune。
文摘This paper deals with the bearing capacity determination of strip footing on a rock mass in hilly area by considering the influence of inclined and eccentric loading. Applying the generalized HoekBrown failure criterion, the failure behavior of the rock mass is modeled with the help of the power cone programming in the lower bound finite element limit analysis framework. Using bearing capacity factor(Ns), the change in bearing capacity of the strip footing due to the occurrence of eccentrically inclined loading is presented. The variations of the magnitude of Ns are obtained by examining the effects of the Hoek-Brown rock mass strength parameters(uniaxial compressive strength(sci), disturbance factor(D), rock parameter(mi), and Geological Strength Index(GSI)) in the presence of different magnitudes of eccentricity(e) and inclination angle(λ) with respect to the vertical plane, and presented as design charts. Both the inclined loading modes, i.e., inclination towards the center of strip footing(+λ) and inclination away from the center of strip footing(-λ), are adopted to perform the investigation. In addition, the correlation between the input parameters and the corresponding output is developed by utilizing the artificial neural network(ANN). Additionally, from sensitivity analysis, it is observed that inclination angle(λ) is the most sensitive parameter. For practicing engineers, the obtained design equation and design charts can be beneficial to understand the bearing capacity variation in the existence of eccentrically inclined loading in mountain areas.
基金the National Key Research and Development Program of China 2016YFA0401200 and 2019YFA0405200the National Numerical Wind tunnel(NNW)project,and National Natural Science Foundation of China under contract 11702307.
文摘Properties of wall pressure beneath a transitional hypersonic boundary layer over a 7°half-angle blunt cone at angle of attack 6°are studied by Direct Numerical Simulation.The wall pressure has two distinct frequency peaks.The low-frequency peak with f≈10−50 kHz is very likely the unsteady crossflow mode based on its convection direction,i.e.along the axial direction and towards the windward symmetry ray.Highfrequency peaks are roughly proportional to the local boundary layer thickness.Along the trajectories of stationary crossflow vortices,the location of intense high-frequency wall pressure moves from the bottom of trough where the boundary layer is thin to the bottom of shoulder where the boundary layer is thick.By comparing the pressure field with that inside a high-speed transitional swept-wing boundary layer dominated by the z-type secondary crossflow mode,we found that the high-frequency signal originates from the Mack mode and evolves into the secondary crossflow instability.
