The long-term growth and economic success of any country is heavily dependent on the availability and progress of its infrastructure services, since these resources are the basic factors that control the country's economy while contributing to the well-being of individuals. A rapid industrialization and urbanism has resulted in a constant requirement for technological advancement and research throughout the sector of construction and engineering. In the past few decades, there has taken place a tremendous transformation in the growth of infrastructure services, and these amenities or buildings are erected over the ground surface, and necessitates significant expenditures throughout the pre and post constructions phases. The SSS is frequently linked to the failure of the ground and the collapse of buildings. The friction, cohesion as well as interlocking between two particle mainly depends on the SSS under various cases of loading (Das and Sobhan, 2013). The SS for any geotechnical materials may be expressed using the Mohr-Coulomb theory. Cohesion and the angle of internal friction (c and φ) are two SS components that, based on a theory vary according to normal stress (Zhang et al., 2010):
Where τ is the SS, c is the cohesion, σ is the normal stress, and φ is the angle of internal friction.
The intercept and slope of the tangent that was made on the failure envelope that was suggested by Mohr-Coulomb are what define its characteristics (Fig. 1). According to Mollahasani et al. (2011) and Murthy (2008), the intercept in this case represents nothing else than c, however the slope in degrees represents the φ. Various factors that affect SSS are: IP, clay content (CC), and others (Das and Sobhan, 2013). Three different types of stress always exist in slope materials i.e., major, intermediate, and minor principal stress—that act on three principal axes that are at right angles to one another. Normal stress on the slip surface, angle of internal friction, and cohesion, are all functions of the SSS. The angle of rupture, stability condition of slope materials, safety factor, and SS are all affected by the soil's key physical qualities of cohesion, and angle of internal friction. Any soil's values for these parameters depend on a variety of variables, including the soil's textural characteristics, its past development, and its initial condition the soil's permeability characteristics and the drainage conditions permitted during the test (Murthy, 2008).
The SSS is influenced by its constituents: specific gravity (G), e, wc, PL, LL, CC, stress history, and relative density (Pham et al., 2020). Because soil frequently has varied particle sizes, higher wc, and larger voids, its physical characteristics are complex (Das and Sobhan, 2013). The exact assessment of both SS characteristics should be a primary priority for the design of any constructions that will be sitting on soil. These measurements can be determined either in the laboratory or out in the field. In the lab, these parameter of interest (c, φ) may be measured either with the help of direct shear test (Fig. 2a), tri-axial test (Fig. 2b), unconfined compressive strength test (Fig. 2c), whereas in the field, it may be measured by vane shear test apparatus (Fig. 2d), or with the help of any indirect method of soil testing (Murthy, 2008; Mollahasani et al., 2011; Pham et al., 2018).
Computing is the procedure of transforming one type of information into another desirable form of outcome via the use of commands operations. Computer-aided techniques are among the most promising options for simulating a variety of structural engineering-related issues as a result of technological improvements (Nguyen et al., 2020). Companies and developers all around the world are discussing for incorporating artificial intelligence (AI), deep learning (DL), and machine learning (ML) in this new era of technology. In the world of technology, such abbreviations are frequently used inappropriately. Since the 1980s, many searching techniques have been established under the aegis of AI. Certain approaches imitate biological processes like neurological connections, the development of species through natural selection, and the behaviors of social groupings of organisms like ants, birds, bees, etc. On the contrary side, other searching methods rely on mathematical, logical, and statistics rather than any natural processes in order to get the best answer. AI is a broad field that includes all aspects of computational intelligence.
ML techniques are being used more and more to make accurate predictions about real-world problems like clustering, correlation, regression, and classification (Varma et al., 2023; Xu et al., 2021; Xie et al., 2020; Kaveh & Iranmanesh, 1998; Kaveh et al., 2008; Kaveh & Servati, 2001). Geotechnical engineering is one of the engineering fields where AI is routinely used for mapping the non-linear correlation in between output and input parameters (Bardhan et al., 2022; Zhang et al., 2022; Zhang et al., 2021; Wu et al., 2021). In recent years, neural networks have also been successfully used as an alternative approach to handle a variety of challenges associated in soil mechanics (Pham et al., 2017; Shahin et al., 2009). The testing and training are the two critical phases on which ANN completely depends. Large amounts of data must be labeled in the training phase along with their corresponding characteristics, while in the testing phase, conclusions are drawn from prior experience and new, untouched data is labeled (Dargan et al., 2019). An input dataset is given to the ANN during training, and weights between the interconnections are changed to produce the output determined by the input dataset. Among the various ANN algorithms used for classification and regression issues, multilayer perceptron (MLP) is regarded as best one of the most effective method.
