溶洞内超厚回填路基沉降监测与预测研究  

Research on monitoring and prediction of settlement of super-thick backfill subgrade in karst cave

作　　者：李明 LI Ming(China Railway Construction Dawan District Construction Co., Ltd., Guangzhou 511458, China)

机构地区：[1]中铁建大湾区建设有限公司,广东广州511458

出　　处：《山东建筑大学学报》2022年第2期87-94,共8页Journal of Shandong Jianzhu University

摘　　要：西南山区岩溶广泛分布,增大了高铁隧道建设时揭露大(巨)型溶洞的风险,黔张常铁路DK53+678高山隧道巨型溶洞是我国首个穿越百米隧道的溶洞,具有溶洞空腔大、稳定性差、岩溶堆积物厚等施工难点,处置难度极大,“洞砟回填+上部注浆加固”的综合处置方法得到应用。针对超厚洞砟回填体沉降问题,建立了表层和分层沉降监测系统。结果表明:回填体沉降与施工荷载相关性高,洞砟回填体上部注浆加固可减少表层沉降量并缩短沉降收敛时间。对比分析指数模型、抛物线模型和双曲线模型等经典沉降模型,结合回填体分层沉降规律及注浆减沉作用,提出双指数模型以预测沉降,其预测结果与沉降监测值吻合良好,更能真实地反映“洞砟回填+上部注浆加固”处置条件下的回填体沉降规律。Karst widely distributes in the mountainious of southwest China,increasing the risk of the large(giant)karst cave in the construction of the high-speed railway tunnels.Qian Zhang Chang Railway DIK53+678 mountain tunnel large karst cave is the first one through a 100-meter tunnel in China,featured with great construction difficulties such as big cavity,poor stability and massive karst deposits.The research suggests that it should apply the comprehensive disposal method of"backfill with tunnel ballast+upper grouting reinforcement".For super thick ballast settlement of backfill body,surface and layered settlement monitoring system is established.The results show that the settlement of backfill body has high correlation with the construction load and that upper grouting reinforcement of the ballast backfill body can reduce the surface settlement and the convergence rate of the settlement.After comparing and analyzing the classical settlement models such as the index model,parabolic and hyperbolic model,combined with the settlement regularity of the backfill body and the function of reducing the settlement by grouting,the double exponential model is proposed as a way to predict the settlement.The prediction results of this model are in good agreement with those settlement monitoring value.Therefore,it can reflect a more real regularity of backfill body settlement under the condition of"ballast backfilling+upper grouting reinforcement".

关 键 词：巨型溶洞 高铁隧道 回填处置 双指数模型 沉降分析 

分 类 号：U25[交通运输工程—道路与铁道工程]