Abstract
In order to prevent the disruption of groundwater flow due to shield tunneling construction, the research discussed in this paper developed a backfill injection material including water-absorbent polymers which are able to expel the water as a result of reaction with alkali and achieve necessary permeability in early stage. Mix proportion of the materials based on target values of the material properties such as permeability and modulus of elasticity were examined. The effectiveness of expanding materials and permeable aggregates for improvement of the permeability was also studied during the examing the mix proportion of materials. The workability and the properties were verified by actual casting tests. The results of these tests enabled the determination of a mix proportion of the materials to satisfy the target performance and verified suitable performance of the material for pumping or filling work, and then, we confirmed its adequacy in actual work procedures.
