An experimental study of the dynamic characteristics of the undisturbed laterite under graded cyclic loading
-
摘要: 为研究循环荷载下原状红黏土路基的动力特性，采用SDT-20型动三轴仪对原状红黏土进行了分级循环动三轴试验，研究了围压、频率及动应力幅值对原状红黏土的动应力、动弹性模量-动应变（ Ed-εd）和动剪切模量-动剪切应变（ Gd-γd）关系曲线的影响规律。结果表明：原状红黏土的动应力-动应变关系曲线发展规律可采用Kondner模型进行描述；动应力随动应变先急剧增大后趋于平稳，并给出了急剧增加时动应变的取值范围，即0%～0.05%；分析了不同围压、振动频率下红黏土的动弹性模量及动剪切模量的变化规律，当动应变小于临界值时，红黏土动弹性模量随动应变的增大而增大；当动应变大于临界值时，红黏土材料动弹性模量随动应变的增大而减小，动剪切模量具有相同变化规律；结合红黏土的动力特性变化规律，利用围压对动弹性模量进行折减，在Darendeli模型的基础上建立了红黏土路基动弹性模量、动剪切模量的分段预测模型，经拟合验证，本文分段模型的适用性较好，可预测分级循环荷载下红黏土的动弹性模量-动应变（Ed-εd）和动剪切模量-动剪切应变（Gd-γd）关系曲线发展趋势。
-
关键词:
- 原状红黏土 /
- 分级循环荷载 /
- 动三轴试验 /
- Darendeli模型 /
- 动力特性
Abstract: In order to study the dynamic characteristics of the undisturbed lateritic soil subgrade under cyclic loading, the dynamic triaxial tests of undisturbed laterite are carried out with the SDT-20 dynamic triaxial apparatus. The effects of confining pressure, frequency and dynamic stress amplitude on dynamic stress, elastic modulus-strain（Ed-εd ） and shear modulus-shear strain（Gd-γd） on dynamic behavior are studied. The results show that the development law of the dynamic stress-strain curve of the undisturbed laterite can be described by the Kondner model. The dynamic stress increases rapidly with the dynamic strain and then tends to be stable, and the range of the dynamic strain value is given, that is, 0～0.05%. The elastic modulus-strain and shear modulus-shear strain on dynamic behavior of laterite under different confining pressure and vibration frequency are analyzed. When the dynamic strain is less than the critical value, the dynamic elastic modulus of laterite increases with the increase of dynamic strain. When the dynamic strain is greater than the critical value, the dynamic elastic modulus of laterite decreases with the increase of dynamic strain, and the dynamic shear modulus has the same change rule. Combined with the dynamic characteristics of the laterite material, the dynamic elastic modulus is reduced by the confining pressure, which is established on the basis of the Darendeli model. The segmented prediction model of the dynamic elastic modulus and dynamic shear modulus of laterite subgrade material is proposed in the paper. The applicability of the segmented model is verified by the fitting method, which can predict the development trend of Ed-εd and Gd-γd curves of laterite under the graded cyclic loading. -
-
![]()
图 3 分级循环荷载下原状红黏土的波形及滞回曲线
Figure 3. Waveform and hysteretic curve of the undisturbed laterite under the graded cyclic loading
![]()
图 4 不同加载频率下原状红黏土的σd-εd关系曲线
Figure 4. Dynamic stress-strain curves of the undisturbed laterite under different loading frequencies
![]()
图 5 不同围压下原状红黏土动弹性模量变化曲线
Figure 5. Dynamic elastic modulus-stain curves of the undisturbed laterite under different confining pressures
![]()
图 6 不同围压下原状红黏土动剪切模量变化曲线
Figure 6. Dynamic shear modulus curves of the undisturbed laterite under different confining pressures
![]()
图 7 动弹性模量和动应变归一化关系曲线
Figure 7. Normalized relationship curves between the dynamic elastic modulus and dynamic strain
![]()
![]()
图 10 围压与比例系数的关系
Figure 10. Relationship between the confining pressure and proportional coefficient
表 1 贵阳红黏土物理性质指标
Table 1 Physical property indexes of the Guiyang laterite
天然密度
ρ/（g·cm−3）天然含水率
w/%液限
wL/%塑限
wP/%液性指数
IL塑性指数
IP1.4 34.9 59.2 23.9 0.3 35.3 
下载: 导出CSV
表 2 试验方案
Table 2 Test scheme
组别 围压σ3/kPa 固结比Kc 振动频率f/Hz 含水率w/% 动应力幅值σdmax/kPa 1 100 1.0 1.0,
2.0,
3.034.9 96 2 150 144 3 200 192 4 250 240
下载: 导出CSV
-
