Author(s): Isao Yamaoka; Mutsuhiro Fujita; Kazuyoshi Hasegawa
Linked Author(s): Isao Yamaoka
Keywords: No Keywords
Abstract: Fruitful field measurements of thermal ice thrusts were carried out on the ice cover (40 and a few cm thick) of Taisetsu dam reservoir on 13 to 17 February 1977. The following results are described: (1) Time series of temperature on the surface and in every 4cm below the surface of the ice cover and thermal ice thrust in each depth of 3- 5cm, 8.5cm, 12- 5cm and 17.5cm below the surface of the ice cover were obtained. (2) The relationship of measured thermal ice thrusts to rates of air temperature rise is verified. (3) The changes of ice temperature and thermal thrust profiles in every second hour and vertical distribution of thermal ice thrust at the time of daily maximum ice pressure are investigated (4) Estimated mean ice thrusts averaged over effective ice thickness (17.5cm) are presented and the values of ice pressure per lateral unit meter show fairly good fitness to the chart of E. Rose, if considering safety factors of 1- 8 (no restraint) ~ 2.8 (complete restraint). Finally calculated profiles of ice temperature and thermal ice thrust at any time using four elements visco-elastic model and three boundary conditions of ice cover are presented. And the results of ice thrust computed from given ice temperature are compared with observed data- Then the case of no lateral restraint is proved to be suitable for this measurement of Taisetsu dam reservoir.
Year: 1988