Superstructure–foundation interaction in multi-objective pile group optimization considering settlement response

Leung, Yiu-Wing; Klar, Assaf; Soga, Kenichi; Hoult, Neil A.

doi:10.1139/cgj-2016-0498

Cited by 25 publications

(14 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This procedure is repeated for all the degrees of freedom to result in a relatively small, fully populated, condensed matrix that incorporates the structural response within a lean representation of the foundation system. This condensation approach was recently used for incorporating the structure response in a foundation optimization problem (Leung et al 2017). An illustration of the process is provided in Fig.…”

Section: Formulationmentioning

confidence: 99%

Nonlinear elastoplastic formulation for tunneling effects on superstructures

Elkayam

Klar

2019

Can. Geotech. J.

View full text Add to dashboard Cite

The paper presents a formulation for evaluating the effect of tunneling on existing buildings. The formulation involves the matrix condensation method to represent the response of a linear elastic building and macroelements to represent the nonlinear elastoplastic soil behavior. The formulation includes new features that allow interaction between macroelements, both through the soil continuum and the structure, to result in the final displacements of the foundations due to tunneling. One of the advantages of the formulation is its ability to incorporate a general input of a greenfield field displacement for the interaction analysis, allowing consideration of various tunneling scenarios. The formulation is evaluated by a comparison with a continuum-based solution obtained using the finite difference method. The formulation is then used to conduct a parametric analysis of tunneling–soil–superstructure interaction, considering three different approaches: (i) the suggested elastoplastic formulation, (ii) purely elastic analysis, and (iii) simplified analysis in which the foundations are forced to displace as a greenfield. It is shown that the vertical settlements of the foundations, due to tunneling, are the greatest when the first approach is considered. This is an outcome of the combined vertical and horizontal yielding, depicted in the formulation by the coupled yield function and plastic flow potential. Yet damage, which relates to differential settlement, appears to be smaller in the elastoplastic formulation.

show abstract

Section: Formulationmentioning

confidence: 99%

Nonlinear elastoplastic formulation for tunneling effects on superstructures

Elkayam

Klar

2019

Can. Geotech. J.

View full text Add to dashboard Cite

show abstract

“…For efficient optimisation of the parameters, this study employs the heuristic algorithm known as differential evolution, which is conceptually similar to other evolutionary algorithms such as the genetic algorithm. Details of the differential evolution algorithm are described by Storn and Price 38 and in recent engineering applications such as Leung et al 39 Essentially, a population of candidate solutions is first generated randomly in the optimisation process. The candidate solutions are vectors of the six variables (i.e.…”

Section: Model Calibration By Differential Evolutionmentioning

confidence: 99%

Thermal integrity testing of cast in situ piles: An alternative interpretation approach

Sun

Elshafie

Barker

et al. 2020

Structural Health Monitoring

View full text Add to dashboard Cite

Integrity testing of deep cast in situ concrete foundations is challenging due to the intrinsic nature of how these foundations are formed. Several integrity test methods have been developed and are well established, but each of these have strengths and weaknesses. A relatively recent integrity testing method is thermal integrity testing. The fundamental feature is the early age concrete release of heat during curing; anomalies such as voids, necking, bulging and/or soil intrusion inside the concrete body result in local temperature variations. Temperature sensors installed on the reinforcement cage collect detailed temperature data along the entire pile during concrete curing to allow empirical identification of these temperature variations. This article investigates a new approach to the interpretation of the temperature variations from thermal integrity testing of cast in situ concrete piles and presents a field case study of this approach. The approach uses the heat of hydration and heat transfer theory and employs numerical modelling using the finite element method. The finite element model can be customised for different concrete mixes and pile geometries. The predicted temperature profile from the numerical model is then compared, in a systematic manner, to the field test temperature data. Any temperature discrepancies indicate potential anomalies of the pile structure. The proposed new interpretation approach could potentially reduce construction costs and increase the anomaly detection accuracy compared to traditional interpretation methods.

show abstract

“…It is conceptually similar to other evolutionary algorithms such as genetic algorithms and is not prone to converging at local maxima. The DE algorithm has been effectively used in many recent engineering applications, such as geotechnical modelling (Uchida et al, 2016), damage detection (Jena et al, 2013;Liu & Mao, 2016) and superstructure-foundation interaction (Leung et al, 2017).…”

Section: Differential Evolutionmentioning

confidence: 99%

Concrete Hydration Model Characterization Using Evolutionary Optimization

Sun¹,

Elshafie²,

Rui³

2020

Proceedings of the International Conference on Civil Infrastructure and Construction (CIC 2020)

View full text Add to dashboard Cite

Pile thermal integrity assessment by means of temperature measurement has received increasing attention in recent years. The thermal integrity testing method measures temperature changes during the concrete curing process; using an appropriate concrete hydration model together with tracking temperature development during the curing process, defects within piles could be detected. However, the implementation of thermal integrity testing in practice faces, potentially, many uncertainties including undocumented concrete mixes, lack of knowledge of ground thermal properties, uncertain boundary conditions for pile, etc... These uncertainties increase the complexity of determining appropriate parameters for the hydration model, which directly affects the defect detection capacity of the method. This paper presents an inverse approach using differential evolution (DE) algorithms to determine the concrete hydration model. With this approach, the finite element (FE) analysis is integrated into the DE algorithm to generate approximate solutions that match a controlled dataset instead of approximating the concrete hydration parameters with limited prior knowledge as currently used in practice. Firstly, a field test temperature dataset with a well-defined boundary condition is selected. The temperature development corresponding to the selected dataset is then numerically simulated using an uncalibrated general hydration model. Finally, the hydration model parameters are determined using DE algorithms based on the measured and simulated temperature development as inputs. A field case study is presented in the end of this paper. The results indicate that the proposed inverse approach using DE algorithms can be used effectively in thermal integrity testing.

show abstract

Superstructure–foundation interaction in multi-objective pile group optimization considering settlement response

Cited by 25 publications

References 34 publications

Nonlinear elastoplastic formulation for tunneling effects on superstructures

Nonlinear elastoplastic formulation for tunneling effects on superstructures

Thermal integrity testing of cast in situ piles: An alternative interpretation approach

Concrete Hydration Model Characterization Using Evolutionary Optimization

Contact Info

Product

Resources

About