Study And Numerical Analysis Of Concrete Under The Action Of Hydraulic Fracturing In Double K Fracture

Hydraulic fracturing originates from the oil and gas industry, with the development ofhalf a century, and now it has been widely used in geotechnical engineering, hydraulicstructures. The study of hydraulic fracturing services not only for production and life, but alsofor prediction, prevention, research for accidents that may occur in practical engineering,which is of great value.This paper simulates the concrete in Ⅰand Ⅰ-Ⅱ mixed mode fracture under the actionof hydraulic fracturing. Double-K fracture criterion results in crack initiation and instabilitycriterion under two different loading modes. According to Prefabricated crack and width ofthe specimen, Experimental study of hydraulic fracturing, and the two different loadingmodes fracture Standards of the specimen were fitted to making the angle formed by the fourbatches of24specimens to be0°,30°,45°and60°respectively. Though simulations of Ⅰ-Ⅱmixed mode fracture by ANSYS FEM, comparative analysis of test data and analog values intwo loads modes.Study show that,(1) Constant axial force can be better controlled, but under constantpressure, cracks began to expand with an increase in the axial force cracks, water began toseep out, resulting in the beginning of constant pressure decreasing, so water press is constantbefore the destruction of the specimen under pressure in the axial force when constantpressure before, trends appear that water pressure is reduced when specimen cracks andgradually extended when there is reduced when water pressure.(2) In the test, the measuredcrack angle of specimen increase with the increasing of Prefabricated crack and width undertwo different loading, the cracks of specimen under constant pressure and axial force aregreater than which under constant axial force in the same type of test piece.(3) In the study ofⅠ-Ⅱ mixed mode fracture, under the two loading modes, Ⅰ fracture components decreasewith the increasing angle of prefabricated crack and width, and Ⅱ fracture componentsincrease with increasing angle of prefabricated crack and width.(4) Comparative test crack tipstrain and ANSYS simulation value, its value were close, within the margin of error.(5)Observing the cloud picture of crack tip stress and strain, Impact of the crack tip strain andstress factors including the type of specimen and loading methods. External load is the mainexternal factor affecting crack propagation, but the inner fracture pressure also plays a vitalrole (in) the development of cracks.