A study on expanding characteristic of weathered granite

Weathered granite is a typical weak rock. It contains some viscidity minerals which swell when encountered with water, such as montmorillonite, kaolinite, illite, etc. Therefore, weathered granite brings about adverse influence upon rock and soil engineering. Based on in-situ tests, this paper studies the expanding characteristic of weathered granite under engineering conditions. Test results indicate that the number of free faces is an important factor affecting the expanding characteristic of weathered granite, that the more the free faces, the more remarkable the expansion, and that the magnitude of expansion force is mainly affected by montmorillonite content but hardly by the illite and kaolinite contents.