Influence of rock inhomogeneity degree on the crustal stress results measured by hydraulic fracturing method
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摘要: 准确揭示原位地应力状态，对地下工程开挖支护设计和长期稳定性分析等具有十分重要的意义。利用水压致裂技术开展了纱岭金矿主竖井地应力测试工作，获得了20个测段地应力状态；室内进行了主竖井测试孔岩芯的岩石力学试验，包括巴西劈裂试验、单轴压缩试验及声发射监测试验，获得了岩石空间非均质度和强度分布特征，并分析了岩石非均质度与水压致裂测试结果的关系。结果表明：主应力大小随测量深度近似呈线性增大，测试孔的最大水平主应力值为20.78~45.20 MPa，最小水平主应力值为14.94~35.33 MPa，平均最大水平主应力方向为 NW65°；测试孔岩芯各层位非均质度不同，变辉长岩非均质度系数为0.1~0.3，且岩石不同强度条件下声发射信号数量变化不显著，岩石离散度较小，花岗岩非均质度系数最高，可达1.0，以加载后期强相破裂产生的声发射信号为主；岩石非均质度影响水压致裂裂纹的扩展方向，扩展方向和最大水平主应力方向的夹角$\varphi $影响着最大、最小水平主应力的测量结果，且对最小水平主应力的影响尤为显著。分析水压致裂测量结果与岩石性质之间的关系，对精确探测非均质地层的地应力场分布规律具有一定的指导作用。Abstract: Accurate in-situ crustal stress data are essential for excavation support design and long-term stability analysis of underground projects. We tested the main shaft of the Shaling Gold Mine for crustal stress using hydraulic fracturing technology, and the crustal stress state of 20 measurement points was obtained. The Brazilian test, uniaxial compression test, and acoustic emission test of the cores were conducted indoors to obtain the rock’s spatial inhomogeneity and strength distribution. We analyzed the relationship between the inhomogeneity of the rock and the hydraulic fracturing results. The analysis results show that the magnitude of the principal stress increases nearly linearly with the measurement depth, with the maximum horizontal principal stress value ranging from 20.78 to 45.2 MPa and the minimum principal stress value from 14.94 to 35.33 MPa. The average direction of the maximum horizontal principal stress is NW 65°. The inhomogeneity of each layer of the cores varies, and the inhomogeneity coefficient of the metagabbro is from 0.1 to 0.3. The number of acoustic emission signals under each intensity of the rock is basically the same, and the dispersion of the rock is small. The non-homogeneity coefficient of granite is up to 1.0, dominated by the acoustic emission signals generated by the intense-phase rupture at the late loading stage. The non-homogeneity of the rock affects the direction of expansion of the hydraulic fracture, and the angle $\varphi $ between the expansion direction and the maximum horizontal principal stress affects the measurement results of the horizontal maximum and minimum principal stresses and has a more significant effect on the horizontal minimum principal stress. The relationship between hydraulic fracture measurements and rock properties was analyzed, which is helpful for accurately detecting the distribution of stress fields in inhomogeneous strata.
