隧道湿喷混凝土回弹率控制技术

Study on Control Technology for Rebound Rate of Wet Shotcrete Used in Tunnel

为解决特长隧道大断面开挖初期支护湿喷混凝土回弹率高的问题,以江习高速四面山特长隧道为工程实例,阐述了对湿喷混凝土顶拱回弹、边墙回弹、流态滑落问题产生的现状从岩石与喷混凝土附着性、喷射厚度、工人操作、岩层涌水等方面展开的调查分析,针对主要因素调整了湿喷混凝土配合比与爆破参数,有效降低了施工现场湿喷混凝土回弹率,提高了围岩支护质量,加快了施工进度。

In order to solve the problem of high rebound rate of wet shotcrete for primary support at large excavation sections in super long tunnels,this paper,taking Simianshan Super Long Tunnel of Jiangxi Expressway as the engineering object,investigates and analyzes the problems of rebound at top arch,on side wall and flow slip,from adhesion between rock and shotcrete,shotcrete thickness,workers'operation performance,water gushing from rock and so on.Based on the investigation and analysis,main factors as mix ratio and blasting parameters are adjusted,which effectively reduces the rebound rate of wet shotcrete on site,improves the support quality of surrounding rock and speeds up the construction progress.