Research On Evaluation And Countermeasure Of Maintenance For National And Provincial Highway Subgrade In Guangdong Province

Subgrade is the basis of pavement,the quality of subgrade will directly affect the use of pavement.Guangdong Province is located in the tropical and subtropical monsoon climate zones.On one hand,it has perennial high temperature?abundant rainfall and every year from June to October suffered frequent typhoons and storms,the problem of subgrade damaged by water is quite prominent.On the other hand,the Pearl River Delta regions have deep soft soil,the differential settlement problem of subgrade is quite serious.But,at present,Guangdong and even China lacks technical specifications for subgrade maintenance,subgrade evaluation and mainentance technical regulation is too simple,maintenance measures are mainly depending on experience,maintenance is seriously lagged behind the construction.This paper take Guangdong provincial highway as study object,and the theoretical basis? index system?data acquisition method?evaluation model?typical subgrade maintenance technology are systematically studied.The results can provide scientific reference for our subgrade maintenance works,and promote the perfection of our technical specifications and standards.Firstly,the paper refer to the related documents,specifications and standards,as well as based on the investigation of typical subgrade diseases in Guangdong national and provicial highway,determined the applicable evaluation objects and index for subgrade maintenance,and established a suit of evaluation system.In addition,analysed the data collection method and the standard of deduction,verified the maneuverability and rationality of the method using the test sections.Secondly,based on the modeling theory and mathematical statistics,this paper studies the mathematical relationship between the evaluation index,according to the datas and expert surveys in test sections,the regression analysis and hierarchical analysis have been proceeded,so as to set up the subgrade maintenance evaluation models for Guangdong national and provicial highway.The research results were verified on the test sections.Finally,combining with the maintenance status and the evaluation method introduced in this paper,the subgrade maintenance countermeasures suitable for Guangdong national and provicial highway was drawn up.At the same time,enumerate the typical subgrade maintenance methods and their applicable conditions,provide a lot certain reference for specific maintenance projects.