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Key words:
- deep layers /
- in-situ stress /
- hydraulic fracturing /
- rock inhomogeneity /
- rock mechanics testing
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图 1 纱岭金矿区域地质构造简图与主井地质剖面图简图
Figure 1. Sketch map of the regional geological structure and the geological profile of the main shaft of the Shaling Gold Mine
图 3 主应力、孔隙水压力随深度变化规律
Figure 3. Distribution of principal stress and pore water pressure with depth
图 4 单轴试件安装及劈裂试件应变片布置图
Figure 4. Uniaxial rock sample installation and splitting specimen strain gauge layout drawing
图 5 不同深度岩石的劈裂应变及变异系数
Figure 5. Splitting strains and coefficients of variation for rocks at different depths
图 6 岩样应力−应变曲线、声发射幅值演化及各应力下声发射信号占比
Figure 6. Stress–strain curves of rock samples, evolution of acoustic emission amplitude, and percentage of acoustic emission signal at each stress
图 7 水压致裂岩石强弱相分布示意图
σH、σh—最大、最小水平主应力；$\varphi $—岩体和测试孔中心连线与最大水平主应力方向的夹角；r—测试孔半径
Figure 7. Schematic diagram showing the strong and weak phase distribution of rocks using hydraulic fracturing
σH and σh–maximum and minimum horizontal principal stresses; $\varphi $–angle between the connecting line of the center of the rock and the test borehole and the direction of the maximum horizontal principal stress; r–radius of the test borehole
图 8 水压致裂远场应力状态和坐标转化后应力状态
Figure 8. The far-field stress state and the stress state after coordinate transformation using hydraulic fracturing
图 9 水压致裂测得水平主应力及误差与$\varphi $关系变化图
Figure 9. Plot of horizontal principal stress and error measured by hydraulic fracturing versus $\varphi $
表 1 水压致裂地应力测量结果
Table 1. In-situ stress measurement results using hydraulic fracturing
测段深度/m 压裂参数/MPa 主应力值/MPa 破裂方位 Pb Pr Ps P0 T ${\sigma _{\text{H}}}$ ${\sigma _{\text{h}}}$ ${\sigma _{\text{v}}}$ −632.00 21.05 17.85 14.94 6.19 3.20 20.78 14.94 16.72 — −700.00 21.19 16.71 15.33 6.86 4.48 22.42 15.33 18.52 — −757.54 16.93 15.86 15.58 7.42 1.07 23.46 15.58 20.04 — −789.00 21.64 16.98 16.52 7.73 4.66 24.85 16.52 20.88 — −814.75 23.22 18.19 17.27 7.98 5.03 25.64 17.27 21.56 — −856.20 24.24 18.71 18.12 8.39 5.53 27.26 18.12 22.66 — −900.00 26.47 20.58 19.46 8.82 5.89 28.98 19.46 23.81 — −950.08 28.94 23.20 21.34 9.31 5.74 31.51 21.34 25.14 NW66.2° −993.00 30.67 26.26 23.48 9.73 4.41 34.45 23.48 26.27 — −1071.62 35.23 29.00 24.83 10.50 6.23 34.99 24.83 28.36 — −1119.00 37.11 30.10 25.31 10.97 7.01 34.86 25.31 29.61 — −1160.27 38.68 32.16 26.06 11.37 6.52 34.65 26.06 30.70 — −1236.14 34.82 33.74 27.21 12.11 1.08 35.78 27.21 32.71 — −1307.30 39.85 36.91 28.95 12.81 2.94 37.13 28.95 34.59 — −1340.02 46.22 38.03 29.87 13.13 8.19 38.45 29.87 35.46 NW63.8° −1355.00 44.85 38.80 30.63 13.28 6.05 39.81 30.63 35.85 — −1417.68 47.26 41.91 32.72 13.89 5.35 42.36 32.72 37.51 — −1435.90 52.10 43.65 33.58 14.07 8.45 43.02 33.58 37.99 — −1483.00 47.77 45.71 34.96 14.53 2.06 44.64 34.96 39.24 — −1527.15 51.41 45.82 35.33 14.97 5.59 45.20 35.33 40.41 — 
