Citation: | ZHANG Zhen, CHEN Yong, YANG Tianliang, YE Guanbao, ZHENG Wenqiang. An experimental study of the dynamic characteristics of cement soils subjected to staged cyclic loading[J]. Hydrogeology & Engineering Geology, 2021, 48(2): 89-96. doi: 10.16030/j.cnki.issn.1000-3665.202007042 |
With the change in vehicle loading, the load amplitude will also change. However, most of the existing studies focused on the dynamic characteristics of cement soil under the constant dynamic loading, and the dynamic characteristics of cement soil under staged cyclic loading were seldom examined. Using the GDS dynamic triaxial apparatus, a series of dynamic triaxial tests of cement soil are carried out to investigate the influence of static deviator stress and confining stress on the dynamic characteristics of cement soil. The results show that the axial plastic strain of cement soil increases with the increasing confining stress and static deviator stress ratio. The axial strain of cement soil is in the range of 0.1%~0.5%, and its strain development belongs to a stable type. The staged loading and unloading have a great influence on the development process of the plastic strain of the cement soil, but have little influence on the ultimate strains. The empirical model of plastic strain considering loading and unloading conditions, confining stress and static deviator stress ratio is established. The correlation coefficient of staged unloading is greater than 0.95, while that of staged loading is between 0.8 and 0.9. The results show that the first stage load plays a leading role in the strain development, while the maximum dynamic stress ratio cannot dominate the strain development when the first stage load is small. Under the condition of staged loading and unloading, the backbone curve of the cement soil shows two modes: ascending type and descending type, which can be simplified as a multi-segment straight line. Based on the established cumulative plastic strain calculation method, a method to determine the dividing point of the multi segment straight line is proposed, and its feasibility is also verified. The research results lay a foundation for systematic analyses of the dynamic mechanical properties of cement soil under traffic loading.
[1] | 黄春霞, 韩爱民, 隋志龙, 等. 水泥土搅拌桩复合地基承载力的确定[J]. 水文地质工程地质,2009,36(3):99 − 102. [HUANG Chunxia, HAN Aimin, SUI Zhilong, et al. Determination of bearing capacity for composite foundation of cement-soil mixing piles[J]. Hydrogeology & Engineering Geology,2009,36(3):99 − 102. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-3665.2009.03.021 |
[2] | TIKA T, KALLIOGLOU P, KONINIS G, et al. Dynamic properties of cemented soils from Cyprus[J]. Bulletin of Engineering Geology and the Environment,2010,69(2):295 − 307. |
[3] | PANTAZOPOULOS I A, ATMATZIDIS D K. Dynamic properties of microfine cement grouted sands[J]. Soil Dynamics and Earthquake Engineering,2012,42:17 − 31. |
[4] | 张敏霞, 徐平, 简文彬. 动荷载作用下水泥土的疲劳寿命分析[J]. 岩土力学,2010,31(4):1264 − 1268. [ZHANG Minxia, XU Ping, JIAN Wenbin. Analysis of cemented soil fatigue life under dynamic load[J]. Rock and Soil Mechanics,2010,31(4):1264 − 1268. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2010.04.045 |
[5] | MA Q Y, GAO C H. Effect of basalt fiber on the dynamic mechanical properties of cement-soil in SHPB test[J]. Journal of Materials in Civil Engineering,2018,30(8):04018185. |
[6] | 唐朝生, 施斌, 蔡奕, 等. 聚丙烯纤维加固软土的试验研究[J]. 岩土力学,2007,28(9):1796 − 1800. [TANG Chaosheng SHI Bin, CAI Yi, et al. Experimental study on polypropylene fiber improving soft soils[J]. Rock and Soil Mechanics,2007,28(9):1796 − 1800. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2007.09.006 |
[7] | 鹿群, 郭少龙, 王闵闵, 等. 纤维水泥土力学性能的试验研究[J]. 岩土力学,2016,37(增刊 2):421 − 426. [LU Qun, GUO Shaolong, WANG Minmin, et al. Experimental study of mechanical properties of fiber cement soil[J]. Rock and Soil Mechanics,2016,37(Sup 2):421 − 426. (in Chinese with English abstract) |
