Compaction quality assessment of earth-rock dam materials using roller-integrated compaction monitoring technology

Abstract

Abstract The compaction quality of earth-rock dams is normally controlled through compaction parameters (i.e., compaction passes, roller velocity, vibration status, and compacted thickness) during construction and random spot tests after construction. However, using limited spot samples to represent the construction quality of the entire work area can be unreliable and misleading. Additionally, given the time-consuming process, the spot testing method leads to delays in rectifying compaction quality issues at the jobsite. This research utilized roller-integrated compaction monitoring (RICM) technology combined with real-time kinematic global positioning systems (RTK-GPS), adopted compaction value (CV) as a real-time monitoring index for the dam compaction quality, and subsequently proposed a CV-based assessment method to estimate the compaction quality of earth-rock dam materials. Furthermore, the Kriging interpolation method was adopted to obtain estimates for both CVs and compaction quality at any location on the working area, enabling the analysis of the passing rate of compaction quality for the entire work area. A case study on the NZD Project in China indicated that the CV is highly correlated with the compaction parameters, the compactness of the gravel-mixed cohesive soil, and the dry density of rock-fill dam materials; therefore, it can serve as a reliable index for monitoring compaction quality. Quick and continuous assessments of compaction quality on the entire work area can be achieved using the proposed method, which provides a basis for informing the construction with timely feedback information to effectively avoid quality defects and to improve the construction quality of earth-rock dams.