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[1] BAO L H, DU Y, GUO Q L, et al. , 2017. In-situ stress measurement and research on tectonic stress field distribution law of Chengdu-Lanzhou railway[J]. Journal of Geomechanics, 23(5): 734-742. (in Chinese with English abstract) [2] BELL J S, GOUGH D I, 1979. Northeast-southwest compressive stress in Alberta evidence from oil wells[J]. Earth and Planetary Science Letters, 45(2): 475-482. doi: 10.1016/0012-821X(79)90146-8 [3] CAI M, QIAO L, YU J, 1995. Study and tests of techniques for increasing overcoring stress measurement accuracy[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 32(4): 375-384. [4] CAI M, KAISER P K, TASAKA Y, et al. , 2004. Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations[J]. International Journal of Rock Mechanics and Mining Sciences, 41(5): 833-847. doi: 10.1016/j.ijrmms.2004.02.001 [5] CAI M F, LIU W D, LI Y, 2010. In-situ stress measurement at deep position of Linglong gold mine and distribution law of in-situ stress field in mine area[J]. Chinese Journal of Rock Mechanics and Engineering, 29(2): 227-233. (in Chinese with English abstract) [6] CAI M F, JI D, GUO Q F, 2013a. Study of rockburst prediction based on in-situ stress measurement and theory of energy accumulation caused by mining disturbance[J]. Chinese Journal of Rock Mechanics and Engineering, 32(10): 1973-1980. (in Chinese with English abstract) [7] CAI M F, GUO Q F, LI Y, et al. , 2013b. In situ stress measurement and its application in the 10th Mine of Pingdingshan Coal Group[J]. Journal of University of Science and Technology Beijing, 35(11): 1399-1406. (in Chinese with English abstract) [8] CHEN J L, 2019. Numerical simulation methods and experimental investigation of the hydraulic fracturing of heterogeneous Glutenites[D]. Beijing: China University of Mining & Technology (Beijing). (in Chinese with English abstract) [9] CHEN N, WANG C H, GAO G Y, et al. , 2021. Characteristics of in-situ stress field in the powerhouse area on the right bank of Baihetan based on stress polygon and borehole breakout method[J]. Rock and Soil Mechanics, 42(12): 3376-3384. (in Chinese with English abstract) [10] CHEN Y Q, NAGAYA Y, ISHIDA T, 2015. Observations of fractures induced by hydraulic fracturing in anisotropic granite[J]. Rock Mechanics and Rock Engineering, 48(4): 1455-1461. doi: 10.1007/s00603-015-0727-9 [11] GOODMAN R E, 1963. Subaudible noise during compression of rocks[J]. GSA Bulletin, 74(4): 487-490. doi: 10.1130/0016-7606(1963)74[487:SNDCOR]2.0.CO;2 [12] HOU K K, WU Q Z, ZHANG F P, et al. , 2022. Application of different in-situ stress test methods in the area of 2 005 m shaft construction of Sanshandao gold mine and distribution law of in-situ stress[J]. Rock and Soil Mechanics, 43(4): 1093-1102. (in Chinese with English abstract) [13] HUBBERT M K, WILLIS D G, 1957. Mechanics of hydraulic fracturing[J]. Petroleum Transactions, 210(1): 153-168. [14] JIANG M Y, 2019. Metallogeneses and tectonic setting analysis of Shaling gold deposit in Jiaodong[D]. Hebei GEO University. (in Chinese with English abstract) [15] LEE H, ONG S H, 2018. Estimation of in situ stresses with hydro-fracturing tests and a statistical method[J]. Rock Mechanics and Rock Engineering, 51(3): 779-799. doi: 10.1007/s00603-017-1349-1 [16] LEEMAN E R, HAYES D J, 1966. A technique for determining the complete state of stress in rock using a single borehole[C]//Proceedings 1st congress international society of rock mechanics. Lisbon: 17-24. [17] LI B, ZHANG W, WEN R, 2022. Study on the hydraulic fracturing in-situ stress measurement in super-long highway tunnels in southern Shaanxi: engineering geological significance[J]. Journal of Geomechanics, 28(2): 191-202. (in