[8] | 王闵闵, 鹿群, 郭少龙, 等. 循环荷载作用下纤维水泥土动力特性[J]. 岩土力学,2018,39(5):1753 − 1760. [WANG Minmin, LU Qun, GUO Shaolong, et al. Dynamic behavior of soil with fiber and cement under cyclic loading[J]. Rock and Soil Mechanics,2018,39(5):1753 − 1760. (in Chinese with English abstract) |
[9] | 王军, 郑晓, 蔡袁强, 等. 应变控制下水泥土动静力特性试验[J]. 浙江大学学报(工学版),2010,44(10):1857 − 1862. [WANG Jun, ZHENG Xiao, CAI Yuanqiang, et al. Experimental research on static and dynamic characteristics of cement soil under strain control[J]. Journal of Zhejiang University (Engineering Science),2010,44(10):1857 − 1862. (in Chinese with English abstract) doi: 10.3785/j.issn.1008-973X.2010.10.003 |
[10] | 宁宝宽, 陈四利, 刘斌. 环境侵蚀下水泥土力学特性的时间效应分析[J]. 水文地质工程地质,2005,32(2):82 − 86. [NING Baokuan, CHEN Sili, LIU Bin. The timing effects of mechanical properties of cemented soil under environmental erosion[J]. Hydrogeology & Engineering Geology,2005,32(2):82 − 86. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-3665.2005.02.018 |
[11] | 潘昌实, 谢正光. 地铁区间隧道列车振动测试与分析[J]. 土木工程学报,1990,23(2):21 − 28. [PAN Changshi, XIE Zhengguang. Measurement and analysis of vibrations caused by passing trains in subway running tunnel[J]. China Civil Engineering Journal,1990,23(2):21 − 28. (in Chinese with English abstract) |
[12] | 屈畅姿, 王永和, 魏丽敏, 等. 武广高速铁路路基振动现场测试与分析[J]. 岩土力学,2012,33(5):1451 − 1456. [QU Changzi, WANG Yonghe, WEI Limin, et al. In-situ test and analysis of vibration of subgrade for Wuhan-Guangzhou high-speed railway[J]. Rock and Soil Mechanics,2012,33(5):1451 − 1456. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2012.05.027 |
[13] | 温日琨, 王常晶, 陈云敏. 交通荷载引起的静偏应力对饱和软粘土变形影响[J]. 岩土力学,2009,30(增刊 2):119 − 122. [WEN Rikun, WANG Changjing, CHEN Yunmin. Effect of traffic loading induced static deviator stress on deformation of saturated soft clay[J]. Rock and Soil Mechanics,2009,30(Sup 2):119 − 122. (in Chinese with English abstract) |
[14] | 陈善民, 王立忠, 李挺, 等. 水泥土动力特性室内试验及复合地基抗震特性分析[J]. 浙江大学学报(工学版),2000,34(4):398 − 403. [CHEN Shanmin, WANG Lizhong, LI Ting, et al. Experimental determination of dynamic properties of cement-treated soil and earthquake behavior of composite foundation[J]. Journal of Zhejiang University (Engineering Science),2000,34(4):398 − 403. (in Chinese with English abstract) doi: 10.3785/j.issn.1008-973X.2000.04.010 |
[15] | 郑晓, 郭玺. 动荷载作用下水泥土小应变剪切模量试验研究[J]. 路基工程,2008(4):84 − 85. [ZHENG Xiao, GUO Xi. Experimental study on small shear modulus of cement soil under dynamic load[J]. Subgrade Engineering,2008(4):84 − 85. (in Chinese with English abstract) doi: 10.3969/j.issn.1003-8825.2008.04.042 |
[16] | 董城, 冷伍明, 李志勇, 等. 水泥改良高液限黏土动态回弹模量试验研究[J]. 岩土力学,2013,34(1):133 − 138. [DONG Cheng, LENG Wuming, LI Zhiyong, et al. Experimental study of dynamic resilient modulus of cement-improved high liquid limit clay[J]. Rock and Soil Mechanics,2013,34(1):133 − 138. (in Chinese with English abstract) |
[17] | MONISMITH C L, OGAWA N, FREEME C R. Permanent deformation characteristics of subgrade soils due to repeated loading[J]. Transportation Research Record,1975,537:1 − 17. |
Schematic diagram of staged cyclic loading
Relationship between the plastic strain and cyclic times under different confining stresses:(a)staged loading; (b)staged unloading
Relationship between the plastic strain and cyclic loading times under different static deviator stresses:(a)staged loading;(b)staged unloading
Fitting curves of the plastic strains of cement soils under different confining stresses:(a)staged loading; (b)staged unloading
Fitting curves of the plastic strains of cement soils under static deviator stress:(a)staged loading;(b)staged unloading
Backbone curves of the cement soil under different confining stresses:(a)staged loading;(b)staged unloading
Backbone curves of the cement soils under different static deviator stresses:(a)staged loading;(b)staged unloading
Simplified model of the cement soil backbone curve: (a)staged loading;(b)staged unloading