Paper (In Japanese)
PUNCHING TEST TO EARLY-AGE BASE CONCRETE AND ITS DISCRETE ELEMENT SIMULATION
2019 Volume 75 Issue 1 Pages 56-74
Details
2019 Volume 75 Issue 1 Pages 56-74
Sprayed concrete lining is often applied to the excavated rough surface of face and its circumference in order to prevent the accidents due to rock falls in a cutting face of tunnel construction. Around 10 minutes time, workers approach the face to mount the steel arch support on the circumference. In this study, we aim to reveal the resistance and mechanism of a sprayed concrete punched into by an unstable rock came off the face, and so we developed the experimental equipment which could punch a rock into a early-age base concrete and then evaluated the strength and deformation characteristics of the concrete using a three-dimensional laser scanner etc. In addition, its experimental test was simulated by Discrete Element Method and then the mechanism of punching failure was revealed. Especially, the punching behavior of the concrete was expressed using the tensile softening curve based on the fracture process zone and then its punching resistance was supposed to be arisen by tension rather than shear.
