APPLICATION OF CSG METHOD TO CONSTRUCTION OF GRAVITY DAM

摘要

In Japan, many new technologies including the RCD construction method have been developed and efforts have made to reduce construction costs. This paper describes the application of the CSG construction method to the sediment trap dam constructed inside the reservoir at the Nagashima Dam as one example of technology development of this kind. The CSG (cemented sand and gravel) construction method was adopted to construct the sediment trap dam in order to reduce costs and shorten the construction period. The CSG construction method is executed by mixing riverbed gravel, excavation muck or other rock-like material produced around a construction site with cement and using it as materials for embankments to increase their strength. It can be used to increase the erosion resistance of embankment and to reap economic benefits by permitting steep gradient of its slopes. For the construction of the sediment trap dam as a permanent structure, a mechanical evaluation and material design of the CSG material was undertaken on the premise that it is a concrete-like material because the design system of concrete dam using elastic theory is simpler than that of embankment dam and reliable safety is obtained as the results.