投影寻踪模型在膨胀岩判别与分级中的应用

Application of projection pursuit model to swelling identification and grading of argillaceous rock

由于泥质岩富含黏土矿物,尤其是成岩程度较低的中新生代泥质岩常具有显著的膨胀性,而成为膨胀岩的主要类型。在对现有膨胀岩判别指标进行全面分析后,提出以蒙脱石含量、胶结系数和比表面积作为泥质岩膨胀性判别与分级的三大指标。基于投影寻踪模型方法,以新疆大坂隧洞工程中采集的20个泥质岩样为样本进行了分析。根据20个样本最优投影值的移动平均趋势线,该处泥质岩的膨胀性可分为非膨胀、微膨胀、弱膨胀和强膨胀4个等级。与较为常用的岩块干燥饱和吸水率指标判别结果基本一致,结果表明,所选指标和方法是可靠的。

Owing to abundant argillaceous minerals,argillaceous rocks often take on notable dilatability,in particular the lower diagenesis argillaceous rocks formed during Mesozoic and Cenozoic,which is the main type.After general analysis of existing discrimination factors,it is presented that the montmorillonite content,cementation coefficient and surface area are as three main indices for dilatability identification and grading of argillaceous rock.According to projection pursuit cluster statistical method,some analyses of twenty samples coming from Daban tunnel in China’s Xinjiang Autonomous Region are done.Based on moving average trend line of the sample＇s projection value,these argillaceous rocks can be divided into four grades,just as no-swell,micro-swell,weak-swell and strong-swell,which is approximately in accord with the result by dry block saturation water absorption index,so,here the factor and distinction way are reliable.