Jeoloji Münendisliği Dergisi

Problems faced im the applications of the point load index test

ABSTRACT: The point load index, test is .based on the principle that rock sample is broken between two conical platens..Faiiure load and specimen dimensions are used to calculaie the point load strength index and this index is usedin engineering geological studies.. In this paper, the problems related to the point load testing device and the common mistakes of the users are discussed. Based- on the experience of the author, a proposal far including "B* "dimension of the rock, failure time, and. textuml and structural information of the failure stiff ace of rock in thepoint load test form is given, k-value, defining the ratio between the uniaxial compressive strength (s&J and thepoint load strength index (Js(50))f varies significantly for different rocks. Therefore, k-values for different rocksshould be assessed for engineering projects. In this study, a linear relationship with high correlation coefficientbetween (oc) and (ls^{rj) is given for tuffs,