Estimates of strength and cracking behaviors of pre-flawed granite specimens treated by chemical corrosion under triaxial compression tests

doi:10.1007/s11707-021-0954-1

Front. Earth Sci.

2022, Vol. 16

Issue (2) : 411-434 https://doi.org/10.1007/s11707-021-0954-1

RESEARCH ARTICLE

Estimates of strength and cracking behaviors of pre-flawed granite specimens treated by chemical corrosion under triaxial compression tests

Zhicong LI, Richeng LIU(

), Shuchen LI, Hongwen JING, Xiaozhao LI, Liyuan YU

State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China

Download: PDF(43049 KB) HTML
Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks

Abstract

Four types of granite specimens were prepared and treated by chemical corrosion for 5 and 30 days, which were then used to carry out triaxial compression tests under different confining pressures σ₃. Type A is the intact sample with no preexisting flaws. Types B and C are the samples containing two relatively low-dip flaws and two relatively high-dip flaws, respectively. Type D is the sample including both relatively low-dip and relatively high-dip flaws. The influences of pH value of chemical solutions, flaw distribution, corrosion time and σ₃ on triaxial stress-strain curves and ultimate failure modes are analyzed and discussed. The results show that the pH value of the chemical solution, corrosion time and the arrangement of preexisting flaws play crucial roles in the cracking behaviors of granite specimens. Type A specimens have the largest peak axial deviatoric stress, followed by Type C, Type D, and Type B specimens, respectively. It is because the decrease in the inclination of preexisting flaws induces the weakening effect due to the decrease in the shadow area along the compaction direction. Under a σ₃ of 5 MPa, the peak axial deviatoric stress drops by approximately 40.89%, 29.08%, 4.08%, and 23.53% for pH = 2, 4, 7, and 12, respectively. For intact granite (Type A) specimens, the ultimate failure mode displays a typical shear mode. The connection of two secondary cracks initiated at the tips of preexisting cracks is always the ultimate failure and crack coalescence mode for Type B specimens. The ultimate failure and crack coalescence mode of Types C and D specimens are significantly affected by pH value of the chemical solution, corrosion time and σ₃, which is different from those of Types A and B specimens due to the differences in flow distributions.

Keywords granites preexisting flaws chemical corrosion triaxial compression strength cracking behavior

Corresponding Author(s): Richeng LIU

About author: Tongcan Cui and Yizhe Hou contributed equally to this work.

Online First Date: 29 March 2022 Issue Date: 26 August 2022

Cite this article:

Zhicong LI,Richeng LIU,Shuchen LI, et al. Estimates of strength and cracking behaviors of pre-flawed granite specimens treated by chemical corrosion under triaxial compression tests[J]. Front. Earth Sci., 2022, 16(2): 411-434.

URL:

https://academic.hep.com.cn/fesci/EN/10.1007/s11707-021-0954-1
https://academic.hep.com.cn/fesci/EN/Y2022/V16/I2/411

Fig.1 Four types of tested granite specimens.

Tab.1 Tested granite specimens

Fig.2 (a) MTS815 rock mechanics testing system. (b) Strain measurement with extensometers.

Fig.3 Triaxial stress–strain curves of Type A granite specimens under different confining pressures and soaking days.

Fig.4 Typical triaxial stress–strain curves of Type B granite specimens under different confining pressures and soaking days.

Fig.5 Typical triaxial stress–strain curves of Type C granite specimens under different confining pressures and soaking days.

Fig.6 Typical triaxial stress–strain curves of Type D granite specimens under different confining pressures and soaking days.

Fig.7 Typical triaxial stress–strain curve with four stages of Type A granite specimens treated by pH = 2 chemical solution for 5 days.

