Characterization of roughness and shear behavior of thermally treated granite fractures

doi:10.1016/j.enggeo.2021.106287

	Characterization of roughness and shear behavior of thermally treated granite fractures
	Meng, Fanzhen 1; Song, Jie 1; Wong, Louis Ngai Yuen 2; Wang, Zaiquan 1; Zhang, Chuanqing 3
刊名	ENGINEERING GEOLOGY
	2021-11-01
卷号	293 页码:20
关键词	High temperature Thermal crack Roughness degradation Shear strength Stress drop
ISSN号	0013-7952
DOI	10.1016/j.enggeo.2021.106287
英文摘要	Despite a large number of studies examining the effects of high temperature on the physical and mechanical properties of various rock types, few studies have addressed the effects of high temperature on the frictional behavior of rough fractures. As a benchmark of high temperature effects on rock integrity, we measure the uniaxial compression strength (UCS) and p-wave velocity (Vp) of granite samples after they are heated to various temperatures as high as 500 degrees C and allowed to cool to room temperature. We then investigate changes in the roughness and shear behavior of thermally treated rough granite fractures using direct shear tests. The results indicate that the UCS increases by 37% at 200 degrees C compared with that of granite without thermal treatment, and then decreases with temperature, while the Vp decreases almost linearly with increasing treatment temperature. The strengthening of rock upon heating is very likely associated with the thermal expansion of minerals, water evaporation and microcrack blunting, while the decrease in the UCS is closely related to the increase in thermal cracks. The degradation of the fracture roughness increases with normal stress, and it also tends to be greater for higher treatment temperatures. The peak shear strength, post-peak stress drop and stick-slip magnitude, which are not significantly influenced by the treatment temperature between room temperature and 300 degrees C, decrease with treatment temperatures above 300 degrees C. In particular, no post-peak stress drop occurs for the thermally treated fractures sheared under low normal stress, and the post-peak stress drop is inhibited in fractures with much higher temperature treatments and shearing under high normal stress. Our new findings contribute to a better understanding of fault slip mechanics at high temperatures in geothermal recovery and high-level radioactive waste repositories.
资助项目	National Natural Science Foundation of China[51879135] ; National Natural Science Foundation of China[41877217] ; National Natural Science Foundation of China[51808306] ; National Natural Science Foundation of China[U1865203] ; Taishan Scholars Program[2019KJG002] ; Taishan Scholars Program[2019RKB01083] ; Research Grants Council of Hong Kong[17303917]
WOS研究方向	Engineering ; Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000696814500010
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27923]
专题	中科院武汉岩土力学所
通讯作者	Wong, Louis Ngai Yuen
作者单位	1.Qingdao Univ Technol, Coll Sci, Qingdao 266033, Shandong, Peoples R China 2.Univ Hong Kong, Dept Earth Sci, Pokfulam, Hong Kong, Peoples R China 3.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China
推荐引用方式 GB/T 7714	Meng, Fanzhen,Song, Jie,Wong, Louis Ngai Yuen,et al. Characterization of roughness and shear behavior of thermally treated granite fractures[J]. ENGINEERING GEOLOGY,2021,293:20.
APA	Meng, Fanzhen,Song, Jie,Wong, Louis Ngai Yuen,Wang, Zaiquan,&Zhang, Chuanqing.(2021).Characterization of roughness and shear behavior of thermally treated granite fractures.ENGINEERING GEOLOGY,293,20.
MLA	Meng, Fanzhen,et al."Characterization of roughness and shear behavior of thermally treated granite fractures".ENGINEERING GEOLOGY 293(2021):20.