Characterization Of Internalstructure And Permeability Of Fault Zone

The fault is a fault structure where the formation or rock mass breaks under stress conditions and undergoes a significant displacement along the rupture.Compared with the crustal complete rock,the fault rock usually has a large porosity and permeability,so the fault zone is considered to be deep flow of the shell of the seepage channel,its internal structure determines the performance of the macro seepage characteristics.Since the 20th century,we have accumulated a large number of magmatic rocks and sedimentary rocks permeability data,but with the fracture zone rock related work for nearly 30 years to gradually carry out.The study of the permeability characteristics of the fault zone is not only widely used in related fields such as geological resources,geological environment and geological engineering(such as geothermal mining,exploration of fluid genesis,etc.),and it is of great significance for seismological research.The permeability of the fault is the most important physical parameter to understand the stability of the fault and the deep fluid state.In particular,deep samples of the fracture zone are difficult to obtain due to field conditions.It is important to study the internal structure and seepage characteristics of different tectonic units in the deep fault zone by obtaining the core samples of about 20 meters through the October well fault.In this paper,the pit exploration and the new field fault zone in October of Beishan,Gansu Province are selected as the research object,and the permeability characteristics and internal structure of the karst and new field trenches are studied in detail.The main research work and achievements are as follows:(1)The field investigation and sampling work of the crusty tectonic unit,breccia tectonic unit,fractured tectonic unit and fragmentation zone of the pit excavation,the new field fault zone are carried out.By reviewing a large number of literature on the internal structure of the fault,the system summarizes the previous research results and research methods to guide the research work of this paper.(2)The X-ray diffraction,X-ray fluorescence spectroscopy,scanning electron microscopy,electron probe,trace element analysis and laser particle size measurement were used to systematically study the micropowder The particle size characteristics,mineral element composition,microstructure and other intrinsic structural properties of the broken powdery tectonic unit.The results show that the tectonic unit of the fault zone has a strong zoning,and there are obvious differences in the internal structure of fault rocks with different depths at different depths.(3)Based on the casting test,gas adsorption and mercury intrusion test,the characteristics of the pulverized pore structure of the shallow field development of the new field fault are studied,and compared with the deep crushed powder in October,the pore characteristics,pore distribution,Pore throat classification and other parameters were analyzed.The results reflect the differences in porosity characteristic parameters of different tectonic units and the differences in porosity properties of the same tectonic unit at different depths.(4)The permeability coefficient of different tectonic units at different depths in the fracture zone was obtained by the improvement of the infiltration and the test method.The particle size characteristics,pore size,mineral composition,elemental content and microstructure(including di Dimensional,three-dimensional)and other characteristics,to explore the inherent mechanism of its permeability.(5)The microfluidic CT scanning technique was used to study the internal pore distribution of the deep crushed crushed powder and the surface crushed powder.The three-dimensional distribution of the rock fissure structure and the crushed powder pore structure was realized by Matlab,Ansys and AVIZO image processing software.Extraction and penetration of the simulation.