Roller Working-Based Method Of Real-time Monitoring And Rapid Assessment For Rock-fill Dam Compaction Quality And Its Application

It is the key to effectively control the compaction quality for ensuring rock-filldam safety. The conventional method of controlling compaction quality for rock-filldam is to control compacting process parameters and sample pits in-situ aftercompaction. However, the compaction parameters, such as exciting force frequencyand exciting force, are not available to be monitored in time during compactingprocess by manual way. Thus it is impossible to reflect the working power and effectprovided by rollers for compacting dam materials. In addition, the compacting processparameters (e.g., roller speed, exciting force, compaction passes and lift thickness) arenot available to reveal the real compaction quality (e.g., compaction, porosity, drydensity) directly. And the pits sampling method is hard not only to reflect thecompaction quality of whole work unit for using limited samples, but also realizetimely feedback control at job site as the testing results can’t be obtained rapidly. So itis really significant to research a monitoring index which can reflect the compactionquality of rock-fill dam material in real time and a rapid method for evaluatingcompaction quality. The main contents and results of this paper are as follows:(1) The unit volume compaction power (UVCP) and the Total HarmonicDistortion (THD0), which are respectively obtained from the view of compactioneffect of roller and vibration behavior of roller wheel are employed as compactionquality real-time monitoring indices. The definitions and calculation methods of thesetwo indices are introduced. In addition, the obtaining method of sample data isproposed based on the developed real-time monitoring system of compaction qualityfor rock-fill dam and the field test.(2) The effectiveness of THD0for compaction quality assessment of rock-filldam is validated, and then the relationship among UVCP, THD0, dam materialproperties and compaction quality is analyzed. Thus the impacts of various factors oncompaction quality are determined, which provides the basis for establishingcompaction quality assessment models.(3) Compaction quality assessment models for rock-fill dam materialscharacterized by different variables are established. And the model with the variablesof UVCP and THD0is verified the best because it can effectively overcome theshortage of the insufficiency caused by employing above variables separately to therelated models.(4) A roller working-based method of rapid quality assessment of rock-fill dammaterials is proposed. On the basis of UVCP and THD0being interpolated by thespatial interpolation method, and using the established models, the dry density of rock-fill dam materials can be calculated at any location and its distribution indicatingunqualified area of compaction quality can also be obtained. Thus real-timemonitoring and rapid assessment of compaction quality for rock-fill dam materials onthe entire work unit can be realized which provides a potential way to improve thequality control of rock-fill dam.