Characteristics of dynamic mode Ⅱ fracture of frozen saturated sandstones under varying low temperatures and loading rates
-
摘要:背景
研究动力扰动下冻结饱和砂岩Ⅱ型断裂，包括临界应力强度因子(断裂韧度)变化特征以及能量耗散机制，对煤矿冻结井筒安全钻爆掘砌至关重要。
方法利用分离式霍普金森压杆装置，在不同温度和不同加载速率下进行一系列动态SCC试验，分析了冻结饱和砂岩应力强度因子−时间曲线、断裂韧度和能量耗散机制随温度和加载速率的演化规律。总结宏观与微观层面上砂岩剪切断裂面特征，并利用核磁手段揭示了冻结效应的微观影响机制。此外，基于有限元模拟，进一步分析了断裂特性的加载速率效应。
结果和结论结果表明：(1)随温度下降，冻结饱和砂岩断裂过程中岩石断裂韧度增大，相应地砂岩吸收的能量增加，能量利用率呈现一定的增长趋势。随加载速率增加，砂岩断裂韧度呈线性增加，岩石断裂吸收的能量也呈现增加趋势，而能量利用率呈现减小的趋势。(2)试件剪切面存在2种不同的断裂模式：“阶梯状”剪切滑移和“断口状”剪切滑移。(3)依据核磁数据总结了孔隙水冻结的3个阶段：过冷阶段，此阶段未冻水含量不变；快速冻结阶段，此阶段自由水与毛细水基本相变，大部分结合水冻结，断裂韧度迅速增加；缓慢冻结阶段，此阶段少部分结合水冻结，断裂韧度缓慢提升。(4)模拟应变−时间曲线与试验应变−时间较为吻合，表明模拟结果合理可靠，经模拟发现岩桥上出现明显的应力集中现象，并且随加载速率的增加剪应力呈现增加趋势，砂岩的断裂韧度与断裂吸收能均存在加载速率强化机制。研究成果对西部富水软岩地层冻结井筒的钻爆掘砌具有指导作用。
Abstract:BackgroundInvestigating the mode Ⅱ fracture of frozen saturated sandstones under dynamic disturbances, including changes in their critical stress intensity factor (SIF; i.e., fracture toughness) and energy dissipation mechanisms, is crucial for the safe excavation of frozen wellbores through drilling and blasting in coal mines.
MethodsUsing a split Hopkinson pressure bar (SHPB), this study conducted experiments on the dynamic mode Ⅱ fracture of a sandstone specimen using the short core in compression (SCC) method (also referred to as dynamic SCC experiments) under varying temperatures and loading rates. Accordingly, this study analyzed the SIF versus time curves of the frozen saturated sandstones, as well as the evolutionary patterns of their fracture toughness and energy dissipation mechanisms varying with the temperature and loading rate. Furthermore, it summarized the characteristics of the shear fracture planes of the sandstone specimen at macroscopic and microscopic scales and revealed the microscopic mechanisms behind the low-temperature strengthening effect using nuclear magnetic resonance (NMR). Additionally, this study further analyzed the effects of the loading rate on fracture characteristics using finite element simulation.
Results and ConclusionsThe results indicate that with a decrease in temperature, the frozen saturated sandstones exhibited intensifying fracture toughness. Accordingly, energy absorbed during sandstone fracture increased, and the energy utilization ratio showed an increasing trend. With an increase in the loading rate, the fracture toughness increased linearly, energy absorbed during sandstone fracture also showed an increasing trend, but the energy utilization ratio exhibited a decreasing trend. Two different fracture modes were observed on the shear planes of the SCC specimen: stepped and fracture-shaped shear slips. The NMR data revealed that the pore water freezing of the sandstones can be divided into three stages: supercooling, rapid freezing, and slow freezing sequentially. In the first stage, the unfrozen water content remained unchanged. In the rapid freezing stage, the free and capillary water roughly experienced phase transition, and most of the bound water froze, leading to rapidly enhanced fracture toughness. In the slow freezing stage, a small amount of bound water froze, with fracture toughness increasing slowly. The strain versus time curves derived from numerical simulation agreed well with those obtained using experiments, suggesting reasonable and reliable simulation results. The simulation results revealed significant stress concentration on the rock bridge of the SCC specimen and that the shear stress showed an increasing trend with the loading rate. Moreover, both the fracture toughness of the sandstones and energy absorbed during sandstone fracture increased with an increase in the loading rate. The results of this study can serve as a guide for the excavation of frozen wellbores through drilling and blasting in water-rich soft rock formations in West China.
