Approach for Measuring Swelling Stress of Buffer Backfilling Material

The characteristics of swelling stress of buffer backfilling material have been studied by forcebalance method and constant volume test method in this paper. The constant volume test apparatus was designed by the authors. Results show that swelling stress changing with time is a little different between the two methods. The value of swelling stress measured by constant volume test is more accurate; besides, uptaking water with time could also be monitored by constant volume test. The constant volume test method is more suitable for measuring the swelling stress of buffer backfilling material.