-
摘要:
膨胀土引发的工程地质问题成为了制约城市地质安全的关键。为了研究玄武岩纤维改良膨胀土的效果和机理，以湖北宜昌三峡机场弱膨胀土为研究对象，通过掺入质量分数为0.2%，0.4%和0.6%的玄武岩纤维改良土的三轴压缩试验和干湿循环试验，并结合数字图像处理技术，研究改良土的强度和干湿循环下的表面裂隙随纤维掺量的变化规律。结果表明：玄武岩纤维掺量对改良土的黏聚力影响明显，对内摩擦角影响不显著，玄武岩纤维掺量为0.4%时，改良土的黏聚力提高了57.1%；不同玄武岩纤维掺量的改良系数均大于1.0，掺量为0.4%时改良效果最佳；首次干湿循环后，改良土和素膨胀土没有出现裂隙，后续循环期次玄武岩纤维改良土裂隙面积率和分形维数均比原土小，裂隙面积率的最大差值由2.41%增至4.54%，分形维数的最大差值由0.058降至0.037，掺量为0.4%时，玄武岩纤维抑制土的裂隙效果最好。“嵌固”在土体中的纤维使裂隙尖端的应力集中程度降低，从而限制了裂隙的发展。研究结果可为区域性玄武岩纤维改良弱膨胀土的工程应用提供参考。
Abstract:The engineering geological problems caused by expansive soil have become a key factor restricting urban geological safety.
Objective and Methods In order to study the effect and mechanism of basalt fiber in improving expansive soil, weak expansive soil from Three Gorges Airport, Yichang, Hubei, was taken as the research object. By adding 0.2%, 0.4%, and 0.6% basalt fiber to the soil, triaxial compression test and dry-wet cycle test were conducted, combined with digital image processing technology, to investigate the strength of the improved soil and the variation of surface cracks under the dry-wet cycle with fiber content.
Results The results showed that the content of basalt fiber had a significant effect on the cohesion of the improved soil but had no significant effect on the internal friction angle. When the content of basalt fiber was 0.4%, the cohesion of the improved soil increased by 57.1%. The improvement coefficient for different basalt fiber contents was greater than 1.0, with the best improvement effect occurring at 0.4%. After the first dry-wet cycle, no cracks were observed in either the improved soil or the untreated expansive soil. The crack area ratio and fractal dimension of the basalt fiber-improved soil in subsequent cycles were smaller than those of the original soil. The maximum difference in the crack area ratio increased from 2.41% to 4.54%, and the maximum difference in the fractal dimension decreased from 0.058 to 0.037. When the content was 0.4%, the fiber had the best effect in inhibiting the cracking of the soil. The fiber embedded in the soil reduced the stress concentration at the crack tip, which limited the development of the crack.
Conclusion The research results can provide valuable references for the engineering application of basalt fiber-improved weak expansive soil at the regional scale.
-
图 5 各围压下的主应力差−轴向应变曲线
Figure 5. Major principal stress difference-axial strain curves under different confining pressures
图 6 各纤维掺量下的孔隙水压力−轴向应变曲线
Figure 6. Pore water pressure-axial strain curves under different fiber contents
图 8 干湿循环过程中试样裂隙二值化图像
Figure 8. Binarized images of cracks in samples during dry-wet cycles
图 9 试样裂隙参数与循环次数的关系
Figure 9. Relationship between crack parameters and number of cycle in samples
图 10 试样裂隙参数与纤维掺量的关系
Figure 10. Relationship between crack parameters and fiber content in samples
图 11 玄武岩纤维的“嵌固”作用示意图（a. 膨胀土；b. 纤维改良膨胀土）
Figure 11. Schematic diagram of "embedding" effect of basalt fiber
表 1 膨胀土基本物理指标
Table 1. Basic physical properties of expansive soil
液限
ωL/%塑限
ωP/%塑性
指数IP天然含
水率ω/%天然湿密
度/(g∙cm−3)最优含
水率ω/%最大干密
