scholarly journals Optimum Design of Braced Steel Space Frames including Soil-Structure Interaction via Teaching-Learning-Based Optimization and Harmony Search Algorithms

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Ayse T. Daloglu ◽  
Musa Artar ◽  
Korhan Ozgan ◽  
Ali İ. Karakas
Keyword(s):  
Optimum Design ◽  
Soil Structure ◽  
Harmony Search ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Space Frames ◽  
Foundation Model ◽  
Teaching Learning Based Optimization ◽  
Teaching Learning ◽  
Steel Space Frames

Optimum design of braced steel space frames including soil-structure interaction is studied by using harmony search (HS) and teaching-learning-based optimization (TLBO) algorithms. A three-parameter elastic foundation model is used to incorporate the soil-structure interaction effect. A 10-storey braced steel space frame example taken from literature is investigated according to four different bracing types for the cases with/without soil-structure interaction. X, V, Z, and eccentric V-shaped bracing types are considered in the study. Optimum solutions of examples are carried out by a computer program coded in MATLAB interacting with SAP2000-OAPI for two-way data exchange. The stress constraints according to AISC-ASD (American Institute of Steel Construction-Allowable Stress Design), maximum lateral displacement constraints, interstorey drift constraints, and beam-to-column connection constraints are taken into consideration in the optimum design process. The parameters of the foundation model are calculated depending on soil surface displacements by using an iterative approach. The results obtained in the study show that bracing types and soil-structure interaction play very important roles in the optimum design of steel space frames. Finally, the techniques used in the optimum design seem to be quite suitable for practical applications.

Optimum design of steel space frames including soil-structure interaction

2016 ◽  
Vol 54 (1) ◽  
pp. 117-131 ◽  
Author(s):  
Ayse T. Daloglu ◽  
Musa Artar ◽  
Korhan Özgan ◽  
Ali İ. Karakas
Keyword(s):  
Optimum Design ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Space Frames ◽  
Steel Space Frames

An Optimum Tuning Application of Mass Dampers Considering Soil-Structure Interaction

2018 ◽  
pp. 44-73
Author(s):  
Gebrail Bekdaş ◽  
Sinan Melih Nigdeli
Keyword(s):  
Optimum Design ◽  
Soil Structure ◽  
Damping Ratio ◽  
Harmony Search ◽  
Soil Structure Interaction ◽  
Tuned Mass Dampers ◽  
Maximum Displacement ◽  
Structure Interaction ◽  
High Rise ◽  
Design Variables

In order to obtain a significant reduction for seismic responses of structures using tuned mass dampers (TMDs), optimization is a mandatory process. A music-inspired metaheuristic algorithm called harmony search is employed in the proposed method for optimum design of TMDs implemented on structures considering soil-structure interaction (SSI). The present approach considers time domain analyses conducted for several earthquake excitations. The optimum design variables, such as mass, period, and damping ratio of TMD are searched for an optimization objective (the maximum displacement of structure) and a design constraint (the maximum scaled stroke capacity of TMD). The proposed method was investigated with a 40-storey high-rise structure for different soil characteristics and the optimum results were compared with a previously developed metaheuristic approach. Results show that the proposed method is feasible and more effective than the compared method.

Parameter identification of the dynamic Winkler soil–structure interaction model using a hybrid unscented Kalman filter–multi-objective harmony search algorithm

2020 ◽  
Vol 23 (12) ◽  
pp. 2653-2668
Author(s):  
Javier Naranjo-Pérez ◽  
Javier Fernando Jiménez-Alonso ◽  
Andrés Sáez
Keyword(s):  
Kalman Filter ◽  
Parameter Identification ◽  
Soil Structure ◽  
Optimization Problem ◽  
Unscented Kalman Filter ◽  
Harmony Search ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Multi Objective ◽  
Winkler Model

Soil–structure interaction is a key aspect to take into account when simulating the response of civil engineering structures subjected to dynamic actions. To this end, and due to its simplicity and ease of implementation, the dynamic Winkler model has been widely used in practical engineering applications. In this model, soil–structure interaction is simulated by means of spring–damper elements. A crucial point to guarantee the adequate performance of the approach is to accurately estimate the constitutive parameters of these elements. To this aim, this article proposes the application of a recently developed parameter identification method to address such problem. In essence, the parameter identification problem is transformed into an optimization problem, so that the parameters of the dynamic Winkler model are estimated by minimizing the relative differences between the numerical and experimental modal properties of the overall soil–structure system. A recent and efficient hybrid algorithm, based on the combination of the unscented Kalman filter and multi-objective harmony search algorithms, is satisfactorily implemented to solve the optimization problem. The performance of this proposal is then validated via its implementation in a real case-study involving an integral footbridge.

