Western Han Expressway Expansive Soil Slope Reinforcement Technology

The expansive clay is a kind of soil with special engineering properties which has severe harm and effect to construction and exertion of freeway. The shape of expansive clay slope is an ordinary disease of highway engineering.The paper study about engineering of Xi'an～Hanzhong freeway, studying laboratory experiments of the expansive clay of via Yang country～Mian country, according to experiments of lime improved expansive clay the engineering properties of expansive soil by Xi'an～Hanzhong freeway are summarized. The failure types of expansive clay slope on road cutting along Xi'an — Hanzhong freeway have characteristic of surface and shallow. In allusion to characteristic of surface destroy which have stripping, erosion and mud flow and shallow destroy which has slope, that bring forward the methods of surface and shallow reinforcement which have the beating-cover of soil modified , retaining+ geocell and quicklime pile group. To learn theory of the failure of expansive clay slope on road cutting, analyze expansive slope in different conditions (before reinforcement and after reinforcement) with nonlinear Finite Element program of MARC. The modification of expansive clay slope on road cutting reduced at rate of 70%～80%, stress and strain reduced at rate of 80% after reinforcement. Field test shows that the method of reinforcement is better than the method of the previous prevention.