度/(g∙cm−3)自由膨胀
率FS/%55.01 16.18 38.83 20.94 2.02 18.25 1.73 48.00 
下载: 导出CSV
表 2 玄武岩纤维物理力学参数
Table 2. Physical and mechanical parameters of basalt fiber
抗拉强度/MPa 弹性模量/GPa 纤维密度/(g·cm−3) 断裂伸长率/% 熔点/℃ 2000 ～2200 85～90 2.699 2.8 1450
下载: 导出CSV
表 3 三轴压缩试验方案
Table 3. Triaxial compression test scheme
试验方法 围压/kPa 纤维掺量/% 含水率/% 剪切速率/（mm·min−1） 固结不
排水
（CU）100，200，
3000 18.25 0.8 0.2 18.25 0.8 0.4 18.25 0.8 0.6 18.25 0.8
下载: 导出CSV
表 4 各围压下不同纤维掺量改良土的最大主应力差
Table 4. Maximum major principal stress difference of improved soil with different fiber contents under different confining pressures
围压/kPa 纤维掺量0 纤维掺量0.2% 纤维掺量0.4% 纤维掺量0.6% 100 205.8 215.3 245.9 214.0 200 286.0 321.4 327.3 307.8 300 394.2 408.7 422.8 400.1
下载: 导出CSV
表 5 玄武岩纤维改良土强度指标
Table 5. Strength indices of basalt fiber-improved soil
纤维掺量/% $ C $/kPa $ \varphi $/(°) $ C' $/kPa $ \varphi ' $/(°) 0 36.4 18.7 35.0 18.0 0.2 44.4 19.0 42.9 18.6 0.4 56.5 17.9 55.0 17.8 0.6 43.2 18.5 42.2 17.4 注：C. 黏聚力；φ. 内摩擦角；C'. 有效黏聚力；φ'. 有效内摩擦角
下载: 导出CSV
表 6 强度改良系数
Table 6. Strength improvement coefficients
纤维掺量/% 围压/kPa 100 200 300 0 1 1 1 0.2 1.05 1.12 1.04 0.4 1.19 1.14 1.07 0.6 1.04 1.08 1.02
下载: 导出CSV
-
[1] ZHANG C, WANG W, ZHU Z D, et al. Mechanical behaviors and damage model of expansive soil admixed with composite materials[J]. Arabian Journal of Geosciences, 2021, 14(15): 1439. doi: 10.1007/s12517-021-07865-y [2] 廖世文. 膨胀土与铁路工程[M]. 北京: 中国铁道出版社, 1984.LIAO S W. Expansive soil and railway engineering[M]. Beijing: China Railway Publishing House, 1984. (in Chinese) [3] 郝建斌, 李耕春, 刘志云, 等. 干湿循环作用下剑麻纤维加筋膨胀土的抗裂作用及影响因素[J]. 湖南大学学报(自然科学版), 2024, 51(1): 147-158. doi: 10.16339/j.cnki.hdxbzkb.2024014HAO J B, LI G C, LIU Z Y, et al. Anti-cracking mechanism of sisal fiber-reinforced expansive soil under dry-wet cycle and its influencing factors[J]. Journal of Hunan University (Natural Sciences), 2024, 51(1): 147-158. (in Chinese with English abstract doi: 10.16339/j.cnki.hdxbzkb.2024014 [4] 雷胜友, 丁万涛. 加筋纤维抑制膨胀土膨胀性的试验[J]. 岩土工程学报, 2005, 27(4): 482-485. doi: 10.3321/j.issn:1000-4548.2005.04.024LEI S Y, DING W T. Experiment on restraining expansibility of expansive soil with reinforced fiber[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(4): 482-485. (in Chinese with English abstract doi: 10.3321/j.issn:1000-4548.2005.04.024 [5] DIAMBRA A, IBRAIM E, MUIR WOOD D, et al. Fibre reinforced sands: Experiments and modelling[J]. Geotextiles and Geomembranes, 2010, 28(3): 238-250. doi: 10.1016/j.geotexmem.2009.09.010 [6] 李丽华, 万畅, 刘永莉, 等. 玻璃纤维加筋砂土剪切强度特性研究[J]. 武汉大学学报(工学版), 2017, 50(1): 102-106. doi: 10.14188/j.1671-8844.2017-01-015LI L H, WAN C, LIU Y L, et al. Shear strength characteristics of glass fiber reinforced sandy soil[J]. Engineering Journal of Wuhan University, 2017, 50(1): 102-106. (in Chinese with English abstract doi: 10.14188/j.1671-8844.2017-01-015 [7] WANG Y X, GUO P P, REN W X, et al. Laboratory investigation on strength characteristics of expansive soil treated with jute fiber reinforcement[J]. International Journal of Geomechanics, 2017, 17(11): 04017101. doi: 10.1061/(ASCE)GM.1943-5622.0000998 [8] NAMJOO A M, SOLTANI F, TOUFIGH V. Effects of moisture on the mechanical behavior of sand-geogrid: An experimental investigation[J]. International Journal of Geosynthetics and Ground Engineering, 2021, 7(1): 5. doi: 10.1007/s40891-020-00243-w [9] 宋飞, 石磊, 樊明尊. 