# Laboratory Testing and Analysis of Clay Soil Stabilization Using Waste Marble Powder
## 1 Introduction  
In the past few decades, there has been a growing interest in researching sustainable and cost-effective techniques for improving the mechanical properties of clay soils [1]. Clay soils are widely distributed worldwide, but their poor geotechnical properties, such as low strength and high compressibility, make them unsuitable for civil and mining engineering projects [2; 3]. Stabilizing clay soils with waste materials has emerged as a viable method for improving these properties in an economically and environmentally friendly manner [4; 5; 6; 7]. However, the durability of stabilization techniques depends on the specific materials and processes used and the application. It is essential to conduct a comprehensive life cycle assessment (LCA) to evaluate the environmental impacts from cradle to grave, e.g., extraction of raw materials, manufacturing, transportation, construction, use, and disposal [8]. LCA provides a holistic perspective on sustainability by analyzing trade-offs between improved soil properties and potential consequences such as carbon emissions or toxicity [9]. With careful LCA, stabilization techniques can be optimized to balance improved effectiveness and minimal environmental impact. Soil stabilization is an essential aspect of geotechnical engineering, as it involves enhancing the engineering characteristics of the soil to make it appropriate for future construction [10; 11; 12]. The development potential of waste marble dust (WMP) as a soil stabilization admixture lies in its ability to increase the stability and strength of the soil. WMP, when combined with soil, can enhance soil geo-engineering characteristics such as ultrasonic pulse velocity (UPV) and unconfined compressive strength (UCS) [13]. Waste marble dust is a by-product of the marble industry that is often dumped in landfills, causing environmental concerns [14]. Nevertheless, recent research has shown it can be effectively reused as a soil stabilizer. The WMP particles occupy the voids in the soil matrix, resulting in improved compaction and reduced settlement. In this way, the chemical composition of marble dust, which contains calcium carbonate, can react with soil particles to form cementitious compounds, thereby increasing the strength of the soil [15; 16]. Predicting the mechanical properties of stabilized clay soils remains problematic due to the non-linear relationships between soil properties and stabilization parameters [17; 18], despite encouraging results from experimental investigations. All geotechnical engineering designs apply strength analysis to determine the feasibility of engineering techniques, including the design and stability analysis of foundations, backfills, retaining walls, slopes, and embankments [19; 20; 21; 22]. It can be used to monitor the effectiveness of soil stabilization, determine the optimum percentage of stabilizer, and evaluate the significance of factors that influence the strength of stabilized soil [23; 24]. The purpose of this paper was to determine the applicability of artificial neural networks (ANNs) as a reliable and effective tool for predicting the geo-engineering properties, such as ultrasonic pulse velocity (UPV) and unconfined compressive strength (UCS), of clay soils stabilized with WMP at different water contents and curing days via numerous models of laboratory tests and analyses. Artificial neural networks (ANNs) are computational models inspired by the function and structure of the human brain. They can learn from data and make predictions based on the patterns they have learned [25; 26]. The use of artificial neural networks (ANNs) to predict mechanical properties of stabilized soils, such as ultrasonic pulse velocity (UPV) and unconfined compressive strength (UCS), has gained popularity in recent years. However, the majority of existing studies have focused on ANN modeling of soil stabilization with lime or cement [27; 28; 29; 30; 31].