摘要：Cyclic hydraulic fracturing has been proved to be an effective stimulation technique to explore EGS resouces. The shear friction behaviors under cyclic normal stress are essential to understand the hydro-shearing mechanisms. This paper proposed a cyclic shear friction test to understand the friction characteristics of granite fracture during cyclic hydraulic fracturing. A cyclic normal force in sinusoidal function and a constant shear velocity were enforced on the rock specimen. The time-dependent friction behaviors were observed. Results indicate that the frictional coefficient is highly correlated with the variation of the normal force. Futhermore, the frequency dependency of cyclic shear friction was observed. High-frequency normal force motivates a lower frictional shear slip. However, the amplitude of normal force displays an irregular influence on the frictional coefficient. Microstructure analysis demonstrated that numerous scratches and a powder-lubrication layer were generated along the sheared asperity between the fracture surfaces. High-frequency shear friction accelerates jumping shear and creates finer powder to lubricate the shear slip. The present work is helpful to understand the mechanisms of cyclic hydraulic fracturing to activiate the existing natural fractures.
© 2020

ISSN号：0013-7944

卷、期、页：v 238,

发表日期：2020-01-01

收录情况：SCIE（科学引文索引网络版）,EI（工程索引）

发表期刊名称：Engineering Fracture Mechanics

参与作者：庄晓莹

通讯作者：李璞,王剑波

第一作者：盛茂

论文类型：期刊论文

论文概要：盛茂,李璞,庄晓莹,王剑波，Influence of cyclic normal stress on shear friction of EGS granite fractures，Engineering Fracture Mechanics，2020，v 238,

论文题目：Influence of cyclic normal stress on shear friction of EGS granite fractures