陆地声纳法在探测岩溶区高铁隧道基底隐患中的应用

Application of the landsonar to detecting hidden hazards of tunnel base on high-speed railway in karst areas

沪昆高铁的麻拉寨隧道和贵广高铁的高天隧道在联调联试阶段均发生不均匀沉降和底鼓现象,为了摸清隧道基底致灾原因并对注浆质量进行检测研究,采用陆地声纳法在隧道岩溶段进行了检测,在基底下方探测出较多中、小溶洞,多组中、小断层延伸到基底下方使溶洞之间互相连通,由于雨季隧道周边水压力强烈的变化,造成了隧道不均匀沉降与底鼓,根据数据图像的特殊反应确定了破碎区域和浆注入区,依据探测结果确定治理方案并在治理施工中得到验证。

It is reported that uneven subsidence and floor bulge occurred in the joint test stages of the Malazhai tunnel of the Shanghai-Kunming railway and Gaotian tunnel of the Guiyang-Guangzhou railway,implying potential geologic hazards there.In order to find out the cause of this phenomenon and the quality of grouting,landsonar method was used to detect the karst sections of these tunnels.Results show that there are many medium and small karst caves below the tunnel foundation,which are interconnected by several sets of medium to small faults extending below the tunnel foundation.During rainy seasons,intense change of water pressure surrounding the tunnel caused uneven subsidence and floor bulge.To remove such a hidden hazard,the fractured zone and grouting zone were identified according to landsonar data and a treatment plan was determined,which has been verified by its implementation.