Predictive Models for Uniaxial Compressive Strength of Dry and Saturated Marble: An Empirical Approach

Abstract In this study, marble samples were collected from a quarry near the Karakoram Highway, and core samples were prepared for direct compressive strength, indirect strength, pulse velocity, and Schmidt hammer value testing. The study revealed a strong linear relationship between the point load index (PLI) and uniaxial compressive strength (UCS) for both dry and saturated samples, demonstrating the predictive value of PLI, especially in dry conditions. However, it is important to note the reduced reliability of this relationship in saturated samples, which is likely due to factors such as pore water pressure. An exponential relationship was also observed between ultrasonic pulse velocity (Vp) and UCS, with most samples exhibiting lower Vp values than the typical marble average. This suggests variations in the subsurface structure of the marble and warrants further investigation to understand its mechanical implications. The linear correlation between the degree of weathering and Schmidt hammer readings offers a practical method for assessing weathering conditions. Grade I marble exhibited Schmidt hammer rebound values greater than 45, while values ranged between 35 and 45 for Grade II and were less than 35 for Grade III. The stress-strain curve revealed a decrease in peak stress (from 60 MPa to 32 MPa) with saturation. These results enhance the understanding of Ghulmet marble's mechanical behavior and its suitability for diverse applications, emphasizing the importance of considering varying conditions and characteristics in geotechnical assessments.