Makoto Kito

Design Load of ECL Method Tunnel Lining considering the Creep Characteristic of Ground

This research proposes a new design method for tunnel lining with the ECL (Extruded Concrete Lining) method considering creep displacement based on the results of measurement and analysis of ground displacement. This method clarifies the following points.According to the results of displacement measurement, the amount of elastic displacement reached convergence at a distance of approximately 20 m behind the tunnel face.Afterwards, displacement increasing gradually as elapse of time was observed. The displacement is considered to have been caused by the creep of ground. The findings demonstrate that a load corresponding to the creep displacement is acted on the concrete lining.The creep displacement is simulated with the two-dimensional elastic FEM analysis.In the analysis, a stress-releasing rate is used to quantify the creep displacement.The analyzed values correspond very well to the measured ones.

STUDY ON COMPUTATION FOR CAPACITY OF EXTRUDED CONCRETE LINING

To apply a steel fiber reinforced concrete (SFRC) to the extruded concrete lining, it is necessary to study the estimation of its capacity of member cross section. As a result of carrying out the loading experiment of SFRC, the fundamental datum for design was obtained, such as the relation between tensile strength and width of crack opening. This paper mentions study on computation for capacity of extruded concrete lining by limit states design method.