摘要
为解决南京某地铁冻结法施工联络通道运营期间发生的后融沉问题,从地层特性、施工工艺和外界环境等方面对融沉原因进行分析,地基软弱、工序衔接不当、融沉注浆不足等是联络通道及附近隧道发生融沉与破坏的主要原因。提出融沉治理原则和工艺,采用"多点,均匀,少量,多次"的劈裂-挤密注浆方法对联络通道周围地层加固,并在施工影响范围内布置监测点对注浆效果实时监测。结果表明:在劈裂-挤密注浆方法的基础上,辅以地层排水能够有效防止地层沉降,确保隧道结构稳定;在注浆过程中,联络通道沉降可分为快速回落、稳定回落和稳定3阶段,各阶段的沉降速率和排水量都有鲜明的特点;加固后隧道上行线最大隆起31.2 mm、下行线最大隆起29.8 mm,联络通道342 d沉降监测结果小于1 mm,表明隧道已处于稳定状态,治理效果较好。
The thaw settlement occurs in cross passage of a metro in Nanjing constructed by freezing method during operation period. The causes for the thaw settlement,i. e. soft ground,irrational procedure connection and insufficient thaw settlement grouting,are analyzed in terms of ground characteristics,construction technology and environment factors. The thaw treating principle and technology of splitting-compaction grouting are adopted to reinforce the surrounding ground of cross passage,and grouting effect monitoring points are arranged within construction influencing scope. The results show that： 1） The thaw settlement can be effectively controlled by supplemented ground drainage on the basis of splitting-compaction grouting. 2） The settlement of cross passage during grouting can be divided into 3phases,i. e. fast slowing down period,low slowing down period and stable period; the settlement rates and drainage volumes of every period are distinctive. 3） The maximum rising height of upline and downline of separated tunnels is31. 2 mm and 29. 8 mm respectively; and the settlement of cross passage 342 days after grouting is less than 1 mm which indicates the rationality and feasibility of the grouting method.
出处
《隧道建设》
北大核心
2017年第8期1032-1036,共5页
Tunnel Construction
关键词
地铁
联络通道
软土
冻结法
融沉
注浆加固
metro
cross passage
soft soil
freezing method
thaw settlement
grouting reinforcement
