The Theory And Method Of Durability Roadbed Calculation Based On Interval Parameters

With the rapid development of China's economy,the construction of expressway has also accelerated,but it also exposes a problem:the actual life of the highway is far below the design service life.It has been shown that the stability durability of roadbed has important influence on the service life of pavement structure.And the modulus of resilience of subgrade,subgrade work area and subgrade settlement are important parameters to characterize the performance of subgrade,Its computational theory and method have been closely watched.In China's current roadbed design specifications,the design parameters and indicators are mostly represented by the value of the points.Due to the representative problem of test sampling,the precision and stability of the test equipment are not fully reflected in the complex properties such as the volatility and uncertainty of parameters and indicators.Therefore,this paper takes the interval number as a substitute for point parameter,and makes a preliminary discussion on the application of interval theory in the durability subgrade.The research contents are as follows:(1)First,the basic theory of interval mathematics is introduced,the geotechnical test process is briefly introduced,and the interval value method of the geotechnical parameters is summarized based on the statistical analysis of the probability distribution of geotechnical parameters.(2)According to the characteristics of interval parameters of subgrade soil,establish different subgrade modulus interval prediction model.Combining the highway roadbed design code failed to fully consider in the design of subgrade humidity change on the influence of the subgrade modulus of resilience,the subgrade modulus of resilience of the balanced humidity is analyzed.(3)The interval theory is combined with the calculation method of roadbed workspace.Based on the modified Bussinesq formula,the interval expression of the roadbed workspace is established.And discusses the influence rule of pavement structure thickness,square index and modulus of compressive modulus,the recommended value of subgrade workspace depth is proposed.(4)Based on the theoretical analysis of subgrade settlement in highway engineering,a method for calculating subgrade settlement based on interval parameters is established and analyzed by an example.Finally,taking the Hunan Lian-Zhu highway as an example,The model of highway widening subgrade is established by FLAC3D,The influence law of roadbed subsidence is analyzed by simulation analysis of roadbed parameters such as height,intensity and modulus of subgrade...