The testing of soaked Khon Kaen loess embankment with and without geosynthetics

摘要

Loess deposits exist above the water table in abundance in Khon Kaen Province, Thailand. Dry loess is very strong but wet loess is very weak. The use of loess as embankment material is uncertain while transportation of material from distant borrow pit makes some construction projects become costly. This paper presents the results obtained mainly from large scale tests. Plain loess embankment with 53° side slope reached failure state after it was soaked for several days, even if there was not any surcharge load. The material of another vertical side slope embankment was the loess reinforced by 2 types of geosynthetics. Its stability was observed during a long time of heavy rain. After that, 2-meter width strip load of 21 kPa was applied on the top of reinforced loess embankment and then, it was soaked again. Geosynthetics proved useful to loess stabilization in fill work. The embankment showed very good stability under both soaking and soaking combined with surcharge strip load situations. The good stress distribution of reinforced loess was also found. Two problems one should be aware of are: even if reinforced loess has very good stability, it may fail because of erosion. The second problem is that the ground bearing capacity must be checked whether it can bear the load transferred from the embankment.