在河势水流对险工险段成因研究成果的基础上,重点分析了堤基地质条件的影响。对广东省省管河道范围内的历史险工险段进行调研,梳理出了不同成因险段占比。以此为基础,选取江新联围进行水流与地质双因素的险工险段成因调查研究,通过水文测试、河床质取样以及室内试验,分析了各历史险段的成因。结果表明除水流条件较差外,各险段堤基也多以软土为主。基于此,增选了3个河势条件较差的非险段作为参照对比组,结果显示若地质条件较好,即使水流条件较差也不会形成险段。调查分析表明,河道险工险段的成因与河势水流和地质因素均密切相关,尤其是分布于软土地基区域的堤段,地质因素更是不可忽视。

The impact of geological condition on dangerous segments of river was analyzed in this paper on the basis of previous research results of the impact of flow. Through investigation of historical dangerous segments under the administration of Guangdong Province, we acquired the proportions of dangerous segments caused by different factors. Hydrological measurement, bedload sampling, and indoor experiment demonstrates that besides unfavorable flow condition. Furthermore we selected three non-dangerous segments with unfavorable flow regime as comparison, and the result shows that despite unfavorable flow condition, good geological condition will not give rise to dangerous segments. In conclusion, dangerous river segments are closely related to both river regime and geological condition. In particular, in soft soil foundation area, the geological condition of dike should not be neglected.