Reliability Based Analysis and Optimum Design of Laterally Loaded Piles

One of the most crucial geotechnical engineering problems is the stability of slopes that are still attracting scientists and engineers. In this study, five recently developed meta-heuristic methods are utilized to determine the Critical Failure Surface (CFS) and its corresponding Factor of Safety (FOS). Through the FOS calculations, the Finite Element Method (FEM) is employed to convert the strong form of the main differential equation to a weak form. Additional to the general loading, seismic forces and seepage effect are considered, as well. Finally, the proposed optimization procedure is applied to numerical benchmark examples, and results are compared with other methods.

Section: Introductionsupporting

confidence: 73%

Optimization of Slope Critical Surfaces Considering Seepage and Seismic Effects Using Finite Element Method and Five Meta-Heuristic Algorithms

Kaveh

Seddighian

2020

“…Movahedi Rad [11] concludes that penetration depth affects the lateral bearing capacity of piles. According to his results, with a greater depth of immersion, the pile, compressed by the soil, acts as an elasto-plastic frame rod structure with a certain resistance to bending [12].…”

Section: Introductionmentioning

confidence: 99%

Equations Used to Calculate Vertical Bearing Capacity of Driven Piles with Shaft Broadenings

Atenov¹,

Bekbasarov²

2020

In a pile foundation setting practice driven piles with an unconventional (variable) longitudinal shape of surface are widely used. Such piles are made with various slopes of the side faces, may have different types of broadenings, thickenings, etc. The effectiveness of such piles is due to their design features, allowing full use of the natural bearing capacity of the soil base without additional reinforcement. The obvious advantages of these piles make it relevant to study the features of their interaction with the soil stratum, especially the bearing capacity of piles. This study was aimed to investigate vertical bearing capacity of driven reinforced concrete piles with several broadening of the shaft. Numerical calculations and experimental studies of the bearing capacity of piles with broadening under the static loading have been carried out. Equations for calculating the bearing capacity of piles with broadenings are proposed and their verification is performed. The equations include a coefficient that takes into account the features of soil behavior underneath of the pile broadening during palification. Correlation dependence is presented which makes it possible to determine the values of that coefficient depending on the number of pile broadening and the liquidity index of soil. A correlation that makes allow calculations the bearing capacity of piles with broadening via the bearing capacity of a prismatic pile is proposed. The equations are recommended to be used at the stage of variant design of piles with broadening as part of the pile foundations of buildings and structures.

“…On the other hand, the FORM and SORM methods, which are part of the moment methods, are useful in structural engineering problems [10][11][12][13][14][15][16]. A reliability index, which defined as the shortest geometric distance between the origin of standard normal space and the LSF, is presented.…”

Section: Introductionmentioning

confidence: 99%

Heuristic Operator for Reliability Assessment of Frame Structures

Kaveh

Vaez

Hosseini³

et al. 2021

In structural design of steel frames, in order to achieve proper safety, the effect of uncertainties in the design and loading parameters of the structure must be considered. This approach is obtained by defining a reliability index. In this study, the Modified Dolphin Monitoring (MDM) operator was used to evaluate the reliability index of three well-known steel frame structures based on the Hasofer-Lind method. The reliability index was evaluated using the EVPS and VPS algorithms and with considering the MDM operator on them. The constraint of the last story drift is considered as limit state function. The random variables consist of external loads, modulus of elasticity, moment of inertia and cross-sectional areas. According to the number of evaluations of the limit state function, the results show the efficiency of this method in comparison to the Monte Carlo simulation method. Also, the values of the most probable point (MPP) are examined.