摘要
围岩冻胀导致寒区隧道衬砌破坏,但是目前围岩冻胀力计算几乎都没有同时考虑冻融循环所导致的岩石弹性模量降低及孔隙率增加的共同影响。为此,首先,介绍前人提出的圆形隧道围岩冻胀力弹性力学计算模型;其次,基于Griffith断裂理论及细观损伤理论建立岩石弹性模量与冻融循环次数之间的关系式;最后,提出能同时考虑冻融循环下岩石弹性模量及孔隙率变化的围岩冻胀力损伤力学计算方法。研究结果表明:随着冻融循环次数增加,围岩冻胀力逐渐增加,并趋于定值。岩石冻胀力主要是由岩石孔隙水的冻结膨胀所致,因此,要减轻围岩冻胀破坏应采用截排水措施以控制水的渗入。
The failure of the tunnel lining in the cold region is often caused by the surrounding rock frost heaving,but nearly none of the existing calculation methods of the frost heaving pressure in the tunnel surrounding rock considers the co-effect of the reduction of elastic modulus and the increase of void ratio.Firstly,the elastic mechanical calculation model for the frost heaving pressure in the tunnel surrounding rock proposed by other researchers was introduced.Then,the relationship between the rock elastic modulus and the number of freezethaw cycles was set up based on Griffith fracture theory and mesodamage theory.Finally,the damage mechanics calculation method of the surrounding rock frost heaving pressure by considering the change of the rock elastic modulus and void ratio at the same time was proposed.The results show that the surrounding rock frost heaving pressure gradually increases and tends to be constant with the freeze-thaw cycles.It is assumed that the rock frost heaving pressure is mainly caused by the freezing and expansion of the water in the microcracks.So the intercepting and draining water measures which can control the water infiltration into the surrounding rock should be adopted to reduce the frost heaving failure of the surrounding rock.
作者
刘红岩
赵雨霞
LIU Hongyan;ZHAO Yuxia(College of Engineering&Technology,China University of Geosciences(Beijing),Beijing 100083,China;Key laboratory of Deep Geodrilling Technology,Ministry of Land and Resources,Beijing 100083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第4期1049-1058,共10页
Journal of Central South University:Science and Technology
基金
国家重点研发计划项目(2019YFC1509701)。
关键词
冻融循环
圆形隧道
冻胀力
损伤弹性模量
冻胀率
freeze-thaw cycles
circular tunnel
frost heaving pressure
damage elastic modulus
frost heaving ratio
