冲击荷载下花岗岩残积土的滞回曲线特征与损伤定量评价

PDF(3713 KB)

振动与冲击 ›› 2021, Vol. 40 ›› Issue (1) : 58-67.

论文

刘新宇1,2，张先伟1，孔令伟1，张世兴3，徐超4

作者信息 +

Hysteretic curve features and damage quantitative evaluation of granite residual soil under impact load

LIU Xinyu1, 2, ZHANG Xianwei1, KONG Lingwei1, ZHANG Shixing3, XU Chao4

Author information +

文章历史 +

摘要

为评价冲击荷载下花岗岩残积土的损伤发展规律，基于不同振幅(A=100~400kPa)、频率(f=3~15Hz)和围压(σ'3=50~500kPa)下室内循环冲击试验得到滞回曲线的形态特征，提出4个反映试样在冲击荷载下的能量消耗、损伤程度、刚度衰减和塑性应变发展特性的定量结构损伤参数：累积耗散能量EN、累积损伤度dN、刚度退化度δN和残余塑性应变εN。借助各参数的演化规律和相互关系实现了冲击损伤的定量评价，并提出试样的损伤与破坏机理。结果表明，高振幅(A=400kPa)、低频及超高频(f=3或15Hz)的冲击荷载作用下EN增长迅速，试样的dN较大。相同频率和围压下高振幅试样的dN为低振幅试样(A=200kPa)的9.5倍，同等条件下高频和超高频试样的dN也比中等频率(f=10Hz)试样的dN高出24%。更高的损伤度引起试样刚度衰减更加严重，发生破坏试样的δN普遍超过0.65。这进一步导致试样εN快速发展，最终产生破坏。高围压(σ'3=500kPa)下试样能量耗散慢，dN较小，δN仅为低围压(σ'3=50kPa)的13%，因此抵抗冲击变形的能力也增强。根据试验结果指出，冲击荷载下试样的变形与破坏实质上是冲击能量耗散引起的土体结构损伤，从而导致的刚度衰减进而产生宏观塑形变形累积的综合体现。工程中应尽可能避免采用高振幅与低频率及超高频率荷载冲击土体，必要时可通过挤密加固土体有效防范冲击荷载的危害。研究有助于深化冲击破坏机理的理解，为我国花岗岩残积土地层的施工与设计提供技术指导。

Abstract

In order to evaluate damage development law of granite residual soil under impact load, laboratory cyclic impact tests based on different amplitudes, frequencies and confining pressures were conducted to obtain morphological features of hysteretic curves. 4 quantitative structure damage parameters including accumulative dissipated energy EN, cumulative damage degree dN, stiffness degradation degree δN and residual plastic strain εN were proposed to reflect specimens’ energy dissipation, damage degree, stiffness degradation and development characteristics of plastic strain under impact load. The quantitative evaluation of impact damage was realized by means of evolution laws and relations of parameters, and damage and failure mechanisms of specimens were proposed. The results showed that EN increases rapidly under impact load with high amplitude (A=400 kPa), low frequency or ultra-high one (f=3 or 15 Hz), specimens’ dN is larger; under the same frequency and confining pressure, dN of high amplitude specimen is 9.5 times of that of low amplitude one (A=200 kPa), and dN of high frequency and ultra-high frequency specimen is 24% higher than that of medium frequency one (f=10 Hz); the higher the damage degree, the more serious the specimen stiffness attenuation; δN of failure specimen is generally more than 0.65, this further leads to the rapid development of specimen εN, and finally leads to failure; under high confining pressure (σ′3=500 kPa), energy dissipation is slow and dN is smaller, δN is only 13% of that of low confining pressure (σ′3=50 kPa), so the ability to resist impact deformation is also enhanced. According to test results, it was pointed out that deformation and failure of specimen under impact load is essentially damage of soil structure caused by dissipation of impact energy, the caused stiffness attenuation generates the comprehensive embodiment of macro plastic deformation accumulation; high amplitude, low frequency and ultra-high frequency impact load should be avoided as far as possible in the project; if necessary, compaction and reinforcement of soil can be used to effectively prevent damage of impact load; the study is helpful to deepen the understanding of impact failure mechanism and provide a technical guidance for the construction and design of granite residual soil layer in China.