[1] 尤志国, 杨志年. 土力学与基础工程[M]. 北京: 清华大学出版社, 2019. YOU Zhiguo, YANG Zhinian. Soil mechanics and foundation engineering [M]. Beijing: Tsinghua University Press, 2019. (in Chinese)
[2] 工程地质手册编委会. 工程地质手册[M]. 5版. 北京: 中国建筑工业出版社, 2018. Editorial Committee of Engineering Geology Manual. Engineering Geology Handbook [M]. 5th ed. Beijing: China Construction Industry Press, 2007. (in Chinese)
[3] 陈正汉, 郭楠. 非饱和土与特殊土力学及工程应用研究的新进展[J]. 岩土力学,2019,40(1):1 − 54. [CHEN Zhenghan, GUO Nan. New developments of mechanics and application for unsaturated soils and special soils[J]. Rock and Soil Mechanics,2019,40(1):1 − 54. (in Chinese with English abstract) [4] 龙万学, 陈开圣, 肖涛, 等. 非饱和红黏土三轴试验研究[J]. 岩土力学,2009,30(增刊 2):28 − 33. [LONG Wanxue, CHEN Kaisheng, XIAO Tao, et al. Research of general triaxial test for unsaturated red clay[J]. Rock and Soil Mechanics,2009,30(Sup 2):28 − 33. (in Chinese with English abstract) [5] 李志勇, 董城, 邹静蓉, 等. 湘南地区红黏土动态回弹模量试验与预估模型研究[J]. 岩土力学,2015,36(7):1840 − 1846. [LI Zhiyong, DONG Cheng, ZOU Jingrong, et al. Research on experiment and prediction model of dynamic resilient modulus of laterite soil in Southern Hunan[J]. Rock and Soil Mechanics,2015,36(7):1840 − 1846. (in Chinese with English abstract) [6] 刘晓红, 杨果林, 方薇. 红粘土动本构关系与动模量衰减模型[J]. 水文地质工程地质,2011,38(3):66 − 72. [LIU Xiaohong, YANG Guolin, FANG Wei. Dynamic constitutive relation and dynamic modulus attenuation model of red clay[J]. Hydrogeology & Engineering Geology,2011,38(3):66 − 72. (in Chinese with English abstract) DOI: 10.3969/j.issn.1000-3665.2011.03.012 [7] 吴建奇, 杨骁, 徐旭, 等. 部分排水条件下饱和红黏土循环试验研究[J]. 浙江大学学报(工学版),2017,51(7):1309 − 1316. [WU Jianqi, YANG Xiao, XU Xu, et al. Cyclic triaxial tests on saturated red clay under partially drained condition[J]. Journal of Zhejiang University (Engineering Science),2017,51(7):1309 − 1316. (in Chinese with English abstract) DOI: 10.3785/j.issn.1008-973X.2017.07.006 [8] 刘晓红, 方薇, 杨果林. 循环荷载下原状结构红粘土累积塑性应变模型[J]. 水文地质工程地质,2013,40(2):56 − 62. [LIU Xiaohong, FANG Wei, YANG Guolin. Accumulated plastic strain models of red clay in original structure under cyclic loading[J]. Hydrogeology & Engineering Geology,2013,40(2):56 − 62. (in Chinese with English abstract) [9] 罗文俊, 王海洋, 马斌, 等. 单向循环荷载作用下饱和重塑红黏土的动力特性[J]. 土木与环境工程学报(中英文),2020,42(2):1 − 9. [LUO Wenjun, WANG Haiyang, MA Bin, et al. Dynamic characteristics of saturated remodeling red clay under uniaxial cyclic loading[J]. Journal of Civil and Environmental Engineering,2020,42(2):1 − 9. (in Chinese with English abstract) [10] 杨果岳, 程雨竹, 徐运龙, 等. 交通荷载作用下安宁地区超固结重塑红黏土的动力特性试验研究[J]. 实验力学,2019,34(4):675 − 683. [YANG Guoyue, CHENG Yuzhu, XU Yunlong, et al. Experimental study on dynamic characteristics of over-consolidated remolded red clay subjected to traffic load in Anning area[J]. Journal of Experimental Mechanics,2019,34(4):675 − 683. (in Chinese with English abstract) DOI: 10.7520/1001-4888-18-020 [11] 刘晓红. 高速铁路无砟轨道红黏土路基动力稳定性研究[D]. 长沙: 中南大学, 2011. LIU Xiaohong. Research on dynamic stability of red clay subgrade under ballastless track of high-speed railway[D]. Changsha: Central South University, 2011. (in Chinese with English abstract)
[12] 穆锐. 贵阳地区红黏土动力特性及其动本构关系研究[D]. 贵阳: 贵州大学, 2019 MU Rui. Study on dynamic constitutive relationship and dynamic characteristics of red clay in Guiyang area[D]. Guiyang: Guizhou University, 2019. (in Chinese with English abstract)
