摘要
为体现围岩塑性区扩展与隧道掘进之间的动态关系,基于空间约束效应等效模型对Mohr-Coulomb准则和广义Hoek-Brown准则下塑性区半径公式进行修正。讨论空间约束效应合理等效函数的选取,给出约束范围的定量求解方法,并结合文献中3种代表性岩体进行算例验证,进一步总结空间约束效应与围岩属性、隧道支护力之间的关系,最终揭示了空间约束效应的本质属性。对比考虑约束效应影响下,2个修正后的塑性区半径公式间的关联性与适用性。研究结果表明,空间约束效应决定了塑性区的发展路径,但不会影响塑性区上限值,不同围岩条件下约束范围各异,而非固定的5倍洞径。为准确预测塑性区扩展规律,应根据围岩情况选取适宜的强度准则,在岩体参数c、φ等效基础上,硬岩条件下,可任意选用Mohr-Coulomb准则或广义Hoek-Brown准则;软岩条件下,采用广义Hoek-Brown准则比Mohr-Coulomb准则计算的塑性区范围大。
In order to reflect the dynamic relationship between the expansion of the plastic zone of rock mass and tunnel excavation,solutions of plastic zone radius based on Mohr-Coulomb criterion and generalized Hoek-Brown criterion were modified subjected to the equivalent model of spatial constraint effect.The reasonable equivalent function of the spatial constraint effect was selected while a quantitative method to obtain the constraint range was given.Based on the verification of the spatial constraint effect with three representative rock masses,the correlation between the spatial constraint effect,the rock mass quality and the tunnel supporting force was summarized,and finally the essential attribute of spatial constraint effect was revealed.Subjected to the constraint effect,the above-mentioned two revised plastic zone solutions were further associated and compared.The results show that the spatial constraint effect determines the developing path of the plastic zone,but will not change the upper limit value of the plastic zone.Each rock mass has a specific constraint range,which is not the conventionally fixed value of five times the tunnel radius.To predict the plastic zone expansion accurately,appropriate strength criteria should be selected based on the rock mass features.With the establishment of rational parameters of rock mass(c andφ),for hard rock,the results by Mohr-Coulomb criterion and generalized Hoek-Brown criterion differ slightly.In this case,the Mohr-Coulomb criterion or generalized Hoek-Brown criterion can be arbitrarily selected.For soft rock,however,the generalized Hoek-Brown criterion will overestimate the result compared with that by the Mohr-Coulomb criterion.
作者
姚毅
来弘鹏
张秦
刘禹阳
YAO Yi;LAI Hongpeng;ZHANG Qin;LIU Yuyang(School of Highway,Chang’an University,Xi’an 710064,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,China;School of Architectural Engineering,Chang’an University,Xi’an 710064,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2023年第8期176-183,共8页
Journal of the China Railway Society
基金
国家自然科学基金(51978064,51908051)。
关键词
隧道工程
空间约束效应
塑性区半径
塑性区发展路径
tunnel engineering
spatial constraint effect
plastic zone radius
developing path of plastic zone
