铁路隧道早高强喷射混凝土设计标准及应用研究

Standard for Design of Early High-strength Shotcrete for Railway Tunnels and Application Research

早高强喷射混凝土在施工过程具有抗拉、抗剪强度形成迅速的特点,可提高围岩的稳定性,确保作业安全高效,在国外工程实践中应用广泛,并形成了较为系统的技术标准规定。虽然我国对喷射混凝土早期强度的重视较晚,但现阶段在国内建筑工业、公路、铁路等行业中也逐步得到推广应用。铁路行业更加强调24 h龄期内的强度要求,在近年来的工程现场试验及应用表明,喷射混凝土早期强度可满足相关的要求。另外,虽然早高强喷射混凝土较普通喷射混凝土材料成本略有增加,但考虑材料损耗、工作效率、质量安全等因素后,相对普通喷射混凝土具有显著优势。

Early high strength shotcrete is characterized by rapidly forming tensile and shear strength during construction, which can improve the stability of surrounding rock and ensure safe and efficient operation. It has been widely used in foreign engineering practices, and relevant systematic technical standards have been formed. Although the early strength of shotcrete received attention relatively late in China, at present, it has been gradually popularized and applied in domestic building, highway, railway and other industries. More emphasis has been paid on the strength requirements within 24 hours in the railway industry. In recent years, field tests and applications have shown that the early strength of shotcrete can meet relevant requirements. Moreover, although the cost of early high-strength shotcrete is slightly higher than that of ordinary shotcrete, it has significant advantages over the ordinary shotcrete when taking into consideration such factors as material loss, work efficiency, quality and safety.