摘要
综合考虑中间主应力系数n、渗流体积力p _(w)及剪胀系数β等的影响,采用统一强度理论和D-P准则,根据应力、位移连续性条件,计算得到了圆形水工隧洞径向应力σ_(r)、环向应力σ_(θ)的解析解;推导出隧洞围岩塑性区半径r和最小覆盖层厚度h;分析了渗透系数比k _(d)/k _(c)、剪胀系数β、岩体强度参数c、φ及中间主应力系数n对最小覆盖层厚度h的影响。结果表明:当k _(d)/k _(c)≤500时,h值相对较小,当k _(d)/k _(c)>500时,h值趋于一定值;不考虑渗流时,h值增大约94%;c、φ值对h值影响较明显;采用统一强度理论计算,h值随着n的增大而增大,采用D-P准则计算,h值则出现波动,呈现中间主应力的区间性;采用两种理论计算的h值均随着β的增大而增大。
Considering the influence of intermediate principal stress coefficient n,seepage body force p_(w) and dilatancy coefficientβ,the analytical solutions of radial stress σ_(r) and circumferential stress σ_(θ) of circular hydraulic tunnel were obtained by unified strength theory and D-P criterion according to the continuous conditions of stress and displacement.The plastic zone radius r and the minimum overburden thickness h of tunnel surrounding rock were deduced.And the influences of permeability coefficient k _(d)/k _(c),dilatancy coefficientβ,rock strength parameters c andφ,and intermediate principal stress coefficient n on the minimum overburden thickness h were analyzed.The results show that when k _(d)/k _(c) is equal or less than 500,h is small;when k_(d)/k_(c) is greater than 500,h tends to be a certain value;and when the seepage is not considered,h is increased by about 94%.The c andφvalue have obvious influence on h.Using the unified strength theory,h increases with the increase of n,while using the D-P criterion,h fluctuates,showing the interval of intermediate principal stress.The minimum overburden thickness h calculated by the two kinds of strength criteria increases with the increase of dilatancy coefficientβ.
作者
杨自友
程长清
孙天宇
俞凡
杨明
YANG Ziyou;CHENG Changqing;SUN Tianyu;YU Fan;YANG Ming(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China)
出处
《重庆交通大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第2期95-101,共7页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家自然科学基金项目(51774007)
安徽省高校自然科学研究重点项目(KJ2021A0610)。
关键词
隧道工程
岩土工程
渗流
剪胀系数
中间主应力
tunnel engineering
geotechnical engineering
seepage
dilatancy coefficient
intermediate principal stress