Chinese with English abstract) [18] LIU J, HUI C, FAN J M, et al. , 2021. Distribution characteristics of the present-day in-situ stress in the Chang 6 tight sandstone reservoirs of the Yanchang Formation in the Heshui Area, Ordos Basin, China and suggestions for development[J]. Journal of Geomechanics, 27(1): 31-39. (in Chinese with English abstract) [19] LIU Y D, LIN J, FENG Y J, et al. , 2018. Research on tensile strength of rock based on hydraulic fracturing method[J]. Rock and Soil Mechanics, 39(5): 1781-1788. (in Chinese with English abstract) [20] LJUNGGREN C, CHANG Y T, JANSON T, et al. , 2003. An overview of rock stress measurement methods[J]. International Journal of Rock Mechanics and Mining Sciences, 40(7-8): 975-989. doi: 10.1016/j.ijrmms.2003.07.003 [21] MENG X B, XU Y D, ZHANG Y J, et al. , 2019. Study on the variation law of crustal stress field in tight reservoir under multi field coupling[J]. Journal of Geomechanics, 25(4): 467-474. (in Chinese with English abstract) [22] QIN X H, CHEN Q C, ZHAO X G, et al. , 2020. Experimental study on the crucial effect of test system compliance on hydraulic fracturing in-situ stress measurements[J]. Chinese Journal of Rock Mechanics and Engineering, 39(6): 1189-1202. (in Chinese with English abstract) [23] QIU Y C, LIANG W G, LI J, et al. , 2022. Study on fracture morphology of hydraulic fracturing in heterogeneous elastoplastic coal[J]. Journal of China Coal Society, 47(10): 3668-3679. (in Chinese with English abstract) [24] REN Y, WANG D, LI T B, et al. , 2021. In-situ geostress characteristics and engineering effect in Ya’an—Xinduqiao section of Sichuan—Tibet Railway[J]. Chinese Journal of Rock Mechanics and Engineering, 40(1): 65-76. (in Chinese with English abstract) [25] SU X B, JI H G, QUAN D L, et al. , 2020. Relationship between spatial variability of rock strain and b value under splitting condition[J]. Journal of China Coal Society, 45(S1): 239-246. (in Chinese with English abstract) [26] TEUFEL L W, 1983. Determination of in-situ stress from anelastic strain recovery measurements of oriented core[C]//Symposium on low permeability gas reservoirs. Denver, Colorado: 421-430. [27] WANG L J, SUN D S, LIN W R, et al. , 2012. Anelastic strain recovery method to determine in-situ stress and application example[J]. Chinese Journal of Geophysics, 55(5): 1674-1681. (in Chinese with English abstract) [28] WU J W, ZHANG W Y, PENG H, et al. , 2021. In-situ stress measurement by hydraulic fracturing method around Panji coal mine exploration area in Huainan coalfield[J]. Journal of Engineering Geology, 29(4): 972-984. (in Chinese with English abstract) [29] YANG T H, TAN G H, TANG C A, et al. , 2002. Influence of heterogeneity on hydraulic fracturing in rocks[J]. Chinese Journal of Geotechnical Engineering, 24(6): 724-728. (in Chinese with English abstract) [30] ZHANG C Y, DU S H, HE M C, et al. , 2022. Characteristics of in-situ stresses on the western margin of the eastern Himalayan syntaxis and its influence on stability of tunnel surrounding rock[J]. Chinese Journal of Rock Mechanics and Engineering, 41(5): 954-968. (in Chinese with English abstract) [31] ZHANG H, SHI G, WU H, et al. , 2020. In-situ stress measurement in the shallow basement of the shanghai area and its structural geological significance[J]. Journal of Geomechanics, 26(4): 