نوع مقاله : پژوهشی
نویسندگان
1 دانشکده مهندسی عمران، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران
2 پژوهشگاه بین المللی زلزله شناسی و مهندسی زلزله
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Most of the available soils in nature are non-homogeneous and can be considered as a homogeneous layer with simplifications. So far, different methods have been presented in order to achieve bearing capacity of these soil types. Stress Characteristic Lines Method, presented by previous researchers, is one of the best numerical methods able to determine the bearing capacity of foundations. The important advantage of this method over the other numerical methods is that it neither requires the customary and troublesome meshing nor uses complex and specific behavioral models of soil, whereas only the stress field is required
at the collapse moment not the strain field, and the computations are performed with higher speed and simplicity. So far, previous researchers have been able to provide programs through this method in order to estimate the bearing capacity of homogeneous soil. However, this is not true in all cases. Layered soils are mostly encountered in practice. The thickness and also cohesion of
layers are the effective parameters in this regard. The present article evaluates the bearing capacity coefficient ($N_{C}^{*}$ ) of a strip in foundation for two undrained clay soil layers (upper layer is weaker than lower layer) with respect to changes in the upper layer thickness as well as variations in cohesion ratio of two layers by using the mentioned method. Therefore, in addition to briefly reviewing the technical literature and calculation procedure of strip foundation based on homogeneous soil, an algorithm for two layered soil is presented. Then, by using BCTL software (Bearing Capacity of Two Layer) obtained by this algorithm, changes of static load bearing capacity of the strip foundations ($N_{C}^{*}$ ) on the two undrained clay layers have been evaluated. As expected, by increasing the ratio of Cu1/Cu2 to one (for different \ thickness of top \ layer over width of \ strip footing), bearing \ capacity coefficient ($N_{C}^{*}$ ) is converged into number 5.142.
کلیدواژهها [English]
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