Quality Evaluation Method Of Rock-fill Dam Materials Compaction Using Real-time Field Operation Data And Its Application

The effective compaction quality control is the key to high rock-fill dam safety.The traditional control method of rock-fill dam materials compaction quality, whichprimarily relies on pits sampling after compaction, is difficult to realize feedbackcontrol and restricts the construction schedule because of time consuming of pits test.The previous researches on the core-wall dam materials is not applicable to rock-fillmaterials, due to the great differences between these two kinds of materials ofphysical characters, compaction mechanism, compaction influence factors and qualitycharacterization index. Basing on the previous researches, further study on qualityevaluation method of rock-fill dam materials need to be conducted using real-timefield operation data. It is extremely significant for not only ensuring the constructionquality of high rock-fill dam, but also realizing the quality real-time evaluation andfeedback control. The content and achievements of this research include asfollowings:(1) The rock-fill dam materials compaction mechanism and the qualitativeinfluences between influence factors and the compaction quality were analyzed. Thecompaction monitoring value as the quality representation index of rock-fill dammaterials was put forward, and the field test methods of acquiring data was introducedin details.(2) Correlation between quality influence factors and compaction quality ofrock-fill dam materials, which includes the correlation analysis between thecompacting process parameters (i.e. rolling passes, roller speed, compaction thicknessand exciting force state) and the compaction monitoring value, and the correlationanalysis of the compaction monitoring value, material property parameters (P5content or water moisture) and the compaction dry density, were analyzed. Accordingto the correlation analysis, the influence of every factor to the compaction quality wasrepresented quantitatively, which offers the basis for determining the correct variableto build multiple regression models of compaction quality.(3) Multiple regression models of compaction quality were established, includingthe regression model of the compaction monitoring value based on the real-timemonitoring compaction process parameters and the regression model of the dry density based on the compaction monitoring value and the content of P5. The modelscan be employed to evaluate timely the compaction quality (namely dry density) ofrock-fill dam materials.(4) An evaluation method of rock-fill dam material compaction quality of theentire work unit based on Kriging interpolation was proposed. According to thereal-time monitored compacting parameters and the established multiple regressionmodel of the dry density, the dry density value at any position of work units and thepassing rate of compaction quality of the entire work unit can be achieved. Themethod can evaluate the compaction quality quickly, overcome the shortage of theinsufficiency of pits sampling, and provide a new way to realize the timely feedbackcontrol of rock-fill dam materials compaction quality.