中国矿山工程

Moisture content is a key factor affecting the mechanical properties and failure modes of granite. In order to explore the influence of different moisture contents on the mechanical properties and failure modes of granite, three groups of uniaxial compression and acoustic emission tests of granite with different moisture contents (dry, natural and saturated) were carried out. The influence of moisture content on granite was discussed from the mechanical behavior, fracture mode and acoustic emission parameter characteristics of samples. The results show that with the increase of water content, the peak stress and elastic modulus of granite decrease gradually. Compared with dry samples, the peak stress of saturated samples decreases by about 5152%, and the elastic modulus decreases by about 2277%. The peak strain decreases first and then increases. The peak strain of granite in natural state is the lowest, about 0694%. Poissons ratio increased linearly from 021 to 025. The higher the water content, the more obvious the stress drop phenomenon in the stress-strain curve of the granite sample. With the increase of water content, the number of tensile cracks on the surface of granite samples decreases, and the volume of rock collapse increases. The failure mode of rock changes from splitting failure to tensile-shear mixed failure, and finally to X-type conjugate shear failure. With the increase of water content, the hydration reaction weakens the cohesion between particles, and the rock is more prone to micro cracks.