Case study of stability evaluation method related with preservation of
historic erosion control facilities
|Taking the Kamatsusawa Erosion Control Dam, Inari River, Nikko City, as an
example|
Taku NISHIYAMA, Koji OOYA, Osamu TAINAKA and Takao ITOU
Abstract
The history of erosion control dams started with a series of dams constructed
with stones by dry masonry method, as part of the erosion control dam program
under the direct control of the Ministry of Home Affairs during the Meiji Era.
Many of those old dams have been destroyed as a result of frequent sediment discharges.
However, some of the existing old dams have blended in with local landscaper and
have been registered at tangible cultural properties due to their historical significance.
Most of those valuable old dams, however, are decayed from repeated outflow of
earth and sand, and repairs and/or reinforcement measures must be taken for them
immediately. This paper focuses on the Kamatsusawa Erosion Control Dam, which
is one of the historic erosion control dams registered as tangible cultural properties,
forming a group along the Inari River, Nikko City, Tochigi Prefecture, as an example
of efforts to effectively preserve historic erosion control facilities. Appropriate
stability collation constants are set on the basis of in]situ tests and laboratory
experiments, and it is indicated that aging facilities can be maintained effectively
by taking minimum reinforcement and/or repair measures involving stability collations
with a multilayered structure weight calculation method for the dam body and multilayered
ground banking]sand calculation method applied.