基于岩石CT扫描的冻融作用对花岗岩细观结构及力学强度影响研究

侯圣山; 何箫; 孟宪森; 陈亮; 冯振; 刘明学; 李昂; 郭长宝; 吉锋

doi:10.12090/j.issn.1006-6616.2022126

基于岩石CT扫描的冻融作用对花岗岩细观结构及力学强度影响研究

doi: 10.12090/j.issn.1006-6616.2022126

侯圣山^{1, 2, 3,},
何箫^{1, 4},
孟宪森^{1, 4},
陈亮^{1, 2, 3},
冯振^{1, 2, 3},
刘明学^{1, 2, 3},
李昂^{1, 2, 3},
郭长宝⁵,
吉锋⁴

1.
中国地质环境监测院，北京 100081
2.
自然资源部四川雅安地质灾害野外科学观测研究站，四川雅安 625099
3.
自然资源部地质灾害智能监测与风险预警工程技术创新中心，北京 100081
4.
成都理工大学地质灾害防治与地质环境保护国家重点实验室，四川成都 610059
5.
中国地质科学院地质力学研究所，北京 100081

基金项目: 国家重点研发计划项目（2021YFC3000505，2021YFB2301304）；中国地质调查局地质调查项目（DD20221748）

详细信息

作者简介:
侯圣山（1977—），男，博士，正高级工程师，主要从事地质灾害调查监测研究。Email：26198334@qq.com

中图分类号: P642
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出版历程
- 收稿日期: 2022-11-04
- 修回日期: 2023-10-11
- 录用日期: 2023-10-16
- 预出版日期: 2023-11-07
- 刊出日期: 2024-06-28

Mesostructure and strength characteristics of granite under freeze-thaw cycles based on CT scanning

HOU Shengshan^{1, 2, 3
,},
HE Xiao^{1, 4},
MENG Xiansen^{1, 4},
CHEN Liang^{1, 2, 3},
FENG Zhen^{1, 2, 3},
LIU Mingxue^{1, 2, 3},
LI Ang^{1, 2, 3},
GUO Changbao⁵,
JI Feng⁴

1.
Chinese Institute of Geological and Environmental Monitoring, Beijing 100081, China
2.
Observation and Research Station of Geological Hazard in Ya’an, Sichuan, Ministry of Natural Resources, Ya’an 625099, Sichuan, China
3.
Technology Innovation Center for Geohazard Monitoring and Risk Early Warning, Ministry of Natural Resources, Beijing 100081, China
4.
State Key Laboratory of Geological Disaster Prevention and Geoenvironmental Protection, Chengdu 610059, Sichuan, China
5.
Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China

Funds: This research is financially supported by the National Key Research and Development Program of China (Grant No. 2021YFC3000505 and 2021YFB2301304) and the Geological Survey Project of the China Geological Survey (Grant No.DD20221748).

