Study On The CBR Value Distribution Law Of The Loess Layers In Wutian Of Weinan

Loess is widely distributed in China, especially in the vast areas of the Middle andWest China. With the rapid economic development, specifications on highway constructionin loess area are also more and more strict, especially the loess which is used as roadbedfiller, and plays an increasingly important role on the stability and security of roadbed. TheCBR value which is used as a basis for the roadbed to select and decide if the filler is goodor bad is inevitable to contact with the loess.Loess is an important road construction material. And it has a complex structure withlarge holes and porosity, and is difficult to compact. So it is not an ideal material for roadconstruction. Part of the loess has obvious collapsibility which has a great bad impact on thehighway roadbed. Therefore it is necessary to explore the collapsible loess. In addition,loess’s deposited in a long period of time, and becoming more thicker. Affected by thechange of earth climate, the loess layers can be divided into many layers based on thechemical structure and physical properties, and this decides the different external properties.The CBR value of subgrade is specified in the specification, so it is necessary to do somedetailed research on the CBR value of loess, to avoid problems in the use of the highway fortraffic safety.The paper is based on the CBR test, then explores and analyzes a series of issues on theCBR value about loess. In this experiment, the test materials from Wutian of Weinan arechosen, because it is a typical case in the field of loess research.In this paper, firstly, the whole layer of loess is divided into many different small layersaccording to the obvious features of the loess. And then use the earth from each small layerof loess to make a series of experiments. So we can summarize all the test results andanalyze the distribution law of the CBR value, the influencing factors and mechanism.Therefore law is got.Secondly, compare the CBR value of Wu Tian loess layer with the CBR value of RenJiapo loess layer in Xi’an Bailuyuan to identify similarities and differences.