导出引用

刘新宇1,2，张先伟1，孔令伟1，张世兴3，徐超4. 冲击荷载下花岗岩残积土的滞回曲线特征与损伤定量评价[J]. 振动与冲击, 2021, 40(1): 58-67

LIU Xinyu1, 2, ZHANG Xianwei1, KONG Lingwei1, ZHANG Shixing3, XU Chao4. Hysteretic curve features and damage quantitative evaluation of granite residual soil under impact load[J]. Journal of Vibration and Shock, 2021, 40(1): 58-67

参考文献

[1] ZHANG X W, KONG L W, LI J J. Influence of dry and wet seasons on disintegration characteristics of basalt residual soil from the Leizhou Peninsula, China[J]. Quarterly Journal of Engineering Geology and Hydrogeology, 2018, 51(4): 450-460.
[2] 周小文, 刘攀, 胡黎明, 等. 结构性花岗岩残积土的剪切屈服特性试验研究[J]. 岩土力学, 2015, 36(S2): 157-163.
Zhou Xiaowen, Liu Pan, Hu Liming, et al. An experimental study of shear yield characteristics of structured granite residual soil[J]. Rock and Soil Mechanics, 2015, 36(Supp.2): 157－163.
[3] 尹松, 孔令伟, 杨爱武, 等. 循环振动作用下残积土动力变形特性试验研究[J]. 振动与冲击, 2017, 36(11): 224-231
Yin Song, Kong Lingwei, Yang Aiwu, et al. Tests for dynamic deformation characteristics of residual soil under cyclic loading[J]. Journal of Vibration and Shock，2017，36(11) : 224-231．
[4] 张先伟, 刘新宇, 孔令伟, 等. 爆破冲击荷载下花岗岩残积土的力学响应试验研究[J]. 中国科学(技术科学), 2019, 49, 1-13, DOI: 10.1360/N092018-00319.
Zhang Xianwei, Liu XinYu, Kong Lingwei, et al. Experimental study on mechanical characteristics of granite residual soil under blast loading[J]. SCIENTIA SINICA Technologica, 2019, 49: 1-13, DOI: 10.1360/ N092018-00319.
[5] 吕晓聪, 许金余, 赵德辉,等. 冲击荷载循环作用下砂岩动态力学性能的围压效应研究[J]. 工程力学, 2011, 28(1): 138-144.
LU Xiao-cong, XU Jin-yu, ZHAO De-hui, et al. Research on confining pressure effect of sandstone dynamic mechanical performance under the cyclical impact loadings[J]. Engineering Mechanics, 2011, 28(1): 138-144.
[6] XUE X H, REN T H, ZHANG W H. Analysis of fatigue damage character of soils under impact load[J]. Journal of Vibration and Control, 2013, 19(11): 1728–1737.
[7] ZHANG DAN, ZHU Z W, LIU Z J, et al. Dynamic mechanical behavior and numerical simulation of frozen soil under impact loading[J]. Shock and Vibration, 2016, 2016(6): 1–16.
[8] 胡华, 蔡亮, 梁健业, 等. 花岗岩残积土冲击损伤与损伤演化特性试验研究[J]. 岩土力学, 2015, 36(S1): 25-30.
Hu Hua, Cai Liang, Liang Jianye, et al. Experimental research on impact damage and damage evolution characteristics of granite saprolite[J]. Rock and soil mechanics, 2015, 36(S1): 25–30.
[9] 席道瑛, 刘小燕, 张程远. 由宏观滞回曲线分析岩石的微细观损伤[J]. 岩石力学与工程学报, 2003, 22(2): 182-187.
Xi Daoying, Liu Xiaoyan, Zhang Chengyuan. Analysis on micro and meso-damage of rock by macro-hysteresis curve[J]. Chinese Journal of Rock Mechanics and Engineering, 2003, 22(2): 182－187.
