Pseudodynamic Bearing Capacity Analysis of Shallow Strip Footing Using the Advanced Optimization Technique “Hybrid Symbiosis Organisms Search Algorithm” with Numerical Validation (original) (raw)
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International Journal of Geotechnical Earthquake Engineering, 2015
The evaluation of bearing capacity of shallow strip footing under seismic loading condition is an important phenomenon. This paper presents a pseudo-dynamic approach to evaluate the seismic bearing capacity of shallow strip footing resting on c-F soil using limit equilibrium method considering the composite failure mechanism. A single seismic bearing capacity coefficient (N?e) presents here for the simultaneous resistance of unit weight, surcharge and cohesion, which is more practical to simulate the failure mechanism. The effect of soil friction angle(F), soil cohesion(c), shear wave and primary wave velocity(Vs, Vp) and horizontal and vertical seismic accelerations(kh, kv) are taken into account to evaluate the seismic bearing capacity of foundation. The results obtained from the present analysis are presented in both tabular and graphical non-dimensional form. Results are thoroughly compared with the existing values in the literature and the significance of the present methodolog...
Pseudo-dynamic analysis for bearing capacity of foundation resting on c –Φ soil
International Journal of Geotechnical Engineering, 2014
Estimation of seismic bearing capacity of foundation in earthquake prone area is an important parameter in the design of any substructure. This paper presents a pseudo-dynamic approach for calculating the seismic bearing capacity of shallow strip footing resting on c-W soil using limit equilibrium method. Considering the Coulomb failure mechanism, the effect of wall friction angle and soil friction angle, soil cohesion, shear wave and primary wave velocity, and horizontal and vertical seismic accelerations are taken into account to evaluate the seismic bearing capacity of foundation. In this paper, the seismic bearing capacity presents in a single coefficient (N ce) for the simultaneous resistance of unit weight, surcharge, and cohesion, which is reasonable and easy to use. The results obtained from the present analysis thoroughly compared with the existing values in the literature and the significance of the present methodology for designing the shallow strip footing is discussed.
Optimization of Shallow Foundation Using Gravitational Search Algorithm
Research Journal of …, 2012
In this study an effective method for nonlinear constrained optimization of shallow foundation is presented. A newly developed heuristic global optimization algorithm called Gravitational Search Algorithm (GSA) is introduced and applied for the optimization of foundation. The algorithm is classified as random search algorithm and does not require initial values and uses a random search instead of a gradient search, so derivative information is unnecessary. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the foundation. To verify the efficiency of the proposed method, two design examples of spread footing are illustrated. To further validate the effectiveness and robustness of the GSA, these examples are solved using genetic algorithm. The results indicate that the proposed method could provide solutions of high quality, accuracy and efficiency for optimum design of foundation.
Engineering Geology, 2011
In this study, two different approaches are proposed to determine the ultimate bearing capacity of shallow foundations on granular soil. Firstly, an artificial neural network (ANN) model is proposed to predict the ultimate bearing capacity. The performance of the proposed neural model is compared with results of the Adaptive Neuro Fuzzy Inference System, Fuzzy Inference System and ANN, which are taken in literature. It is clearly seen that the performance of the ANN model in our study is better than that of the other prediction methods. Secondly, an improved Meyerhof formula is proposed for the computation of the ultimate bearing capacity by using a parallel ant colony optimization algorithm. The results achieved from the proposed formula are compared with those obtained from the Meyerhof, Hansen and Vesic computation formulas. Simulation results showed that the improved Meyerhof formula gave more accurate results than the other theoretical computation formulas. In conclusion, the improved Meyerhof formula could be successfully used for calculating the ultimate bearing capacity of shallow foundations.
