Theoretical And Experimental Research On Resistivity Properties Of Rock Under Loading

In the construction of rock engineering, as external load broke the internal stressand equilibrium state and make the stress changed, So we must carry on themonitoring, judge the stability and damage of rocks. Using resistivity method toobservate the resistivity change, pushing the mechanics properties of rock, andjudgeing the internal stress state and damage, which can solve the problems related tostress state.But considering that lack of deep and detailed research on resisitivityproperties of rock under loading now,make resistivity testing is short of thecorresponding theory support in practical projects,so this paper puts forward thetheoretical and experimental research on resisitivity properties of rock underloading.The main research contents and results as follows:⑴Based on the conductive properties of rock, on the basis of study that influencefactors of resistivity such as composition and structure,water content and degree ofmineralization,porosity and shale,draw the conclusion that the development of the pore,fractures and the nature of the pore water play a dominant role in rock resistivitychange.⑵According to the development and changecharacteristics of pore, fractures inthe loading process, using the fracture mechanics theory,analysis the deformationcharacteristics of rock. relate to rock porosity and volumetric strain which by microfracture closed, expansion and poen combined with Archie formula, established thetheoretical model of rock resistivity-stress under single axis loading. Through theexample calculation, it concluded the rock resistivity change rules under stress.⑶I n order to validate the rationality of theoretical model， selected thesandstone,mudstone and limestone to test, used the high density resistivity method tomeasure the rock resistivity, get the rock stress-strain curves and rock resistivity-stresscurves under the single axis loading,And compared with the theoretical curves. theresult indicates that the theoretical results and experimental results is similar,Itexplained the theory model can reflect the rock resistivity change characteristics inloading process.⑷C ombined with the change characteristics of rock stress-strain curves and theinfluence factors of rock resistivity, Analysis of the mechanism of resistivity change ofrocks under loading, The results show that, through the change characteristics of resistivity can reflect the change characteristics of stress in the destruction process ofrock,so as to solve the mechanical problems related to stress.