INSTANT SHOTCRETE SUPPORT IN ROCK TUNNELS

Abstract

SHOTCRETE PRACTICE & EQUIPMENT, WHICH HAS BEEN SPECIALLY DEVELOPED TO MEET THE TUNNELLER'S DEMANDS, IS DESCRIBED. THE HYDRAULICALLY OPERATED ROBOT; THE SPECIAL TRANSPORTING AND MIXING UNIT, TRIXER; AND THE USE OF CHEMICAL ACCELERATING ADMIXTURES ARE DISCUSSED. IT HAS BEEN REPORTED THAT THE USE OF SHOTCRETE HAS REDUCED THE COST OF SUPPORTS AND LINING BY 70% AS COMPARED TO A CONVENTIONAL STEEL SUPPORT SYSTEM. FOR SOME PROJECTS THE OVERALL FINANCIAL SAVING HAS BEEN 20 TO 25%.