This paper presents an experimental and field investigation on the efficiency of plugging by pouring aggregate in different sequences through multiple boreholes in a tunnel with flowing water. There have been controversies surrounding the selection of the pouring order for different particle sizes of aggregates and the order in different boreholes. A visualized experimental setup is used to investigate the influence of the pouring orders on the efficiency of plugging through multiple boreholes under the flowing-water condition. A case study of the salvage of a flooded mine using ground directional boreholes was investigated and compared with the experimental results. The water-pressure difference at the aggregate-capping moment, when fine aggregate was poured first and coarse aggregate later, was relatively small, compared to that when fine aggregate was poured upstream and coarse aggregate, downstream. The result implies that the efficiency of plugging with the order of pouring fine aggregate first and coarse aggregate later in different boreholes is better than that with the order of pouring fine aggregate upstream and coarse aggregate downstream. When the poured aggregate is about to be capped, increasing the pouring intensity with the same or a larger particle size is more conducive to capping. The case study shows that pouring fine materials in the early stage reduced the cross-sectional area; in the later stage, the aggregate particle size was gradually increased, which can be helpful in forming an effective water-barrier section in the tunnel. The pouring of aggregate provided a base for cement grouting to form a water-plug section with a length of 106 m, resulting in a sealing efficiency of 100% for the case.

中文翻译：

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骨料浇注顺序对钻地孔堵塞淹没隧道效率的影响

本文介绍了通过隧道中的多个钻孔以不同的顺序浇注集料的堵漏效率的实验和现场调查。围绕不同粒径的骨料浇注顺序的选择和不同钻孔的浇注顺序一直存在争议。使用可视化实验装置研究了在流水条件下浇注顺序对多钻孔封堵效率的影响。对使用地面定向钻孔打捞被淹矿山的案例研究进行了调查，并与实验结果进行了比较。先浇细骨料后浇粗骨料时，骨料压盖时刻的水压差较小，与细骨料在上游和粗骨料在下游时相比。结果表明，在不同的钻孔中，先浇细骨料，后浇粗骨料的封堵效率优于上游细骨料，下游浇粗骨料的顺序。当浇筑的骨料即将封顶时，增加相同或较大粒径的浇筑强度更有利于封顶。案例研究表明，早期浇注细料减少了横截面积；后期，骨料粒径逐渐增大，有助于在隧道内形成有效阻水断面。