Strain Accumulation Characteristics and Empirical Model of Saturated Soft Clay

SUN Lei

doi:10.11988/ckyyb.20210299

PDF(2826 KB)

Journal of Changjiang River Scientific Research Institute ›› 2022, Vol. 39 ›› Issue (8) : 77-85. DOI: 10.11988/ckyyb.20210299

ROCK-SOIL ENGINEERING

Strain Accumulation Characteristics and Empirical Model of Saturated Soft Clay

SUN Lei

Author information +

History +

Abstract

Partially drained CCP (constant confining pressure) and VCP (variable confining pressure) cyclic triaxial tests were carried out on Wenzhou soft clay by using GDS (Global Digital Systems) to investigate the permanent deformation behavior of saturated soft clay in subgrade under long-term traffic load more realistically.Special attention was paid to the influences of cyclic stress ratio (CSR),stress path (α) and length (L) on the permanent axial strain of saturated soft clay.The test results unveiled that at a give cycle number (N),the permanent axial strain increased with the increase of CSR and the decrease of α,which can be described by exponential function and logarithmic function respectively.The normalized permanent axial strain undergone 10,000 cycles (ε^p_{a,10 000}/ε^p,CCP_{a,10 000}) was in a logarithmic relationship with the normalized stress path length (L/L_CCP),and a linear relationship with the normalized mean principal stress amplitude (p^ampl/p^ampl_CCP),regardless of the CSR values.Furthermore,a logarithmic empirical model considering the combined effect of CSR,α,and N was established to predict the permanent axial strain under different stress paths,and the predicted results were in good agreement with the measured deformation.

Key words

saturated soft clay / strain accumulation characteristic / GDS dynamic triaxial test with variable confining pressure / partially drained stress path / permanent axial strain / empirical model

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

SUN Lei. Strain Accumulation Characteristics and Empirical Model of Saturated Soft Clay[J]. Journal of Changjiang River Scientific Research Institute. 2022, 39(8): 77-85 https://doi.org/10.11988/ckyyb.20210299

References

[1] 郑华,杜运国,杨洋.交通荷载路径下超固结软黏土变形特性研究[J].长江科学院院报,2018,35(10):126-130.
[2] LI D Q,SELIG E T.Accumulative Plastic Deformation for Fine-grained Subgrade Soils[J].Journal of Geotechnical Engineering,ASCE,1996,122(12):1006-1013.
[3] CHAI J C,MIURA N.Traffic-load-induced Permanent Deformation of Road on Soft Subsoil[J].Journal of Geotechnical and Geoenvironmental Engineering,2002,128(11):907-916.
[4] 李金秋,王秀艳,刘长礼,等.交通荷载作用下焦作地区饱和粉质黏土变形特性及影响因素分析[J].长江科学院院报,2019,36(7):70-76.
[5] 张勇,孔令伟,郭爱国,等.循环荷载下饱和软黏土的累积塑性应变试验研究[J].岩土力学,2009,30(6):1542-1548.
[6] GUO L,WANG J,CAI Y,et al.Undrained Deformation Behavior of Saturated Soft Clay under Long-term Cyclic Loading[J].Soil Dynamics and Earthquake Engineering,2013,50:28-37.
[7] 臧濛,孔令伟,曹勇.描述循环荷载作用下黏土累积变形的改进模型[J].岩土力学,2017,38(2):435-442.
[8] REN X W,XU Q,TENG J,et al.A Novel Model for the Cumulative Plastic Strain of Soft Marine Clay under Long-term Low Cyclic Loads[J].Ocean Engineering,2018,149:194-204.
[9] SAKAI A,SAMANG L,MIURA N.Partially-drained Cyclic Behavior and Its Application to the Settlement of a Low Embankment Road on Silty Clay[J].Soils and Foundations,2003,43(1):33-46.
[10] 丁智,张涛,魏新江,等.排水条件对不同固结度软黏土动力特性影响试验研究[J].岩土工程学报,2015(5):893-899.
[11] MAMOU A,POWRIE W,PRIEST J A,et al.The Effects of Drainage on the Behaviour of Railway Track Foundation Materials During Cyclic Loading[J].Géotechnique,2017,67(10):1-10.
[12] BROWN S F.Soil Mechanicsin Pavement Engineering[J].Geotechnique,1996,46(3):383-426.
[13] LEKARP F,ISACSSON U,DAWSON A.State of the Art I:Resilient Response of Unbound Aggregates[J].Journal of Transportation Engineering,2000,126(1):66-75.
[14] CAI Y Q,GU C,WANG J,et al.One-way Cyclic Triaxial Behavior of Saturated Clay:Comparison Between Constant and Variable Confining Pressure[J].Journal of Geotechnical and Geoenvironmental Engineering,2013,139(5):797-809.
[15] 刘家顺,王来贵,张向东,等.部分排水时饱和粉质黏土变围压循环三轴试验研究[J].岩土力学,2019,40(4):1413-1419,1432.
[16] 孙磊,王军,谷川,等.循环偏应力和循环围压耦合效应对饱和软黏土变形特性的影响[J].岩土工程学报,2015,37(12):2198-2204.
[17] GU C,WANG J,CAI Y,et al.Deformation Characteristics of Overconsolidated Clay Sheared under Constant and Variable Confining Pressure[J].Soils and Foundations,2016,56(3):427-439.
[18] RONDÓN H A,WICHTMANN T,TRIANTAFYLLIDIS T,et al.Comparison of Cyclic Triaxial Behavior of Unbound Granular Material under Constant and Variable Confining Pressure[J].Journal of Transportation Engineering,2009,135(7):467-478.
[19] 莫海鸿,单毅,李慧子,等.基于能量法的尾粉土累积应变增长方式研究[J].岩土工程学报,2017,39(11):17-24.
[20] BIAN X,JIANG J,JIN W,et al.Cyclic and Postcyclic Triaxial Testing of Ballast and Subballast[J].Journal of Materials in Civil Engineering,2016,28(7):04016032.
[21] WICHTMANN T,NIEMUNIS A,TRIANTAFYLLIDIS T.Strain Accumulationin Sand Due to Cyclic Loading:Drained Triaxial Tests[J].Soil Dynamics & Earthquake Engineering,2005,25(12):967-979.