Rock damage and fracture is closely related to each other

and there is a specific relationship between strength criterion parameters and fracture toughness of fracture theory. Based on these

a compact test scheme was designed for three-point bending fracture toughness test

compressive strength test and tensile strength test of sandstone under the states of dry and saturated. The test results show that after saturated in water

the softening effect of modeⅠfracture toughness of sandstone was obviously

and the fracture toughness ratio of water-saturated sample and dry sample is close to the sandstone softening coefficient of the compressive strength

showing a similar softening effect. Meanwhile

the relationship of the modeⅠfracture toughness and the tensile strength was discussed through theoretical analysis; and a large number of experimental data was used to verify the analysis results. As a result the analysis results can provide a theoretical basis for the previous statistical fitting formulas between modeⅠfracture toughness and the tensile strength. Finally

statistics and analysis of the relationship between modeⅠfracture toughness and compressive strength

cohesion

friction angle and some other strength parameters was made. Research results have an important reference value for the study of the correlation between modeⅠfracture toughness and strength parameters of sandstone

and the related test methods

test results and conclusions can provide favorable evidences for the experimental research of other types of rocks.