모형실험을 통한 포화사석층 그라우팅의 차수효과

Abstract

In the case of the ground having underground water, the grouting method is normally used. The grout material includes mortar that is combined with one or more among cement suspension, clay, sand, gravels or bentonite, or the chemical fluid of cement. However, these grout materials are hard to permeate, can be swept away because they take long time to harden. For these reasons, it requires another renovation again within 5 or 10 years due to the eluviation of grout materials. Therefore, it is necessary to develop grout materials which are more suitable for the void of ground and having underground water. Grouting is generally used for the impermeable body of breakwater or reinforcing it, but unavoidably the mixture of boulders or the oddly shaped stones disrupts drilling works. Grouting is not done as effectively as we expect. New grouting methods and materials are being developed and attempted, but the grouting to saturated riprap layer in particular is not effectively done. Especially, when using the grout fluid, the grout materials are hard to fill the void and sometimes the weak durability happens by the eluviation of the grout fluid. Also, when injecting the cement suspension, it could be diluted by the velocity of a moving fluid, and if the velocity is too fast, the filling would not be able to perform well. In this study, four grout materials were developed to evaluate the effectiveness of grouting to saturated riprap layer with flow of underground water . The developed materials are divided into quick-setting and general-type which are also composed of the high and low viscosity. A number of grouting experiments were performed in a model chamber with 0.4m in diameter and 2.0m in length. To reproduce the field conditions of saturated riprap layer, the grouting experiments were done with 0cm/sec and 10cm/sec of the flow velocity and 10L/min and 20L/min of the injection velocity. Based on the grouting experiments, the quick setting type was found to be most effective for grouting to the saturated riprap layer.