chapter
The capacity of improved Khon Kaen Loess as a road construction material
ByP. Punrattanasin
Pages 6

The ultimate bearing capacity of the footing in this study is defined at the peak load in pressuresettlement relationship. In the case where large settlement occurred, peak load was not selected but instead the load at a settlement of 10% of footing width (0.1 B or 5 mm) was chosen. Since the tests are displacementcontrolled, the displacement can be continued after the peak load.An ultimate bearing capacity of 1125 kN/m2

at a displacement of 9.0 mm was found in the pressuresettlement relationship (Fig. 7) for the footing resting on the undisturbed sample at natural water content. For the foundation on undisturbed sample at soaked condition, the ultimate bearing capacity of 160 kN/m2

was found at a settlement of 6.0 mm. Fig. 7 clearly demonstrate that the additional water can dramatically decrease the ultimate bearing capacity of the footing on undisturbed loess. The ultimate bearing capacity of compacted loess sample under natural water content in the plot in Figure 8 is about 1300 kN/m2 at a settlement of 4.0 mm. For the compacted sample under soaked condition, it is found that the ultimate bearing capacity of 215 kN/m2 was observed at a displacement of 4.5 mm. Table 3 summarizes both the ultimate bearing

capacity and the bearing capacity of footings at a settlement of 0.1 B or 5.0 mm. It is expected fromTest No. 3 and No. 4 that the higher bearing capacity of loess could be obviously improved by adding more energy by changing the method of compaction from standard to modified proctor.