抄録
Infilling of underground voids using a cement mixture is an effective measure to prevent the collapse of old mines, or to restore the ground reaction against overlying foundations. Normally a slurry mixture with high workability is placed into a void under gravity allowing a wide areas to be filled effectively from a single pouring point. However a different type of mixture, a plastic grout, is needed when only limited area is to be filled or where mixtures spillage would lead to problems. The aim of this study is to better understand the behavior of plastic infilling material in the quest for greater reliability in actual work. Two full-scale model tests using plastic grout are described with the spreading pattern and infilling pressure experimentally and numerically assessed. The first test involved filling a 5 m by 7 m void of 500 mm height with plastic grout in a single filling step. In the second test, 2.6 m by 3.0 m void of 200 mm height, was filled in two steps. Both the tests were numerically simulated, with results that quantitatively recreated the experimental infilling pressures.