摘要

摘要: 近年来随着西部地区的基础工程建设数量及规模不断增加，西部高原地区的季节性冻融循环效应的影响也随之增强，开展冻融循环作用下岩石细观特性及强度劣化性质研究对指导西部寒区基础工程建设至关重要。首先在偏光显微镜下对岩石薄片进行观察，获取岩石的矿物成分和微结构；接着利用CT扫描技术，对冻融后的花岗岩进行扫描，对扫描图层利用阈值分割进行二值化处理，堆叠得到样品内外结构的高分辨3D数据及影像；结合分形理论计算图像计盒维数并由此对图像复杂度做出量化判断，由此对冻融循环对花岗岩内部结构演化分布特点进行分析；进而揭示其强度演化规律，探究结构演化与强度之间的关系。偏光显微镜下，岩石呈块状构造，具有似斑状粗粒不等粒花岗结构，局部见交代蠕虫结构。似斑晶矿物主要为碱性长石；其他矿物粒径0.25~4.0 mm为主，矿物成分主要为石英、斜长石、碱性长石，次要矿物为黑云母、绿帘石，副矿物有磷灰石、锆石、黄铁矿等，镜下鉴定为似斑状粗粒不等粒黑云二长花岗岩。CT扫描显示，冻融循环效应在影响花岗岩细观结构时，会导致花岗岩内部孔隙率的整体上升，但岩石渗透性变化不大，岩石渗透率仅上升0.003×10⁻³ μm²；内部孔隙发育不均匀，试样整体结构改变以萌生较多新的微孔隙为主。冻融循环后岩石内部结构复杂度有所下降，但岩石整体完整性仍然较好，分形维数仍保持在较高水平。分形研究显示，20次冻融循环并未导致花岗岩的结构复杂度发生较大变化，同时试样整体力学特性出现下降，黏性增加以及长期强度出现较大幅度的衰减，进入蠕变试验阶段的应变阈值提高。在评价此类原生结构较致密的岩石的安全性时，仅从结构上进行考量与实际情况往往会出现偏差，应结合必要的强度指标综合评估。岩石在经历冻融循环后，在强度更低的同时会发生更大的变形。该研究可为分形理论在岩石细观结构演化方面的应用及岩石细观结构与强度演化相关研究提供借鉴，并对高寒地区工程施工有指导意义。
- 冻融循环 /
- 阈值分割 /
- CT模型 /
- 分形维数 /
- 结构演化 /
- 长期强度
Abstract: Objective With the rapid increase in construction projects in the western regions in recent years, the impact of seasonal freeze-thaw cycles in the high-altitude areas of western China has become more pronounced. Conducting research on the microscopic characteristics and strength degradation properties of rocks under freeze-thaw cycles is crucial for guiding engineering construction in these cold, high-altitude regions. Methods To study the influence of freeze-thaw cycles on rock structure and mechanical properties, we collected diorite samples from a tunnel in the Kangding area and examined the effects of freeze-thaw cycles on their microstructure and mechanical characteristics. Firstly, thin rock sections were observed under a polarizing microscope to obtain mineral compositions and microstructures. Then, CT scanning technology was used to scan the granite samples after freeze-thaw cycles, and the scanned layers were binarized using threshold segmentation. The scanning images of different layers were binarized using threshold segmentation, and high-resolution 3D data and images of the internal and external structures of the samples were obtained by stacking the binary image layers. Fractal theory was applied to calculate the box-counting dimension of the images and quantitatively assess their complexity. This analysis allowed us to examine the evolution and distribution characteristics of the internal structure of granite under freeze-thaw cycles. Results Under a polarizing microscope, the rock exhibits a block-like structure with a patchy, coarse-grained, and unequal-grained granite texture, with locally visible metasomatic worm structures. The main phenocryst minerals are alkaline feldspar. Other minerals range in size from 0.25 to 4.0 mm and primarily include quartz, plagioclase, and alkaline feldspar. Secondary minerals include biotite and epidote, while accessory minerals comprise apatite, zircon, and pyrite. Microscopically, the rock is identified as porphyritic, coarse-grained, and unequal-grained biotite diorite granite. Freeze-thaw cycles were applied to the granite samples in the laboratory to study the strength evolution and explore the relationship between structural evolution and strength. The results indicate that the freeze-thaw cycle effect leads to an overall increase in the internal porosity of the granite's microstructure, though the rock's permeability changes minimally, with an increase of only 0.003×10⁻³ μm². The internal pore development is uneven, primarily due to the emergence of new micropores, causing changes in the overall structure of the sample. After freeze-thaw cycles, the complexity of the internal structure of the rock decreases, but the overall integrity remains good, with the fractal dimension staying at a high level. Fractal analysis shows that 20 freeze-thaw cycles do not cause significant changes in the structural complexity of granite. However, the overall mechanical properties of the sample decline, viscosity increases, and long-term strength shows significant attenuation, raising the strain threshold for entering the creep test stage. Conclusion When evaluating the safety of rocks with dense primary structures, considering only their structure may lead to deviations from the actual situation. It is essential to combine necessary strength indicators for a comprehensive evaluation. After undergoing freeze-thaw cycles, rocks tend to exhibit more significant deformation while maintaining lower strength. Therefore, appropriate treatments are required for construction in high-altitude areas. [ Significance ] This study provides a reference for applying fractal theory to the evolution of rock microstructure and the relationship between rock microstructure and strength evolution. It also offers valuable guidance for engineering construction in high-altitude and cold regions.
- freeze-thaw cycle /
- threshold segmentation /
- CT model /
- fractal dimension /
- structural evolution /
- long-term strength

