摘要
为研究超大断面浅埋黄土隧道大变形控制技术及效果,依托隧道大变形事故案例,对隧道围岩变形破坏特征及原因进行分析,结合隧道地质条件及围岩特性,提出了合理有效的围岩变形控制技术及施工工艺,并应用数值模拟和现场测试对3种加固措施工况下的变形及应力进行分析。研究结果表明:超大断面浅埋黄土隧道围岩变形主要表现为前期变形速率大,变形持续时间长,累计变形量大,拱顶最大累计沉降为124.3 cm,围岩变形受开挖扰动和持续降雨影响显著;采取临时套拱加固有效抑制变形的持续发展,避免塌方事故的发生,而径向注浆加固和强化支护参数为后续顺利完成大变形段换拱施工提供安全保障;浅埋偏压地段采用地表超前预注浆技术,有效地改善上覆围岩特性,后续施工累计变形均在预留变形量范围内,确保了施工安全和进度。
To investigate the large deformation control technology and effect of shallow-buried loess tunnel with super-large section tunnel,the deformation and failure characteristics and causes of tunnel surrounding rock were analyzed based on the case of large deformation accident.Then,a reasonable and effective control and disposal construction technology of surrounding rock large deformation were proposed,combined with the geological conditions of the tunnel and the characteristics of surrounding rock.The results show that the surrounding rock deformation of shallow-buried loess tunnel with super-large section is mainly characterized by large deformation rate in the early stage,long deformation duration,large cumulative deformation,and the cumulative of the largest crown settlement is 124.3 cm.The surrounding rock deformation is obviously affected by excavation disturbance and continuous rainfall.The temporary arch sleeve reinforcement can effectively restrain the continuous development of deformation and avoid the collapse accidents,while the radial grouting reinforcement and strengthening support parameters provide safety guarantee for the subsequent successful completion of arch replacement construction in large deformation section.Moreover,the surface pre-grouting technology is used in shallow-buried unsymmetrical pressure area to effectively control the infiltration of surface water on the surrounding rock.The maximum settlement rate of surrounding rock is only 6.9 mm/d,and the cumulative deformation is within the range of reserved deformation,which ensures the safety and progress of construction.
作者
赵志刚
吴忠仕
王伟
杨林
冯德定
ZHAO Zhi-gang;WU Zhong-shi;WANG Wei;YANG Lin;FENG De-ding(CCCC Second Harbour Engineering Co.,Ltd.,Wuhan 430040,China;Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan 430040,China;Key Laboratory of Large-span Bridge Construction Technology for Transportation Industry,Wuhan 430040,China)
出处
《科学技术与工程》
北大核心
2020年第6期2470-2477,共8页
Science Technology and Engineering
基金
中国交通建设集团有限公司科技研发项目(HT-A-2018-006)。
关键词
黄土隧道
控制技术
大变形
破坏特征
数值模拟
地表注浆加固
换拱技术
loess tunnel
control technology
large deformation
failure characteristics
numerical simulation
surface grouting reinforcement
arch replacement technology
