桃園縣龜山鄉盜採砂石骨材開挖導致裸露的卵碟石層陡坡中,其坡高超過100公尺、坡度
70度但仍可保持穩定,若根據反算分析研判該區礫石層之摩擦角理應大於60°才能維持如此陡
峭邊坡,但該區礫岩層現地直剪試驗獲得之尖峰抗剪摩擦角多在46°至54°之間。根據該區地
質資料得知該基地內,在高程70~80 公尺內常有2-3 公尺厚砂泥質的岩石凸鏡體夾層,比一偶
現凸鏡岩體夾層是否是促使前述高陡超高礫石邊坡現象之原因將是本文探討的重點。 The high angle slope of gravel formation in 100m high is stable in Taoyen. The internal friction
angle back-calculated from the slope geometry should be greater than 60 degree. However, the
angle taken from the field direct shear tests is never greater than 54 degree. Observing the slope in
the field, we find that an inter-layer rock appears within this gravel formation. The aim of this study
is to examine the effect of inter-layered rock on the stability of gravelly slope.
Relation:
2004岩盤工程研討會論文集=Proceedings of 2004 Taiwan Rock Engineering Symposium,頁304-311