Abstract
The concrete foundation set up on the cut ground has upheaved by 66mm in seven years after unloading of ground which is 25m in thickness. The upheaval of the foundation has been caused only at smectite-bearing crush zone in unweathered crystalline schists. The smectite content in the fault gauge is 10-15%, and the smectite was generated by the hydrothermal alteration. In this paper, the swelling characteristic of the crush zone is shown by the in-situ investigation and the laboratory test. The upheaval of crush zone is estimated to have swelled gradually from the surface to in the ground. The observed swelling depth is coincident with overburden load. The upheaval model was made by the geological structure and using the relation between the load and the swelling rate of the smectite bearing crush zone. The upheaval convergence by the FEM analysis roughly coincides with that by the level observation.