Specimen	Fracture mode	σ₃/MPa	Soaking days	pH value	σ_p/MPa	σ_cd/MPa	σ_cr/MPa	ε_vc/(×10³)	ε_1c/(×10³)
A₂-5-a	A	0	5	2	117.15		0		9.25
A₂-5-b	A	5	5	2	202.52	186.91	58.74	9.37	12.03
A₂-5-c	A	10	5	2	246.48	221.75	70.43	10.64	15.78
A₂-5-d	A	20	5	2	337.53	312.26	48.38	11.83	18.23
A₂-30-a	A	0	30	2	55.61		12.38		9.21
A₂-30-b	A	5	30	2	119.58	113.63	36.70	10.02	13.00
A₂-30-c	A	10	30	2	188.57	161.42	51.92	10.84	14.96
A₂-30-d	A	20	30	2	258.15	236.17	27.51	12.50	19.66
A₄-5-a	A	0	5	4	111.02		0		9.39
A₄-5-b	A	5	5	4	196.34	186.15	60.70	10.07	14.23
A₄-5-c	A	10	5	4	239.45	191.24	105.80	11.22	16.06
A₄-5-d	A	20	5	4	337.53	317.03	151.33	11.96	18.80
A₄-30-a	A	0	30	4	71.43		49.48		9.63
A₄-30-b	A	5	30	4	139.41	121.24	45.18	10.05	14.21
A₄-30-c	A	10	30	4	208.03	173.20	65.61	11.41	15.41
A₄-30-d	A	20	30	4	272.68	248.24	121.32	12.63	17.66
A₇-5-a	A	0	5	7	114.92		0		8.87
A₇-5-b	A	5	5	7	195.77	174.86	156.63	11.14	14.61
A₇-5-c	A	10	5	7	256.83	235.43	94.89	12.04	14.88
A₇-5-d	A	20	5	7	337.53	317.53	20.76	14.54	17.76
A₇-30-a	A	0	30	7	102.35		35.66		6.97
A₇-30-b	A	5	30	7	188.02	165.58	57.01	9.78	13.08
A₇-30-c	A	10	30	7	247.70	225.88	161.17	11.59	16.17
A₇-30-d	A	20	30	7	347.53	313.18	142.23	12.44	19.17
A₁₂-5-a	A	0	5	12	111.41		0		7.78
A₁₂-5-b	A	5	5	12	203.83	187.08	73.49	9.84	12.92
A₁₂-5-c	A	10	5	12	252.98	232.24	101.23	11.93	16.31
A₁₂-5-d	A	20	5	12	337.53	317.53	306.93	13.04	18.45
A₁₂-30-a	A	0	30	12	78.53		59.51		7.58
A₁₂-30-b	A	5	30	12	156.49	132.00	53.86	9.67	13.02
A₁₂-30-c	A	10	30	12	220.98	177.55	101.49	11.91	17.15
A₁₂-30-d	A	20	30	12	289.90	257.50	57.74	19.91	19.08
B₂-5-a	B	0	5	2	45.76		0		4.93
B₂-5-b	B	5	5	2	61.25	51.41	17.39	3.36	8.00
B₂-5-c	B	10	5	2	100.25	86.38	50.88	6.59	8.46
B₂-5-d	B	20	5	2	138.10	106.49	48.82	10.13	5.92
B₂-30-a	B	0	30	2	21.55		0		4.70
B₂-30-b	B	5	30	2	31.34	25.49	10.66	3.49	3.97
B₂-30-c	B	10	30	2	41.15	31.00	1.78	3.63	6.46
B₂-30-d	B	20	30	2	57.64	34.48	2.29	5.11	4.80
B₄-5-a	B	0	5	4	45.60		0		4.17
B₄-5-b	B	5	5	4	60.64	54.51	18.82	3.02	7.49
B₄-5-c	B	10	5	4	105.66	81.92	89.99	4.46	4.03
B₄-5-d	B	20	5	4	145.20	111.28	23.87	6.35	5.25
B₄-30-a	B	0	30	4	33.08		0		6.15
B₄-30-b	B	5	30	4	43.91	33.81	5.79	3.91	5.59
B₄-30-c	B	10	30	4	55.80	44.78	6.06	4.42	5.03
B₄-30-d	B	20	30	4	72.58	50.33	20.14	6.60	8.74
B₇-5-a	B	0	5	7	45.88		0		4.63
B₇-5-b	B	5	5	7	55.68	46.03	34.69	4.04	9.34
B₇-5-c	B	10	5	7	100.22	88.90	40.94	7.21	9.05
B₇-5-d	B	20	5	7	152.41	123.34	20.78	7.95	6.07
B₇-30-a	B	0	30	7	42.63		0		9.19
B₇-30-b	B	5	30	7	64.72	56.69	14.46	3.77	6.57
B₇-30-c	B	10	30	7	91.19	76.32	66.57	5.28	4.65
B₁₂-5-a	B	0	5	12	44.92		0		4.72
B₁₂-5-b	B	5	5	12	60.37	50.44	26.57	3.36	8.65
