摘要
探讨围岩三阶段流变效应对隧道收敛位移的影响。首先基于分数阶微积分理论,采用损伤分数阶Abel黏壶取代传统西原模型黏弹性体及黏塑性体中的理想黏性体,提出改进的西原模型;然后采用改进的西原模型,推导出圆形隧道位移的黏弹塑性解;最后以金瓶岩隧道为例,对解析解的有效性进行了验证。研究结果表明:(1)改进西原模型可以较好地模拟岩石蠕变变形的3个阶段,即衰减蠕变阶段、常速蠕变阶段及加速蠕变阶段;(2)解析得到的围岩蠕变位移曲线与现场实测结果平均值曲线在形态与数值上均较为吻合;(3)随着损伤Able黏壶分数阶阶次的增大,或者损伤系数的增大,围岩的位移呈现增大的趋势。在实际工程中,通过工程手段减弱围岩的黏性或减小围岩的损伤,可以较为有效地抑制围岩的流变变形。
This paper put the emphasis on the discussion of influence of three-stage rheological effect of surrounding rock on tunnel convergence displacement.Firstly,based on the fractional calculus theory,the modified Nishihara model is proposed by replacing the ideal viscoelastic body and viscoplastic body in the traditional Nishihara model with damaged fractional Abel dashpot.Then the viscoelastoplastic solution of circular tunnel displacement is obtained by using the improved Nishihara model.Finally,taking Jinpingyan tunnel as an example,the validity of the analytical solution is verified.The results show that:(1)Three creep stages of rock can be well simulated by the modified Nishihara model,that is,the decay creep stage,the constant creep stage and the accelerated creep stage;(2)The creep displacement curve of surrounding rock obtained by analytical method is in good agreement with the mean value curve of field measured results in both morphology and value;(3)With the increase of the fractional order of damaged Able dashpot or the increase of damage coefficient,the displacement of surrounding rock presents an increasing trend.In practical engineering,the rheological deformation of surrounding rock can be effectively restrained by engineering means to weaken the viscosity of surrounding rock or reduce the damage of surrounding rock.
作者
刘咏梅
LIU Yongmei(The No.3 Engineering CO., Ltd., China Railway 23<rd> Bureau Group, Chengdu 611137, China)
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第2期213-218,238,共7页
Journal of Chengdu University of Technology: Science & Technology Edition
关键词
分数阶微积分
损伤
西原模型
隧道
解析解
fractional calculus
damage
Nashihara model
tunnel
analytical solution
