摘要
基于三剪统一强度准则和弹脆塑性模型,考虑中间主应力、渗流、剪胀、软化和塑性区弹性模量等因素的影响,推导了含有5种因素综合影响的水工圆形隧洞塑性区位移解析解;通过算例分析,得出了各参数对隧洞塑性区位移的影响规律。结果表明:各参数取不同值时,位移解可退化为一系列解,参数值可根据具体工程进行合理选择,具有广泛的适用性;围岩剪胀特性对隧洞塑性区位移的影响显著,若不考虑其影响,将明显低估隧洞的变形以致工程设计偏于危险;考虑中间主应力的影响能发挥围岩的强度潜能,减少支护,节约工程造价;考虑渗流和软化特性对隧洞塑性区半径的影响可使塑性区范围更接近围岩真实的变形范围;塑性区弹性模量采用含有半径幂函数的表达式可充分考虑围岩受扰劣化后的应力重分布及爆破损伤等影响,更符合隧洞真实变形情况;该位移解为隧洞塑性区位移计算提供了理论依据,对工程设计有一定的参考价值。
Based on the triple-shear unified failure criterion and the elastic-brittle-plastic model,taking the integrated influences of intermediate principal stress,seepage,shear dilation,softening,elastic modulus of plastic zone into account,the analytical solution of plastic zone displacement of hydraulic tunnel with 5 factors was deduced.Through example analysis,the influence law of each parameter on the plastic zone displacement of tunnel was obtained.The results show that the analytical solution has wide applicability and can be degenerated into a series of solutions when the parameters are different,the parameter values can be rationally chosen according to the specific project.The shear dilation characteristics of surrounding rock have significant influence on the displacement of plastic zone in tunnel,without considering the influences,the deformation of tunnel will be underestimated obviously,so that the engineering design will be dangerous.Considering the influences of intermediate principal stress,the potential strength of surrounding rock can be brought into play,the support can be reduced,and the engineering cost can be saved. Considering the influence of seepage and softening characteristics on the radius of plastic zone,the plastic zone can be closer to the true deformationrange of surrounding rock.The elastic modulus of plastic zone can be fully considered by the expression of radius power function,the stress redistribution and blasting damage can be fully considered after the disturbed degradation of surrounding rock,and the results are more in line with the true deformation of tunnel.The displacement solution provides a theoretical basis for the displacement calculation of the plastic zone in the tunnel,and has a certain reference value for the engineering design.
出处
《建筑科学与工程学报》
CAS
北大核心
2017年第6期11-20,共10页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(51508028
41202191)
中国博士后科学基金项目(2016T90879
2014M562357)
中央高校基本科研业务费专项资金项目(310828173402)
关键词
深埋水工圆形隧洞
中间主应力
半径相关的弹性模量
脆性软化
剪胀特性
deep circular hydraulic tunnel
intermediate principal stress
radius-dependent elastic modulus
brittle softening
shear dilation characteristic
