饱和砂土-结构物接触面强度特性的三轴试验方法

doi:10.16183/j.cnki.jsjtu.2020.299

摘要/Abstract

摘要：

提出一种利用三轴仪分析应力路径及结构物粗糙度对饱和砂土和结构物接触面强度特性影响的试验方法.通过制作含一定倾角斜面结构物的三轴试样,使得剪切过程中土体沿预设破坏面发生滑移, 结构物斜面粗糙度可进行控制调整.利用三轴仪控制轴压和围压变化,实现不同应力路径下的加载.对饱和福建标准砂和不同粗糙度钢结构物进行不同应力路径下固结排水剪切接触面试验,并对比接触面直剪试验,验证了该方法的有效性.结果表明:在滑动刚发生时,三轴试验常法向应力剪切路径下接触面摩擦角小于常规剪切路径下的接触面摩擦角.光滑情况下,接触面直剪试验所得摩擦角比三轴试验所得摩擦角小30%~40%.粗糙情况下,直剪试验所得接触面摩擦角略小于三轴试验摩擦角,且更接近于常法向应力剪切路径下的摩擦角.

关键词: 三轴试验, 接触面, 粗糙度, 应力路径, 摩擦角

Abstract:

A novel test method for analyzing the influence of stress path and roughness of structure on the strength characteristics of saturated sand-structure interface by using triaxial apparatus is presented. By making a triaxial specimen with a slope structure with a certain inclination angle, the soil slides along the preset failure surface during the shearing process, and the slope surface roughness of the structure can be controlled and adjusted. A triaxial instrument is used to control the changes in axial pressure,confining pressure to achieve loading in different stress paths. The soil slides along the structure surface with a certain angle during shearing when preformed failure surface exists. The roughness of the structure can be controlled and adjusted. The triaxial apparatus is used to control the confining pressure change of the sample to realize loading under different drainage conditions and stress paths. To verify the effectiveness of the method, direct shear test and triaxial shear tests are carried out on the specimen composed of Fujian sand and steel structures with different roughness and different stress paths. The results show that at the beginning of sliding, the friction angle of the interface in the interfacial constant normal stress path is smaller than that in the conventional shear path. Under smooth conditions, the interface friction angle obtained by direct shear test is 30% to 40% lower than that obtained by triaxial test. Under rough conditions, the interface friction angle obtained by direct shear test is slightly smaller than that obtained by triaxial test, and closer to the friction angle in normal stress shear paths.

Key words: triaxial test, interface, roughness, stress path, friction angle

中图分类号:

TU411

刘世奥, 廖晨聪, 陈锦剑, 叶冠林, 夏小和. 饱和砂土-结构物接触面强度特性的三轴试验方法[J]. 上海交通大学学报, 2021, 55(11): 1371-1379.

LIU Shiao, LIAO Chencong, CHEN Jinjian, YE Guanlin, XIA Xiaohe. Strength Properties of Saturated Sand-Structure Interface by Triaxial Test Method[J]. Journal of Shanghai Jiao Tong University, 2021, 55(11): 1371-1379.

