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Due to the complexity of the hydro-mechanical behaviour of soils subjected to internal erosion, a high number of parameters are usually required for the erosion models and the constitutive models. This aspect makes it difficult to determine by trial-error their relevant values from laboratory tests. To address this issue, an efficient optimisation-based procedure for identifying the parameters of a recently developed hydro-mechanical model for internal erosion using an enhanced backtracking search algorithm (so-called MBSA-LS) has been proposed. The MBSA-LS incorporates two points: (1) modifying the mutation of the original Backtracking Search Algorithm (BSA) and (2) incorporating an efficient differential evolution (DE) as a local search to improve the optimisation performance. A mono-objective framework with six different criteria has been proposed to identify the parameters related to the interlocking effect and the erosion process. The proposed procedure was successfully applied to identify the parameters from the erosion tests of Hong Kong-Completely Decomposed Granite mixture (HK-CDG). All results demonstrated that coupling the MBSA-LS and the hydro-mechanical erosion model could efficiently solve the issue of parameter identification accounting for both the mechanical behaviour and internal erosion. [ABSTRACT FROM AUTHOR]

• A framework for long-term serviceability assessment of immersed tunnel is proposed. • Two serviceability failure modes are considered. • A novel beam on elastic foundation model is developed for settlement estimation. • The Bayesian method with the DE-TMCMC algorithm is used to qualify uncertainties. • The proposed framework is verified by field data from the HZM tunnel. In immersed tunnels, the considerable settlement that can develop during their long-term service period may induce structural damage that affects normal operations (i.e., serviceability performance). The long-term serviceability assessment from the perspective of settlement is thusly crucial to ensure the safety of immersed tunnels, whereas a practical assessment framework is lacking to date. This study presents a feasible reliability analysis framework for the long-term serviceability assessment of immersed tunnels for the first time, in which a novel beam on elastic foundation model (BEFM) is developed as a mathematical model for tunnel settlement analysis. The BEFM is easy to be integrated into the probabilistic framework due to its simple modeling procedure and high computational efficiency. The Bayesian approach with an efficient and robust algorithm, differential evolution transitional Markov chain Monte Carlo (DE-TMCMC) algorithm is adopted to guarantee effective model calibration and uncertainty quantification. The application potential of the proposed framework is demonstrated by a case study of the Hong Kong-Zhuhai-Macao (HZM) immersed tunnel. Results show that the developed method can provide a feasible and effective assessment of the long-term serviceability of immersed tunnels, offering a practical tool to enhance the reliability and safety of immersed tunnels during their operation periods. [ABSTRACT FROM AUTHOR]

Abstract: The solar–thermal refrigeration systems, covering the solar absorption refrigeration system (SAbRS) and the solar adsorption refrigeration system (SAdRS), were designed for typical office in the subtropical Hong Kong. The approach of simulation–optimization was adopted in order to determine the optimal design parameters for SAbRS and SAdRS against the conventional design practice. For simulation, dynamic model of each system was refined on the TRNSYS platform. For optimization, the objective was to minimize the annual primary energy consumption of SAbRS or SAdRS in response to the changing loading and climatic conditions throughout a year. This is a constrained optimization problem since the upper limit of comfort temperature was stipulated, such that the minimization of system energy would not sacrifice the indoor thermal comfort. Due to the complex, multidimensional and constrained nature of the dynamic simulation models, the differential evolution (DE), which has been proven effective in evolutionary computation (EC), was used for optimization purpose. Through the simulation–optimization run, the optimized designs of SAbRS and SAdRS were determined, and their corresponding primary energy consumptions could be 12.2% and 7.1% less than those based on the general design practice. The results provide useful guidelines for the equipment design of SAbRS and SAdRS. [Copyright &y& Elsevier]