نوع مقاله : علمی - پژوهشی
1 دانشجوی دکتری مهندسی معدن دانشکدهی مهندسی معدن، نفت و ژئوفیزیک ؛ دانشگاه صنعتی شاهرود
2 دانشیار دانشکدهی مهندسی معدن، نفت و ژئوفیزیک دانشگاه صنعتی شاهرود
عنوان مقاله [English]
Tunneling in urban areas by passing underneath several buildings causes subsidence due to stress relief and development of elastic and plastic deformations. If these subsidences are not controlled, the structures on the ground will be seriously damaged. Nowadays, several methods are used for tunnel analysis and design and for urban tunnels, which excavated in shallow and soft grounds, the best way is using numerical methods. Choosing the Appropriate behavioral model is one of the most basic steps in numerical analysis. tunnel excavation frequently uses the Mohr–Coulomb behavior model in numerical models.
The Mohr-Coulomb elastic-plastic model is one of the most widely used models, used in cases evaluating the hardness of materials, independent of the surface tension. If the Mohr-Coulomb used for modeling of tunnel where in depth tunneling excavation is involved and where an increase in maximum ground surface settlement and decrease in the reliability of stability of tunnels can be seen, which may not be appropriate in some conditions. The more appropriate model should be used to solve this problem, one that can model the hardness of materials based on changes in the level of stress.
In this study, the effect of different soil parameters on the ground surface settlement of Qom metro line A in Hardening Soil, Mohr–Coulomb and Drager Prager behavior models was investigated using the finite difference method. First, modeling of ground surface settlement was performed and the analysis results were compared with instrumentation data. Then, the effect of modulus of elasticity, friction angle, cohesion, Poisson's ratio and specific gravity parameters in different behavior models was investigated. The results of this research indicated that the Hardening Soil behavior model and the Drager Prager behavior model have the most and the least changes from the changes of soil parameters of Qom metro line A, respectively.