The Analysis Of The Dynamic Compaction Quality For The Yellow River Silt Subgrade

As the soil in the Yellow river area mainly formed by silt, the highway roadbed in this area also formed by silt. As it affected by the character of the silt, in the building process of highway roadbed,the roadbed cannot be compacted well by the traditional compaction method. It is necessary to find another way to compact the roadbed instead of the traditional way. There are many advantages to use the dynamic compaction method such as, simple operating, low engineering cost, high working efficiency and lower affected by seasonal construction, and it has been widely used in civil engineering. In recent years, the highway engineering is also try to take the dynamic compaction into the highway roadbed building, and has obtained good result.The research in this paper is depended on the Jinan to Dongying highway engineering, and the test site was chosen in the area full of silt.Firstly, to make sure the test method is workable, selecting different way to begin the research, analysing the different roadbed height, the settlement of roadbed under different tamping times, the degree of compaction at different depth, the moisture content and soil bearing capacity in the whole roadbed space. To confirm the final dynamic compaction Construction parameters, mainly depend on the roadbed height, tamping energy and the tamping times. At the same time, a formula was built between the roadbed settlement and the tamping times in a certain filling height and a certain energy.After determining the dynamic compaction test scheme, we should need to test the subgrade soil state before the dynamic compaction, including the roadbed compaction before the initial degree of compaction, initial moisture content and subgrade bearing capacity and the other physical mechanics indexes. The subgrade construction process of Dynamic compaction consists of two kinds of construction forms, the point of ram and the ram, first point of ram, and then the ram. to test the roadbed after the two kinds of the dynamic compaction, analyse the space distribution rule of the degree and the bearing capacity inside the roadbed. Based on the comparing result of the dynamic compaction, evaluate the quality of the dynamic compaction. According to the degree of compaction, the rebound modulus and the bearing capacity results of the different position and different height, to make sure if the result accept the specifications and design requirements to evaluate the compaction quality for the Yellow river area silt.Finally the roadbed in the effect of the dynamic compaction can fully satisfy the demand of the building construction and the disignment. And has already take out the dynamic compaction constriction parameters for the Yellow river silt area, and for further optimization.The research in this paper not only can provide site test experience in dynaminc compaction construction for the Yellow river area, but also establish a new type of roadbed pressure engineering implementation for the bad soil instead of the traditional layered rolling compaction. It also can promote the dynamic compaction to a further application in subgrade construction.