Lateral load tests were carried out on vertical piles embedded in sandy layer with sloping surface and the following results are obtained.
1. The lateral resistance of a vertical pile changes considerably with the change of the angle of slope. It decreases with the increase of angle of slope in the case of downslope loading, and increases in the case of upslope loading.
2. The new expression p=k・x・y0.5 for the relationship between soil reaction p and pile deflection y, can also be applied in the case of vertical piles in sandy layer with sloping surface provided a simple modification according to the angle of the slope is introduced.