Abstract

Unconfined compressive strength is one of the most important engineering parameters in rock mechanics, used to characterize and study the behavior of solid rocks. A good correlation between the unconfined compressive strength test (UCS) and the point load test (PLT) can be very useful because it allows for faster and cheaper testing than others with the same security to calculate the structures and performances of solid rocks.           A preliminary step to implement the correlation is to have a good method for determining the resistance to point load.This determination is quite correct if you have enough number of tests on specimens of the same nature, but usually it does not occur and it is necessary to apply a size correction factor F = (De / 50)α, with α= 0,45.  In this paper, we study how adequate this factor and begin the study of an alternative factor. The expression proposed to define this alternative factor contains an exponent α, theα*type α*= C1 - C2 xIs(50),F, where Is(50),F is the resistance index to the point load obtained with the normative factor (F). It is also important to know before PLT tests, the optimum size of the specimens       (L / D). This study is based on the limestone from Comunidad Valenciana (Spain) because they represent a very high percentage of their rocks. The implementation has been conducted over 700 tests between field and laboratory, of which 346 are PLT test, 45 are UCS test and the rest are other parameters such as: porosity and specific weight, Slake - Durability, ultrasonic velocity, among others.  All these determinations are intended to start a database for future research.

 

 

 

 

Keywords

Resistance to point load. Point load test (PLT). Franklin test. Size Correction factor. Uniaxial compressive strength. Correlation. Modeling. Rock Mechanic.