地下連続壁トレミーの閉塞防止対策

抄録

In constructing a particularly deep slurry wall down to a depth of 120 m by the tremie method, the tremie became blocked with concrete during the casting of one of the elements. This demonstrated a need for clarification of the mechanism of tremie clogging, knowledge of which would enable us to improve methods for the trouble-free construction of deep slurry walls. Of particular relevance is deciding on suitable materials and how to mix them, as well as managing concrete quality control and control of the tremie casting process. We have therefore tested concrete for various characteristics, separated it into components for analysis, measured pressures within the tremie, and carried out pressurization and dehydration tests on concrete to determine the. cause of tremie blocking. Based on our measurements, we have reached important conclusions regarding the selection of high-strength, high-fluidity concrete materials and their mixing, as well as regarding other measures to prevent tremie blocking. In this paper, we identify the mechanism of concrete clogging in a tremie and propose measures to prevent it.