原状土的强度问题一直是岩土工程领域非常关心的问题之一,然而由于土样扰动的存在,真正获得原状土样的强度存在较大的困难。基于扰动插值函数的物理概念,提出了一种通过扰动土样强度预测原状土样强度的方法。该方法在Z.Hong和K.Onitsuka扰动度定义的基础上,结合黏性土弹塑性损伤力学模型,将扰动插值函数视为扰动度Dd的指数函数关系式,根据扰动土样的强度及压缩试验结果,通过插值函数推求得到原状土样的强度。基于连云港典型软黏土的振动试验对模型的适用性进行了检验,模型验证结果表明,该预测方法能较好地反映连云港典型软黏土的原状强度。
Abstract
Strength of undisturbed soil has gained significant interest among researchers in the field of geotechnical engineering. However, there are difficulties for us to obtain the strength of undisturbed soil due to soil disturbance.Based on the physical concept of interpolation function on disturbance, we propose a new method to predict the strength of undisturbed soil according to the strength of disturbed soil. According to the definition of soil disturbance degree(Dd) by Z.Hong and K.Onitsuka, in association with elastoplastic damage mechanics model of clay, we assume that the relationship between disturbance function and Dd shows tendency of exponential function. Furthermore, we deduce the strength of undisturbed soil by using interpolation function and the results of compression test and strength of disturbed soil. Typical undisturbed soft clay in Lianyungang district of Jiangsu province is taken as an example. We carry out vibration test of the clay to verify the model, and the test results show that the prediction method in this paper could well reflect the undisturbed soil strength of typical soft clay in Lianyungang.
关键词
原状土 /
土样扰动 /
插值函数 /
扰动度 /
扰动因子 /
土体强度
Key words
undisturbed soil /
soil disturbance /
interpolation function /
soil disturbance degree(Dd) /
disturbance factor /
soil strength
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参考文献
[1]HVORSLEV M J. Surface Exploration and Sampling of Soils for Civil Engineering Purposes[M].Vicksburg, Mississippi, USA:Waterways Experiment Station, 1949.
[2]魏汝龙,王年香.赤湾港软土取土质量的研究[J].港口工程,1989,(6):1-6
[3]BALIGH M M,AZZOUZ A S,CHIN C T. Disturbances Due to “Ideal” Tube Sampling[J]. Journal of Geotechnical Engineering, 1987, 113(7): 739-757.
[4]SANTAGATA M C, GERMAINE J T. Sampling Disturbance Effects in Normally Consolidated Clays [J].Journal of Geotechnical and Geoenvironmental Engineering, 2002, 128(12):997-1006.
[5]NAGARAJ M,CHUNG S G. Analysis and Assessment of Sampling Disturbance of Soft Sensitive Clays[J]. Geotechnique,2003,53(7):679-683.
[6]魏汝龙.软粘土的土样扰动及其影响[J]. 水利水运科学研究, 1986, (2):75-90.
[7]LADD C C, FOTT R. New Design Procedure for Stability of Soft Clays [J]. Journal of the Geotechnical Engineering Division, ASCE,1974, 100( 7): 736-786.
[8]BJERRUM L. Problems of Soil Mechanics and Construction on Soft Clay and Structurally Unstable Soils[C]∥Proceedings of the 8th International Conference on Soil Mechanics and Foundation Engineering, August 6-11,1973:111-159.
[9]王国欣,肖树芳,黄宏伟,等. 基于扰动状态概念的结构性粘土本构模型研究[J]. 固体力学学报,2004,25(2):191-197.
[10]BUTTERFIELD R. A Natural Compression Law for Soils(An Advance on E-lgp′) [J]. Geotechnique,1979,29(4):469-480.
[11]HONG Z, ONITSUKA K. A Method of Correcting Yield Stress and Compression Index of Ariake Clays for Sample Disturbance [J]. Soils and Foundations,1998,38(2):211-222.
[12]SANTAGATA M,SINFIELD J V,GERMAINE J T.Laboratory Simulation of Field Sampling: Comparison with Ideal Sampling and Field Data[J]. Journal of Geotechnical and Geoenvironmental Engineering,2006,132(3): 351-362.
[13]罗晓辉, 白世伟. 结构性土体强度的统计损伤模型分析[J]. 岩土工程学报, 2004, 26(5): 712-714.
[14]沈珠江. 结构性粘土的弹塑性损伤模型[J]. 岩土工程学报, 1993, 15(3): 21-28.
[15]邓永锋,刘松玉. 扰动对软土强度影响规律研究[J]. 岩石力学与工程学报,2007,26(9):1940-1944.
基金
国家自然科学基金项目(51279049);深圳市科技研发资金资助项目(CXZZ20120829154820942)
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