A non-linear creep function embedded in an elastic visco-plastic (EVP) model can simulate the decrease of creep compression rate with time. It overcomes the limitation of a linear…
Abstract
Purpose
A non-linear creep function embedded in an elastic visco-plastic (EVP) model can simulate the decrease of creep compression rate with time. It overcomes the limitation of a linear logarithmic creep function, by which creep continuously increases to infinite value as time approaches infinity. However, the determination of the creep model parameters is a challenging task to apply the EVP model. Therefore, this paper presents a new numerical solution to determine the EVP model parameters applying trust-region reflective least square optimisation algorithm and the finite difference scheme to simulate stress-strain behaviour of soft soil.
Design/methodology/approach
In this paper, the developed method is verified against the field case study of Väsby test fill. A set of EVP model parameters is obtained by applying the developed method to the available laboratory consolidation results of Väsby clay. Then, the predictions of settlement and the excess pore water pressure at different depths are compared to the available field measurement.
Findings
The analysis results show the developed method is a reliable tool to evaluate the long-term performance of soft soils under embankments.
Practical implications
Practicing engineers can use the proposed optimisation algorithm to increase the accuracy of the soil visco-plastic model parameters by utilising all laboratory results of several loading stages during and after the dissipation of the excess pore water pressure.
Originality/value
A novel numerical solution to determine the viscoplastic model parameters applying trust-region reflective least square optimisation algorithm has been developed.
Goudarz Alibakhshi, Hossein Abdollahi and Behzad Nezakatgoo
This study aimed at exploring the antecedents of English as a Foreign Language (EFL) teachers' self-efficacy (SE). That is, the main purpose was to deeply delve into the main…
Abstract
Purpose
This study aimed at exploring the antecedents of English as a Foreign Language (EFL) teachers' self-efficacy (SE). That is, the main purpose was to deeply delve into the main variables and latent which lead to a high sense of SE among teachers of English as a foreign language.
Design/methodology/approach
A phenomenological inquiry was employed to explore the antecedents of language teachers from their eyes. In this study, the phenomenon is SE antecedents. The researchers employed this method to help identify the meaning behind the human experience as it is related to a phenomenon or notable collective occurrence. A semistructured interview checklist was developed, carefully worded, reviewed by five teacher educators known as experts in qualitative research methodology and teacher education and edited based on the experts' feedback
Findings
The findings showed that the antecedents of SE can be categorized into personal variables, educational variables and institutional variables. Personal variables include verbal intelligence, language proficiency and some other traits. The institutional variables include support from administration, support from colleagues, support from the community and quality of work life. The educational antecedents include preservice and in-service training courses. Preservice training courses included the following: the courses on general language skills, courses on teaching methods, practicum courses, etc.
Originality/value
This study was undertaken in a specific context and the participants are specific. Almost all studies on SE are quantitative, and this qualitative study explored the antecedents of teachers' SE from their own eyes. Some of the explored studies were not mentioned in any of the related studies.