B₁₂-5-c	B	10	5	12	102.26	79.13	86.52	5.24	5.03
B₁₂-5-d	B	20	5	12	138.47	114.27	22.85	6.61	7.24
B₁₂-30-a	B	0	30	12	37.90		0		5.07
B₁₂-30-b	B	5	30	12	48.45	34.40	6.18	5.37	6.89
B₁₂-30-c	B	10	30	12	63.99	52.50	3.59	6.09	6.00
B₁₂-30-d	B	20	30	12	130.60	100.01	100.42	8.54	11.44
C₂-5-a	C	0	5	2	103.48		0		7.99
C₂-5-b	C	5	5	2	160.71	135.38	68.16	10.87	12.86
C₂-30-a	C	0	30	2	61.79		0		8.35
C₂-30-b	C	5	30	2	102.60	73.70	56.40	9.21	16.53
C₂-30-c	C	10	30	2	170.08	153.98	85.70	12.91	13.72
C₂-30-d	C	20	30	2	229.72	202.10	128.51	13.85	19.56
C₄-5-a	C	0	5	4	107.94		0		8.12
C₄-5-b	C	5	5	4	164.03	135.93	99.19	9.82	13.69
C₄-5-c	C	10	5	4	215.19	201.51	111.35	11.24	13.18
C₄-5-d	C	20	5	4	272.36	243.60	22.04	11.39	15.65
C₄-30-a	C	0	30	4	76.59		0		8.59
C₄-30-b	C	5	30	4	121.90	91.81	60.07	11.38	16.13
C₄-30-c	C	10	30	4	183.84	162.15	92.65	11.05	14.84
C₄-30-d	C	20	30	4	254.50	228.00	135.59	14.05	18.78
C₇-5-a	C	0	5	7	106.45		0		6.19
C₇-5-b	C	5	5	7	160.41	148.65	89.29	8.71	12.00
C₇-5-c	C	10	5	7	227.24	188.83	51.01	10.04	11.05
C₇-5-d	C	20	5	7	267.85	199.46	126.27	16.31	15.74
C₇-30-a	C	0	30	7	96.10		0		7.70
C₇-30-b	C	5	30	7	158.35	137.24	23.63	7.63	10.53
C₇-30-c	C	10	30	7	198.34	181.15	110.57	10.88	16.65
C₁₂-5-a	C	0	5	12	102.45		0		6.29
C₁₂-5-b	C	5	5	12	167.43	146.06	66.31	8.77	12.75
C₁₂-5-c	C	10	5	12	244.52	232.36	100.34	12.15	14.17
C₁₂-5-d	C	20	5	12	289.32	263.85	156.63	12.98	19.50
C₁₂-30-a	C	0	30	12	93.95		0		7.41
C₁₂-30-b	C	5	30	12	137.67	127.53	64.81	8.74	10.96
D₂-5-a	D	0	5	2	52.35		0		5.94
D₂-5-b	D	5	5	2	103.28	97.01	70.51	11.29	14.02
D₂-5-c	D	10	5	2	164.83	150.07	126.73	14.70	23.21
D₂-5-d	D	20	5	2	228.17	185.50	202.36	12.50	24.81
D₂-30-a	D	0	30	2	27.99		0		7.24
D₂-30-b	D	5	30	2	58.59	51.43	43.74	9.05	12.49
D₂-30-c	D	10	30	2	110.68	96.57	99.74	13.22	20.13
D₄-5-a	D	0	5	4	54.20		0		7.58
D₄-5-b	D	5	5	4	104.12	96.09	71.81	9.05	12.04
D₄-5-c	D	10	5	4	167.19	151.84	125.93	9.56	12.47
D₄-30-a	D	0	30	4	34.89		0		6.67
D₄-30-b	D	5	30	4	80.79	69.53	56.24	10.68	13.36
D₇-5-a	D	0	5	7	51.57		0		5.82
D₇-5-b	D	5	5	7	100.56	88.77	84.30	9.02	13.15
D₇-5-c	D	10	5	7	154.72	129.49	129.61	11.03	24.43
D₇-5-d	D	20	5	7	237.14	155.62	195.79	13.59	25.18
D₇-30-a	D	0	30	7	49.36		0		6.07
D₇-30-b	D	5	30	7	91.68	78.36	69.20	11.29	15.88
D₇-30-c	D	10	30	7	151.07	130.61	103.37	13.11	17.08
D₁₂-5-a	D	0	5	12	51.23				6.29
D₁₂-5-b	D	5	5	12	103.73	92.33	77.13	13.59	16.11
D₁₂-5-c	D	10	5	12	173.44	131.16	130.84	14.66	20.27
D₁₂-5-d	D	20	5	12	236.47	215.16	187.94	14.85	16.83
D₁₂-30-a	D	0	30	12	42.34		0		6.76
D₁₂-30-b	D	5	30	12	87.68	79.49	67.29	8.67	22.03
D₁₂-30-c	D	10	30	12	135.13	121.68	115.67	12.65	16.94

