天津蓟县中上元古界岩溶裂隙介质发育特征及其渗透性研究

DEVELOPMENT CHARACTERISTICS OF KARST FRACTURE MEDIUM AND ITS PERMEABILITY STUDY OF THE UPPERMIDDLE PROTEROZOIC SUBERATHEM IN JIXIAN, TIANJIN

本文以大量的裂隙测量、统计资料论述了裂隙几何参数(?)产状、隙宽和隙间距等在于同层位和区域上的变化规律。探讨了构造应力场、岩性、层厚诸因素的影响作用。并运用渗透张量理论对研究区岩溶裂隙的各向异性渗透性和非均质性逆行了研究,获得一些新认识,对查明岩溶水分布、运移规律有一定指导意久。

Based on a large number of measurements and statistics about fractures in Jixian area, the author expounds the regularity of variation of fracture geometric parameter--occurrences, fracture-width and-spacing in different strata and regions; and approaches the influnce of various factor on that, such as tectonic stress field, lithology, strata thickness. Fracture-width of different orientations of fracture sets and effective fracture rate are mainly controlled by state of tectonic stress and tectonic position, and fracture-spacing is bound up with lithology, strata thickness and strata association. Regionally, the fracture -width and effective fracture rate of micrite-powder-crystalline dolomite and lime-dolomite are relatively large. Also, by applying permeability tensor theory, a detailed study for the anisotropic permeability and heterogeneity of fissured rock are given in this paper. The major (long) axis of permeability ellipse is in accord with the orientation of main tectonic fracture and principal compressive stress of tectonic stress field. The regional chang of heterogeneity is controlled by syncline structure, the permeability coefficient reduces gradually from the limb to axis, showing a lower value area along the axis of syneline These new knowledges are of certain significance both in making clear the distribution, migrational law of karst water and in study of this set of dolomite strata widely distributed in North China.