BEARING CAPACITY OF FOOTINGS ON PILE-STABILIZED SLOPES

The results indicate that when Sf=0 and the pile row is located at upper half of the slope (Lx>0.7L), the footing bearing capacity decreases with increase in the foundation width. Because the footing bearing capacity determined from the slope stability method is minimum and the pile length in the stable layer decreases because the foundation width affects the rupture surface. When the pile is located within the lower half of the slope (LxSf>B (Sf=5 m), the slope stability method gives the minimum footing bearing capacity in foundations with various widths. In these cases, the footing bearing capacity decreases with increase in the foundation width when Lx>0.7L. However, this change is not remarkable and the footing bearing capacity increases with increasing the foundation width when the pile row is installed at the lower half of the slope. When Sf=10 m, the effect of the bearing capacity is negligible. This is because the slope stability method gives the minimum bearing capacity in foundations with various widths, and part of the foundation located in the failed zone is almost equal in two foundations with various widths (Sf=10 m). When Sf>15 m (outside the failed zone), any increase in foundation width causes an increase in the footing bearing capacity and the slope does not affect it. The results also indicate that the maximum bearing capacity is achieved when the pile which is not fixed in stable layer is installed at the middle of slope in various values of Sf and B (Fig. 9). 2. Effect of fixity of pile head: In this section, the footing bearing capacity is compared in a free head pile and a hinged head used for slope reinforcement (Fig. 10). The results show that the hinged head affects the footing bearing capacity when the pile row is located near the slope toe and slope crest ( Lf. =2). This is because the footing bearing capacity determined from the virtual retaining wall method is mHinimum when the pile row with hinged head piles is located at the slope toe. In fact, when the pile row