Tab.2 Physical and mechanical properties of tested granite specimens

Fig.8 Typical deviatoric stress versus axial strain curves, and corresponding volumetric strain versus axial strain curves. The samples are treated with pH =2 chemical solution for 30 days under a confining pressure of 5 MPa.

Fig.9 Variations in peak axial stress σ_p and σ_cd versus confining pressure σ₃ varying from 0 to 20 MPa. The samples are treated with pH=2 chemical solution for 5 and 30 soaking days, respectively.

Fig.10 Variations in peak axial stress σ_p and σ_cd versus confining pressure σ₃ varying from 0 to 20 MPa. The samples are treated with pH=12 chemical solution for 5 and 30 soaking days, respectively.

Tab.3 Peak strength and crack damage parameters of tested granite specimens in accordance with the linear Mohr-Coulomb criterion

Fig.11 Variations in peak axial stress σ_p and σ_cd versus confining pressure σ₃ varying from 0 to 20 MPa. The samples are treated with pH=4 chemical solution for 5 and 30 soaking days, respectively.

Fig.12 Variations in peak axial stress σ_p and σ_cd versus confining pressure σ₃ varying from 0 to 20 MPa. The samples are treated with pH=7 chemical solution for 5 and 30 soaking days, respectively.

Fig.13 Variations in peak axial stress σ_p versus pH for specimens under confining pressures of 0, 5, 10, 20 MPa and 5 and 30 soaking days, respectively.

Fig.14 Crack types observed in specimens with crack in compression (modified after Yang and Jing, 2009).

Fig.15 Crack coalescence manners (modified slightly from Wong et al., 2008a; Yang et al., 2008): (a) non-coalescence, (b) direct coalescence, (c) and (d) indirect coalescence.

Fig.16 Typical failure of the tested intact (type A) granite specimens treated with pH=2 chemical solution for 30 days under different confining pressures: (a) 5 MPa, (b) 10 MPa and (c) 20 MPa.

Fig.17 Typical failure and crack coalescence of the tested type B granite specimens treated with pH = 2 chemical solution for 30 days under different confining pressures: (a) 5 MPa, (b) 10 MPa and (c) 20 MPa.

Fig.18 Ultimate failure modes of Type C granite specimens treated with different chemical solutions for 5 and 30 days.

Fig.19 Ultimate failure modes of Type D granite specimens treated with different chemical solutions for 5 and 30 days.

