In paper II and III a simple numerical model for calculation of frost depth and frost heave in highways is presented. Calculation results are compared with data obtained from two different test sites. Comparison is also made to laboratory tests conducted by using a new laboratory-testing device, developed by the author. It is further argued, that frost heave to great extent is caused by ice lenses formed by water from the pores in unfrozen soil and only to a minor extent by water taken from the ground water, which is normally assumed. Good correlation is found between calculated and observed frost penetration and frost heave, in both field and laboratory condition.
Special attention is paid to the influence of heave rate and water intake rate.