Research conclusions: In the process of the excavation of the foundation，the deformation of guard pile increased with the increase of the excavation depth． The maximum deformation of the guard pile appeared in the middle － low part of the excavation depth． The place in where the maximum deformation appeared shifted down with the increase of the excavation depth． The supporting axial force increased largely at the beginning，but it varied a little with the excavation of the foundation pit and installation of the next support． The tested axial force of the various supports during construction was to the 70% of the design value．