The penetration effect of the rectangular pile is different from the conventional circular cross-section pile. However

conventional theoretical models and experimental techniques are not suitable for investigating the rectangular cross-section pile. Based on deformation visualization technique of transparent soil

this paper investigated the displacement field variation law induced by the rectangular pile. Experimental results show that after driving of rectangular pile

the soil displacement of the surrounding soil after installing a rectangular pile can be divided into two typical areas. A transition area is produced around the rectangular pile

where soil displacement is non-columnar symmetry characteristics

and its radius is around 4deq-5deq. The expansion area of the circular hole is located away from the pile

and its displacement presents the characteristics of cylindrical symmetry. According to pile driving compaction tests of the rectangular cross-section pile

this study proposed a modified cavity expansion mode for rectangular pile and verified the rationality of the modified model by comparing theoretical values with experimental data.