Construction Technology Analysis And Compaction Numerical Simulation Of Cement Stabilized Macadam Base

Cement stabilized gravel is widely used in the construction of high-grade highways in our country,and its good performance and condition directly affect the durability and service life of the road surface.The construction of cement stabilized gravel is one of the important links to ensure its performance.However,compared with the pavement surface layer,the current attention to the construction of the base layer is not enough.During the construction process,the production technology is often backward,the uniformity of the mixture is poor,and effective construction is lacking.Control and detection.For the construction of cement stabilized crushed stone base,it is very important to determine the construction method and compaction process.At present,there are still the following two problems: On the one hand,when the thickness of the base is large,the upper and lower layers are usually selected for intermittent construction.,That is,pave the upper base layer after the construction of the lower base layer is completed and cured for 7 days.This construction method will result in weakening of the bonding performance between the base layers and lower overall performance;on the other hand,the choice of on-site compaction technology cannot be combined with the actual force of the mixture The state can only be inspected and compared through the paving test section,and the evaluation index is single,but the traditional compaction detection method has large subjective factors,large damage to the grassroots,low accuracy,and cannot quickly and continuously reflect the compaction quality.This article relies on the Jilin Province Transportation Science and Technology Project,combined with the construction of Jishuang Expressway in Jilin Province,and on the basis of summarizing the existing research results at home and abroad,the construction method of cement stabilized macadam base is studied from the perspective of mechanical analysis.The compaction performs rapid detection analysis and simulation to provide a theoretical basis for the construction control of the cement stabilized macadam base of high-grade highways,in order to improve the construction quality of the cement stabilized macadam base.The main research contents include:1.Comprehensive analysis of the advantages and disadvantages of existing cement stabilized macadam base construction methods,use ABAQUS finite element software to establish pavement structure analysis model,calculate the mechanical response of pavement structure of different base construction methods,and take shear stress,deflection,and flexural tensile stress as Analyze the indicators,use the grey relational analysis method to study the comprehensive influence of each construction method on the three indicators,conduct mechanical analysis and evaluation of the construction methods of cement stabilized macadam base,and use it to guide the selection of construction methods of cement stabilized macadam base in the test section.2.During the construction of the base of the test section,the acceleration sensor is embedded to test the rolling compaction process of the cement stabilized crushed stone base in real time and the whole process,and the measured acceleration signal is filtered,Fourier transform,and wavelet analysis.Establish a correlation with the compaction index detected by the conventional sand filling method,and seek methods and means to quickly detect the compaction of the base.3.In order to further study the compaction effect of cement stabilized crushed stone base,combining the parameter indexes of the compaction machinery on the construction site and the constitutive relationship of cement stabilized crushed stone,a simulation model of "cement stabilized crushed stone base compaction" is established,which is based on dynamics.The basic principle is the modal analysis of the vibrating wheel model of the roller.The DP elastoplastic model is used as the constitutive model of the cement stabilized crushed stone base to study the compaction effect of different compaction modes and the stress and strain law of the base material during the compaction process.The following main conclusions have been obtained through research: From a mechanical point of view,considering the interlayer bonding state of different construction methods,it is recommended to adopt integral construction or double-layer continuous paving as the construction method of cement stabilized macadam base.The acceleration sensor is embedded and its test value can effectively predict the compaction degree of the cement stabilized crushed stone base.Through signal processing of the collected acceleration data,when the number of rolling increases gradually,the acceleration maximum value and effective value appear as a whole An increasing trend can establish a good correlation with the degree of compaction.The compaction simulation results show that during the compaction process,the stress distribution of the base layer under the vibrating wheel of the roller,especially the upper part of the base layer,is quite different.The strain from the center of the wheel to the edge of the base layer is gradually attenuated during the entire rolling process.