Expansive soils, when wetted, exert swell pressure on the structures built over them, often leading to damage. To quantify this additional pressure, researchers have often measured the vertical and lateral swell pressure. However, when expansive soils surround the structures in all directions, measuring the all-round swell pressure becomes more appropriate. In this context, an Isotropic - Pressure Monitoring Device (I-PMD) was employed in the present study for the measurement of all-round swell pressure for the soils C1, C2, C3, and C4 by wetting them from different initial states at constant volume conditions and was observed to be in the range of 20 kPa to 850 kPa. Also, comparative studies have been performed to comprehend the significance of all-round swell pressure measurement over conventional methods. Additionally, a relationship was proposed to predict the all-round swell pressure of the soil based on its vertical swell pressure measured by conventional methods.

This experimental research has been conducted to improve the mechanical properties of the problematic expansive soil using copper slag. The copper slag has been utilized to improve the Talab soil in Nainwa for the first time. The swelling properties show that the collected soil has a high degree of expansive nature and low specific gravity. Therefore, the copper slag has been added to the soil from 5% to 30% at a 5% variation by its oven-dry weight. The experimental results reveal that the free swell index of soil has decreased by 69.88% with the addition of 30% copper slag. It has also been observed that the liquid and plastic limits have been decreased. The plastic limit of soil decreases, because copper slag takes place in voids. Due to this phenomenon, the maximum dry density of soil has been increased by 14.75% with the addition of 25% copper slag. The California bearing ratio (CBR) value of soil has been increased to 1.13% (soaked condition) and 3.8% (unsoaked condition) by adding 25% copper slag. This research introduces an empirical relationship between unsoaked and soaked CBR with a determination coefficient (R2) of 0.8254. Moreover, it has been observed that the unconfined compressive strength of soil has increased by 51.68% with the addition of 25% copper slag. Furthermore, the value of R2 for the experimental results obtained in this research is higher than the published experimental results, presenting the experimental study's accuracy and reliability. In addition, the analysis of variance (ANOVA) test accepts the research hypothesis for the present investigation.