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摘要: 为了解决传统原位土体强度测试探测深度浅与过度依赖经验公式等问题，提出了钻孔原位剪切测试系统构想，并设计了样机，整个测试系统由孔内切削子系统和孔内变径剪切子系统组成，前者能够在钻孔内任意位置锚固并切削土环，后者能够对土环进行剪切试验，并通过传感器记录剪切力和剪切位移；基于模型箱钻孔剪切试验和室内直剪试验，进一步检验了钻孔原位剪切测试系统的可靠性。研究结果表明：模型箱钻孔剪切试验的剪切面平行于剪切力的方向，应力-应变曲线符合基本规律；黄土在模型箱钻孔剪切试验和室内直剪试验中均出现应变软化现象，且黄土的峰值剪切强度随含水率升高而下降；在室内直剪试验中黄土发生了脆性破坏，而在钻孔剪切试验中黄土表现出塑性破坏，在相同的孔隙比、含水率与加载压力下，钻孔剪切试验的峰值强度比室内直剪试验大，原因在于室内直剪试验剪切面的应力分布不均匀，而钻孔原位剪切试验的剪切面受力稳定且保持不变，与室内直剪试验相比，钻孔原位剪切测试系统具有更高的测试准度。Abstract: In order to solve the problems of shallow detection depth and over-reliance on empirical formulas in the traditional in-situ soil strength test, a borehole in-situ shear test system was proposed, and a prototype was developed. The whole test system consisted of an in-hole cutting subsystem, which could anchor and cut the soil ring at any position in the borehole, and an in-hole shear subsystem with a reducing wing, which could perform shear tests on the soil ring and record shear force and shear displacement through sensors. Based on the borehole shear test in the model box and the direct shear test in the laboratory, the reliability of the borehole in-situ shear test system was verified. Research results show that the shear plane of the borehole shear test in the model box is parallel to the direction of the shear force, and the stress-strain curve is found to be consistent with the expectation. The strain softening behavior occurs for loess in the borehole shear test in the model box and direct shear test in the laboratory, and the peak shear strength of the loess decreases with the increase in water content. The brittle failure is found in the direct shear test in the laboratory, while in the borehole shear test, the loess shows plastic failure. The peak strength is higher in the borehole shear test than in the direct shear test in the laboratory under the same void ratio, water content, and loading pressure. The above discrepancy is attributed to the fact that the stress distribution along the shear plane is not uniform in the direct shear test in the laboratory, while in the borehole in-situ shear test, the stress on the shear plane is stable and remains unchanged. Compared with the direct shear test in the laboratory, the borehole in-situ shear test system exhibits a higher test accuracy.
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图 1 土体强度原位测试技术发展历程
Figure 1. Development history of in-situ test technology for soil strength
表 1 试验黄土基本物理参数
Table 1. Basic physical parameters of test loess
含水率/% 颗粒比重 塑限/% 液限/% 粒径级配/% 黏粒(< 5 μm) 粉粒(5~75 μm) 砂粒(>75 μm) 11.6 2.65 16.1 27.8 10.5 83.2 6.3 
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表 2 试验概况
Table 2. Summary of tests
试验编号 孔隙比 剪切速率/(mm·min-1) 含水率/% 加载压力/kPa A-1 0.75 0.08 15 25 A-2 10 50 B-1 15 25 B-2 10 50 B-3 20
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[1] 景宏君, 张斌. 黄土路基强度规律[J]. 交通运输工程学报, 2004, 4(2): 14-18. https://www.cnki.com.cn/Article/CJFDTOTAL-JYGC200402004.htmJING Hong-jun, ZHANG Bin. Loess subgrade strength law[J]. Journal of Traffic and Transportation Engineering, 2004, 4(2): 14-18. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JYGC200402004.htm [2] 程东幸, 刘大安, 丁恩保, 等. 滑带土长期强度参数的衰减特性研究[J]. 岩石力学与工程学报, 2005, 24(增2): 5827-5834. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2005S2097.htmCHENG Dong-xing, LIU Da-an, DING En-bao, et al. Study on attenuation characteristics of long-term strength for landslide soil[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(S2): 5827-5834. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2005S2097.htm [3] 许强, 陈婉琳, 蒲川豪, 等. 