Abstract：
Statistics, summary and analysis are carried out in terms of karst ground collapse cases in Wuhan, karst treatment schemes and measures in various regions, with the aim of showing the importance of karst grouting.Hongjian Road Station and running tunnel sections at its both ends of Wuhan Metro Line 6 cross the hourglassshaped karst geological structure in the first terrace of the Yangtze River, where such karst treatment measures as curtain grouting in rocks as well as grouting and filling in karst caves are adopted. However, a series of problems are encountered during the construction, e.g. sand particles leak due to drilling and grouting, steel casing could not be pulled out, grouts penetrate into the sand layer, grouting pressure could not be maintained so that karst caves could not be filled effectively, grouts could not be measured effectively, and so on. In order to solve these problems, the traditional karst grouting hole forming process, flow monitoring process, grout ratio and final grouting completion stan? dard are optimized through consultation, demonstration and with reference to water conservancy construction experience and preliminary experimental study. A set of karst grouting technologies, e.g. "steel casing + inner PP-R pipe+ hole forming in rocks with drill rod + grout stop plug + grouting flow recorder", are studied and explored. In karst grouting, different grout ratios are selected in different periods, and the final grouting completion standard suitable for geological characteristics of the project is explored as well. The karst treatment practice at Hongjian Road Station and the running tunnel sections at its both ends verified the applicability and effectiveness of the new grouting technology.
LI Shenkui Tao Lan WU Shengxian
.Discussion and Application of New Grouting Technology in Hourglass-shaped Karst in Wuhan Metro Project[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 187-195
2021, Vol. 58 