摘要
地下工程中,岩体有蠕变特性和应力松弛特性,但在很多工程实践中,岩体变形既不是纯蠕变,也不是纯应力松弛,而是随着时间的增加,应力和应变同时发生变化,表现出时间依存性变形,导致岩体最终发生破坏,这种现象用一般的蠕变和应力松弛特性很难解释清楚,是岩石力学研究工作者所面临的一个难题。为确保地下工程及其构筑物在长期运营过程中的安全与稳定,需要通过广义流变理论对岩体流变力学特性进一步深入研究。在线性黏弹性理论中,蠕变柔量和松弛模量分别由蠕变试验和松弛试验获得,两者呈线性流变特征,数值上互为倒数关系,且可相互转化,没有本质区别。但在非线性黏弹性理论中,蠕变柔量和松弛模量两者关系还不明确,由应力归还控制实现的广义流变为研究两者关系提供了可能。利用应力归还控制的伺服试验系统执行启动点为50%和80%田下凝灰岩的广义流变试验,使用同样的加载方式执行启动点为50%、65%和80%三城目安山岩广义流变试验,两种岩石的广义流变方向系数均为3.0、±∞、–3.0、–1.0、–0.3、0、0.3。结果显示:两种岩石的广义流变演化规律具有相似性,且应力和应变随时间变化的规律符合对数法则。本文在线弹性蠕变柔量和松弛模量的基础上,定义了广义关联应变和广义关联应力,并提出广义流变柔量和模量的计算方法。对两种岩石的广义流变试验结果进行计算。由计算结果可以看出,该计算方法具有广义性;蠕变柔量和松弛模量是广义流变属性的两种特殊形式。两种岩石广义流变柔量和模量都与黏弹性变形相关,具有明显的时间依存性、方向系数依存性和非线性流变特征;广义流变柔量和模量的比值随着时间的增加逐渐减小,表明破坏前岩石刚性逐渐降低,变形逐渐增大。因此,本文构建的计算方法可进一步分析岩石破坏前和破�
Creep deformation and stress relaxation are two properties of rock mass in underground engineering,but in many construction practices,rock mass is neither pure creep deformation nor pure stress relaxation,with stress and strain of rock masses simultaneously changed with time,which is time-dependent,and may ultimately cause failure.It’s hard to explain the phenomenon simply by creep deformation and stress relaxation,so it is a challenge for rock mechanics researchers.To ensure the long-term stability of underground engineering and its structures,it is necessary to further study the properties of rock mass in the generalized theory of rheological mechanics.In the linear viscoelastic theory,the creep compliance was obtained by creep deformation test while the relaxation modulus by stress relaxation test,and the two values were showing linear rheological features,in a reciprocal relationship with each other,and could be converted in each other under certain conditions,so they were no essential difference.But in non-linear viscoelastic theory,their relationship was not clear,and the generalized rheological theory by the stress-feedback controlling method provided the possibility to study mutual relationship.The generalized rheological tests of Tage tuff at 50%,85%of the peak stress level,Sanjome andesite at 50%,65%and 80%of the peak stress level were carried out by using the stress-feedback testing method,the generalized rheological direction coefficient for two rocks were 3.0,±∞,-3.0,-1.0,-0.3,0,0.3,respectively.The experimental results showed that the generalized rheological law for two rocks was similar,and the variation of stress and strain obeyed the logarithms law.Based on the defin-itions of creep compliance and relaxation modulus in the linear viscoelastic theory,the generalized related strain and stress were defined,the cal-culating method for generalized rheological-compliance(GRC)and generalized rheological-modulus(GRM)was proposed.According to the test-ing results analyses,the proposed method was gene
作者
张海龙
汤杨
任汀
大久保诚介
ZHANG Hailong;TANG Yang;REN Ting;OKUBO Seisuke(School of Civil Eng.,Chongqing Univ.of Arts and Sci.,Chongqing 402160,China;China Construction Seventh Eng.Division Co.Ltd.,Zhengzhou 450004,China;School of Civil Eng.,Chongqing Three Gorges Univ.,Chongqing 404000,China)
出处
《工程科学与技术》
EI
CSCD
北大核心
2021年第5期62-69,共8页
Advanced Engineering Sciences
基金
重庆市基础与前沿研究一般项目(cstc2018jcyjAX0634,cstc2019jcyj–msxmX0488)
重庆市教委科学技术研究计划项目(KJQN201801307,KJQN201901338)。
关键词
广义流变柔量
广义流变模量
非线性黏弹性
刚性
塑性变形
generalized rheological-compliance
generalized rheological-modulus
nonlinear-viscoelasticity
rigidity
plastic deformation
