膨胀土原位剪切模量–剪应变衰减曲线与特征分析

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摘要为了评价原位应力状态膨胀土在小应变作用下的刚度衰减特性，综合原位地震扁铲侧胀和室内共振柱试验，分析应力历史、应力状态和试样扰动对膨胀土剪切模量衰减规律的影响。结果表明，应力状态和应力历史对膨胀土剪切模量影响较大，相同应力历史下，剪切模量随围压增加而增大，随着应变的发展，衰减较快；相同应力状态下，经历加载–卸载过程的剪切模量–剪应变(G-?)衰减曲线位于仅经历加载过程的曲线上方，但经历加载–卸载和加载–卸载–再加载过程后土的G-?衰减曲线基本重合；另外，相同应力历史条件下，土的原位剪切模量较室内共振柱试验所得剪切模量值大，且衰减更快，说明取样卸荷、运输及制样等扰动因素对土体结构造成了不可逆的损伤，通过室内加卸载过程无法还原其原位力学性状；参考剪应变不同时，推求得到的原位G-?衰减曲线的中间部分差异较大，参考剪应变越小，剪切模量衰减越快，说明合理选取参考曲线和小应变剪切模量是推求原位G-?衰减曲线的关键。该研究可为类似场地地震分析和沉降分析提供理论基础和技术支持。

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	李晶晶1
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	孔令伟1
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	金磊3

关键词 ：土力学, 膨胀土, 地震扁铲试验, 共振柱, G-衰减曲线

Abstract：In order to evaluate the characteristics of stiffness decay of expansive soil at the in-situ stress state under the small strain condition，the in-situ seismic dilatometer test and the resonant column test are carried out to analyze the influence of stress history，stress state and disturbance on the modulus decay of expansive soil. Results show that both the stress state and stress history significantly affect the shear modulus of expansive soil. The shear modulus increases with the increasing of the confining pressure under the same stress path and the modulus decays faster with the development of shear strain. The shear modulus of soils following the loading-unloading path is greater than that of soils only following the loading path，while the G-? decay curve of former is nearly the same as that of soils following the loading-unloading-reloading path. Besides，the in-situ shear modulus is greater than that from the resonant column tests of the same stress history，which indicates that disturbance caused by sampling，unloading，transportation and sample preparation contributes to the irreversible damage，so that the in-situ characteristics were not be presented in the indoor test results following the loading and unloading path. The in-situ G-? decay curves derived with different reference strains exhibit an evident difference in the middle strain range，which shows the shear modulus decays faster with smaller reference strain. Selecting a reasonable reference curve and the shear modulus of small strain are the key to get the right in-situ G- decay curves.

Key words： soil mechanics expansive soil seismic dilatometer test resonant column test G- decay curve

引用本文:

李晶晶1，2，孔令伟1，2，金磊3. 膨胀土原位剪切模量–剪应变衰减曲线与特征分析[J]. 岩石力学与工程学报, 2017, 36(4): 1032-1039.
LI Jingjing1，2，KONG Lingwei1，2，JIN Lei3. In situ shear modulus and shear strain decay curves in expansive soils and analysis of its characteristics#br#. , 2017, 36(4): 1032-1039.

链接本文:

http://www.rockmech.org/CN/Y2017/V36/I4/1032

[15]	MARCHETTI S，MONACO P，TOTANI G，et al. In situ tests by seismic dilatometer(SDMT)[J]. From Research to Practice in Geotechnical Engineering，2008，180：292-311. " target="_blank">
[10]	AMOROSO S. G-? decay curves by seismic dilatometer (SDMT)[Ph. D. Thesis][D]. L?Aquila, Italy：University of L?Aquila，2011. " target="_blank">
[20]	李广信. 高等土力学[M]. 北京：清华大学出版社，2004：121-122.(LI Guangxin. Advanced soil mechanics[M]. Beijing：Tsinghua University Press，2004：121-122.(in Chinese)) " target="_blank">
[1]	谷川，蔡袁强，王军，等. 循环应力历史对饱和软黏土小应变剪切模量的影响[J]. 岩土工程学报，2012，34(9)：1 654-1 660.(GU Chuan，CAI Yuanqiang，WANG Jun，et al. Effects of loading history on small-strain shear modulus of saturated clays[J]. Chinese Journal of Geotechnical Engineering，2012，34(9)：1 654-1 660.(in Chinese))
[6]	FAHEY M，SCHNEIDER J A，LEHANE B M. Self-boring pressuremeter testing in Spearwood dune sands[J]. Australian Geomechanics，2007，42(4)：57-71. " target="_blank">
[2]	FAHEY M，LEHANE B，STEWART D. Soil stiffness for shallow foundation design in the Perth CBD[J]. Australian Geomechanics，2003，38(3)：61-89. " target="_blank">
[4]	JARDINE R J. Nonlinear stiffness parameters from undrained pressure meter tests[J]. Canadian Geotechnical Journal，1992，29(3)：436-447. " target="_blank">
[11]	柏立懂. 荷载历史对砂土最大剪切模量影响的共振柱试验研究[J]. 岩石力学与工程学报，2011，30(11)：2 366-2 374.(BAI Lidong. Effects of loading history on maximum shear modulus of sand by resonant column tests[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(11)：2 366-2 374.(in Chinese))
[12]	李剑，陈善雄，姜领发，等. 重塑红黏土动剪切模量与阻尼比的共振柱试验[J]. 四川大学学报：工程科学版，2013，45(4)：62-68. (LI Jian，CHEN Shanxiong，JIANG Lingfa，et al. Resonant column test on dynamic shear modulus and damping ratio of the remolded red clay[J]. Journal of Sichuan University：Engineering Science，2013，45(4)：62-68.(in Chinese))
[14]	毛成，邱延峻. 膨胀土与改性膨胀土的动力特性试验研究[J]. 岩石力学与工程学报，2005，24(10)：1 783-1 788.(MAO Cheng，QIU Yanjun. Testing study on dynamic properties of expansive soil and improved expansive soil[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(10)：1 783-1 788.(in Chinese))
[16]	AMOROSO S，LEHANE B M，FAHEY M. Determining G-? decay curves in sand from a seismic dilatometer test(SDMT)[C]// Proceedings of the International Conference on Geotechnical and Geophysical Site Characterization 4. London：Taylor and Francis Group，2012：447-452. " target="_blank">
[21]	MARCHETTI S，MONACO P，CALABRESE M，et al. Comparison of moduli determined by DMT and back figured from local strain measurements under a 40 m diameter circular test load in the Venice area[C]// Proceedings of the 2nd International Conference on the Flat Dilatometer. Washington D C：[s. n.]，2006：220-230. " target="_blank">
[3]	HARDIN B O，DRNEVICH V P. Shear modulus and damping in soils：measurement and parameter effects[J]. Journal of the Soil Mechanics and Foundations Division，1972，98(6)：603-624. " target="_blank">
[5]	YOUN J U，CHOO Y W，KIM D S. Measurement of small-strain shear modulus Gmax of dry and saturated sands by bender element，resonant column，and torsional shear tests[J]. Canadian Geotechnical Journal，2008，45(10)：1 426-1 438. " target="_blank">
[8]	MAYNE P W. Class“A”footing response prediction from seismic cone tests[C]// Proceedings of the 3rd International Symposia on the Deformation Characteristics of Geomaterials. Lisse，Abingdon：A. A. Balkema，2003：883-888. " target="_blank">
[13]	周小生. 双向循环荷载作用下膨胀土的动力特性与路基响应特征研究[硕士学位论文][D]. 北京：中国科学院大学，2010.(ZHOU Xiaosheng. The dynamic characteristics of expansive soil and dynamic behaviors of subgrade under the bidirectional cyclic loading[M. S. Thesis][D]. Beijing：Chinese Academy of Sciences，2010.(in Chinese)) " target="_blank">
[18]	STOKOES K H I， DARENDELI M B，ANDRUS R D，et al. Dynamic soil properties： Laboratory，field and correlation studies[C]// Proceedings of the 2nd International Conference on Earthquake and Geotechnical Engineering. Lisbon，Portugal：[s.n.]，1999：811-845. " target="_blank">
[9]	LEHANE B M，FAHEY M. Using SCPT and DMT data for settlement prediction in sand[C]// Proceedings of the 2nd International Conference on Site Characterization. Rotterdam：Mill Press，2004： 1 673-1 680. " target="_blank">
[19]	冯玉勇，曲永新，徐卫亚. 南阳膨胀土的宏观结构与路堑边坡病害治理[J]. 工程地质学报，2005，13(2)：169-173.(FENG Yuyong，QU Yongxin，XU Weiya. Macrostructure of Nanyang expansive soils and treatment of hazards along the railroad trench[J]. Journal of Engineering Geology，2005，13(2)：169-173.(in Chinese))
[7]	MAYNE P W，SCHNEIDER J A，MARTIN G K. Small-and large-strain soil properties from seismic flat dilatometer tests[C]// Proceedings of the International Symposia on Pre-Failure Deformation Characteristics of Geomaterials. Rotterdam：A. A. Balkema，1999：419-426. " target="_blank">
[17]	AMOROSO S，MONACO P，LEHANE B，et al. Examination of the potential of the seismic dilatometer(SDMT) to estimate in situ stiffness decay curves in various soil types[J]. Soils and Rocks，2014，37(3)：177-194. " target="_blank">