583-594. (in Chinese with English abstract) [32] ZHANG T Z, JI H G, SU X B, et al. , 2022. Evaluation and classification of rock heterogeneity based on acoustic emission detection[J]. International Journal of Minerals, Metallurgy and Materials, 29(12): 2117-2125. doi: 10.1007/s12613-021-2381-4 [33] ZHANG Z X, 2002. An empirical relation between mode I fracture toughness and the tensile strength of rock[J]. International Journal of Rock Mechanics and Mining Sciences, 39(3): 401-406. doi: 10.1016/S1365-1609(02)00032-1 [34] ZHAO X G, WANG J, MA L K, et al. , 2014. Distribution characteristics of geostress field in Xinchang rock block of candidate Beishan area for high level radioactive waste repository in China[J]. Chinese Journal of Rock Mechanics and Engineering, 33(S2): 3750-3759. (in Chinese with English abstract) [35] ZHUANG L, ZANG A, JUNG S, 2022. Grain-scale analysis of fracture paths from high-cycle hydraulic fatigue experiments in granites and sandstone[J]. International Journal of Rock Mechanics and Mining Sciences, 157: 105177. doi: 10.1016/j.ijrmms.2022.105177 [36] 包林海, 杜义, 郭啟良, 等, 2017. 成兰铁路地应力测量与构造应力场分布规律研究[J]. 地质力学学报, 23(5): 734-742. doi: 10.3969/j.issn.1006-6616.2017.05.010 [37] 蔡美峰, 刘卫东, 李远, 2010. 玲珑金矿深部地应力测量及矿区地应力场分布规律[J]. 岩石力学与工程学报, 29(2): 227-233. [38] 蔡美峰, 冀东, 郭奇峰, 2013a. 基于地应力现场实测与开采扰动能量积聚理论的岩爆预测研究[J]. 岩石力学与工程学报, 32(10): 1973-1980. [39] 蔡美峰, 郭奇峰, 李远, 等, 2013b. 平煤十矿地应力测量及其应用[J]. 北京科技大学学报, 35(11): 1399-1406. doi: 10.13374/j.issn1001-053x.2013.11.003 [40] 陈佳亮, 2019. 非均质砂砾岩水压致裂的数值模拟方法与实验研究[D]. 北京: 中国矿业大学(北京). [41] 陈念, 王成虎, 高桂云, 等, 2021. 基于应力多边形与钻孔崩落的白鹤滩右岸厂房区地应力场特征研究[J]. 岩土力学, 42(12): 3376-3384. doi: 10.16285/j.rsm.2021.0380 [42] 侯奎奎, 吴钦正, 张凤鹏, 等, 2022. 不同地应力测试方法在三山岛金矿2 005 m竖井建井区域的应用及其地应力分布规律研究[J]. 岩土力学, 43(4): 1093-1102. [43] 姜梦瑶, 2019. 胶东纱岭金矿床成矿机制及构造背景分析[D]. 河北地质大学. [44] 李彬, 张文, 文冉, 2022. 陕南特长公路隧道水压致裂法地应力测量结果及工程地质意义分析[J]. 地质力学学报, 28(2): 191-202. [45] 刘建, 惠晨, 樊建明, 等, 2021. 鄂尔多斯盆地合水地区长6致密砂岩储层现今地应力分布特征及其开发建议[J]. 地质力学学报, 27(1): 31-39. [46] 刘跃东, 林健, 冯彦军, 等, 2018. 基于水压致裂法的岩石抗拉强度研究[J]. 岩土力学, 39(5): 1781-1788. [47] 孟宪波, 徐佑德, 张曰静, 等, 2019. 多场耦合作用下致密储层地应力场变化规律研究: 以准噶尔盆地某区为例[J]. 地质力学学报, 25(4): 467-474. doi: 10.12090/j.issn.1006-6616.2019.25.04.044 [48] 秦向辉, 陈群策, 赵星光, 等, 2020. 水压致裂地应力测量中系统柔度影响试验研究[J]. 岩石力学与工程学报, 39(6): 1189-1202. doi: 10.13722/j.cnki.jrme.2019.1204 [49] 邱宇超, 梁卫国, 李静, 等, 2022. 非均质弹塑性煤体水压致裂裂纹形态研究[J]. 煤炭学报, 47(10): 3668-3679. doi: 10.13225/j.cnki.jccs.2021.1684 [50] 任洋, 王栋, 李天斌, 等, 2021. 川藏铁路雅安至新都桥段地应力特征及工程效应分析[J]. 岩石力学与工程学报, 40(1): 65-76. doi: 10.13722/j.cnki.jrme.2020.0537 [51] 苏晓波, 纪洪广, 权道路, 等, 2020. 劈裂条件下岩石应变空间变异性与b值关系[J]. 煤炭学报, 45(S1): 239-246. [52] 王连捷, 孙东生, 林为人, 等, 2012. 地应力测量的非弹性应变恢复法及应用实例[J]. 地球物理学报, 55(5): 1674-1681. doi: 10.6038/j.issn.0001-5733.2012.05.024 [53] 吴基文, 张文永, 彭华, 等, 2021. 淮南煤田潘集煤矿外围勘查区水压致裂地应力测量研究[J]. 工程地质学报, 29(4): 972-984. doi: 10.13544/j.cnki.jeg.2021-0302 [54] 杨天鸿, 谭国焕, 唐春安, 等, 2002. 非均匀性对岩石水压致裂过程的影响[J]. 岩土工程学报, 24(6): 724-728. doi: 10.3321/j.issn:1000-4548.2002.06.011 [55] 张重远, 杜世回, 何满潮, 等, 2022. 喜马拉雅东构造结西缘地应力特征及其对隧道围岩稳定性的影响[J]. 岩石力学与工程学报, 41(5): 954-968. [56] 张浩, 施刚, 巫虹, 等, 2020. 上海地区浅部地应力测量及其构造地质意义分析[J]. 地质力学学报, 26(4): 583-594. doi: 10.12090/j.issn.1006-6616.2020.26.04.051 [57] 赵星光, 王驹, 马利科, 等, 2014. 高放废物地质处置库北山预选区新场岩体地应力场分布规律[J]. 岩石力学与工程学报, 33(S2): 3750-3759. doi: 10.13722/j.cnki.jrme.2014.s2.044 -
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