-
-
![]()
图 4 CSRF恒定应变率和计算原理
Fig. 4 Constant strain rate factor (CSRF) and its calculating principle
![]()
图 6 冻结饱和砂岩Ⅱ型动态断裂应力强度因子−时间曲线
Fig. 6 Curves showing mode Ⅱ dynamic fracture SIF vs. time for frozen saturated sandstones
![]()
图 7 不同温度下冻结砂岩Ⅱ型动态断裂韧度−加载速率曲线
Fig. 7 Fracture toughness vs. loading rate for the dynamic mode Ⅱ fracture of frozen saturated sandstones under varying temperatures
![]()
图 8 不同加载速率下冻结饱和砂岩Ⅱ型动态断裂韧度−温度曲线
Fig. 8 Curves showing the temperature-varying fracture toughness of the dynamic mode Ⅱ dynamic fracture of frozen saturated sandstones under varying loading rates
![]()
图 9 吸收能与能量利用率随加载速率变化
Fig. 9 Curves showing the absorbed energy and energy utilization ratio varying with the loading rate
![]()
图 10 吸收能与能量利用率随温度变化
Fig. 10 Curves showing the temperature-varying absorbed energy and energy utilization ratio
![]()
图 11 SCC试件断裂模式以及剪切面破坏特征
Fig. 11 Overall fracture mode and shear plane failure characteristics of the SCC specimen
![]()
图 12 SCC试件断裂面微观形貌
Fig. 12 Microscopic morphologies of the fracture planes of the SCC specimen
![]()
图 13 冻结饱和砂岩未冻水含量随温度变化
Fig. 13 Temperature-varying unfrozen water content in frozen saturated sandstones
![]()
图 14 微观机理
Fig. 14 Enhancing micromechanisms of saturated sandstones under low temperatures
![]()
图 16 不同加载速率下试件模型动态剪应力分布
Fig. 16 Distribution of dynamic shear stress of the specimen model under varying loading rates
表 1 砂岩基本物理参数
Table 1 Fundamental physical parameters of sandstones
饱和密度/(g·cm−3) 孔隙率/% 抗压强度/MPa 弹性模量/GPa 2.56 4.65 82 7.2 
下载: 导出CSV
表 2 拟合曲线相关参数
Table 2 Related parameters of the fitted curves of fracture toughness vs. loading rate
温度/℃ a b R2 25 0.98 0.014 0.97 −0.2 1.15 0.018 0.97 −5 1.59 0.023 0.99 −10 2.43 0.021 0.97 −15 2.03 0.025 0.96 −20 3.49 0.018 0.94
下载: 导出CSV
表 3 模拟参数设定
Table 3 Simulation parameter setting
类别 弹性模量/GPa 密度/(g·cm−3) 黏聚力/MPa 泊松比 入射杆 210 7.8 — 0.3 反射杆 210 7.8 — 0.3 透射杆 210 7.8 — 0.3 试件 8.43 2.5 20 0.15 紫铜片 115 8.93 — 0.34 注：“—”表示该类别没有设置参数。
下载: 导出CSV
-
[1] YAO Wei,WANG Jiaxuan,WU Bangbiao,et al. Dynamic mode Ⅱ fracture toughness of rocks subjected to various in situ stress conditions[J]. Rock Mechanics and Rock Engineering,2023,56(3):2293−2310. DOI: 10.1007/s00603-022-03178-y
[2] 李纯纯,熊峰,张国华,等. 超低温作用下花岗岩力学特性及地下LNG储库稳定性研究[J/OL]. 岩土工程学报,2024:1–9 [2024-12-03]. http://kns.cnki.net/kcms/detail/32.1124.tu.20240925.1124.016.html. LI Chunchun,XIONG Feng,ZHANG Guohua,et al. Study on mechanical properties of granite under ultra–low temperature and stability of underground LNG storage facility[J/OL]. Chinese Journal of Geotechnical Engineering,2024:1–9 [2024-12-03]. http://kns.cnki.net/kcms/detail/32.1124.tu.20240925.1124.016.html.
