Theory And Its Application Of Real-time Compaction Quality Evaluation For Earth-rock Dam Material At Core Wall

High core rock-fill dam proposes higher quality control standard in construction for dam safety. The traditional quality assessment method bases primarily on testing sampled spots of job site, which usually causes unreliable representation of the compaction quality of the entire work and leads to delay not only in performing the construction work but also in rectifying quality issues. Based on a compaction quality real-time monitoring system of earth dam developed by our team is employed to collect rolling parameters (compaction pass, roller velocity, exciting force status and compacted thickness, etc.), and on line compaction quality value (compaction meter value ) and dam material properties to do correlation analysis with the compactness. Then a stepwise regression model is established to predict compaction quality using independent variable data obtained from the real-time quality-monitoring system. using the model and Kriging interpolation, the compactness distribution and compaction quality satisfaction rate of entire work area can be obtained. The case study demonstrates the effectiveness and feasibility of the proposed method. It not only makes possible the evaluation of compaction quality covering entire work area, thus reducing the uncertainty of quality inspection associated with spot tests, but also enables feedback for quality control and improvement of earth core rock-fill dam construction timely. The main contents and achievements of this paper are as follows:(1) Methods of acquisition the compaction process parameters and the field test data, including material property parameters and compactness, are introduced firstly. Then a method is proposed for corresponding the parameters among real-time roller compacting parameters, material properties, CV and the compactness in space-time.(2) According to the partial correlation between roller compacting parameters, material properties, CV and compactness, a model for core materials compactness estimation using stepwise regression method is established, and then the effectiveness of the model is validated.(3) A method for real-time evaluating the compactness of entire work unit in earth-rock dam core area is proposed. Based on spatial statistical analysis, employing Kriging spatial interpolation method, the compactness at any position of working stripe and entire work unit can be obtained, so that real-time compaction quality estimation at job site is achieved.