| 分级循环荷载下原状红黏土动力特性试验研究 |
| |
| 引用本文： | 穆锐,黄质宏,姚未来,成鑫磊,雷屹欣,杨成.分级循环荷载下原状红黏土动力特性试验研究[J].水文地质工程地质,2022,49(3):94-102. |
| |
| 作者姓名： | 穆锐 黄质宏 姚未来 成鑫磊 雷屹欣 杨成 |
| |
| 作者单位： | 1.陆军勤务学院军事设施系，重庆 401331 |
| |
| 基金项目： | 国家自然科学基金项目（51368010；51668011）；陆军勤务学院青年科研资助项目（2020）；中建四局科技研发课题(CSCEC4B-2019-KT-47) |
| |
| 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 |
| 收稿时间： | 2021-08-25 |
An experimental study of the dynamic characteristics of the undisturbed laterite under graded cyclic loading |
| |
| Affiliation: | 1.Department of Military Installations, Army Logistics Academy of PLA, Chongqing 401331, China2.Chongqing Key Laboratory of Geomechanics and Geoenvironment Protection, Army Logistics University of PLA, Chongqing 401331, China3.School of Civil Engineering, Guizhou University, Guiyang, Guizhou 550025, China4.Guizhou Construction Science Research and Design Insititute Co. Ltd. of CSCEC, Guiyang, Guizhou 550006, China |
| |
| 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. |
| |
| Keywords: | |
|
| 点击此处可从《水文地质工程地质》浏览原始摘要信息 |
|
点击此处可从《水文地质工程地质》下载全文 |
|
