合理的支护荷载确定方法是膏溶角砾岩深埋隧道设计和施工过程中的关键科学问题。以石太客运专线太行山隧道累计穿越4 410 m膏溶角砾岩地层为依托,通过现场支护荷载量测试验,统计得到初支围岩压力和二衬接触压力。采用泰沙基理论、比尔鲍曼理论、谢家烋理论、铁路隧道设计规范和普氏理论共5种方法分别计算围岩压力,并与现场实测值相比较。结果表明:围岩压力以竖向为主,泰沙基理论值与现场实测统计值最为接近;围岩压力在竖向、水平分布模式不同于传统计算方法,推荐竖向压力采用双峰型或均匀分布,水平压力采用折线型分布;初支和二次衬砌共同承担荷载,二衬分担比例为50.1%。研究成果可为高速铁路膏溶角砾岩以及类似地质条件深埋隧道修建提供参考。
Reasonable method for determining supporting load of deep tunnel is a critical scientific problem during design and construction at present. Taihang mountain tunnel goes through gypsum breccia region of about 4 410 meters on Shijiazhang-Taiyuan high-speed passenger railway. In situ experiments on supporting load were carried out to investigate statistical surrounding rock pressure of primary support and contact pressure of lining. According to Terzaghi theory, Bierbaumer theory, Xie Jia-xiu theory, Code of Design on Tunnel of Railway and M. M. Promojiyfakonov theory, surrounding rock pressure is calculated; and comparison between the theoretical values and the monitoring data is made. The results show that surrounding rock pressure is dominated by vertical mainly. Calculation result by Terzaghi theory is mostly close to monitoring value. Obviously, vertical and horizontal distribution patterns are different from traditional calculation methods. Vertical pressure is recommended as double peak type or uniform distribution. Horizontal pattern is recommended as folded line type. Furthermore, primary support and lining bear load compatibly. The ratio of lining is about 50.1%. The results can provide references for construction of deep tunnel on high-speed railway in gypsum breccia stratum and similar geological tunnel.