基于自然的解决方案在黄土高原重大工程灾变防控中的理论与实践[J]. 工程地质学报, 2022, 30(4): 1179-1192. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202204019.htmXU Qiang, CHEN Wan-lin, PU Chuan-hao, et al. Theoretical and practical approach based on nature-based solutions in disasters control of major engineering in loess plateau[J]. Journal of Engineering Geology, 2022, 30(4): 1179-1192. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ202204019.htm [4] 蔡怀恩, 张继文, 李鹏军, 等. 黄土挖填方场地形成的关键岩土工程问题[J]. 岩土工程技术, 2022, 36(1): 22-25. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGJ202201005.htmCAI Huai-en, ZHANG Ji-wen, LI Peng-jun, et al. Key geotechnical engineering problems in loess excavation and filling site formation[J]. Geotechnical Engineering Technique, 2022, 36(1): 22-25. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGJ202201005.htm [5] 王龙, 张连科, 马伊明, 等. 工程扰动对黄土抗蚀性与抗冲性的影响[J]. 水土保持学报, 2021, 35(4): 14-20, 26. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQS202104003.htmWANG Long, ZHANG Lian-ke, MA Yi-ming, et al. Influence of engineering disturbance on soil anti-erodibility and anti-scourability of loess[J]. Journal of Soil and Water Conservation, 2021, 35(4): 14-20, 26. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TRQS202104003.htm [6] 彭建兵, 王启耀, 庄建琦, 等. 黄土高原滑坡灾害形成动力学机制[J]. 地质力学学报, 2020, 26(5): 714-730. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLX202005008.htmPENG Jian-bing, WANG Qi-yao, ZHUANG Jian-qi, et al. Dynamic formation mechanism of landslide disaster on the Loess Plateau[J]. Journal of Geomechanics, 2020, 26(5): 714-730. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-DZLX202005008.htm [7] 李宏儒, 梁恒楠. 不同胶结剂人工结构性黄土的力学特性差异研究[J]. 岩土力学, 2023, 44(5): 1416-1424. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202305016.htmLI Hong-ru, LIANG Heng-nan. Study on the difference of mechanical properties of artificial structured loess with different binders[J]. Rock and Soil Mechanics, 2023, 44(5): 1416-1424. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202305016.htm [8] 方涤华, 宋永祥, 窦宜. 土的强度测试技术和自动化[J]. 岩土工程学报, 1986, 8(1): 83-105. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC198601003.htmFANG Di-hua, SONG Yong-xiang, DOU Yi. Soil strength testing technology and automation[J]. Chinese Journal of Geotechnical Engineering, 1986, 8(1): 83-105. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC198601003.htm [9] 沈珠江. 原状取土还是原位测试——土质参数测试技术发展方向刍议[J]. 岩土工程学报, 1996, 18(5): 90-91. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC605.015.htmSHEN Zhu-jiang. Undisturbed soil sampling or in-situ testing—on the development direction of soil parameter testing technology[J]. Chinese Journal of Geotechnical Engineering, 1996, 18(5): 90-91. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC605.015.htm [10] 刘恩龙, 沈珠江, 范文. 结构性粘土研究进展[J]. 岩土力学, 2005, 26(增1): 1-8. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2005S1000.htmLIU En-long, SHEN Zhu-jiang, FAN Wen. Advance in researches on structured clay[J]. Rock and Soil Mechanics, 2005, 26(S1): 1-8. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2005S1000.htm [11] 鲁泰山, 刘松玉, 蔡国军, 等. 软土地层基坑开挖扰动及土体再压缩变形研究[J]. 岩土力学, 2021, 42(2): 565-573, 580. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202102029.htmLU Tai-shan, LIU Song-yu, CAI Guo-jun, et al. Study on the disturbance and recompression settlement of soft soil induced by foundation excavation[J]. Rock and Soil Mechanics, 2021, 42(2): 565-573, 580. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202102029.htm [12] 周江平, 彭雄志. 土体抗剪强度的尺寸效应[J]. 