Abstract:

The bearing capacity and load transfer behavior of a single T-shaped deep mixing column are analyzed by 3-D numerical simulation based on field test. The results indicate that when other parameters stay the same, the ultimate bearing capacity of a single T-shaped deep mixing column increases with the height H and diameter D of enlarged column cap; but the ultimate bearing capacity of unit cement volume increases with H/L and D/d at first to the maximum, and then decreases; where L is pile length, d is pile diameter. There is critical column length of T-shaped deep mixing column on bearing capacity. Most of the column load concentrates on the enlarged column cap which is the main bearing part of T-shaped deep mixing column. As the effect of enlarged column cap, the column load at the variable section attenuates greatly. When other parameters stay the same, the axial force and side friction of lower T-shaped deep mixing column are larger than those of conventional deep mixing column under their respective ultimate loads.

Key words: T-shaped deep mixing column, bearing capacity, load transfer, numerical simulation