Due to rapid growth in infrastructure sector, the construction of high-rise buildings is becoming very popular among all the countries. Engineers face significant issues with high rise buildings, particularly in terms of structural and foundation aspects. Many old design approaches can't be used with certainty since they involve extrapolation far beyond the domains of existing experience, hence structural and geotechnical engineers are being compelled to use more advanced analysis and design methodologies. The current study is an attempt to predict the bearing capacity and settlement behavior of piled-raft footing when embedded into cohesionless deposit. The numerical analysis has been carried out to examine the effect of numerous key parameters of pile and raft such as pile length (10, 15, 20 m), pile diameter (0.3, 0.4, 0.5 m), pile number (16, 20, 24), pile spacing (2D, 3D, 4D) (where “D” is diameter of the pile), raft thickness (0.4, 0.5, 0.6 m), and angle of internal friction of soil (25°, 30°, 35°) on load-settlement behavior of the piled- raft foundation using Abaqus software. A constant spacing between the piles, i.e. 3D was used throughout the analysis. The results of numerical investigation revealed an improvement in bearing capacity and a reduction in settlement value on increasing length, diameter and number of piles and also with increasing angle of internal friction. The current study not only increases the bearing capacity of the foundation but provides a cost-effective foundation technique to engineers.

Precast prestreesed concrete braces are a new method for seismic strength of Concrete Structures which has the following benefits: a) no wet concrete work in construction site b) no bolt or anchorage to the existing frame c) easy to apply d) short construction period e) low construction cost; to evaluate seismic performance of strengthened structure. A model consist of existing frame and concrete braces were created using Abaqus (nonlinear-finite element) software. Comparison existing and strengthened frame showed that braces are effective in lateral drift decreasing. Study concrete compressive strength on seismic behavior of brace showed that when compression strength of brace is lower than existing frame; retrofitting system has low stiffness and wasn’ t effective in reducing lateral drift. But, in specimen with compressive strength ratio (brace to frame) two times or more, braces showed high strength and stiffness.

The stability of soil slopes and the determination of safety factors have always been the subject of study for engineers and researchers. The safety factor of slopes can be determined by using the methods of limit equilibrium method (L.E.M.), limit analysis, and strength reduction method (S.R.M.). The equilibrium method determines the slope safety factor based on the equilibrium of the inter-slice force and without the analysis of tension and strain. In the strength reduction method, based on the tension-strain analysis, the strength of various points of the slope is reduced until it reaches the critical state, and by connecting all of the critical points, the critical rupture level will be obtained. Finite element software and finite difference software determine the safety factors in soil slopes by using the concepts of the strength reduction method. In this paper, the safety factors of soil slopes are determined by using Abaqus software, and using the concept of strength reduction method. There is no option in Abaqus for the determination of safety factors and it should be obtained by defining the concepts of strength reduction. The purpose of this study is to implement a strength reduction method in a finite element program to calculate the safety factor of slopes. The results of this research indicate that the changes in friction angle affect the safety factor changes more than variations in cohesion. Also, slope angle and its changes affect the safety factor changes more than other factors.