TN659 : Seismic Bearing Capacity Evaluation and Study of Shallow Foundation on Rock Masses
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2016
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Abstarct: Foundation on the environment during a seismic, due to their below position is causing financial losses and loss of human lives. Lack of sufficient strength of the rock masses the greatest cause of the foundation's structural damage. For this reason, the importance of research in the field of the seismic bearing capacity of shallow foundations seismically active country like Iran cannot be ignored.
Laboratory and experimental research have shown that the bearing capacity of shallow foundations during a seismic is significantly reduced. Researchers have used a different method in their studies, in that we can note limit equilibrium method, limit analysis, Slip line, experimental and numerical method, such as finite element and finite difference. In this study, the various researcher's studies in estimating bearing capacity of shallow foundation on rock masses in static and seismic has been studied and numerical and analytical study has been done. In this study, a detailed study of a host rock mass surface foundation, by using analytical and numerical modeling through commercial software FLAC2D, for static and dynamic loads caused by seismic has been done.
Determine the bearing capacity of foundation stone often has been done without considering the effect of seismic load. This is while the bearing capacity of shallow foundations under seismic loads reduced, and settlement rotation in foundation increases. The reduction of the bearing capacity of the foundation depends on the nature and type of the rock mass. In this research, upper bound limit analysis and the numerical modeling also static and seismic bearing capacity of foundations on flat ground is done.
The upper bound limit analysis is the most powerful analytical method for the evaluation of bearing capacity. The method is baxsed on velocity hedograph failure mechanisms of Prand-tl type and the of multi-wedge translation, offspring's rate of the work performed by the external forces and the rate of resisting work can be calculated baxsed on the principle of superposition of forces. By equating the work rate depreciated external forces and total internal resisting work, the ultimate bearing capacity of the overall equation can be calculated by using the upper bound limit method. The best value is obtained by minimizing the load-bearing capacity equation with respect to the parameters of failure mechanisms, which are numerically done. The optimal solution is minimizes amount generated by two mechanisms is given. Optimization of the objective function has been done in MATLAB® software and by using the Genetic algorithm.
In order to study structural discontinuities and the weak structural factor, the geological strength index (GSI) was used. Investigation shows that the discontinuities have a great impact on the static and dynamic bearing capacity of the foundation stone. So as to enhancing the quality of the rock mass and increased seismic acceleration, reducing the amount of seismic bearing capacity increases.
Keywords:
#Seismic bearing capacity #Rock mass #Upper bound theory #Failure criteria Hoek Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: