基于隧道检测钢筋分布不均状况下判定衬砌结构安全性应用研究

近年来隧道内出现的越来越多的质量安全事故,引起各方高度重视,相应的最适宜隧道主体工程衬砌质量控制的地质雷达无损检测方法被广泛应用。通过雷达无损检测可揭露出衬砌内欠厚、脱空、钢筋分布不均等大量各类型缺陷,针对欠厚脱空等缺陷制定的注浆或开窗等治理措施是目前工程中常见的整改闭合工序,但钢筋分布不均对结构安全影响如何判定,怎么界定处理尚无成熟方案与规定。本文针对隧道项目中实际检测出的钢筋分布不均缺陷,在不宜大范围扰动结构及围岩进行整治的情况下,以及在避免其他问题共存等不利因素的前提下,应用有限元数值模拟计算分析强度安全系数,并结合现场外观等综合因素对衬砌结构安全性进行分析判定研究。

Study on Application of Determining Safety of Lining Structures Based on the Uneven Distribution of Reinforcement Bars in Tunnel Detection

In recent years,more and more quality and safety accidents have occurred in tunnels,which has attracted great attention of all parties.The corresponding geological radar non-destructive testing method,which is most suitable for the quality control of tunnel lining,has been widely used.Through radar non-destructive testing,a large number of defects such as underthickness,void and uneven distribution of steel bars in lining can be revealed.Grouting or window opening measures for such defects as underthickness and void are common renovation and closure procedures in engineering at present.However,how to determine the impact of uneven distribution of steel bars on structural safety and how to define and deal with them are still not mature schemes and regulations.Aiming at the uneven distribution defects of reinforcing bars detected in tunnel projects,the author applies finite element numerical simulation to calculate and analyze the strength safety factor under the condition that it is not suitable to disturb the structure and surrounding rock in a large scale,and on the premise of avoiding other unfavorable factors such as coexistence of other problems.In combination with the comprehensive factors such as field appearance,the safety of lining structure is analyzed and determined.