HTML全文

图 1 花岗岩薄片及矿物组成

Q—石英； Pl—斜长石； Bi—黑云母； Mic—微斜长石

Figure 1. Thin section and mineral composition of the granite sample (a) Microscopic image of thin section; (b) Pie chart of mineral composition

Q–quartz; Pl–plagioclase; Bi–biotite; Mic–microcline

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图 2 全自动冻融循环机

Figure 2. Automatic freeze-thaw cycling machine

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图 3 冻融循环路径

Figure 3. Freeze-thaw cycle path

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图 4 CT扫描仪内部结构

Figure 4. Internal structure of CT scanner

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图 5 花岗岩试样扫描分层

Figure 5. Scanning stratification of granite samples

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图 6 试样灰度四视图

a—俯视图；b—正视图；c—左侧视图；d—立体图

Figure 6. Four-view grayscale of the sample

(a) Top view; (b) Front view; (c) Left view; (d) 3D stereogram

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图 7 力学试验加载平台

Figure 7. Mechanical test loading platform

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图 8 二值化处理后CT立体模型

Figure 8. CT stereo model after binarization processing

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图 9 试样Z方向逐层面孔隙率

Figure 9. Surface porosity of each layer in Z direction of the sample

下载: 全尺寸图片幻灯片

图 10 20次冻融循环花岗岩试样的N_d -D曲线

Figure 10. N_d -D curve of granite samples after 20 freeze-thaw cycles

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图 11 冻融前后花岗岩卸荷蠕变时间−应变曲线

Figure 11. Time-strain curves of unloading creep of granite before and after freeze-thawing

(a) Before freeze-thawing; (b) After 20 freeze-thaw cycles

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图 12 冻融前后花岗岩偏应力−应变曲线

a—冻融前；b—20次冻融循环后

Figure 12. Deviatoric stress–strain curve of granite before and after freeze-thawing

(a) Before freeze-thawing; (b) After 20 freeze-thaw cycles

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表 1 花岗岩物理力学参数

Table 1. Physical and mechanical parameters of granite

冻融循环次数泊松比弹性模量/GPa 单轴抗压强度/MPa

0 0.19 11.2 106

20 0.22 10.4 88

下载: 导出CSV

参考文献(66)

