摘要
深入研究了加锚节理面的变形特点和节理面附近锚杆的变形特点;把断裂力学与损伤力学相结合,采用应变能等效的方法,建立了加锚断续节理岩体在压剪应力作用下的本构关系;按自洽理论的方法,得到了加锚断续节理岩体在拉剪应力状态下的本构关系,并将其理论模型应用于某大型地下厂房的三维稳定性分析中。应用加锚断续节理岩体断裂损伤模型模拟锚杆的支护效应,锚杆通过与围岩的联合作用,有效地限制了围岩变形,改善了围岩的应力状态,阻止了围岩破损区的发展演化,从而提高了围岩的稳定性。将断裂损伤计算结果与一般弹塑性(FLAC3D)计算结果进行了对比分析。相比于普通的弹塑性模型,加锚断续节理岩体断裂损伤模型考虑了岩体中节理裂隙对洞室围岩稳定性的影响,以及锚杆针对节理裂隙的加固作用,能更好地反映裂隙岩体洞室围岩稳定性特征,从而验证了该模型的有效性和优越性。
According to the theories of fracture mechanics and damage mechanics, the deformation characteristics of bolted joint face and the bolt near the joint face are systematically studied. By using the method of equivalent strain energy, the constitutive relation of anchored discontinuous jointed rockmass is derived under the state of compression-shearing stress. The constitutive relation under the state of tension-shearing stress is developed according to the theory of self-consistence. Through 3-D FEM programming, the above constitutive models are applied to a certain actual project. The fracture-damage model of the anchored brittle discontinuous jointed rockmass is applied to simulating the reinforcing effect of the bolts. Through the united actions with the adjacent rock, the bolts restrict the deformation of the adjacent rock, improve the stress state of the adjacent rock, and prevent the evolution of damage zones, and so enhance the stability of the underground structures effectively. Synthesizing the facture-damage computation results and the FLAC3D results, we can conclude that the facture-damage computation values exceed the FLAC3D values owing to the appearance of joint in the rock mass. Taking the reinforcing action of the bolt on the joint face into account, the facture-damage computation model brought forward in the paper adapts better to the deformation and damage characteristics of the anchored discontinuous jointed rockmass. So the computation model is proved to be valid and advantageous.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2008年第1期261-268,共8页
Rock and Soil Mechanics
基金
国家自然科学基金委联合基金重点项目(No.50539080)
国家自然科学基金委面上项目(No.50574053)
关键词
节理岩体
本构关系
地下洞室群
岩锚支护
jointed rockmass
constitutive relation
underground cavern group
supporting of rock-bolt