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参考文献 18

[1]	SABERI M, ANNAN C D, KONRAD J M. On the mechanics and modeling of interfaces between granular soils and structural materials[J]. Archives of Civil and Mechanical Engineering, 2018, 18(4):1562-1579. doi: 10.1016/j.acme.2018.06.003 URL
[2]	胡黎明, 濮家骝. 土与结构物接触面物理力学特性试验研究[J]. 岩土工程学报, 2001, 23(4):431-435.
	HU Liming, PU Jialiu. Experimental study on mechanical characteristics of soil-structure interface[J]. Chinese Journal of Geotechnical Engineering, 2001, 23(4):431-435.
[3]	胡黎明, 马杰, 张丙印, 等. 粗粒料与结构物接触面力学特性缩尺效应[J]. 清华大学学报(自然科学版) , 2007, 47(3):327-330.
	HU Liming, MA Jie, ZHANG Bingyin, et al. Scaling effect on the mechanical behavior of the interface between coarse-grained materials and a structure[J]. Journal of Tsinghua University (Science and Technology) , 2007, 47(3):327-330.
[4]	张嘎, 张建民. 大型土与结构接触面循环加载剪切仪的研制及应用[J]. 岩土工程学报, 2003, 25(2):149-153.
	ZHANG Ga, ZHANG Jianmin. Development and application of cyclic shear apparatus for soil-structure interface[J]. Chinese Journal of Geotechnical Engineering, 2003, 25(2):149-153.
[5]	张嘎, 张建民. 粗粒土与结构接触面单调力学特性的试验研究[J]. 岩土工程学报, 2004, 26(1):21-25.
	ZHANG Ga, ZHANG Jianmin. Experimental study on monotonic behavior of interface between soil and structure[J]. Chinese Journal of Geotechnical Engineering, 2004, 26(1):21-25.
[6]	张嘎, 张建民, 梁东方. 土与结构接触面试验中的土颗粒细观运动测量[J]. 岩土工程学报, 2005, 27(8):903-907.
	ZHANG Ga, ZHANG Jianmin, LIANG Dongfang. Measurement of soil particle movement in soil-structure interface test[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(8):903-907.
[7]	ZHANG G, ZHANG J M. Unified modeling of monotonic and cyclic behavior of interface between structure and gravelly soil[J]. Soils and Foundations, 2008, 48(2):231-245. doi: 10.3208/sandf.48.231 URL
[8]	SAMANTA M, PUNETHA P, SHARMA M. Influence of surface texture on sand-steel interface strength response[J]. Géotechnique Letters, 2018, 8(1):1-25. doi: 10.1680/jgele.17.00039 URL
[9]	NARDELLI A, CACCIARI P P, FUTAI M M. Sand-concrete interface response: The role of surface texture and confinement conditions[J]. Soils and Foundations, 2019, 59(6):1675-1694. doi: 10.1016/j.sandf.2019.05.013 URL
[10]	WANG T L, WANG H H, HU T F, et al. Experimental study on the mechanical properties of soil-structure interface under frozen conditions using an improved roughness algorithm[J]. Cold Regions Science and Technology, 2019, 158:62-68. doi: 10.1016/j.coldregions.2018.10.015 URL
[11]	邬俊杰, 刘帅君, 陈锦剑, 等. 桩土接触面三轴模拟试验设备研究与应用[J]. 上海交通大学学报, 2014, 48(11):1523-1527.
	WU Junjie, LIU Shuaijun, CHEN Jinjian, et al. Development and application of a triaxial model test system for pile-soil interface[J]. Journal of Shanghai Jiao Tong University, 2014, 48(11):1523-1527.
[12]	ZIOGOS A, BROWN M, IVANOVIC A, et al. Chalk-steel interface testing for marine energy foundations[J]. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering, 2017, 170(3):285-298. doi: 10.1680/jgeen.16.00112 URL
[13]	CHANDLER R J. The measurement of residual strength in triaxial compression[J]. Géotechnique, 1966, 16(3):181-186. doi: 10.1680/geot.1966.16.3.181 URL
[14]	MEEHAN C L, TIWARI B, BRANDON T L, et al. Triaxial shear testing of polished slickensided surfaces[J]. Landslides, 2011, 8(4):449-458. doi: 10.1007/s10346-011-0263-y URL
[15]	REILLY C C, ORR T L L. Physical modelling of the effect of lubricants in pipe jacking[J]. Tunnelling and Underground Space Technology, 2017, 63:44-53. doi: 10.1016/j.tust.2016.11.005 URL
[16]	REILLY C C. The influence of lubricant slurries on skin friction resistance in pipe jacking[EB/OL]. [2020-09-15]. https://xueshu.baidu.com/usercenter/paper/show?paperid=ee00a20f1321215b19b2ee9 f1e2c5fb0&site=xueshu_se.
[17]	陈超斌, 叶冠林. 基于LVDT的小应变三轴仪研制及其软土试验应用[J]. 岩土力学, 2018, 39(6):2304-2310.
	CHEN Chaobin, YE Guanlin. Development of small-strain triaxial apparatus using LVDT sensors and its application to soft clay test[J]. Rock and Soil Mechanics, 2018, 39(6):2304-2310.
[18]	RAGHUNANDAN M E, SHARMA J S, PRADHAN B. A review on the effect of rubber membrane in triaxial tests[J]. Arabian Journal of Geosciences, 2015, 8(5):3195-3206. doi: 10.1007/s12517-014-1420-0 URL

序列	围压/kPa	应力路径	接触情况
P1-R1	50、100、150、200、300	P1	R1
P2-R1	50、100、150、200、300	P2	R2
P1-R2	50、100、150、200、300	P1	R1
P2-R2	50、100、150、200、300	P2	R2

试验	纯土试样摩擦角/(°)	R1粗糙度下接触面摩擦角/(°)	R2粗糙度下接触面摩擦角/(°)
P1路径三轴试验	38.2	18.9	27.7
P2路径三轴试验	37.2	16.7	25.6
直剪试验	—	11.3	25.4