1	E G Bombolakis. (1968). Photoelastic study of initial stages of brittle fracture in compression. Tectonophysics, 6(6): 461–473 https://doi.org/10.1016/0040-1951(68)90072-3
2	W Ding. (2012). Study on the time-dependent characteristics of sandstone under chemical corrosion. App Mech Mater, 256–259: 174–178 https://doi.org/10.4028/www.scientific.net/AMM.256-259.174
3	X T Feng, S Li, S Chen. (2004). Real-time computerized tomography (CT) experiments on sandstone damage evolution during triaxial compression with chemical corrosion. Int J Rock Mech Min Sci, 41(2): 181–192 https://doi.org/10.1016/S1365-1609(03)00059-5
4	X T Feng, S Chen, S Li. (2001). Effects of water chemistry on microcracking and compressive strength of granite. Int J Rock Mech Min Sci, 38(4): 557–568 https://doi.org/10.1016/S1365-1609(01)00016-8
5	T Han, J Shi, X Cao. (2016). Fracturing and damage to sandstone under coupling effects of chemical corrosion and freeze–thaw cycles. Rock Mech Rock Eng, 49(11): 4245–4255 https://doi.org/10.1007/s00603-016-1028-7
6	D Huang, D Gu, C Yang, R Huang, G Fu. (2016). Investigation on mechanical behaviors of sandstone with two preexisting flaws under triaxial compression. Rock Mech Rock Eng, 49(2): 375–399 https://doi.org/10.1007/s00603-015-0757-3
7	H Lee, S Jeon. (2011). An experimental and numerical study of fracture coalescence in pre-cracked specimens under uniaxial compression. Int J Solids Struct, 48(6): 979–999 https://doi.org/10.1016/j.ijsolstr.2010.12.001
8	H Li, L N Y Wong. (2014). Numerical study on coalescence of pre-existing flaw pairs in rock-like material. Rock Mech Rock Eng, 47(6): 2087–2105 https://doi.org/10.1007/s00603-013-0504-6
9	H Li, D Yang, Z Zhong, Y Sheng, X Liu. (2018). Experimental investigation on the micro damage evolution of chemical corroded limestone subjected to cyclic loads. Int J Fatigue, 113: 23–32 https://doi.org/10.1016/j.ijfatigue.2018.03.022
10	N Li, Y Zhu, B Su, S Gunter. (2003). A chemical damage model of sandstone in acid solution. Int J Rock Mech Min Sci, 40(2): 243–249 https://doi.org/10.1016/S1365-1609(02)00132-6
11	S Lu. (2018). A global review of enhanced geothermal system (EGS). Renew Sustain Energy Rev, 81: 2902–2921 https://doi.org/10.1016/j.rser.2017.06.097
12	J Luo, Y Zhu, Q Guo, L Tan, Y Zhuang, M Liu, C Zhang, M Zhu, W Xiang. (2018). Chemical stimulation on the hydraulic properties of artificially fractured granite for enhanced geothermal system. Energy, 142: 754–764 https://doi.org/10.1016/j.energy.2017.10.086
13	S Sagong, A Bobet. (2002). Coalescence of multiple flaws in a rock-model material in uniaxial compression. Int J Rock Mech Min Sci, 39(2): 229–241 https://doi.org/10.1016/S1365-1609(02)00027-8
14	A R Maligno, S Rajaratnam, S B Leen, E J Williams. (2010). A three-dimensional (3D) numerical study of fatigue crack growth using remeshing techniques. Eng Fract Mech, 77(1): 94–111 https://doi.org/10.1016/j.engfracmech.2009.09.017
15	S Miao, M Cai, Q Guo, P Wang, M Liang. (2016). Damage effects and mechanisms in granite treated with acidic chemical solutions. Int J Rock Mech Min Sci, 88: 77–86 https://doi.org/10.1016/j.ijrmms.2016.07.002
16	P Olasolo, M C Juárez, M P Morales, S D’Amico, I A Liarte. (2016). Enhanced geothermal systems (EGS): a review. Renew Sustain Energy Rev, 56: 133–144 https://doi.org/10.1016/j.rser.2015.11.031
17	S Portier, F D Vuataz, P Nami, B Sanjuan, A Gérard. (2019). Chemical stimulation techniques for geothermal wells: experiments on the three-well EGS system at Soultz-sous-Forêts, France. Geothermics, 38(4): 349–359 https://doi.org/10.1016/j.geothermics.2009.07.001
