Shallow biogenetic gassy sand is one of special unsaturated soil. Because of containing closed biogenetic gas
whose existence has great influence on the engineering property of sand
the sandy soil has special engineering characteristic from other common ones. In this paper
the initial judgment is drawn on whether sand contains biogenetic gas
and then the in-situ and laboratory tests are done to compare the bearing capacities of sand before and after gas release. It is found that with avoiding seepage failure happening
the slow release of biogenetic gas can increase the bearing capacity of sand
which will be good for the stability of upper buildings.