土工格室加筋正常固结粉质黏土应力应变响应[J]. 地质科技通报, 2024, 43(1): 184-193. doi: 10.19509/j.cnki.dzkq.tb20220428SONG F, SHI L, FAN M Z. Stress-strain response of geocell-reinforced normally consolidated silty clay[J]. Bulletin of Geological Science and Technology, 2024, 43(1): 184-193. (in Chinese with English abstract doi: 10.19509/j.cnki.dzkq.tb20220428 [10] 张家俊, 龚壁卫, 胡波, 等. 干湿循环作用下膨胀土裂隙演化规律试验研究[J]. 岩土力学, 2011, 32(9): 2729-2734. doi: 10.3969/j.issn.1000-7598.2011.09.028ZHANG J J, GONG B W, HU B, et al. Study of evolution law of fissures of expansive clay under wetting and drying cycles[J]. Rock and Soil Mechanics, 2011, 32(9): 2729-2734. (in Chinese with English abstract doi: 10.3969/j.issn.1000-7598.2011.09.028 [11] 马鸿发, 刘清秉, 李靖. 掺砂率与干密度对膨润土收缩特性影响[J]. 地质科技通报, 2023, 42(6): 76-85. doi: 10.19509/j.cnki.dzkq.tb20220099MA H F, LIU Q B, LI J. Effect of shrinkage characteristics of bentonite with different sand mixing rates and dry densities[J]. Bulletin of Geological Science and Technology, 2023, 42(6): 76-85. (in Chinese with English abstract doi: 10.19509/j.cnki.dzkq.tb20220099 [12] 黄晓虎, 易武, 黄海峰, 等. 优势流入渗与坡体变形关系研究及应用[J]. 岩土力学, 2020, 41(4): 1396-1403. doi: 10.16285/j.rsm.2019.0704HUANG X H, YI W, HUANG H F, et al. Study and application of the relationship between preferential flow penetration and slope deformation[J]. Rock and Soil Mechanics, 2020, 41(4): 1396-1403. (in Chinese with English abstract doi: 10.16285/j.rsm.2019.0704 [13] 宋琨, 陈伦怡, 刘艺梁, 等. 降雨诱发深层老滑坡复活变形的动态作用机制[J]. 地球科学, 2022, 47(10): 3665-3676.SONG K, CHEN L Y, LIU Y L, et al. Dynamic mechanism of rain infiltration in deep-seated landslide reactivate deformation[J]. Earth Science, 2022, 47(10): 3665-3676. (in Chinese with English abstract [14] QI Y Z, WANG Z Z, XU H Q, et al. Instability analysis of a low-angle low-expansive soil slope under seasonal wet-dry cycles and river-level variations[J]. Advances in Civil Engineering, 2020, 2020(1): 3479575. doi: 10.1155/2020/3479575 [15] ZHAO G T, ZOU W L, HAN Z, et al. Evolution of soil-water and shrinkage characteristics of an expansive clay during freeze-thaw and drying-wetting cycles[J]. Cold Regions Science and Technology, 2021, 186: 103275. doi: 10.1016/j.coldregions.2021.103275 [16] ZHOU Z H, BAI Y, WU Y T, et al. Multiscale study on the microstructural evolution and macromechanical deterioration of expansive soil under dry-wet cycles[J]. Journal of Mechanics, 2022, 38: 610-620. doi: 10.1093/jom/ufac048 [17] HUANG Z, SUN H Y, DAI Y M, et al. A study on the shear strength and dry-wet cracking behaviour of waste fibre-reinforced expansive soil[J]. Case Studies in Construction Materials, 2022, 16: e01142. doi: 10.1016/j.cscm.2022.e01142 [18] 张丹, 许强, 郭莹. 玄武岩纤维加筋膨胀土的强度与干缩变形特性试验[J]. 