[1]	CAI P C, QUE Y, LI X, 2021. Numerical simulation of water-gas two-phase displacement process in unsaturated granite residual soil[J]. Hydrogeology & Engineering Geology, 48(6): 54-63. (in Chinese with English abstract
[2]	DAI J, ZHANG M, YANG F, et al , 2022. Study on the mechanical properties of microwave irradiation granite[J]. Research & Application of Building Materials(2): 1-6. (in Chinese with English abstract
[3]	FAN S L, 2020. Evolution of fractal and mechanical properties of cyclic dry-wet alered granite based on SEM[J]. Journal of Yangtze River Scientific Research Institute, 37(3): 102-107. (in Chinese with English abstract
[4]	HAI W G, 2021. Primary study on stress field characteristics and genetic mechanism of Xianshuihe tectonic belt in western Sichuan[D]. Beijing: China University of Geosciences (Beijing). (in Chinese with English abstract
[5]	HAO K Y, LI Y W, ZHANG N, et al, 2020. Application of fractal dimension in SEM image of activated sludge under MATLAB environment[J]. Environmental Science & Technology, 43(7): 22-27. (in Chinese with English abstract
[6]	HAO Z Y, 2022. Study on mechanical properties of fractured rock considering mesoscopic structure[J]. Anhui Architecture, 29(4): 135-136. (in Chinese)
[7]	INNOCENTE J C, PARASKEVOPOULOU C, DIEDERICHS M S, 2021. Estimating the long-term strength and time-to-failure of brittle rocks from laboratory testing[J]. International Journal of Rock Mechanics and Mining Sciences, 147: 104900. doi: 10.1016/j.ijrmms.2021.104900
[8]	JIA H L, XIANG W, SHEN Y J, et al, 2017. Discussion of the key issues within calculation of the fatigue damage of rocks subjected to freeze-thaw cycles[J]. Chinese Journal of Rock Mechanics and Engineering, 36(2): 335-346. (in Chinese with English abstract
[9]	LI D J, JIA X N, MIAO J L, et al, 2010. Analysis of fractal characteristics of fragment from rockburst test of granite[J]. Chinese Journal of Rock Mechanics and Engineering, 29(S1): 3280-3289. (in Chinese with English abstract
[10]	LI H Q, WANG F Q, 1992. Fractal theory and its development[J]. Studies in Dialectics of Nature(11): 20-23. (in Chinese)
[11]	LI M M, ZOU C S, 2022. Research on threshold image segmentation method based on improved genetic algorithm[J]. Software Engineering, 25(1): 37-40. (in Chinese with English abstract
[12]	LIU H M, WANG X J, DU Z J, et al, 2020. Study on pore structure characteristics of tight sandstone in Block 4 of the central Junggar Basin[J]. Journal of Geomechanics, 26(1): 96-105. (in Chinese with English abstract
[13]	LIU H T, QIN J K, ZHOU B, et al, 2022. Effects of curing pressure on the long-term strength retrogression of oil well cement cured under 200°C[J]. Energies, 15(16): 6071. doi: 10.3390/en15166071
[14]	LIU T S, FANG J D, ZHAO Y D, 2022. Comparative research on image segmentation based target detection method[J]. Computer Era(1): 14-18. (in Chinese with English abstract
[15]	MIAO C Y, YANG L, XU Y Z, et al, 2021. Experimental study on strength softening behaviors and micro-mechanisms of sandstone based on nuclear magnetic resonance[J]. Chinese Journal of Rock Mechanics and Engineering, 40(11): 2189-2198. (in Chinese with English abstract
[16]	QI L R, WANG J D, ZHANG D F, et al, 2021. A study of granite damage in the macro and microscopic scales under freezing-thawing cycles[J]. Hydrogeology & Engineering Geology, 48(5): 65-73. (in Chinese with English abstract
