红层砾岩岩溶发育特征及其工程地质问题分析——以丹江口水利枢纽坝址区为例

Analysis on characteristics and engineering geological problems of red conglomerate karst:an example of dam site area of Danjiangkou Water Control Project

为准确评价坝址区红层砾岩对丹江口水利枢纽左岸土石坝地基稳定的地质影响,通过详细勘察、历史比较、试验与测试等综合分析,查明了这种不同于一般碳酸盐岩的红层岩溶工程特性。结果表明:红层砾岩岩溶发育程度主要受山体形状、上覆岩层性状、阶地发育等因素控制,具有明显的水平分带性;以这类砾岩作为坝基,可能存在沉陷变形、抗滑稳定、渗透变形等问题,需要进行专门处理。研究成果可为红层砾岩岩溶勘察及红层砾岩上建坝的主要工程地质问题分析提供了参考。

In order to accurately evaluate the geological influence of the red conglomerate in the dam site area on the foundation stability of the left bank earth-rock dam of Danjiangkou Water Control Project,the engineering characteristics of the red bed karst different from the general carbonate rock were identified through comprehensive analysis of detailed investigation,historical comparison,test and measurement.The results showed that the karst development degree of the red conglomerate was mainly controlled by the mountain shape,overlying strata properties,terrace development and other factors,and had obvious horizontal zoning.If this kind of conglomerate was used as the dam foundation,there would be some problems such as subsidence deformation,anti-sliding stability,seepage deformation and so on,which required special treatment.The research results can provide a reference for the investigation of karst in the red conglomerate and the analysis of the main engineering geological problems of the dam built on the red conglomerate.