[3] LIU Manman,DING Yanan,LIU Yong,et al. Macro–mesoscopic correlation investigation on damage evolution of sandstone subjected to freeze–thaw cycles[J]. Rock Mechanics and Rock Engineering,2025,58(1):887−903.
[4] 赵涛,冯云枫,贾海梁,等. 冰充填裂隙对冻结岩体压缩破坏特征的影响研究[J]. 冰川冻土,2024,46(4):1246−1258. ZHAO Tao,FENG Yunfeng,JIA Hailiang,et al. Study on the effects of the ice–filled fissure on the failure features of frozen rock mass[J]. Journal of Glaciology and Geocryology,2024,46(4):1246−1258.
[5] 蒋力帅,杨一鸣,赵阳,等. 动载下含内部裂隙类岩体力学响应与能量耗散规律[J/OL]. 煤炭科学技术,2024:1–15 [2024-12-03]. http://kns.cnki.net/kcms/detail/11.2402.TD.20241114.2104.002.Html. JIANG Lishuai,YANG Yiming,ZHAO Yang,et al. Mechanical response and energy dissipation law of rock–like mass with internal fractures under dynamic load[J/OL]. Coal Science and Technology,2024:1–15 [2024-12-03]. http://kns.cnki.net/kcms/detail/11.2402.TD.20241114.2104.002.Html.
[6] 孙热,谢全民,仇志龙,等. 基于SHPB的红砂岩冲击破碎特征的试验研究[J]. 爆破器材,2024,53(6):18−23. DOI: 10.3969/j.issn.1001-8352.2024.06.003 SUN Re,XIE Quanmin,QIU Zhilong,et al. Experimental study on impact fragmentation characteristics of red sandstone based on SHPB[J]. Explosive Materials,2024,53(6):18−23. DOI: 10.3969/j.issn.1001-8352.2024.06.003
[7] WU Dongwei,ZHOU Lei,NIE Fukuan,et al. Experimental and numerical investigation on the failure behavior of far–field–crack–tunnel rock mass under dynamic loads[J]. Tunnelling and Underground Space Technology,2025,156:106225.
[8] 张慧梅,高培雄,贾海梁,等. 单轴压缩过程中冻结砂岩的损伤局部化规律研究[J]. 冰川冻土,2024,46(2):565−577. ZHANG Huimei,GAO Peixiong,JIA Hailiang,et al. Study on the damage localization law in frozen sandstone during uniaxial compression[J]. Journal of Glaciology and Geocryology,2024,46(2):565−577.
[9] 李强,贾海梁,杨更社,等. 夹冰裂隙岩体的压缩破坏响应与热融软化效应[J]. 岩石力学与工程学报,2024,43(1):103−119. LI Qiang,JIA Hailiang,YANG Gengshe,et al. Compressive failure response and thawing–induced softening effect of frozen ice–sandwiched rock mass[J]. Chinese Journal of Rock Mechanics and Engineering,2024,43(1):103−119.