东南大学学报(自然科学版), 2012, 42(5): 975-980. doi: 10.3969/j.issn.1001-0505.2012.05.032ZHANG D, XU Q, GUO Y. Experiments on strength and shrinkage of expansive soil with basalt fiber reinforcement[J]. Journal of Southeast University (Natural Science Edition), 2012, 42(5): 975-980. (in Chinese with English abstract doi: 10.3969/j.issn.1001-0505.2012.05.032 [19] 韩春鹏, 田家忆, 张建, 等. 干湿循环下纤维加筋膨胀土裂隙特性分析[J]. 吉林大学学报(工学版), 2019, 49(2): 392-400. doi: 10.13229/j.cnki.jdxbgxb20180019HAN C P, TIAN J Y, ZHANG J, et al. Analysis of crack characteristics of fiber-reinforced expansive soil under wetting-drying cycle[J]. Journal of Jilin University (Engineering and Technology Edition), 2019, 49(2): 392-400. (in Chinese with English abstract doi: 10.13229/j.cnki.jdxbgxb20180019 [20] 郝建斌, 张焕, 李耕春, 等. 粉煤灰-剑麻纤维复合改良膨胀土强度及裂隙发育特性[J]. 铁道科学与工程学报, 2022, 19(9): 2620-2628. doi: 10.19713/j.cnki.43-1423/u.T20211117HAO J B, ZHANG H, LI G C, et al. Strength and cracking characteristics of expansive soil improved by fly ash and sisal fiber[J]. Journal of Railway Science and Engineering, 2022, 19(9): 2620-2628. (in Chinese with English abstract doi: 10.19713/j.cnki.43-1423/u.T20211117 [21] 朱锐, 王燕杰, 黄英豪, 等. 木质素纤维改良膨胀土的冻融特性及微观机理[J]. 农业工程学报, 2024, 40(2): 263-272. doi: 10.11975/j.issn.1002-6819.202309194ZHU R, WANG Y J, HUANG Y H, et al. Freeze-thawing characteristics and microscopic mechanism of expansive soil treated with lignin fibers[J]. Transactions of the Chinese Society of Agricultural Engineering, 2024, 40(2): 263-272. (in Chinese with English abstract doi: 10.11975/j.issn.1002-6819.202309194 [22] 苏玲霞, 雷云, 刘旭, 等. 干湿循环下纤维改良膨胀土裂隙特性研究[J]. 非金属矿, 2023, 46(6): 32-35. doi: 10.3969/j.issn.1000-8098.2023.06.008SU L X, LEI Y, LIU X, et al. Study on the fracture characteristics of fiber-amended swelling soil under dry and wet cycles[J]. Non-Metallic Mines, 2023, 46(6): 32-35. (in Chinese with English abstract doi: 10.3969/j.issn.1000-8098.2023.06.008 [23] 中华人民共和国住房和城乡建设部. 土工试验方法标准: GB/T 50123−2019[S]. 北京: 中国计划出版社, 2019.Ministry of Housing and Urban-Rural Development of the People's Republic of China. Standard for geotechnical testing method: GB/T 50123−2019[S]. Beijing: China Planning Press, 2019. (in Chinese) [24] 中华人民共和国住房和城乡建设部. 膨胀土地区建筑技术规范: GB 50112−2013[S]. 北京: 中国建筑工业出版社, 2013.Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Technical code for building in expansive soil regions: GB 50112−2013[S]. Beijing: China Architecture & Building Press, 2013. (in Chinese) [25] 毛正君, 耿咪咪, 毕银丽, 等. 紫花苜蓿-黄土复合体抗剪强度时间效应研究[J]. 煤炭科学技术, 2023, 51(11): 234-247. doi: 10.13199/j.cnki.cst.2022-2230MAO Z J, GENG M M, BI Y L, et al. Study on the time effect of shear strength of alfalfa-loess composite[J]. Coal Science and Technology, 2023, 51(11): 234-247. (in Chinese with English abstract doi: 10.13199/j.cnki.cst.2022-2230 [26] 张鹏宇, 朱喜文, 田苏茂, 等. 宜昌蒸发站2010-2021年土壤墒情变化规律分析[J]. 水资源研究, 2023, 12(2): 190-197. doi: 10.12677/JWRR.2023.122022ZHANG P Y, ZHU X W, TIAN S M, et al. Law analysis of soil moisture change in Yichang evaporation station from 2010 to 2021[J]. Journal of Water Resources Research, 2023, 12(2): 190-197. (in Chinese with English abstract doi: 10.12677/JWRR.2023.122022 [27] LIU C, TANG C S, SHI B, et al. Automatic quantification of crack patterns by image processing[J]. Computers & Geosciences, 2013, 57: 77-80. [28] 尤波, 徐洪钟, 董金梅. 