滞弹性衰减特征及其损伤的累积效应  

Attenuation characteristics of anelasticity and cumulative effect of damage

作　　者：席道瑛[1] 席军[2] 宛新林 XI DaoYing;XI Jun;WAN XinLin(Mengcheng Geophysical National Field Station,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;School of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China;College of Civil Engineering,Anhui Jianzhu Universty,Hefei 230022,China)

机构地区：[1]中国科学技术大学蒙城地球物理国家野外观测站地球和空间科学学院,合肥230026 [2]北京石油化工学院机械工程学院,北京102617 [3]安徽建筑大学土木工程学院,合肥230022

出　　处：《地球物理学报》2023年第5期2019-2038,共20页Chinese Journal of Geophysics

摘　　要：在地铁、高速铁路等基础设施的快速发展下,长期滞弹性微损伤累积效应应引起人们的关注,尤其是对动载和高频效应的关注.本文在频率0.01~1000 Hz、温度-50~200℃内研究了弹性范围内的饱和砂岩、大理岩,在强迫共振、单轴循环加载下的温度和频率的滞弹性行为的弛豫衰减峰.结果显示,弹性模量和波速随温度的升高而下降,且下降梯度比一般岩石的力学实验结果要陡;随着频率提高,弹性模量和波速显著增大,频散效应会加强.该结果反映了在应力诱导下岩石内部微缺陷等微损伤之间的运动和相互作用的微观过程,该过程会导致微结构变化,进而引起微观的位移,产生微损伤;微损伤经历一段时间或很长时间的积累过程,就可能造成疲劳损伤断裂.岩石内部微观结构的非均匀性和矿物晶粒间界等缺陷是最薄弱的部位,在循环应力作用下再次形成新的微裂纹系统,从而加速损伤的积累,引起断裂.除此之外,岩石中多种渠道的残余应力会导致疲劳损伤;振动频率的提高,也会加速岩石的损伤;结合温度升高的综合效应会引起岩石内部微裂纹增长,导致岩石微结构变化并引起微损伤,虽然这是在屈服点以下引发的滞弹性微损伤,但最终它们都将使岩石的品质劣化.With the rapid development of infrastructure such as subway and high-speed railway,people should pay attention to long-term elastic fatigue load,especially dynamic load and high-frequency effect.In this paper,the relaxation attenuation peaks of temperature and frequency anelastic behavior of saturated sandstone and marble under forced resonance anduniaxial cyclic loading in the elastic range are studied at frequencies ranging from 0.01 to 1000 Hz and temperatures ranging from -50 to 200℃.The results show that the elastic modulus and wave velocity decrease with the increase of temperature,and the decreasing gradient is steeper than that of general rock mechanics experiments.With the increase of frequency,the elastic modulus and wave velocity increase significantly,and the dispersion effect will strengthen.The results reflect the micro process of movement and interaction between micro damage such as micro defects in rock induced by stress,which will lead to the change of microstructure,and then cause micro displacement and micro damage.Micro damage may cause fatigue damage and fracture after a period or a long time of accumulation.The non-uniformity of microstructure in rock and filling or inclusion defects in rock is the weakest part form in rock,which will make a new microcrack system again under the action of cyclic stress,so as to accelerate the accumulation of damage and cause fracture.In addition,the residual stress of various channels in rock will lead to fatigue damage.The increase of vibration frequency will also accelerate the damage of rock.Combined with the comprehensive effect of temperature rise,it will cause the growth of microcracks in rock,lead to the change or damage of rock microstructure,degrade the quality of rock and rock mass media,and then lead to the damage of rock foundation.Although the anelastic damages are caused below the yield point,they will eventually degrade the quality of the rock.

关 键 词：饱和砂岩 弛豫衰减峰 滞弹性损伤 弹性模量亏损 频率和温度效应 

分 类 号：P313[天文地球—固体地球物理学]