圆砾地层中地铁联络通道水平冻结孔施工技术

Construction Technology for Horizontal Freezing Holes in Metro Connecting Passages in Gravel Strata

文章结合昆明北站地铁联络通道的工程实践,总结了冻结孔施工的组织环节及施工环节中的重点和难点,给出了圆砾地层中水平冻结孔施工工序和关键技术;通过对造成冻结孔成孔偏差的原因分析,提出了保障造孔质量的施工技术和钻孔测斜技术;并指出在冻结孔施工过程中,需注重加强同步注浆,通过造孔同步注浆填充联络通道局部溶洞,以防止溶洞坍塌,进而提高联络通道及地表建筑的安全性。

Based on the engineering practices of the connecting passages of the Kunming North Railway Station Metro Project, the key and difficult points in organization and construction procedures for freezing holes are summarized, and the construction procedures and key technologies for horizontal freezing holes in gravel strata are introduced. The technologies for qualified drilling construction and drill hole inclinometry are presented after an analysis of the cause of drilling deviation of freezing holes. Simultaneous grouting for filling some local caves of the connecting passage should be intensive during the construction of the freezing holes, improving the safety of both the connecting passage and the surface buildings and preventing caves from collapsing.