The Influence of the Groundwater Table and the Surcharge on the Slope Surface upon the Collapsed Slope Stability

• Main Authors: Lai, Jenn-Huei, 賴振輝
• Other Authors: Hsu, Hai-Lung
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/87270858904853800364

碩士 === 國立交通大學 === 土木工程學研究所 === 86 === 　　In Taiwan, most of the slopes was failed after typhoons and the pouring rain. For this reason, we choose the collapsed area at the southern Hu-ko Plateau as the research area. In this researching, we prospected and explored the land, set up the instruments (including inclinometer, extensometer, strain pipe, groundwater level measurement, rain gage), kept records, observed the movement of the sliding surface and analyzed the stability of the slopes. We discuss the effects of the groundwater and the surcharge on the top of slop in Hu-ko landslide. 　　The slopes slid and collapsed after pouring rain in June 1997,especially the area where people dump the dirt at the tops of the slopes The strain pipe shows that there are two sliding surfaces (6m and 12m underground), located between the mud layer and the sand layer. By analyzing the stability of slopes, we find that the surcharge on the slope surface and the rising level of ground water will decrease the stability of slopes. The leading cause of collapse areas at Hu-ko is because of the increasing weight of the discarded dirt on the top of the slopes by pouring rain, and enlarges the shear strength of the downward sliding. At the same time, the level of ground water risen by rainfall leads the strength softening in the mud layer, and finally the slopes failure between the mud layer and the sand layer. The judgment equation is (Ref. to Fig 4.32) 　　Y≧-0.36X-3 where Y: ground water table (meter) 　　　　　　　　　　 X: Surcharge height on the top of slop (meter)