[10] CEN Duofeng,LI Yage. Frost heave cracking and uniaxial compression failure behavior of sandstone samples containing a flaw filled with water[J]. Scientific Reports,2024,14(1):28711.
[11] LIU Kai,WANG Tingting. Dynamic mechanical behaviours of frozen rock under sub–zero temperatures and dynamic loads[J]. International Journal of Rock Mechanics and Mining Sciences,2024,180:105813.
[12] 张嘉凡,徐荣平,刘洋,等. 冻融循环作用下注浆裂隙岩体微观孔隙演化规律及剪切力学行为研究[J]. 岩石力学与工程学报,2022,41(4):676−690. ZHANG Jiafan,XU Rongping,LIU Yang,et al. Study on micro–pore evolution law and shear mechanical behavior of grouting fractured rock mass under freeze–thaw cycle[J]. Chinese Journal of Rock Mechanics and Engineering,2022,41(4):676−690.
[13] 赵涛,乔煜哲,冯云枫. 裂隙几何形态对冻结岩体压缩破坏特征的影响[J]. 西安科技大学学报,2023,43(2):342−351. ZHAO Tao,QIAO Yuzhe,FENG Yunfeng. Influence of fracture geometry on the compressional damage characteristics of frozen rock masses[J]. Journal of Xi’an University of Science and Technology,2023,43(2):342−351.
[14] WANG Ting,JIA Hailiang,SUN Qiang,et al. Effects of thawing–induced softening on fracture behaviors of frozen rock[J]. Journal of Rock Mechanics and Geotechnical Engineering,2024,16(3):979−989. DOI: 10.1016/j.jrmge.2023.07.016
[15] 谢凯迪,邱艳宇,邢灏喆. 低温/饱水耦合作用下红砂岩静动态Ⅱ型断裂特性试验研究[J]. 振动与冲击,2023,42(16):236−242. XIE Kaidi,QIU Yanyu,XING Haozhe. Coupled effects of water and low temperature on quasistatic and dynamic mode–Ⅱ fracture properties of red sandstone[J]. Journal of Vibration and Shock,2023,42(16):236−242.
[16] FANG Shizheng,YANG Yang,ZHAO Yong,et al. Dynamic mechanical properties and energy dissipation of frozen weakly cemented red sandstone under high strain rate loading[J]. Bulletin of Engineering Geology and the Environment,2023,82(11):418.
[17] 方士正,杨仁树,李炜煜,等. 基于NSCB方法的冻结红砂岩动态断裂特性试验[J]. 工程科学学报,2023,45(10):1704−1715. FANG Shizheng,YANG Renshu,LI Weiyu,et al. Investigation of dynamic fracture characteristics of frozen red sandstone using notched semi–circular bend method[J]. Chinese Journal of Engineering,2023,45(10):1704−1715.
[18] JIA Hailiang,ZI Fan,YANG Gengshe,et al. Influence of pore water (ice) content on the strength and deformability of frozen argillaceous siltstone[J]. Rock Mechanics and Rock Engineering,2020,53(2):967−974. DOI: 10.1007/s00603-019-01943-0
[19] CHEN Huaxin,WU Yongchang,XIA Huiyun,et al. Review of ice–pavement adhesion study and development of hydrophobic surface in pavement deicing[J]. Journal of Traffic and Transportation Engineering(English Edition),2018,5(3):224−238. DOI: 10.1016/j.jtte.2018.03.002
[20] WANG Ting,SUN Qiang,JIA Hailiang,et al. Linking the mechanical properties of frozen sandstone to phase composition of pore water measured by LF–NMR at subzero temperatures[J]. Bulletin of Engineering Geology and the Environment,2021,80(6):4501−4513. DOI: 10.1007/s10064-021-02224-3
[21] YAO Wei,HE Taiming,XIA Kaiwen. Dynamic mechanical behaviors of Fangshan marble[J]. Journal of Rock Mechanics and Geotechnical Engineering,2017,9(5):807−817. DOI: 10.1016/j.jrmge.2017.03.019
[22] HUANG S,FENG X T,XIA K. A dynamic punch method to quantify the dynamic shear strength of brittle solids[J]. Review of Scientific Instruments,2011,82(5):053901. DOI: 10.1063/1.3585983
