The failure of a 3 m x 4 m transport tunnel constructed below a dolomite stockpile has been investigated. It was found that the cracking of the reinforced concrete lining had most likely been caused by lateral distortion (sidesway) of the tunnel. The transverse shears across the tunnel roof and in the residual soil below the stockpile caused by the sloping stockpile were very high. The average shear stress even exceeded the shear strength of the weathered material around the tunnel. It is thus important to consider the transverse shear forces across the roof slab and the horizontal shear stresses in the surrounding soil in the design of a tunnel lining. In addition to strengthening the tunnel section by means of steel frames, an embankment was constructed at the toe of the stockpile in order to increase the stability. The embankment also reduced the average slope of the stockpile