玄武岩纤维加筋膨胀土三轴试验研究[J]. 防灾减灾工程学报, 2015, 35(4): 503-507. doi: 10.13409/j.cnki.jdpme.2015.04.015YOU B, XU H Z, DONG J M. Triaxial tests of expansive soil reinforced with basalt fibe[J]. Journal of Disaster Prevention and Mitigation Engineering, 2015, 35(4): 503-507. (in Chinese with English abstract doi: 10.13409/j.cnki.jdpme.2015.04.015 [29] 庄心善, 余晓彦. 石灰-玄武岩纤维改性膨胀土强度特性的试验研究[J]. 土木工程学报, 2015, 48(增刊1): 166-170.ZHUANG X S, YU X Y. Experimental study on strength characteristics of expansive soil modified by lime-basalt fiber[J]. China Civil Engineering Journal, 2015, 48(S1): 166-170. (in Chinese with English abstract [30] 徐洪钟, 彭轶群, 赵志鹏, 等. 短切玄武岩纤维加筋膨胀土的试验研究[J]. 建筑科学, 2012, 28(9): 44-47. doi: 10.3969/j.issn.1002-8528.2012.09.010XU H Z, PENG Y Q, ZHAO Z P, et al. Experimental study on short basalt fiber reinforced expansive soil[J]. Building Science, 2012, 28(9): 44-47. (in Chinese with English abstract doi: 10.3969/j.issn.1002-8528.2012.09.010 [31] 王协群, 郭敏, 胡波. 土工格栅加筋膨胀土的三轴试验研究[J]. 岩土力学, 2011, 32(6): 1649-1653. doi: 10.3969/j.issn.1000-7598.2011.06.009WANG X Q, GUO M, HU B. Triaxial testing study of expansive soil reinforced with geogrid[J]. Rock and Soil Mechanics, 2011, 32(6): 1649-1653. (in Chinese with English abstract doi: 10.3969/j.issn.1000-7598.2011.06.009 [32] 顾欣, 徐洪钟. 干湿循环作用下纤维加筋膨胀土的裂隙及强度特性研究[J]. 南京工业大学学报(自然科学版), 2016, 38(3): 81-86. doi: 10.3969/j.issn.1671-7627.2016.03.014GU X, XU H Z. Study on crack properties of fiber-reinforced expansive soil under condition of wetting-drying circle[J]. Journal of Nanjing Tech University (Natural Science Edition), 2016, 38(3): 81-86. (in Chinese with English abstract doi: 10.3969/j.issn.1671-7627.2016.03.014 [33] 宋成林, 张大亮, 王迎超, 等. 基于主客观赋权和功效系数法的膨胀土胀缩性评价[J]. 地质科技通报, 2024, 43(6): 136-143. doi: 10.19509/j.cnki.dzkq.tb20240074SONG C L, ZHANG D L, WANG Y C, et al. Evaluation of swelling-shrinkage of expansive soil based on subjective and objective weighting and efficiency coefficient methods[J]. Bulletin of Geological Science and Technology, 2024, 43(6): 136-143. (in Chinese with English abstract doi: 10.19509/j.cnki.dzkq.tb20240074 [34] TANG C S, CHENG Q, LENG T, et al. Effects of wetting-drying cycles and desiccation cracks on mechanical behavior of an unsaturated soil[J]. Catena, 2020, 194: 104721. doi: 10.1016/j.catena.2020.104721 [35] TIAN B G, CHENG Q, TANG C S, et al. Healing behaviour of desiccation cracks in a clayey soil subjected to different wetting rates[J]. Engineering Geology, 2023, 313: 106973. doi: 10.1016/j.enggeo.2022.106973 [36] 郭永春, 刘家志, 尤安俊, 等. 基于颗粒堆积模型的膨胀土结构膨胀机制[J]. 工程地质学报, 2025, 33(1): 58-65. doi: 10.13544/j.cnki.jeg.2022-0356GUO Y C, LIU J Z, YOU A J, et al. Expansion mechanism of expansive soil structure based on particle packing model[J]. Journal of Engineering Geology, 2025, 33(1): 58-65. (in Chinese with English abstract doi: 10.13544/j.cnki.jeg.2022-0356 -
下载:
点击查看大图
计量
- 文章访问数: 42
- PDF下载量: 11
- 被引次数: 0
