碾压式沥青混凝土心墙土石坝渗流特征及安全评判分析OA

In China,the leakage characteristics of earth-rock dams with roller compacted asphalt concrete core walls exhibit considerable diversity.Since 2010,leakage incidents in newly constructed dams of this type have been relatively infrequent,and when they occur,the leakage paths are mainly located at the riverbed foundation,foundation on both abutments,the gallery,and the abutment mountains on both sides.Groundwater seepage velocities in the dam body and foundation are generally low,ranging from 0 to 3 cm/s.The heterogeneity of the dam body and foundation strata increases the difficulty of applying non-destructive testing methods.Although the accuracy of non-destructive techniques still requires improvement,they offer advantages such as minimal impact on dams and low costs,making them suitable for preliminary surveys to identify potential leakage areas.In contrast,destructive testing methods involve substantial effort and high costs,and their effectiveness depends on the correct identification of leakage areas and the proximity of additional boreholes to the actual leakage paths.Therefore,they are more appropriate for detailed investigation of the horizontal location and vertical extent of leakage.The diversity of leakage characteristics complicates the seepage safety assessment of dams,and no consensus has yet been reached within the industry on assessment criteria.This paper systematically summarizes the leakage characteristics of earth-rock dams with roller compacted asphalt concrete core walls.By analyzing observable leakage phenomena and safety monitoring data,the likely leakage zones can be preliminarily identified,thereby narrowing the scope of both non-destructive and destructive investigations.Furthermore,the paper discusses issues related to seepage safety assessment from the perspectives of leakage discharge,seepage stability,phreatic line,and gallery conditions,providing a reference for leakage detection and remediation measures in a phased and regionally differentiated manner.