The Research And Appliance On The Widening And Rebuilding Of Expressway Technology

In recent years, with the rapid development of the national economy, the rapid growth ofthe volume of traffic, a considerable portion of the highway has been built has been unable tomeet the requirements of rapid traffic growth and social development. Compared with thenew constructing highway, the project of widening of original highway can save occupationof land. And early construction of the highway is prominently in the road network, it’sbasically traffic arteries of the developed regions. So a growing number of highway needwidened and rebuild to increase its capacity. The project of the expressway widening andrebuilding is new issues that we facing in the highway construction, there aren’t yet technicalspecifications for design or construction recently. The research of this technique is a newsubject in our country, therefore，it’s much important.Firstly, combined with practical engineering, we proposed three options as increaseddensity of road network, constructed the new highway close to the Original one, widened theOriginal highway, there are two ways to widened the Original road by unilateral widening andbilateral widening. and then from the technical and economic aspects of the widening andrebuilding of highway program to illustrate the advantages and disadvantages of eachprogram, by comparison, the bilateral widening program is less Occupation of land and lessdemolition, less investment project, so we decided to use the bilateral widening program. Inold road widening project, the emphasis and difficulty is to solve the pavement deformation,cracking and other diseases caused by differential settlement between the new and oldroadbed.In the article, we analyzes the reasons for the formation of differential settlement,from the load distribution’s characteristics of subgrade widening, discussed the controlstandards of sedimentation, and made a series of specific Treatment Measures. For example,the technical measures as foundation treatment, dug stairs, increased the degree of compaction,reinforced by geosynthetic can significantly reduce the difference settlement between the newand old subgrade. It has a certain significance for the design and construction of the wideningand rebuilding of highway.