Earth pressure exerted on tunnels due to the subsidence of sandy ground

In this paper, the change in the earth pressure acted on the tunnel lining and shear band formation of its Surrounding soft sandy ground were investigated by the indoor tunnel heaving tests and F.E.M analyses. In the case of the rectangular tunnel model, the curved shear bands were developed from the edges of the tunnel roof toward to the ground surface and the earth pressure resulted in a dramatic increase just inside the edge of the roof. When circular tunnel model was lifted, the soil fractured at the points which leaned about 45 degrees from the crown and the vertical pressure increased on the both sides of the crown.