Studies on landslides of agricultural land in Kobe group, tertiary deposit. Part 5. On the stability analysis of landslide-slope in the agricultural land at K-section, Kobe City.

Abstract

About the sliding slope of agricultural land at K-section in Kita ward, Kobe City, where C. I. P. concrete piles were constructed as slide check works, we computed the safety factors before and after the construction of piles and obtained the following results.1) The safety factor of slope decreased with the decrement in values of soil angle of internal friction φ and cohesion C.2) The safety factor computed by the expedient method of the pile-unconstructed slope as control showed that the slope wasn't in a state of stability.3) There was a small difference between a safety factor modified by Bishop's method and that by the expedient one. Therfore, the safety factors by Bishop's also showed that the slope wasn't in a state of stability.4) The safety factor of the pile-unconstructed slope processed on the computer was less than Fs=1.2. And it showed that the slope wasn't in a state of stability.5) In the case of K-section where the groundwater level was deep and the slide plane was shallow, the safety factor of the pile-unconstructed slope showed the considerably large value.6) The safety factor of slope was increased after the construction of piles, showing that the slope became stable.7) Examing on an economy of the slide check works in case that the safety factor of the pileunconstructed slope is considerably large, the following may be comprehended; i.e., even if the interval of piles is expanded to a certain extent, the slope is in a state of stability.8) Similarly even if the number of pile-lines is decreased to a certain extent, the slope is in a state of stability.