龙塘坪隧道超大型溶洞处理技术

龙塘坪隧道施工开挖揭示为一超大型溶洞，水平投影面积近3 000 m2，将该溶洞分为Y1和Y2两部分，其中Y1溶洞顶板节理密集带发育，岩体较破碎，厚度与洞跨比值小，稳定性差，给施工及运营造成很大的安全隐患。在对该溶洞形态及工程地质条件详细分析的基础上，制定了相应处理方案的原则以及溶洞处理的措施、工序和关键技术。实施后，效果良好。

Technology on Treatment of a Great Karst Cave in Longtangping Tunnel

A great karst cave is disclosed by excavation of Longtangping Tunnel，in respect of which the horizontal projection area is close to 3000 m2；and then it is divided into Y1 and Y2 portions，wherein the Y1 portion，due to the joints intensive roof，broken roof rock，small ratio of roof thickness to cave span，and poor stability of cave roof，endangers tunnel construction and operation.Based on detailed analysis of the cave morphology and geological conditions，the principles，measures，process and key techniques for the corresponding treatment are established and through practice，the distinct effect is demonstrated.Its favorable effect is obtained.