牡绥铁路双丰隧道富水第三系砂泥岩地层超前注浆加固施工技术

双丰隧道是牡绥铁路最长隧道和重点控制性工程。隧道洞身长约2.3 km段穿越第三系砂泥岩及砂泥岩与其他岩层接触带的地层,其中第三系砂泥岩成岩作用差,属于极软岩;而隧道埋深较深,地形起伏不大,地下水在第三系砂岩及砂泥岩与其他岩层接触带处呈现富集,具有水量大、补给来源广和空间分布极不均一的特点,导致隧道变形大,塌方、涌水涌泥的风险极高,造成施工困难。结合本地层特点研究并采用上半断面加固全断面的超前注浆加固方案,经综合效果评价和施工开挖验证,加固效果良好,有效地保证了隧道的施工安全和顺利贯通。

Construction Techniques of Pre-grouting in Tertiary of Rich-water Sand-shale in Shuangfeng Tunnel on Mudanjiang-Suifenhe Railway

Shuangfeng Tunnel is the longest tunnel and the key controlling project of MudanjiangSuifenhe Railway. About 2. 3 km of the tunnel passes through tertiary sand shale and contact zone with other rock strata. The diagenesis of tertiary sand-shale is of poor quality in part of soft rock and the tunnel is deep-burial with gentle topography. Plenty of water is gathered in the contact zone of the tertiary sandstone and other rocks. The groundwater in this area is characterized by large amount and far uneven in supply source and spatial distribution,which may result in big tunnel deformation,tunnel collapse,water Inflow and soil leakage, and make tunnel construction very difficult. According to this circumstance,the method of full face advance grouting reinforcement after upper bench excavation is employed. By comprehensive effect evaluation and construction test,this method is proved to be effective in strengthening the rock and ensuring safe and successful tunneling.