1991 年 29 巻 4 号 p. 202-209
There are various defect holes on pipe buried underground.
In this study, a pipe with a circular hole as the defect hole was used. A lining with a Seal Hose was applied inside the pipe, and a series of creep tests for the lining was carried out in order to estimate burst pressure after a long period of time.
As a result, it can be estimated that the long term tensile strength in 50 years will become approx. 80% of the short term tensile strength.
In case that the Seal Hose is installed in a pressure pipe with holes and will be used at 23°C for 50 years, its burst pressure at holes will become 60% of the calculated value from the short term tensile strength.