[13] 穆坤, 郭爱国, 柏巍, 等. 循环荷载作用下广西红黏土动力特性试验研究[J]. 地震工程学报,2015,37(2):487 − 493. [MU Kun, GUO Aiguo, BAI Wei, et al. Experimental study on dynamic properties of red clay in Guangxi under cyclic loading[J]. China Earthquake Engineering Journal,2015,37(2):487 − 493. (in Chinese with English abstract) DOI: 10.3969/j.issn.1000-0844.2015.02.0487 [14] 崔宏环, 王文涛, 何静云, 等. 循环荷载作用下正融粉质黏土强度特征与滞回环演化规律[J]. 水文地质工程地质,2020,47(4):174 − 182. [CUI Honghuan, WANG Wentao, HE Jingyun, et al. Strength characteristics of the melting silty clay under cyclic loading and the evolution law of hysteresis loop[J]. Hydrogeology & Engineering Geology,2020,47(4):174 − 182. (in Chinese with English abstract) [15] 谢琦峰, 刘干斌, 范思婷, 等. 循环荷载下饱和重塑黏质粉土的动力特性研究[J]. 水文地质工程地质,2017,44(1):78 − 83. [XIE Qifeng, LIU Ganbin, FAN Siting, et al. A study of dynamic characteristics of the saturated remolded clayey silt under circle load[J]. Hydrogeology & Engineering Geology,2017,44(1):78 − 83. (in Chinese with English abstract) [16] 中华人民共和国住房和城乡建设部. 土工试验方法标准: GB/T 50123—2019[S]. 北京: 中国计划出版社, 2019. Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Standard for soil test methods: GB/T 50123—2019[S]. Beijing: China Planning Press, 2019. (in Chinese)
[17] WICHTMANN T, NIEMUNIS A, TRIANTAFYLLIDIS T. Strain accumulation in sand due to cyclic loading: Drained cyclic tests with triaxial extension[J]. Soil Dynamics and Earthquake Engineering,2007,27(1):42 − 48. DOI: 10.1016/j.soildyn.2006.04.001
[18] GU C, WANG J, CAI Y Q, et al. Undrained cyclic triaxial behavior of saturated clays under variable confining pressure[J]. Soil Dynamics and Earthquake Engineering,2012,40:118 − 128.
[19] 刘学毅, 王平. 车辆—轨道—路基系统动力学[M]. 成都: 西南交通大学出版社, 2010 LIU Xueyi, WANG Ping. Dynamics of vehicle track subgrade system [M]. Chengdu: Southwest Jiaotong University Press, 2010. (in Chinese)
[20] 张向东, 刘家顺, 王洪伟. 动荷载作用下高速铁路风积土地基动力特性试验研究[J]. 实验力学,2014,29(1):66 − 72. [ZHANG Xiangdong, LIU Jiashun, WANG Hongwei. Experimental study of dynamic characteristics of aeolian soil subgrade subjected to high-speed train dynamic loading[J]. Journal of Experimental Mechanics,2014,29(1):66 − 72. (in Chinese with English abstract) DOI: 10.7520/1001-4888-13-018 [21] SEED H B, LEE K L. Liquefaction of saturated sands during cyclic loading[J]. Journal of the Soil Mechanics and Foundations Division,1966,92(6):105 − 134. DOI: 10.1061/JSFEAQ.0000913
[22] KONDNER R L. Hyperbolic stress-strain response: cohesive soils[J]. Journal of the Soil Mechanics and Foundations Division,1963,89(1):115 − 143. DOI: 10.1061/JSFEAQ.0000479
[23] 张明, 廖蔚茗, 王志佳, 等. 黏性土的动剪切模量比和阻尼比与剪应变关系的统计分析[J]. 地震工程与工程振动,2013,33(4):256 − 262. [ZHANG Ming, LIAO Weiming, WANG Zhijia, et al. Statistical analysis of the relationship of shear modulus ratio and damping ratio to shear strain for cohesive soil[J]. Journal of Earthquake Engineering and Engineering Vibration,2013,33(4):256 − 262. (in Chinese with English abstract) [24] DARENDELI M B. Development of new family of normalized modulus reduction and material damping curves[EB/OL]. 2001.
[25] 庄心善, 赵汉文, 王俊翔, 等. 合肥膨胀土动弹性模量与阻尼比试验研究[J]. 浙江大学学报(工学版),2020,54(4):759 − 766. [ZHUANG Xinshan, ZHAO Hanwen, WANG Junxiang, et al. Experimental study of dynamic elastic modulus and damping ratio of expansive soil in Hefei[J]. Journal of Zhejiang University (Engineering Science),2020,54(4):759 − 766. (in Chinese with English abstract) [26] 张希栋, 骆亚生. 双向动荷载下黄土的动剪切模量特性研究[J]. 岩土力学,2015,36(9):2591 − 2598. [ZHANG Xidong, LUO Yasheng. Study of dynamic shear modulus of loess under bidirectional dynamic loads[J]. Rock and Soil Mechanics,2015,36(9):2591 − 2598. (in Chinese with English abstract)
计量
- 文章访问数: 522
- HTML全文浏览量: 286
- PDF下载量: 179
邮件订阅
RSS