This paper investigates the mechanical properties of natural moist and saturated moderately weathered sandstone through triaxial compression tests.The study analyzes the effects of transitioning from a natural moist state to a saturated state on key parameters such as sample strength,peak stress,peak strain,and elastic modulus.The experimental results indicate that when the sample changes from a natural to a saturated state,both peak stress and peak strain decrease,while the elastic modulus remains unchanged.Using the lateral strain response(LSR)method,the stress value associated with crack propagation in both natural and saturated moderately weathered sandstone samples is determined by measuring the stress magnitude at maximum volumetric strain.The stress associated with crack propagation is found to be approximately twice that corresponding to crack initiation and ranges between 60%and 95%times the peak stress.Additionally,as confining pressure increases,the primary fracture orientation during the post-failure stage shifts from vertical to horizontal.