[17]	QIAO L J H, HE K H, 2021. Research on coal gangue recognition based on fractal dimension and microscopic pore structure[J]. China Mining Magazine, 30(9): 120-125. (in Chinese with English abstract
[18]	QIN Z M, LEI R D, 2023. Characterization of mesoscopic deterioration of sandstone exposed to freeze-thaw cycles[J]. Mining Research and Development, 43(8): 132-138. (in Chinese with English abstract
[19]	SHAN L Q, LIU C Q, LIU Y C, et al, 2022. Rock CT image super-resolution using residual dual-channel attention generative adversarial network[J]. Energies, 15(14): 5115. doi: 10.3390/en15145115
[20]	TANG Z Q, JI F, XU H H, et al, 2022. Creep characteristics and nonlinear creep damage model of Yanshanian granite in southern Henan[J]. Science Technology and Engineering, 22(16): 6421-6429. (in Chinese with English abstract
[21]	TIAN W, HAN N, 2017. Preliminary research on mechanical properties of 3D printed rock structures[J]. Geotechnical Testing Journal, 40(3): 483-493. doi: 10.1520/GTJ20160177
[22]	TIAN Y D, 2019. Triaxial compression strength and fracture development of shale with different initial porosity[J]. Mineral Engineering Research, 34(4): 40-43. (in Chinese with English abstract
[23]	WANG H Q, 2021. Analysis of image segmentation algorithm based on MATLAB[J]. New Technology & New Products of China(19): 1-3. (in Chinese)
[24]	XIA Y X, CAI J C, PERFECT E, et al, 2019. Fractal dimension, lacunarity and succolarity analyses on CT images of reservoir rocks for permeability prediction[J]. Journal of Hydrology, 579: 124198. doi: 10.1016/j.jhydrol.2019.124198
[25]	XIE T, LI Y G, 2013. Rock surface fractal dimension analysis based on digital camera measurement technology[J]. Engineering Journal of Wuhan University, 46(3): 345-348, 370. (in Chinese with English abstract
[26]	YAN K, GU T F, WANG J D, et al, 2018. A study of the micro-configuration of loess based on micro-CT images[J]. Hydrogeology & Engineering Geology, 45(3): 71-77. (in Chinese with English abstract
[27]	YANG H R, 2022. Study on damage mechanism of glutenite microstructure under freeze-thaw cycles[J]. Geotechnical Investigation & Surveying, 50(7): 22-29. (in Chinese with English abstract
[28]	YU H W, AN L, LI Y H, et al, 2021. Effect of microwave radiation on pore structure and tensile strength of metagranulite[J]. Journal of Northeastern University (Natural Science), 42(10): 1451-1458. (in Chinese with English abstract
[29]	ZHANG C, YU J, BAI Y, et al, 2023. Statistical damage constitutive model of rock brittle-ductile transition based on strength theory[J]. Chinese Journal of Rock Mechanics and Engineering, 42(2): 307-316. (in Chinese with English abstract
[30]	ZHANG G M, 2023. Research on the stratigraphic characteristics of archean ductile shear zone in Wutai Mountain area[J]. Railway Investigation and Surveying, 49(1): 47-52. (in Chinese with English abstract
[31]	ZHANG H M, WANG Y F, 2022. Multi-scale analysis of damage evolution of freezing-thawing red sandstones[J]. Rock and Soil Mechanics, 43(8): 2103-2114. (in Chinese with English abstract
[32]	ZHANG H M, YUAN C, MU N N, et al, 2022. CT image processing and mesoscopic characteristics analysis of freeze-thaw rock[J]. Journal of Xi'an University of Science and Technology, 42(2): 219-226. (in Chinese with English abstract
