桥梁桩基底部溶洞的井间电磁波CT探测研究

岩溶区地质状况复杂,溶洞等缺陷可能会导致其无法承受桥梁转体施工过程中巨大的转体重量和非均匀压力。为保证岩溶区转体施工桥梁的安全和长期稳定性,有必要全面准确地探明桩基区域的地质状况。本文以龙岩大桥桩基区域溶洞勘探为例,探究了井间电磁波CT在岩溶区转体施工桥梁工程地质探测中的应用,并结合钻探资料进行地质分析。统计归纳了地下各种介质与电磁波吸收系数的关系,并详细分析了龙岩大桥桩基区域溶洞的空间位置、形态特征和充填情况等。经钻孔结果验证,井间电磁波CT探测技术能够全面准确地揭示桥墩等局部范围内的岩溶状况,提供可靠的工程建设地质资料。

Study on cross-hole electromagnetic-wave CT exploration of karst caves under bridge piles

Geological conditions in the karst area are often complex,and karst cave may result in the support failure under the huge weight and uneven pressure in the swivel construction process of bridge. In order to ensure the safety and long-term stability of the swivel constructed bridge,it is necessary to fully and accurately investigate the geological conditions within the piling region. A case study of the exploration of karst caves within the piling region in the Longyan Bridge was carried out. The application of cross-hole electromagnetic-wave CT and the geological analysis considering the drilling data was discussed in the geological investigation of the swivel construction bridge in the karst area. The relationship between ground medium and the corresponding electromagnetic-wave absorption coefficient was summarized according to the statistic data. The spatial distribution,features and infilling of karst caves within the piling region in the Longyan Bridge were analyzed in detail. According to the drilling results, the cross-hole electromagnetic-wave CT could fully and accurately reveal the karst conditions in a limited piling area,so as to provide reliable geological data for engineering construction.