西南交通大学学报, 2005, 40(1): 77-81. https://www.cnki.com.cn/Article/CJFDTOTAL-XNJT200501018.htmZHOU Jiang-ping, PENG Xiong-zhi. Investigation on size effect of shear strength of soil[J]. Journal of Southwest Jiaotong University, 2005, 40(1): 77-81. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XNJT200501018.htm [13] 李晓, 廖秋林, 赫建明, 等. 土石混合体力学特性的原位试验研究[J]. 岩石力学与工程学报, 2007, 26(12): 2377-2384. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200712003.htmLI Xiao, LIAO Qiu-lin, HE Jian-ming, et al. Study on in-situ tests of mechanical characteristics on soil-rock aggregate[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(12): 2377-2384. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200712003.htm [14] 徐世强, 折学森, 刘怡琳, 等. 公路黄土坝式路堤稳定性计算方法[J]. 交通运输工程学报, 2006, 6(3): 42-46. https://www.cnki.com.cn/Article/CJFDTOTAL-JYGC200603009.htmXU Shi-qiang, SHE Xue-sen, LIU Yi-lin, et al. Stability computation method of highway loess dam-like embankment[J]. Journal of Traffic and Transportation Engineering, 2006, 6(3): 42-46. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JYGC200603009.htm [15] 李炜. 边坡稳定性联合评价方法[J]. 交通运输工程学报, 2010, 10(5): 8-11. doi: 10.19818/j.cnki.1671-1637.2010.05.002LI Wei. Combined evaluation method of slope stability[J]. Journal of Traffic and Transportation Engineering, 2010, 10(5): 8-11. (in Chinese) doi: 10.19818/j.cnki.1671-1637.2010.05.002 [16] 吉见吉昭. 太沙基与土力学[J]. 岩土工程学报, 1981, 3(3): 114-119. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC198103014.htmJI Jian-jizhao. Terzaghi and soil mechanics[J]. Chinese Journal of Geotechnical Engineering, 1981, 3(3): 114-119. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC198103014.htm [17] 刘松玉, 蔡正银. 土工测试技术发展综述[J]. 土木工程学报, 2012, 45(3): 151-165. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC201203021.htmLIU Song-yu, CAI Zheng-yin. Review of the geotechnical testing[J]. China Civil Engineering Journal, 2012, 45(3): 151-165. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC201203021.htm [18] SKEMPTON A W, ALEXANDER C. A note on his pioneer work in soil mechanics[J]. Géotechnique, 1949, 1(4) : 215-222. [19] 胡建华, 汪稔, 周平, 等. 旁压仪在地基工程原位测试中的应用及其成果分析[J]. 岩土力学, 2003, 24(增2): 418-422. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2003S2098.htmHU Jian-hua, WANG Ren, ZHOU Ping, et al. Application and analysis of pressiometer to in-situ measurement of foundation works[J]. Rock and Soil Mechanics, 2003, 24(S2): 418-422. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2003S2098.htm [20] 肖兵, 张敏勇. 平板载荷试验应思考的几个问题[J]. 岩土力学, 2003, 24(增1): 72-73. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2003S1017.htmXIAO Bing, ZHANG Min-yong. Some cases in plate load test (PLT)[J]. Rock and Soil Mechanics, 2003, 24(S1): 72-73. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2003S1017.htm [21] 徐小明, 杨鸿钧. 关于十字板剪切试验成果分析中主要问题的探讨[J]. 港工技术, 2012, 49(4): 71-73. https://www.cnki.com.cn/Article/CJFDTOTAL-GAOG201204025.htmXU Xiao-ming, YANG Hong-jun. Discussion of vane-shear test result analysis[J]. Port Engineering Technology, 2012, 49(4): 71-73. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GAOG201204025.htm [22] ROBERTSONP K, CAMPANELLA R G. Interpretation of cone penetration tests. Part Ⅰ: sand[J]. Canadian Geotechnical Journal, 1983, 20(4): 718-733. [23] MAYNE P W, KULHAWY F H, KAY J N. Observations on the development of pore-water stresses during penetration in clays[J]. Canadian Geotechnical Journal, 1990, 27(4): 418-428. [24] LUNNE T, ROBERTSON P K, POWELL J J M. Cone Penetration Testing in Geotechnical Practice[M]. New York: Chapman and Hall, 1997. [25] GOLDBERG D. The role of downhole measurements in marine