Reactive/ expansive soils are a type of soil that undergo significant volume changes in response to changes in moisture content. These soils typically contain clay minerals, such as montmorillonite, which have the ability to absorb water and expand, leading to swelling. Conversely, during dry periods, these soils can also shrink, leading to subsidence and structural damage to buildings, roads, and other light weight infrastructure.

Over recent decades, extensive research has been dedicated to understanding the influence of initial conditions on soil swell by numerous researchers. However, a predominant focus of this research has been on small-scale oedometer tests. Although some researchers have conducted large-scale laboratory and field experiments, their implementation has been constrained by factors such as cost, time limitations, and technical complexities. Nevertheless, with anticipated shifts in rainfall patterns due to climate change, a notable gap persists in the literature regarding the impact of these patterns on soil swell. Addressing this gap, this study aims to investigate the effects of two distinct rainfall patterns, Rainfall pattern 1(RP1) and Rainfall Pattern 2 (RP2), on the swelling behaviour of reactive soil through a series of large-scale long-term soil column experiments. The study seeks to explain the mechanisms influencing swelling behaviour and compare the obtained data with existing swell prediction methods to validate commonly used approaches in soil swelling analysis. Furthermore, the study attempts to examine the influence of different geosynthetics on the swelling behaviour of reactive soil. [...]