Experimental Study on the Influence of Grouting on the Compressive Bearing of Micro Steel Pipe Pile

In order to study the influence of grouting on the bearing capacity of steel pipe pile, this paper has carried out the field compressive static load test of 18 test piles under the conditions of Æ160 mm and Æ200 mm pile diameter, 5 m and 8 m soil depth, grouting and non-grouting, and the influence of grouting on the load-displacement curve, ultimate bearing capacity and failure mode of the steel pipe pile was analyzed. The results show that the grouting effect makes the middle curve of the load-displacement curve of the steel pipe pile more obvious, and the plastic deformation zone increases. The bearing capacity of the steel pipe pile increases more than 30% due to grouting, especially for I # pile with the minimum diameter and depth. In the process of grouting, a series of physical and chemical actions such as splitting, seepage expansion, filling, cementation and compaction occur in the soil around the pile. Cement soil and solids are formed at the end of the pile, and cement soil retaining wall is formed at the pile shaft, which improves the physical and mechanical properties of the soil at the pile tip and around the pile, thus improving the bearing capacity of the steel pipe pile.