[23] YAO Wei,XU Ying,WANG Chonglang,et al. Dynamic Mode Ⅱ fracture behavior of rocks under hydrostatic pressure using the short core in compression (SCC) method[J]. International Journal of Mining Science and Technology,2021,31(5):927−937. DOI: 10.1016/j.ijmst.2021.08.001
[24] CAO Rihong,YU Hailong,QIU Xianyang,et al. Influence of loading rate on the mode Ⅱ fracture characteristics of SCC samples:Experiments and numerical simulations[J]. Theoretical and Applied Fracture Mechanics,2024,134:104729. DOI: 10.1016/j.tafmec.2024.104729
[25] 张晨曦,李地元,杨博. 岩石材料Ⅱ型断裂理论与实验测试技术进展[J/OL]. 工程力学,2023:1–18 [2023-07-20]. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=GCLX20230630008&;dbname=CJFD&dbcode=CJFQ. ZHANG Chenxi,LI Diyuan,YANG Bo. Advances in theory and experimental testing techniques of mode Ⅱ fracture for rock materials[J/OL]. Engineering Mechanics,2023:1–18 [2023-07-20]. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=GCLX20230630008&;dbname=CJFD&dbcode=CJFQ.
[26] YAO Wei. Damage and failure of rocks and rock–like materials subjected to thermal and dynamic loadings[D]. Toronto:University of Toronto,2017.
[27] RAO Qiuhua,SUN Zongqi,STEPHANSSON O,et al. Shear fracture (mode Ⅱ) of brittle rock[J]. International Journal of Rock Mechanics and Mining Sciences,2003,40(3):355−375. DOI: 10.1016/S1365-1609(03)00003-0
[28] YAN Zelin,DAI Feng,LIU Yi. Experimental and numerical investigation on the dynamic shear failure mechanism of sandstone using short beam compression specimen[J]. Journal of Rock Mechanics and Geotechnical Engineering,2023,15(8):1911−1923. DOI: 10.1016/j.jrmge.2022.12.014
[29] BACKERS T,STEPHANSSON O,RYBACKI E. Rock fracture toughness testing in mode Ⅱ:Punch–through shear test[J]. International Journal of Rock Mechanics and Mining Sciences,2002,39(6):755−769. DOI: 10.1016/S1365-1609(02)00066-7
[30] LIN Qing,WANG Siqi,PAN Pengzhi,et al. Fracture initiation under pure shear revisited:Remarks on the mode Ⅱ fracture in quasi–brittle materials[J]. Theoretical and Applied Fracture Mechanics,2020,109:102700. DOI: 10.1016/j.tafmec.2020.102700
[31] ZHANG Junchen. Two methods for determining dynamic mode–Ⅱ fracture toughness of rocks[D]. Toronto:University of Toronto,2019.
[32] XU Ying,YAO Wei,ZHAO Geli,et al. Evaluation of the short core in compression (SCC) method for measuring mode Ⅱ fracture toughness of rocks[J]. Engineering Fracture Mechanics,2020,224:106747. DOI: 10.1016/j.engfracmech.2019.106747
[33] 赵环帅,潘永泰,乔鑫,等. 不同加载速率下青砂岩破裂演化规律及能量利用效率分析[J]. 煤田地质与勘探,2024,52(6):69−78. DOI: 10.12363/issn.1001-1986.24.03.0152 ZHAO Huanshuai,PAN Yongtai,QIAO Xin,et al. Fracturing evolutionary law and energy utilization efficiency of green sandstones under different loading rates[J]. Coal Geology & Exploration,2024,52(6):69−78. DOI: 10.12363/issn.1001-1986.24.03.0152
[34] 李明,王磊,崔灏,等. 超大直径盾构隧道联络通道冻结法施工交界面温度场研究:以北京东六环改造工程冻结联络通道为例[J]. 隧道建设(中英文),2025,45(2):352−360. LI Ming,WANG Lei,CUI Hao,et al. Interface temperature field of freezing method construction for a super–large diameter shield tunnel connecting channel:A case study of Beijing East Sixth Ring Renovation Project[J]. Tunnel Construction,2025,45(2):352−360.
