Tunnels in swelling ground: simulation of 3D stress paths by triaxial laboratory testing

The research is devoted to study the swelling behaviour in tunnels. A new triaxial testing procedure is developed, which is able to quantify the swelling behaviour of soft rocks and stiff soils. The Caneva Clay is tested both by conventional oedometer swelling tests and by the new triaxial test. The swelling parameters of the clay are quantified for predictive analyses of the swelling behaviour at the tunnel scale.