The Research And Appliance On The Widening And Rebuilding Of Expressway Technology In Shaanxi Province

In recent years, with the rapid development of the national economy and great trafficgrowth, many freeways built have to improve its capacity by conversion or extension to meetthe demand of the traffic growth and social development. This paper was based on Xi’an toTongguan freeway expansion project, studied on subgrade settlement features and treatmentmeasures, pavement splicing technology and traffic safety organizations of Shanxi Provincefreeway conversion projects, giving references to similar engineering problems. The maincontents are as follows:（1）Surveyed and analyzed the current situation of freeway extending projects, andsummarized the key points and difficulties with the consideration of the situation in ShanxiProvince;（2）Surveyed the geological conditions along Xi’an to Tongguan freeway expansionproject, analyzed and ranked the adverse geological situations in details, and analyzed thekey points of subgrade treatment and the processing technology of the original ground inShaanxi collapsible loess area;（3）Studied on foundation settlement characteristics and the different constructiontechniques in embankment splicing construction, analyzed widening embankment differentialsettlement mechanism, and finally came up to the corresponding embankment differentialsettlement control technology;（4）Surveyed and analyzed the current structures broaden modes of freeway expansion,focused on the causes and the factors which effect of pile foundation settlement with theconsideration of construction technical requirements of Xi’an to Tongguan freeway expansionproject, and strictly controlled the splicing procedure during the construction process;（5）Analyzed pavement diseases, intensity, etc. of Xi’an to Tongguan freeway and theold highway pavement stability in loess area before pavement splicing based on the actualsituation, proposed foamed asphalt recycled pavement construction technology, anddetermined the additional paving types according to deflection measured values, and thedifference between original and design pavement elevation;（6）Described traffic organization principles of freeway extension, analyzed the existingways of road expansion and traffic organization, and proposed expansion mode and trafficorganization plan combined with engineering practice for Xi’an to Tongguan freewayexpansion project.