Settlement pressures on roof structures

Buildings which are located in very heavy snow zones and which could be completely covered with snow during the winter have effective snow roof loads considerably in excess of the actual snow loads on the projected area of the roof. When this happens some weight of snow which would ordinarily be supported by the ground can be transferred through shear to the roof. Although no known experiments have been performed to evaluate the settlement pressures on an actual roof, data from shear and tensile tests on snow gives a means of estimating the weight of snow from the area surrounding a building which would be additive to the weight of snow directly over the roof. An experimental setup is proposed for measuring the increase in snow load due to settlement pressures on a buried roof. Buildings which have been known to have been damaged by settlement pressures are identified.