The results of a six-year field test program conducted near Fairbanks, AK, to investigate the reduction in frost heave obtained by applying a surcharge stress on the soil are presented. Seasonal heaves of 25-ft-square test sections with nominal surcharge loads of 2, 4, 6, and 8 psi were compared with heaves at adjacent unloaded sections. The test sections were on a silt soil in an area where permafrost existed at about a seven-ft depth. Results showed that only a small surcharge load was needed to cause significant reductions in heave. Data are included that indicate that heave reduction was achieved by minimizing groundwater migration. A method for correlating field and laboratory rate-of-heave data is suggested. (Author).

The magnitude and variation of forces and shear stresses, caused by frost heaving in Fairbanks silt and the adfreeze effects of a surface ice layer and a gravel layer, were determined as a function of depth by using electric strain gauges along the upper 2.75 m of a pop pile, 30.5-cm I.D. x 0.95-cm wall, and an H-pile, 25.4-cm web x 85 kg/lineal m. The peak frost heaving forces on the H-pile for three consecutive winter seasons (1982-1985) were 752,790 and 802 kN, respectively. Peak frost heaving forces on the pipe pile of 1118 and 1115 kN were determined only for the second and third winter seasons. Maximum average shear stresses acting on the H-pile were 256,348 and 308 kPa during the three winter seasons. Maximum average shear stresses acting on the pipe pile were 627 and 972 kPa for the second and third winter seasons. Ice collars were placed around the tops of both piles during the first and third winter seasons to measure the adfreeze effects of a surface ice layer. The ice layer may have contributed 15 to 20% of the peak forces measured on the piles. A 0.6-m-thick gravel layer replaced the soil around the tops of both piles for the second and third winter seasons to measure the adfreeze effects of a gravel backfill. The gravel layer on the H-pile may have contributed about 35% of the peak forces measured. Maximum heaving forces and shear stresses occurred during periods of maximum cold and soil surface heave magnitude. These were not related to the depth of frost penetration for most of the winter since forst was present at all depths extending to the permafrost table. (mjm).