大北窑地铁隧道顶板稳定性控制研究

RESEARCH ON THE ROOF STABILITY CONTROL OF DABEIYAO METRO TUNNEL

分析大北窑地铁隧道饱水粉细砂层顶板的地质环境及其工程特性，用超细水泥注浆加固新工艺稳定流砂段及其扰动段的顶板。运用地质工程观点，充分利用顶板底部的粉砂薄层，用钢管加固未扰动段顶板。地面监测资料说明，本文的措施对其顶板稳定性控制非常有效。

The excavation of 76m long Dabeiyao Metro tunnel had to be stopped because of quicksand at its roof. A high cost freezing scheme was suggested to use after some researches and tests for more than one year. Hereafter the problem was studied by the authors from geoengineering view point. The geological environment and engineering geological properties of saturated silt and fine sand roof are analyzed in this paper. A new microcement grouting technique is developed to stabilize the Dabeiyiao tunnel roof at the quicksand and quicksand disturbed section. Steel tube grouting is used to stabilize the roof at the undisturbed section. monitoring data indicate that the measures are effective for the roof stability control.