[10] 张媛, 许江, 杨红伟, 等. 循环荷载作用下围压对砂岩滞回环演化规律的影响[J]. 岩石力学与工程学报, 2011, 30(2): 320－326.
Zhang Yuan, Xu Jiang, Yang Hongwei, et al. Effect of confining pressure on evolution law of hysteresis loop of sandstone under cyclic loading[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(2): 320－
326.
[11] BRENNAN B J, STACEY F D. Frequency dependence of elasticity of rock—Test of seismic velocity dispersion[J]. Nature, 1977, 268: 220－222.
[12] Thilakasiri H S, Gunaratne M, Mullins G, et al. Investigation of impact stress induced in laboratory dynamic compaction of soft soil[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1996, 20(10): 753－767.
[13] 廖红建, 肖正华, 刘健. 动载下饱和重塑黄土的骨干曲线变化研究[J]. 岩土力学, 2011, 32(2): 375-379.
Liao Hongjian, Xiao Zhenghua, Liu Jian. Study of variation of backbone curve of saturated remolded loess under dynamic loading[J]. Rock and Soil Mechanics, 2011, 32(2): 375–379.
[14] ASTM Standard D2487. Standard practice for classification of soils for engineering purposes (Unified soil classification system) [S]. ASTM International, West Conshohocken, PA, 2006.
[15] ASTM Standard D2487. Standard Test Method for Load Controlled Cyclic Triaxial Strength of Soil[S]. ASTM International, West Conshohocken, PA, 2013.
[16] MAYNE P W, JONES J S Jr. Impact stresses during dynamic compaction[J]. Journal of Geotechnical Engineering, 1983, 109(10): 1342－1346.
[17] HENKEL D J, GILBERT G D. The effect of the rubber membrane on the measured triaxial compression strength of clay samples[J]. Géotechnique, 1952, 3(1): 20－29.
[18] 林伟弟, 李彰明, 罗智斌. 三轴冲击荷载作用下淤泥力学响应研究[J]. 岩土力学, 2015, 36(7): 1966–1972. LING Wei-di, LI Zhang-ming, LUO Zhi-bin. Mechanical responses of muck under triaxial impact loading[J]. Rock and Soil Mechanics, 2015, 36(7): 1966–1972.
[19] 周颖，龚顺明，吕西林. 黏弹性阻尼器滞回曲线及特征参数的相似准则[J]. 中南大学学报(自然科学版), 2014, 45(12): 4317-4324.
Zhou Ying, Gong Shunming, Lu Xilin. Similarity of hysteretic loops and characteristic parameters of viscoelastic dampers[J]. Journal of Central South University (Science and Technology), 2014, 45(12): 4317-4324.
[20] 肖杰灵, 刘浩, 刘淦中, 等. 高速铁路有砟道床纵向阻力滞回曲线特征及规律研究[J]. 铁道学报, 2018, 40(2): 91-99.
Xiao Jieling, Liu Hao, Liu Ganzhong, et al. Study on Characteristics and Law of Longitudinal Resistance Hysteretic Curves of Ballast Bed of High-speed Railway[J] Journal of The China Railway Society, 2018, 40(2):91-99.
[21] 张向东, 李军, 孙琦, 等. 基于弹性模量退化的冻土动力损伤特性研究[J]. 岩土力学, 2018, 39(11): 4149-4159+4241.
Zhang Xiangdong, Li Jun, Sun Qi, et al. Study on dynamic damage mechanism of frozen soil based on elastic modulus degradation[J]. Rock and Soil Mechanics, 2018, 39(11) :4149-4159+4241.