新近系富水砂岩隧道注浆加固圈厚度研究  

Research on Thickness of Grouting Consolidation Ring in Tunnels of Neogene Water-rich Sandstone

作　　者：丁祥 姚建青 柴金飞 DING Xiang;YAO Jianqing;CHAI Jinfei(China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China;Yinchuan Construction Directorate,China Railway Lanzhou Group Co.,Ltd.,Lanzhou Gansu 730000,China;Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600 [2]中国铁路兰州局集团有限公司银川工程建设指挥部,甘肃兰州730000 [3]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《中国铁路》2023年第6期32-40,共9页China Railway

摘　　要：新近系富水弱胶结砂岩地层隧道在施工过程会破坏围岩稳定,进而出现突水和涌沙病害,在砂岩地层进行注浆加固是保障隧道安全的关键。以宁夏中卫某富水砂岩隧道为依托,采用FLAC3D建立计算模型,探明不同注浆圈厚度对围岩的影响。结果表明:隧道注浆圈厚度为3m时,围岩累计周边收敛值和拱顶沉降值分别为35.3cm和30.9cm,满足设计允许变形值。随着注浆圈厚度的增加,注浆加固效率先增大后减小,但施工难度及工程投资显著增大。综合考虑隧道施工的安全性、简便性及经济性,当围岩含水率为塑限范围及以下时,建议注浆圈厚度为3m;当围岩含水率为塑限及液限范围之间时,建议注浆圈厚度为4m。研究结果可为富水砂岩隧道的结构设计和施工提供借鉴。The construction of tunnels in Neogene water-rich weakly cemented sandstone strata impairs the stability of surrounding rock,thus causing gushing water and sand.Grouting consolidation in sandstone strata is critical to ensuring tunnel safety.Based on a tunnel in water-rich sandstone in Zhongwei,Ningxia,FLAC 3D is used to build a calculation model to explore the influence of different grouting ring thicknesses on surrounding rock.The results show that when the thickness of grouting ring is 3 m,the cumulative peripheral convergence value of surrounding rock is 35.3 cm and the arch crown settlement value is 30.9 cm,which meet the design allowable deformation value.With the increase of grouting ring thickness,grouting consolidation efficiency rises first and then drops,but construction difficulty and project investment increase significantly.In view of safety,convenience and economic efficiency of tunnel construction,when the water content of surrounding rock is within the plastic limit range or below,a grouting ring thickness of 3 m is recommended;when the water content of surrounding rock is between the plastic limit and the liquid limit,a grouting ring thickness of 4 m is recommended.The results of the study can be used for reference in the structural design and construction of tunnels in water-rich sandstone.

关 键 词：富水砂岩隧道 周边注浆 注浆圈厚度 超前注浆距离 数值分析 

分 类 号：U455[建筑科学—桥梁与隧道工程]