Study On Real-time Compaction Quality Monitoring Indexes Of Earth-rock Dam Based On Intelligent Compaction Theory

With the development and application of real-time monitoring technology for dam compaction quality in recent years,advanced techniques are provided to assure dam construction quality.These monitoring methods only monitor compaction parameters dynamically rather than the compaction quality of dam material directly.Therefore,These methods can't realize the real-time evaluation of compaction quality.There are some limitations in the existing real-time monitoring indexes of compaction quality,such as:the compaction value(CV)can be easily influenced when the roller vibration frequency is changed;the existing ground reaction force index(F_s)ignore the impact of lag phase angle.This paper is based on advanced intelligent theory,and study compaction monitor index and its improvement for earth-rock dam compaction quality control,which promote the accuracy of compaction quality control and evaluation.The main study contents and results will be shown as followed:(1)The theory of intelligent compaction for earth-rock dam and the interaction system of roller and dam material are introduced.The system of intelligent composition is designed.The real-time compaction quality monitoring on-board device is developed and the methods of earth-rock dam compaction quality real-time monitoring and quick assessment are proposed,providing new technologies for earth-rock dam compaction quality control.(2)The roller vibration behaviors are studied,consisting of the analyses of the acceleration on time and frequency domains.Three different stage of compaction were proposed according to the variations in the acceleration spectrum.The lag phase angle in the interaction system of roller and dam material is proposed.The methods using hall sensor or stress method to measure the lag phase angle are given,and establish the mathematical model between the lag phase angle and rolling passes.These studies provide a theoretical basis for proposing and improving compaction monitor index of compaction quality.(3)The compaction detection index based on acceleration and lag phase angle are studied.The limitation of the index of ground reaction force index(_sF)is analyzed by test data,and an improved index of ground reaction force index(_sF?)considering the lag phase angle is proposed.The monitoring index of dam material stiffness(K_b)is proposed and the relationship between K_b and compaction degree is established.Based on Kriging,quick assessment of earth-rock dam materials on the entire work unit is achieved.(4)The compaction indexes based on acceleration frequency domain are studied.Analyze the influence of frequency on compaction value(CV)by test data.The monitoring index of dam compaction with vibration frequency is proposed,reducing the error of CV to evaluate the quality of compaction.The bouncing value(BV)of dam material is proposed,by setting BV threshold,the phenomenon of over-rolling for dam materials can be effectively prevented.