ABSTRACT
Recently, in some in-service tunnels, roadbed heaving caused by swelling and squeezing has damaged the invert concrete. In many of these cases, it is presumed that roadbed displacement was undergoing during construction and the displacement should have been measured and managed. However, it is difficult to accurately grasp the roadbed displacement. Therefore, in the tunnel under construction, the displacement convergence of the whole tunnel is judged from the inner section displacement of the arch part and the like. Then, we newly developed a system which can accurately measure the roadbed displacement during construction, and applied it to the Sankichiyama Tunnel. It was consequently discovered that only the roadbed was significantly raised after inner section displacement of the arch part converged. In this paper, we report the case of roadbed displacement measurement using this new system, and also quantitatively evaluate the measures against heaving by analytical method using measurement data.
