Research On Rapid Nondestructive Testing Technology Of Expressway Subgrade Construction Quality

The quality of compaction has a great impact on the stability of the subgrade.The traditional compaction detection method is represented by sand filling method,which has complex operation process and will damage the structure of the Subgrade after detection.In order to improve the control of compaction quality in subgrade construction,aiming at the shortcomings of traditional compaction quality detection methods,based on the project of SG1 bid section of Jingxiong expressway,combined with the rapid non-destructive detection equipment of subgrade compaction quality,this paper studies the method and application of portable falling weight deflectometer PFWD and soil modulus stiffness meter in subgrade construction compaction quality detection.The use of portable falling weight deflectometer PFWD and soil modulus stiffness meter in the road construction of non-destructive,rapid detection of compaction characteristics,will be able to better guide the subgrade construction,improve the quality of engineering construction.It can promote the development of this field.The main conclusions are as follows.(1)Based on the laboratory test analysis of SG1 subgrade filler,the basic physical properties of the filler are obtained through screening and compaction test.The maximum dry density of silty sand and improved cement soil is 1.82 g/cm3 g and1.821 g/cm3 respectively,and the optimal moisture content is 13.3% and 13.22%respectively.(2)The relationship between the two kinds of testing equipment is analyzed,and the relationship between the two kinds of testing equipment is explained.(3)Based on the correlation between compaction degree and subgrade elastic modulus,the relevant standards for evaluating subgrade compaction quality are established,which improves the control of subgrade construction quality.Through the compaction quality detection of subgrade filling,the modulus of subgrade is proposed to guide the subgrade construction.Through the field data collection of two kinds of soil,the feasibility of the evaluation method in construction is verified.(4)Through on-site distribution and data collection in subgrade construction,and combining with Matlab simulation to analyze the compaction uniformity of subgrade,this paper puts forward the standard value of elastic modulus used to evaluate the compaction quality in the construction compaction process of two kinds of filling sections,and studies the reliability and feasibility of this method.Through the research results show that the use of compaction uniformity evaluation method can timely and accurately correct the weak compaction area,which is conducive to saving manpower and material resources,accelerating construction progress and strengthening construction management,and has a positive role in guiding subgrade construction.