厦门钟鼓山原有隧道衬砌厚度和外侧围岩缺陷的无损检测

Abstract

为建设厦门城市快速交通干线,需要对钟鼓山原有隧道进行扩建。在拆除已有隧道衬砌和开挖外围围岩时,确定原有隧道衬砌厚度和外侧围岩的空洞、破碎、断裂等情况,对施工安全和施工方案制定非常必要。为此,采用探地雷达技术对原有隧道衬砌厚度和外侧围岩状态进行了检测。在隧道顶部布置三条沿隧道方向的检测线,用雷达探头分别对隧道的衬砌厚度和外部岩层缺陷进行探测,结果发现衬砌厚度很不均匀,厚度0.36~1.2米,多处与外部岩石直接接触。衬砌外侧有多处空洞、破碎、断裂或空洞伴有严重的破碎等危险情况存在。拆除衬砌时必须采取针对这些部位的安全措施,这为施工提供了明确的指导,从而保证工程的顺利完成。

For constructing the main rapid traffic line in Xiamen city,the in service tunnel in Zhonggu Mountain must be enlarged.Before demolishing the lining and excavating the nearside wall rock,the lining thickness and the cavity,fragmentation and rupture of nearside wall rock in exiting tunnel are determined by the ground penetrating radar for establishing the construction safety and technology project.The results show that the existing lining thickness is non uniform,from 0.2m to 0.8m,the lining directly contacts with wall rock in many places.There are many cavity,fragmentation and rupture existed in the nearside wall rock.When demolishing the existing lining,the safety precautions must be established.The results of ground penetrating radar testing provided clear guidance for construction.The project has been successfully completed.