18	L Qiao, Z Wang, A Huang. (2017). Alteration of mesoscopic properties and mechanical behavior of sandstone due to hydro-physical and hydro-chemical effects. Rock Mech Rock Eng, 50(2): 255–267 https://doi.org/10.1007/s00603-016-1111-0
19	T D Rathnaweera, W Wu, Y Ji, R P Gamage. (2020). Understanding injection-induced seismicity in enhanced geothermal systems: from the coupled thermo-hydro-mechanical-chemical process to anthropogenic earthquake prediction. Earth Sci Rev, 205: 103182 https://doi.org/10.1016/j.earscirev.2020.103182
20	J Taron, D Elsworth. (2010). Coupled mechanical and chemical processes in engineered geothermal reservoirs with dynamic permeability. Int J Rock Mech Min Sci, 47(8): 1339–1348 https://doi.org/10.1016/j.ijrmms.2010.08.021
21	R H C Wong, K T Chau. (1998). Crack coalescence in a rock-like material containing two cracks. Int J Rock Mech Min Sci, 97(2): 147–164 https://doi.org/10.1016/S0148-9062(97)00303-3
22	L N Y Wong, H H Einstein. (2008a). Crack coalescence in molded gypsum and carrara marble: part 1. Macroscopic observations and interpretation. Rock Mech Rock Eng, 42(3): 475–511 https://doi.org/10.1007/s00603-008-0002-4
23	L N Y Wong, H H Einstein. (2008b). Crack coalescence in molded gypsum and carrara marble: part 2. Microscopic observations and interpretation. Rock Mech Rock Eng, 42(3): 513–545 https://doi.org/10.1007/s00603-008-0003-3
24	L N Y Wong, H H Einstein. (2009). Systematic evaluation of cracking behavior in specimens containing single flaws under uniaxial compression. Int J Rock Mech Min Sci, 46(2): 239–249 https://doi.org/10.1016/j.ijrmms.2008.03.006
25	L N Y Wong, H Li. (2013). Numerical study on coalescence of two pre-existing coplanar flaws in rock. Int J Solids Struct, 50(22–23): 3685–3706 https://doi.org/10.1016/j.ijsolstr.2013.07.010
26	S Xie, J Shao, W Xu. (2011). Influences of chemical degradation on mechanical behavior of a limestone. Int J Rock Mech Min Sci, 48(5): 741–747 https://doi.org/10.1016/j.ijrmms.2011.04.015
27	S Yang, Y Jiang, W Xu, X Chen. (2008). Experimental investigation on strength and failure behavior of pre-cracked marble under conventional triaxial compression. Int J Solids Struct, 45(17): 4796–4819 https://doi.org/10.1016/j.ijsolstr.2008.04.023
28	S Yang, H Jing. (2011). Strength failure and crack coalescence behavior of brittle sandstone samples containing a single fissure under uniaxial compression. Int J Fract, 168(2): 227–250 https://doi.org/10.1007/s10704-010-9576-4
29	X Zhang, L N Y Wong. (2011). Cracking processes in rock-like material containing a single flaw under uniaxial compression: a numerical study based on parallel bonded-particle model approach. Rock Mech Rock Eng, 45: 711–737 https://doi.org/10.1007/s00603-011-0176-z
30	H Zhou, D Hu, F Zhang, J Shao, X Feng. (2016). Laboratory investigations of the hydro-mechanical–chemical coupling behaviour of sandstone in CO2 storage in aquifers. Rock Mech Rock Eng, 49(2): 417–426 https://doi.org/10.1007/s00603-015-0752-8

[1]	Bo HE, Jun LIU, Peng ZHAO, Jingfeng WANG. PFC^2D-based investigation on the mechanical behavior of anisotropic shale under Brazilian splitting containing two parallel cracks[J]. Front. Earth Sci., 2021, 15(4): 803-816.
[2]	Khelifa HARICHANE, Mohamed GHRICI, Hanifi MISSOUM. Influence of natural pozzolana and lime additives on the temporal variation of soil compaction and shear strength[J]. Front Earth Sci, 2011, 5(2): 162-169.
[3]	CHANG Xiaoxiao, MA Wei, WANG Dayan. Study on the strength of frozen clay at high confining pressure[J]. Front. Earth Sci., 2008, 2(2): 240-242.

Viewed

Full text

Abstract

Cited

Shared

Discussed