Research for criteria to define the bottom area of assembled foundation of power transmission line in calculation of the compressive load

The assembled foundation of power transmission line, which is composed of concrete lath and angle steel scaffold, has been applied in practice. But due to the gap of laths, the bottom area of the foundation is not clearly defined when calculating the compressive load. Theoretical study on the ultimate bearing capacity of foundation indicates that soil arching effect exists between the adjacent slabs. The in-site experiments at different lath intervals testify that the difference of soil pressures under the laths and at the gap of laths is relatively large in the shallow soil. But the soil pressures are basically the same in the deep layer where the change of the lath interval has no significant impact on soil pressure. The research suggests that the whole area surrounded by the laths is preferable in the calculation of compressive load on the assembled foundation composed of concrete laths.