Application Study On Settlement Prediction Of Soft Foundation In Guangdong Mountainous Expressway

The soft soil is widely distributed in the coastal areas of Guangdong or the basin in the mountains.Their genetic types,structural and morphological characteristics are different,but they have the characteristics of high water content,high compressibility,low strength and poor water permeability.As the highway extending to the mountains,restricted by geology,terrain conditions,high fill embankment is widespread,and the mountain valleys zone distribution of soft soil directly affects the stability of high fill embankment,foundation treatment is necessary.The treatment of soft soil foundation is a complicated system engineering,many influence factors in the process of ground treatment,master the distribution and engineering characteristics of the soft soil foundation treatment scheme,selection of appropriate and dynamic monitoring of embankment subsidence and long-term prediction is the key of the study.Taking the expressway in mountain area of guangdong province highway soft soil foundation processing key technology as the backing,stack preloading and plastic drainage plate processing scheme,discusses the guangdong mountainous expressway soft soil ground deformation and subsidence prediction.Through the field test and theoretical analysis,obtains the following results:1.Analysis of soft soil genesis types and distribution characteristics of Guangdong mountain area,on the physical and mechanical parameters of soft soil were analyzed with mathematical statistics,analysis shows that the water content and void ratio,density and void ratio,liquid limit and plastic limit have higher correlation.2.According to the distribution of soft soil and the engineering characteristics,choose the appropriate foundation treatment method,developed a soft base monitoring scheme,put forward the soft base monitoring content,monitoring section,subgrade stability control standard,unloading standard of subgrade stability judging method were analyzed.3.Analyzed under different ground treatment scheme for soft soil foundation settlement,lateral displacement and settlement rate change rule.105-1206 mm full section foundation settlement,settlement monitoring section more than 500 mm accounted for 41.7%,the majority of monitoring section of the maximum settlement rate is less than 20mm/d;the lateral displacement is 6.9-234 mm,average 69.2mm,lateral displacement rate of most section is less than 5mm/d,the maximum displacement occurs in the surface 0.5-3.5m below the ground,no sliding instability phenomenon,the treatment effect is good.4.According to the Jiangmen-Luoding expressway soft ground settlement regularity,exponential curve method,hyperbola method and Asaoka method prediction method based on the settlement of highway soft soil foundation are predicted.The prediction results are compared with the measured data analysis results show that these 3 models can be used in engineering practice,the hyperbolic method high correlation.The soft soil subgrade settlement prediction of highway soft soil foundation treatment scheme of the fuzzy reasoning,make up for the highway soft foundation treatment scheme mainly rely on experience to determine the problem,improve the reliability of the relevant decision.