[35] 惠磐科. 新庄煤矿立井白垩系软岩冻结壁温度场研究[D]. 西安:西安科技大学,2020. HUI Panke. Study on temperature field of frozen wall of Cretaceous soft rock shaft in Xinzhuang coal mine[D]. Xi’an:Xi’an University of Science and Technology,2020.
[36] 段继超,宗琦,高朋飞,等. 干湿循环石灰岩动态压缩能量演化及变形破坏特征研究[J/OL]. 煤炭科学技术,2024:1–15 [2024-12-03]. http://kns.cnki.net/kcms/detail/11.2402.td.20240715.1216.006.html. DUAN Jichao,ZONG Qi,GAO Pengfei,et al. Study on dynamic compression energy evolution and deformation and failure characteristics of limestone under dry–wet cycles[J/OL]. Coal Science and Technology,2024:1–15 [2024-12-03]. http://kns.cnki.net/kcms/detail/11.2402.td.20240715.1216.006.html.
[37] HASSAN M,WILLE K. Comparative experimental investigations on the compressive impact behavior of fiber–reinforced ultra high–performance concretes using split Hopkinson pressure bar[J]. Construction and Building Materials,2018,191:398−410. DOI: 10.1016/j.conbuildmat.2018.10.020
[38] HASSAN M,WILLE K. Experimental impact analysis on ultra–high performance concrete (UHPC) for achieving stress equilibrium (SE) and constant strain rate (CSR) in split Hopkinson pressure bar (SHPB) using pulse shaping technique[J]. Construction and Building Materials,2017,144:747−757. DOI: 10.1016/j.conbuildmat.2017.03.185
[39] WATKINS J,LIU K L W. A finite element study of the short beam test specimen under mode Ⅱ loading[J]. International Journal of Cement Composites and Lightweight Concrete,1985,7(1):39−47. DOI: 10.1016/0262-5075(85)90025-9
[40] JUNG Y B,PARK E S,KIM H W. Development and application of mode Ⅱ fracture toughness test method using rock core specimen[J]. Tunnel and Underground Space,2016,26(5):396−408. DOI: 10.7474/TUS.2016.26.5.396
[41] ZHOU Y X,XIA K,LI X B,et al. Suggested methods for determining the dynamic strength parameters and mode–I fracture toughness of rock materials[J]. International Journal of Rock Mechanics and Mining Sciences,2012,49:105−112. DOI: 10.1016/j.ijrmms.2011.10.004
[42] JIA Hailiang,DING Shun,WANG Yan,et al. An NMR–based investigation of pore water freezing process in sandstone[J]. Cold Regions Science and Technology,2019,168:102893. DOI: 10.1016/j.coldregions.2019.102893
[43] JIA Hailiang,DING Shun,ZI Fan,et al. Evolution in sandstone pore structures with freeze–thaw cycling and interpretation of damage mechanisms in saturated porous rocks[J]. CATENA,2020,195:104915. DOI: 10.1016/j.catena.2020.104915
[44] 苏宏明. 冻结砂岩动态劈裂力学性能及数值模拟研究[D]. 西安:西安科技大学,2021. SU Hongming. Dynamic splitting mechanical properties and numerical simulating of frozen sandstone[D]. Xi’an:Xi’an University of Science and Technology,2021.
计量
- 文章访问数: 10
- HTML全文浏览量: 0
- PDF下载量: 1
