The Application Research Of River Sand In Filling The Subgrade

Different geological conditions will be encountered in the process of highway construction, the cost and time about roadbed construction depend on the filling material for a project, in consideration of large cost, it is impossible to transport materials from the far field for filling, although it may use the simple construction process, the price is too expensive, so basically all subgrade filling is to obtain raw material locally, although the cost can be greatly reduced, the process is relatively complex to make full use of local sand materials. The kind of river sand is a weak engineering properties for subgrade filling materials, under the circumstances that construction technology is not reasonable, it is usually difficult to meet the requirements of filling subgrade. on one hand insufficient hand may lead that the subgrade bearing capacity is insufficient, causing the entire surface structure damage; on the other hand,I twill increase the likelihood of ingress roadbed from the rain or other free water, the water stability is not good. According to the experimental results and the actual observation on the construction site, there are mainly two factors to effect sand compaction, the first is the horn andshape of the particles; the second is the filler composition grade. Since the sand angular is relatively smooth, it leads that the interaction between particles is weak, so that the inner frictional resistance is low. In addition to natural gradation is not ideal.it will caused that the compaction effect is not good, the all of mechanical performance is bad.Since there are different properties of the sand in different sand field, the filler properties are not the same, it is not easy to control construction quality in the process of construction, the result will make great effect on the detecting data, molding sand roadbed should keep certain regular water content, otherworse. because of dry weather, it will cause the roadbed loose, vehicle driving wheel stuck, causing difficulty in construction.In the construction of large area, sand indicators test must be based on the difference of sand,in the daily feeding, specific guidance to ensure the quality of filling sand. Machinery equipment in the combination must be reasonable and economic, especially paving and compacting machine, in quantity and mechanical properties is one of the waste, if enough can not meet the requirements of construction, causes the delay of construction period and transport vehicle.Rain water on subgrade slope erosion is more severe, in side slope, to fill sand subgrade, the instability causes the engineering disease,it is particularly prominent and frequent, how to ensure the stability of slope, combined with the actual terrain, resources, geographical and human environment and comprehensive analysis, it may be grouted riprap slope protection wrapping soil,the way in making trees and grasses or precasting concrete block revetment or edge stone slope protection to ensue stability.Making full use of river sand filling roadbed can clear the river, lessly occupy farmland, obtain raw material locally, reduce project cost, in emphasizing the reasonable utilization of resources and sustainable social development today, this point is undoubtedly very attractive and realistic significance for us.