High thermal effects on Point Load Index (P.L.I) of rocks tolerate in mind an essential issue for numerous geotechnical engineering purposes. Many engineering relevancies interact with it as Geothermal power reserve extraction, Fires that occur in tunnels, Underground coal gasification (UCG), and numerous ancient monuments that were made from these rocks and exposed to different thermal impacts. This research aims to carry out Point Load Index (P.L.I) experimental studies of intact rocks as Granite, Sandstone, Marble and, Limestone rocks. In this study, the rock samples are subjected to thermal effects (from room temperature degree 25 oC to a high temperature up to 1100 oC). The results are debated and introduced in terms of rising temperature degrees with different parameters. It has been known that the Point Load Index (P.L.I) of rocks decreased with the elevated temperature, particularly outside particular temperatures.

Keywords: Rock strength, Thermal Effects, Point Load Index, Different Rocks