This paper introduces DEEM (Differential Evolution with Elitism and Multi-populations), a novel heuristic optimisation algorithm of the Differential Evolution family. DEEM integrates elitism and multi-population strategies to improve convergence speed and accuracy. Additionally, a diversity-based restart strategy is employed to significantly reduce the algorithm's susceptibility to being trapped in local minima. The influence of algorithm parameter choices on optimisation success is demonstrated through a sensitivity study. The algorithm's effectiveness is validated against benchmark functions from CEC 2015, 2017, 2020, and 2022, showing superior performance compared to state-of-the-art DE algorithms. Additionally, DEEM's application is showcased through a complex optimisation problem in the field of geotechnical engineering: the calibration of advanced constitutive models for predicting the stress-strain behaviour of soils under monotonic and cyclic loading. This calibration process is notably time-consuming. DEEM not only achieves better objective values but also does so in fewer iterations, thus significantly reducing computational time.

Nonlinear dynamic analyses are required to account for the structural performance of mid- to high-rise buildings and complex structures. Generally, time history analyses are carried out considering several ground motions for a certain seismic action. These analyses are often very time-consuming, mainly because of the high resolution of the ground motion signal. Therefore, performing these calculations based on lower resolution accelerograms can be very useful, especially when dealing with large sets of buildings (e.g., seismic vulnerability studies on an urban scale). In this paper, two methods for signal reduction are tested against each other: i) an open-source Fourier-based resampling implementation; and, ii) a simple reduction algorithm that preserves both the highest and lowest peaks of the signal. The experiments compare the two methods at several levels of resolution reduction and for three different accelerograms. The influence of amplitude scaling on important earthquake demand parameters (EDPs), namely, the peak floor displacements and accelerations have been studied for three reinforced concrete case study buildings modelled in OpenSees: low- (5-storey), mid- (8-storey) and high-rise (11-storey). The results allow establishing a set of criteria to choose the appropriate reduction method and level. This depends on the balance desired of computation time versus calculation accuracy. Real accelerograms without baseline corrections have been for the tests. The simple reduction algorithm method appears to capture better the accelerograms by avoiding excessive interpolation. This results in peaks and areas closer to the original signal. However, it presents greater variability in energy preservation, introducing large abrupt changes in acceleration. These large fluctuations have led to inducing significantly larger displacements in OpenSees, causing greater structural damage. The Fourier method led to better and consistent results than the reduction algorithm proposed. Resolution 50 provided a reduction in time of up to 30% and an error margin of the engineering demand parameters of around +/- 15%.

While drought impacts are widespread across the globe, climate change projections indicate more frequent and severe droughts. This underscores the pressing need to increase resistance and resilience to drought. The strategic application of Preventive Drought Management Measures (PDMMs) is a suitable avenue to reduce the likelihood of drought and ameliorate associated damages. In this study, we use an optimisation approach with a multicriteria decision-making method to allocate PDMMs for reducing the severity of agricultural and hydrological droughts. The results indicate that implementing PDMMs can reduce the severity of agricultural and hydrological droughts, and the obtained management scenarios (solutions) highlight the utility of multi-objective optimisation for PDMMs planning. However, examined management scenarios also illustrate the trade-off between managing agricultural and hydrological droughts. PDMMs can alleviate the severity of agricultural droughts while producing opposite effects for hydrological droughts (or vice versa). Furthermore, the impact of PDMMs displays temporal and spatial variabilities. For instance, PDMMs implementation within a specific subbasin may mitigate the severity of one type of drought in a given month yet exacerbate drought conditions in preceding or subsequent months. In the case of hydrological droughts, the PDMMs may intensify streamflow deficits in the intervened subbasins while alleviating the hydrological drought severity downstream (or vice versa). These complexities emphasise a customised implementation of PDMMs, considering the basin characteristics (e.g., rainfall distribution over the year, soil properties, land use, and topography) and the quantification of PDMMs' effect on the severity of each type of drought.

Advances in the design process and understanding of the structural behaviour of jacket -type foundations for offshore wind turbines are fundamental to the expansion of these devices in medium -depth waters. The structural evaluation of jacket foundations is a complex and computationally expensive task because of the large number of structural elements and numerous load scenarios and requirements imposed by international standards. In this context, the soil-structure interaction is not usually incorporated into the optimisation process of these devices, assuming that the foundation flexibility does not significantly affect the supporting structure. This study investigated an approach for analysing the influence of the soil-structure interaction on the structural design. To perform a relevant analysis, an optimisation process was used to obtain feasible designs for a 10 -MW wind turbine in a specific location. To optimise and evaluate the jackets, a structural model based on static equivalent analysis of the most representative load scenarios for environmental loads was used. The obtained designs highlight the importance of considering the soil-structure interaction for evaluating the technical requirements imposed on these structures, especially in the ultimate limit states.

Lightning strikes can cause equipment damage and power outages, so the distribution system's reliability in withstanding lightning strikes is crucial. This research paper presents a model that aims to optimise the configuration of a lightning protection system (LPS) in the power distribution system and minimise the System Average Interruption Frequency Index (SAIFI), a measure of reliability, and the associated cost investment. The proposed lightning electromagnetic transient model considers LPS factors such as feeder shielding, grounding design, and soil types, which affect critical current, flashover rates, SAIFI, and cost. A metaheuristic algorithm, PSOGSA, is used to obtain the optimal solution. The paper's main contribution is exploring grounding schemes and soil resistivity's impact on SAIFI. Using 4 grounding rods arranged in a straight line under the soil with 10 Omega m resistivity reduces grounding resistance and decreases SAIFI from 3.783 int./yr (no LPS) to 0.146 int./yr. Unshielded LPS has no significant effect on critical current for soil resistivity. Four test cases with different cost investments are considered, and numerical simulations are conducted. Shielded LPSs are more sensitive to grounding topologies and soil resistivities, wherein higher investment, with 10 Omega m soil resistivity, SAIFI decreases the most by 73.34%. In contrast, SAIFIs for 1 klm and 10 klm soil resistivities show minor decreases compared to SAIFIs with no LPS. The study emphasises the importance of considering soil resistivity and investment cost when selecting the optimal LPS configuration for distribution systems, as well as the significance of LPS selection in reducing interruptions to customers.

Open pit mines are large geotechnical structures. Their stability is an important consideration in the mining industry. The deformations of geotechnical structures often involve the coupled interaction between the pore fluid pressure and the nonlinear deformation of soil, characterised by poro-elasto-plastic behaviour. This paper develops the scaled boundary finite element method (SBFEM) to address poro-elasto-plastic in slope stability problems. It builds upon a previously developed elasto-plastic formulation to consider the effect of pore fluid pressure and its interaction with the nonlinear deformation within the soil. The pore pressure field introduces an additional variable in the governing equations that is similarly discretised using SBFEM shape functions. The SBFEM is implemented together with a pixel-based quadtree mesh generation technique, enabling automatic meshing directly from digital images. This leads to efficient automation when modelling problems with iterative changes in the geometry such as in optimisation of construction processes during the rehabilitation of slopes. The formulation is validated first using a standard numerical benchmark. Application of the developed technique in construction applications in slopes where the stability and effect of pore water pressure is considered e.g., tailings dam construction and optimisation of backfilling process is demonstrated in three examples to demonstrate feasibility.