黄龙洞拟建水库坝址岩体渗透性分析与渗漏风险初判

Rock Mass Permeability Analysis and Preliminary Assessment of Leakage Risk at the Dam Site of the Proposed Huanglongdong Reservoir

摘要: 为评价拟建黄龙洞水库坝址的渗漏风险与工程适宜性，本研究综合采用实地考察、高密度电法物探及钻探(ZK1, ZK2)等手段，对坝址区进行了立体化勘察。本次物探沿坝轴线(测线一)及垂直坝轴线方向(测线二)布设，结合压水试验重点分析了坝址区岩溶发育特征与岩体渗透性。结果表明：坝轴线剖面电性结构横向分异显著，左岸坝肩存在明显的低阻异常区，提示构造破碎或强岩溶发育；而河床及右岸坝肩主要表现为中高阻特征，岩体相对完整。钻孔压水试验进一步揭示岩体渗透性具强烈垂向分带规律，浅部强风化带透水率极高(最大118.6 Lu)，44.8 m深度以下进入完整基岩带(<3 Lu)。综合判定：坝址区存在“左岸构造控溶渗漏、右岸浅表弥散渗漏”的风险特征。结论认为，坝址具备工程建设的“有条件适宜性”，建议防渗设计应以左岸深层防渗与右岸浅部帷幕灌浆相结合。

Abstract: To evaluate the leakage risk and engineering suitability of the proposed Huanglongdong Reservoir dam site, this study employed a multi-faceted investigation approach integrating field surveys, the high-density resistivity method, and drilling (ZK1, ZK2). Geophysical exploration was conducted along the dam axis (Line 1) and perpendicular to it (Line 2), with a focus on analyzing the karst development characteristics and rock mass permeability at the dam site through packer tests. The results indicate significant lateral heterogeneity in the electrical structure of the dam axis, with a pronounced low-resistivity anomaly zone in the left abutment, suggesting tectonic fragmentation or strong karst development. In contrast, the riverbed and right abutment exhibit predominantly medium-to-high resistivity, indicating relatively intact rock mass. Borehole packer tests further reveal a strong vertical zonation in permeability, with the shallow, highly weathered zone displaying extremely high permeability (up to 118.6 Lu), while the intact bedrock below 44.8 m depth shows low permeability (<3 Lu). Comprehensive analysis identifies the leakage risk characteristics at the dam site as “structural-controlled leakage on the left bank and shallow diffuse leakage on the right bank”. It is concluded that the dam site demonstrates “conditional suitability” for construction, and it is recommended that anti-seepage measures integrate deep curtain grouting on the left bank with shallow curtain grouting on the right bank.