Field Experimental Study on Deformation Monitoring of Foundation Pit

Based on the deformation monitoring of foundation pit of zhong-hong-tian-di business-living building, in Tongxiang city, Zhejiang province. And soil-compacting during the pile-sinking construction is studied. The area is about 120 times of it's edge-length can come up uplift deformation, when the piles with 40 cm edge-length were pressed. And the variation of differential settlement of people-living houses around the foundation pit is analyzed. The stress state of retaining structure is changed, which causes the retaining structure appears floating phenomenon, during excavation of foundation pit. The horizontal displacement of soil becomes large in pace with the excavating depth of foundation pit, moreover, under the action of soil creep deformation, the horizontal displacement will become more large. In case of rainfall, groundwater level head inside and outside of foundation pit will increase, at the same time, basement retaining structure side pressure will increase, too. Support axial force can be affected by solidification contraction of concrete, temperature difference, different creep of concrete and reinforcement. So the support axial force should be modified.