geology and geophysics[J]. Reviews of Geophysics, 1997, 35(3): 315-342. [26] JUANG C H, YUAN H M, LEE D H, et al. Simplified cone penetration test-based method for evaluating liquefaction resistance of soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2003, 129(1): 66-80. [27] ONDER CETIN K, SEED R B, DER KIUREGHIAN A, et al. Standard penetration test-based probabilistic and deterministic assessment of seismic soil liquefaction potential[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2004, 130(12): 1314-1340. [28] 刘松玉, 吴燕开. 论我国静力触探技术(CPT)现状与发展[J]. 岩土工程学报, 2004, 26(4): 553-556. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200404030.htmLIU Song-Yu, WU Yan-kai. On the state-of-art and development of CPT in China[J]. Chinese Journal of Geotechnical Engineering, 2004, 26(4): 553-556. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200404030.htm [29] 沈小克, 蔡正银, 蔡国军. 原位测试技术与工程勘察应用[J]. 土木工程学报, 2016, 49(2): 98-119. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC201602012.htmSHEN Xiao-ke, CAI Zheng-yin, CAI Guo-jun. Applications of in-situ tests in site characterization and evaluation[J]. China Civil Engineering Journal, 2016, 49(2): 98-119. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC201602012.htm [30] 冯文凯, 易小宇, 葛华, 等. 大光包滑坡滑带碎裂岩体原位钻孔剪切试验研究[J]. 岩土工程学报, 2017, 39(9): 1718-1723. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201709028.htmFENG Wen-kai, YI Xiao-yu, GE Hua, et al. In-situ borehole shear tests on cataclastic rock mass of Daguangbao landslide[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(9): 1718-1723. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201709028.htm [31] 段伟, 蔡国军, 刘松玉, 等. 无黏性土的电阻率CPTU状态参数确定方法及其液化评价[J]. 交通运输工程学报, 2019, 19(2): 59-68. doi: 10.19818/j.cnki.1671-1637.2019.02.006DUAN Wei, CAI Guo-jun, LIU Song-yu, et al. Determining method of cohesionless soil state parameter based on resistivity CPTU and liquefaction evaluation[J]. Journal of Traffic and Transportation Engineering, 2019, 19(2): 59-68. (in Chinese) doi: 10.19818/j.cnki.1671-1637.2019.02.006 [32] 油新华, 汤劲松. 土石混合体野外水平推剪试验研究[J]. 岩石力学与工程学报, 2002, 21(10): 1537-1540. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200210022.htmYOU Xin-hua, TANG Jin-song. Research on horizontal push-shear in-situ test of soil and rock-mixture[J]. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(10) : 1537-1540. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200210022.htm [33] 徐文杰, 胡瑞林, 曾如意. 水下土石混合体的原位大型水平推剪试验研究[J]. 岩土工程学报, 2006, 28(7): 814-818. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200607001.htmXU Wen-jie, HU Rui-lin, ZENG Ru-yi. Research on horizontal push-shear in-situ test of subwater soil-rock mixture[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(7): 814-818. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200607001.htm [34] 胡伟, 闵弘, 陈健, 等. 大型原位直剪试验设备改进研制与应用[J]. 岩土力学, 2015, 36(3): 905-912. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201503050.htmHU Wei, MIN Hong, CHEN Jian, et al. Improvement of a large scale in-situ direct shear test apparatus and its application[J]. Rock and Soil Mechanics, 2015, 36(3): 905-912. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201503050.htm [35] 李广信. 关于土的本构模型研究的若干问题[J]. 岩土工程学报, 2009, 31(10): 1636-1641. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200910035.htmLI Guang-xin. Some problems in researches on constitutive model of soil[J]. Chinese Journal of Geotechnical Engineering, 2009, 31(10): 1636-1641. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200910035.htm -
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