Research On Monitoring And Predicting Method Of Subgrade Settlement About Highway

Since the reform and opening up,China's social and economic development has made rapid progress,including coastal cities,provinces and cities in the construction of high-grade highway demand has increased significantly.Due to the influence of geographical environment,the soft soil area of coastal cities is relatively large and the engineering characteristics are poor,which makes the stability and deformation of roadbed become an important problem in the construction of Expressway on soft foundation.To break through this technical problem,first of all,we must be able to accurately predict the settlement of highway soft soil roadbed.This paper is aimed at this problem.Taking the Guangzhou-Zhuhai section of Beijing-Zhuhai Expressway as the research object,this paper maked a thorough discussion on the settlement mechanism of the soft foundation.Combining with the relevant monitoring data of the settlement of the soft foundation,the influencing factors of the settlement and its variation law are analyzed at first.Through the analysis of the relevant data,it has found that the load,the value of ?p/p,the thickness of the soft foundation have an effect on the roadbed.Surface sedimentation and sedimentation rate have significant effects.Secondly,according to the grey system theory,a suitable settlement prediction model,Grey Model(GM model),is constructed to predict the post-construction settlement of soft foundation,so as to reduce the prediction errors caused by engineering characteristics and other factors.Thirdly,the advantages and disadvantages of grey prediction model and curve fitting method in predicting foundation settlement were discussed and compared.By comparing with the real settlement data measured in the field,it has found that the grey prediction model has closer to the measured values in calculating the relevant settlement parameters.Therefore,it has concluded that the grey prediction model based on grey system theory is more accurate than curve fitting method in predicting the settlement of soft soil foundation.Figure15;Table14;Reference 48.