Based on the observation and research of the umbrella-shaped self-expanding anchor excavated in-situ after its application in foundation pit supporting system
according to monitoring data with and without this kind of anchor
its characters of expanded section and effect in application after grouting have been analyzed. And its quality control method is put forward.The results show this kind of anchor can form expanded section with cement and steel in the earth
so the displacements of the anchored thing can be effectively controlled..