scholarly journals Seismic Analysis of a Curved Bridge Considering Soil-Structure Interactions Based on a Separated Foundation Model

2020 ◽  
Vol 10 (12) ◽  
pp. 4260
Author(s):  
Lixin Zhang ◽  
Yin Gu
Keyword(s):  
Spatial Variation ◽  
Seismic Response ◽  
Ground Motion ◽  
Soil Structure ◽  
Bending Moment ◽  
Soil Structure Interaction ◽  
Small Radius ◽  
Curved Bridge ◽  
Structure Interaction ◽  
Foundation Model

A separated foundation model was proposed in order to reduce the calculation scale of the numerical model for analyzing soil-bridge structure dynamics. The essence of the wave input analysis model considering soil-structure interaction was analyzed. Based on the large mass method, a one-dimensional time-domain algorithm of the free field was derived. This algorithm could simulate the specified ground motion input well. The displacement expansion solution of the free wave field was solved based on the propagation law of waves in a medium. By separating the soil foundations around the pile foundations of the bridge, the ground motion was transformed into an equivalent load applied on an artificial boundary. The separated foundation model could consider the incoherence effect and soil-structure interaction simultaneously; the number of model elements were reduced, and the computational efficiency was improved. In order to investigate the seismic response of a curved bridge considering soil-structure interaction under spatially varied earthquakes, a curved bridge with small radius was adopted in practical engineering. Spatially correlated multi-point ground motion time histories were generated, and the nonuniform ground motion field was simulated based on the wave input method on an artificial viscoelastic boundary. The effects of different apparent wave velocities, coherence values, and site conditions on the seismic response of the bridge were analyzed. The results showed that the spatial variation of seismic ground motion had a considerable effect on the bending moment and the torsion of the girder. The site effect had great influence on the bending moment of the pier bottom. When considering soil-structure interaction, the spatial variation of ground motion should be fully considered to avoid underestimating the structural response.

Seismic Control of High-Rise Buildings Equipped with ATMD Including Soil-Structure Interaction Effects

2018 ◽  
Vol 12 (03) ◽  
pp. 1850010 ◽  
Author(s):  
Mohammad Shahi ◽  
Mohammad Reza Sohrabi ◽  
Sadegh Etedali
Keyword(s):  
Optimum Design ◽  
Ground State ◽  
Seismic Behavior ◽  
Soil Structure ◽  
Tall Building ◽  
Soil Structure Interaction ◽  
Rigid Base ◽  
Control Force ◽  
Structure Interaction ◽  
Lqr Controller

The seismic behavior of the structures equipped with ATMD is often investigated based on the rigid base assumption without considering soil-structure interaction (SSI) effects. The SSI effects significantly modify the dynamic characteristics of the structures, while these changes may be ignored in the design process of the controllers. The present paper aims to address the issue of the SSI effects on the seismic behavior of the structures and performance of the adopted controllers. For this purpose, a mathematical model is developed for the time domain analysis of tall building equipped with ATMD including SSI effects. Considering the fixed base case and three types of ground states, namely soft, medium and dense soil, the numerical studies are carried out on a 40-story structure subjected to different earthquake excitations. Two well-known controllers, proportional-integral-derivative (PID) and linear-quadratic regulator (LQR) controllers, are employed for tuning control force of ATMD in different conditions of ground state. A particle swarm optimization (PSO) algorithm is used for the optimum design of Tuned mass damper (TMD) parameter and the gain matrices of the controllers in both cases without and with SSI effects. It is found that TMDs are more effective for the higher soil stiffness and their efficiencies are degraded in soft soils. Furthermore, the SSI significantly affects on the optimum design of the PID and LQR controllers. The adopted controllers are significantly able to mitigate the peak top floor displacement of the tall building. In addition that the PID controller is a simple strategy with design variables much less than LQR controller, it performs better than the LQR controller in most earthquakes for different conditions of ground state. The performance of the controllers decreases with increasing soil softness, so that ignoring the SSI effects may result in incorrect and unrealistic results of the seismic behavior of the structures.

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