[33]	ZHANG Y, XIONG L X, 2008. Rock rheological mechanics: present state of research and its direction of development[J]. Journal of Geomechanics, 14(3): 274-285. (in Chinese with English abstract
[34]	ZHANG Y B, XU Y D, LIU X X, et al, 2021. Quantitative characterization and mesoscopic study of propagation and evolution of three-dimensional rock fractures based on CT[J]. Rock and Soil Mechanics, 42(10): 2659-2671. (in Chinese with English abstract
[35]	ZHANG Z H, WEI W, ZHANG J, et al, 2022. Determining method of multiscale fractal dimension of red bed sandstone pores based on CT scanning[J]. Bulletin of Geological Science and Technology, 41(3): 254-263. (in Chinese with English abstract
[36]	ZHAO N, ZHANG Y B, WANG L G, 2023. Experimental study on multi-scale creep rupture evolution of sandstone[J]. Chinese Journal of Applied Mechanics, 40(1): 87-95. (in Chinese with English abstract
[37]	ZHU C X, XU J M, ZHONG C J, 2021. Distributions of various compositions in granite specimen using fully convolutional network[J]. The Chinese Journal of Geological Hazard and Control, 32(1): 127-134. (in Chinese with English abstract
[38]	蔡沛辰,阙云,李显,2021. 非饱和花岗岩残积土水-气两相驱替过程数值模拟[J]. 水文地质工程地质,48(6):54-63.
[39]	戴俊,张敏,杨凡,等,2022. 微波照射花岗岩力学性能试验研究[J]. 建材技术与应用(2):1-6.
[40]	樊水龙,2020. 基于SEM的干湿循环蚀变花岗岩分形特征与力学特性演化规律[J]. 长江科学院院报,37(3):102-107. doi: 10.11988/ckyyb.20190037
[41]	郝凯越,李远威,张宁,等,2020. MATLAB环境下分形维数在活性污泥SEM图像中的应用[J]. 环境科学与技术,43(7):22-27.
[42]	郝志远,2022. 考虑细观结构的裂隙岩石力学性质研究[J]. 安徽建筑,29(4):135-136.
[43]	李德建,贾雪娜,苗金丽,等,2010. 花岗岩岩爆试验碎屑分形特征分析[J]. 岩石力学与工程学报,29(S1):3280-3289.
[44]	李后强,汪富泉,1992. 分形理论及其发展历程[J]. 自然辩证法研究(11):20-23.
[45]	李茂民,邹臣嵩,2022. 基于改进遗传算法的阈值图像分割方法[J]. 软件工程,25(1):37-40.
[46]	刘惠民,王学军,杜振京,等,2020. 准中4区块致密砂岩孔隙结构特征研究[J]. 地质力学学报,26(1):96-105.
[47]	刘天舒,房建东,赵于东,2022. 基于图像分割的目标检测方法对比研究[J]. 计算机时代(1):14-18.
[48]	缪澄宇,杨柳,许永震,等,2021. 基于核磁共振监测的砂岩强度软化实验及微观机制研究[J]. 岩石力学与工程学报,40(11):2189-2198.
[49]	戚利荣,王家鼎,张登飞,等,2021. 冻融循环作用下花岗岩损伤的宏微观尺度研究[J]. 水文地质工程地质,48(5):65-73.
[50]	乔力江汉,何克焓,2021. 基于分形维数及细观孔隙结构特征的煤矸石识别研究[J]. 中国矿业,30(9):120-125. doi: 10.12075/j.issn.1004-4051.2021.09.018
[51]	唐志强,吉锋,许汉华,等,2022. 豫南燕山期花岗岩蠕变特性及非线性蠕变损伤模型[J]. 科学技术与工程,22(16):6421-6429.
[52]	田彦德,2019. 不同初始孔隙度页岩的三轴压缩强度及裂隙发育规律[J]. 矿业工程研究,34(4):40-43.
[53]	王慧琴,2021. 基于MATLAB的图像分割算法分析[J]. 中国新技术新产品(19):1-3.
[54]	谢韬,李亚阁,2013. 基于数字摄影测量技术的岩石表面分形维研究[J]. 武汉大学学报(工学版),46(3):345-348,370.
[55]	延恺,谷天峰,王家鼎,等,2018. 基于显微CT图像的黄土微结构研究[J]. 水文地质工程地质,45(3):71-77.
[56]	杨鸿锐,2022. 冻融循环作用下砂砾岩微观结构损伤机制研究[J]. 工程勘察,50(7):22-29. doi: 10.3969/j.issn.1000-1433.2022.7.gckc202207004
[57]	于洪雯,安龙,李元辉,等,2021. 微波辐射对变粒岩孔隙结构及抗拉强度的影响[J]. 东北大学学报(自然科学版),42(10):1451-1458.
[58]	张超,俞缙,白允,等,2023. 基于强度理论的岩石脆延转化统计损伤本构模型[J]. 岩石力学与工程学报,42(2):307-316.
[59]	张光明,2023. 五台山地区太古界韧性剪切带地层特征研究[J]. 铁道勘察,49(1):47-52.
[60]	张慧梅,王云飞,2022. 冻融红砂岩损伤演化多尺度分析[J]. 岩土力学,43(8):2103-2114.
[61]	张慧梅,袁超,慕娜娜,等,2022. 冻融岩石CT图像处理及细观特征分析[J]. 西安科技大学学报,42(2):219-226.
[62]	张艳博,徐跃东,刘祥鑫,等,2021. 基于CT的岩石三维裂隙定量表征及扩展演化细观研究[J]. 岩土力学,42(10):2659-2671.
[63]	张尧,熊良宵,2008. 岩石流变力学的研究现状及其发展方向[J]. 地质力学学报,14(3):274-285.
[64]	张子涵,魏文,张杰,等,2022. 基于CT扫描红层砂岩孔隙多标度分形维数的确定方法[J]. 地质科技通报,41(3):254-263.
[65]	赵娜,张怡斌,王来贵,2023. 砂岩蠕变破裂多尺度演化试验研究[J]. 应用力学学报,40(1):87-95.
[66]	朱楚雄,徐金明,钟传江,2021. 基于全卷积神经网络的花岗岩中不同组分分布特征分析[J]. 中国地质灾害与防治学报,32(1):127-134.