Instead of measuring directly in the lab and field, geotechnical structures' parameters for design are often measured by employing empirical correlations which is created by fitting equations for regression to an established database (Zhang et al., 2020). Nineteen different empirical methods for predicting SSS in unsaturated situations were investigated by Garven and Vanapalli (2006). Several potential soil factors were evaluated for correlation with SSS in the method that was employed. Kiran et al. (2016) employed PNN approach for the prediction of SSS on the basis of input parameter: dry density (ρd), wc, IP, silt proportion, sand proportion, gravel proportion, clay proportion, etc. (Pham et al., 2018). The researchers find that the algorithm falls short of precisely describing the complicated behaviour of soil. The reason could be that such types of algorithms were utilized to mapped curvilinear relationships in between the input and response variable in spite the availability of some of the empirical equations (Farrokhzad et al., 2012).
There has been a rise in the use of SC techniques such as ANN, ANFIS, SVM, etc. for studying parameters having nonlinear relationships to their important components (Gao et al., 2018). Prediction of soils is often performed using ANN, adaptive neuro-fuzzy inference system (ANFIS), and genetic expression programming (GEP) (Kayadelen et al., 2009). Researchers and academics have attempted to improve AI models and developed associated optimization technologies as a result of technological progress and rising geotechnical engineering accuracy needs (Chou et al., 2016). In a general sense, we can say that one of the general forms to enhance the performance of any geotechnical structure and design it with the help of MOAs in the optimization technique. Such techniques are effective and strong methods for tackling stochastic optimization problems. The optimization for the ML performance of predicting approaches may be improved via the optimization of model parameter. The various model parameters are: bias, weight, kennel function penalties.
Many MOAs were developed in the evolutionary work and optimization technique in these days (Abbasi et al., 2021). The latest study has demonstrated that meta-heuristic-based optimization methods can improve the efficiency of ML-based algorithms (Kardani et al., 2021; Bardhan et al., 2021; Raja et al., 2022). MOAs are employed with ML systems with two reasons: (1) improving and predicting parameters for the model while development; and (2) optimizing the hyper-parameters linked to network structure (Yang and Shami, 2020; Alkabbani et al., 2021). This type of optimization not only increases the ANN's prediction capacity, yet also assists in reducing the typical "local minima trap" problem by altering the parameters used for learning (biases/weights), giving notable benefits (Bui et al., 2019; Zhang et al., 2020; Xie et al., 2021; Raja et al., 2022). Now a day, heuristic methods have added reputation, especially GAs and swarm intelligence methods (Biswas and Biswas, 2015). For example, the PSO method is inspired by the migration of bird in the sky (Kennedy & Eberhart, 1995).
Several meta-heuristic optimizations (MOAs) were developed and employed to optimize the configuration of traditional machine learning (TML) techniques. These offer a balanced approach to exploration and exploitation (E&E), which improves traditional ML algorithms' searching performance and capabilities. It implies that optimization of ML algorithms with MOAs will find the real global optimum instead of local minima by producing optimal structures and optimum ML algorithm learning parameters. Additionally, several types of performance parameters, advanced visualization methods, sensitivity analysis, uncertainty analysis, and analysis for feature importance have done and investigated to compare the effectiveness of the suggested models. The main objective of this research work is to optimize the ANN model for the prediction of SSS using three different MOAs: ANN-GA, ANN-MPA, and ANN-PSO, also to develop the most efficient computational model.
Research Significance
Prior to being used to solve important problems, ANNs have computational shortcomings that must be fixed, like risk due to its dimension (Chen et al., 2017), local minima (Akkurt et al., 2003) etc. Additionally, its utilization can be constrained because of over-fitting problems that is considered as TML techniques' primary weaknesses (Mohammadzadeh et al., 2014). Dang et al. (2019) and Rokach (2010) have shown that optimised algorithms enhance the accuracy of predictions while decreasing the issue of over-fitting. By combining TML with MOAs results in a multi-dimensional structure that optimizes the E&E phases during optimization, providing an effective method for resolving difficult problems.