北京地铁某竖井富水砂卵石地层注浆止水施工技术

Construction Technology of Water Stop Grouting of Water-Rich Sand Pebble Formation in a Shaft of Beijing Metro

北京地铁16号线某竖井基坑全断面位于砂卵石地层中,地层地下水位高,渗透系数大,底板下方无隔水层,且现场无降水条件。因此,以注浆止水施工为依托,对富水高渗透性砂卵石地层下不同注浆材料的注入情况进行探讨,通过试验方案设计、注浆过程监控及开挖验证等方面的分析研究,最终形成“桶式”止水帷幕,达到了保证安全开挖的止水效果。

The whole section of a shaft foundation pit of Beijing Metro Line 16 is located in the sand pebble formation,with high groundwater level,large permeability coefficient,no water barrier layer under the floor,and no precipitation conditions on the site.Therefore,based on the grouting water construction,the injection of different grouting material,through the test design,grouting process monitoring and excavation validation analysis and research,the final formation of“bucket”water curtain,to ensure the safety of excavation water effect.