International journal of engineering and applied sciences, 2021
Optimum the cantilever retaining wall design for different soils and dynamic earthquake effects is presented here. In the investigation of optimum wall design-based metaheuristic, the harmony search algorithm was considered for different design cases which include five soil and two earthquake characteristics. Earthquake characteristics of mild and severe were obtained regarding two locations which was selected from Turkey Earthquake Risk Map. For selected two locations and local soil classes, map spectral acceleration coefficients were utilized defined in Turkish Building Earthquake Code-2018. Sliding, overturning, and bearing capacity safety factors were taken as design constraints for checking stability criteria of the cantilever retaining wall which is given in Turkish Building Earthquake Code-2018. Since the cost-based wall weight of the optimization problem was taken as the objective function, obtained optimum wall dimensions which are discrete design variables were compared in terms of different design cases. It is seen that the wall dimensions increase in order to meet the design criteria in case of the earthquake load increases when the obtained optimum design by the optimization analyzes are examined. Another result obtained for the same earthquake zone is that the wall dimensions and therefore the cost mostly increase in weak quality soils.
2019
The present study attempts to predict the ultimate bearing capacity (UBC) of the strip footing resting on sand and subjected to inclined load having eccentricity with respect to the vertical using three different soft computing techniques such as support vector mechanism with radial basis function (SVM RBF kernel), M5P model tree (M5P) and random forest regression (RFR). The UBC was computed in the form of reduction factor and this reduction factor was assumed to be dependent on the ultimate bearing capacity (qu) of the strip footing subjected to vertical load, eccentricity ratio (e/B), inclination ratio (α/ϕ) and the embedment ratio (Df/B). The performance of each model was analyzed by comparing the statistical performance measure parameters. The outcome of present study suggests that SVM RBF kernel predicts the reduction factor with least error followed by M5P and RFR. All the model predictions further outperformed those based on semi-empirical approach available in literature. Fi...
JES. Journal of Engineering Sciences, 2014
In geotechnical investigation, determination oftheseismic bearing capacity of foundation soil constitutes an important task. The bearing capacity of soil under static loading has been extensively studied since the early work of Prandtl (1921).Design of foundation in seismic areas needs special considerations compared to the static case. The inadequate performance of structure during recent earthquake has motivated researches to revise existing methods and to develop new method for seismic resistant design. For foundation of structure built in seismic areas the demands to sustain load and deformation during earthquake will probably be the severe in their design life. Due to seismic loading foundation may experience decreases in bearing capacity and increases in settlement. Two source of loading must be taken into consideration inertial loading caused by lateral forces imposed on the superstructure, kinematic loading caused by the ground movement developed during earthquake. Many techniques used for studying the effect of seismic forces on the soil bearing capacity such as, limit equilibrium method, kinematic approach of yield theory, a variational approach, and unified theory of stress, which the shape of failure surface has been assumed. The seismic forces are considered as pseudostatic forces acting both on the footing and on the soil under the footing. However, finite element and stress characteristics methods shape of the failure is not required to be assumed. In the present paper, a theoretical analysis has been performed on the basis of Krey's method (friction circle method) with radius of friction circle equal to = sin (∅ − tan −1 ℎ 1−)where r is the radius of the circle slip surface to determine the influence of the earthquake acceleration coefficients on the seismic bearing capacity of foundation with assisted by a computer program. The present study is compared with the various theoretical solutions. The comparison of that the present study predicted values of ultimate seismic bearing capacity of soil are less than others theories of ultimate seismic bearing capacity. In order facilitate the calculation of seismic bearing capacity, using the proposed equations. It is a function of (
Iranian Journal of Science and Technology, Transactions of Civil Engineering, 2019
The subject seismic bearing capacity is one of the most important aspects of geotechnical earthquake engineering. As the existing pseudo-dynamic method has certain drawbacks, this paper presents a modified pseudo-dynamic approach to evaluate the seismic bearing capacity of shallow strip footing resting on c-Φ soil considering the log-spiral failure mechanism. Since damping is present in all materials, more realistic results can be obtained by modeling the soil as a visco-elastic material. Here, the passive failure region is considered a fully log-spiral zone with an arbitrary location of the center of log-spiral. A single seismic bearing capacity coefficient (N γe) is evaluated for the simultaneous resistance of unit weight, surcharge and cohesion, which is more practical to simulate the field failure mechanism. The effects of soil and seismic parameters are taken into account to evaluate the seismic bearing capacity of the foundation. The results obtained from the present analysis are presented in both tabular and graphical non-dimensional form. Results are thoroughly compared with the existing values in the literature, and a reasonably good agreement is found with the existing studies.