Experimental Study On Character Of Vibration Compaction Of Coarse Grained Soil

As the expanding of nation's traffic infrastructural construction, total mileage of expressways opened to traffic by the end of 2002 will reach to 20000km. The tide of expressway construction is now moving from the developed areas to the western undeveloped areas. In consideration of the completed expressways and future orientations, stability of suggrade will be a major issue in a period of time, particularly the stability of subgrade filled with soil and stone, in the practice of engineering, there exist unclear attitude towards the soil-stone mixtures. This will both increase the cost of engineering and decrease the lifetime of the road, effect the safety of driving and environment around.coarse grained soil is composed of sand and gravel, stone residual, blasted stones etc., which has a characters of less cohesive force among grains and strong ability of water penetration. It is a kind of soil of loose grain structure with better utilization properties in the engineering. This article emphasize on further realizing the engineering properties of coarse grained soil through test and research, enabling it to serve the society in a better way. The past research methods to the coarse grained soil mainly concentrate on its density with compacting method, very few notices its shear strength. This article mainly emphasize on the classification of coarse grained soil from the viewpoint of engineering application (content of coarse grains), vibrating method is introduced in the shaping. Meanwhile, research is made to the water stability and shear strength.Through research, following conclusions are obtained: coarse grained gradation is the main factors to determine its shear strength, when the coarse grains content is over 70% or around, the maximum shear strength appears: the grains itself have a bigger effect on the shear strength. The more hard, uneven, irregular and dense grains will have higher shear strength. The moisture content can be neglected since it has minor effect on the shear strength. This will have practical significance in directing the construction.