岩体流变对岩壁吊车梁锚杆应力的影响

发布时间：2018-05-12 03:02

本文选题：岩体 + 流变　；参考：《水电能源科学》2017年05期

【摘要】：流变是岩体的固有力学性质,对地下厂房开挖和运行的安全稳定性具有重大影响。但岩壁吊车梁设计时多采用仅考虑岩壁吊车梁自身所受荷载的刚体极限平衡法,忽略了围岩变形尤其是岩体流变变形的影响。因此,结合某水电站地下厂房工程,建立地下厂房系统有限元模型,基于岩体Drucker-Prager弹塑性本构关系和考虑时间硬化的等效流变原理,研究了地下厂房开挖过程和正常运行10年后岩体流变对岩壁吊车梁锚杆应力的影响。结果表明,在地下厂房正常运行10年后下游顶部第一排受拉锚杆在长度6.72 m处应力值达317.83 MPa,随着地下厂房运行时间的延长,岩壁吊车梁锚杆应力值逐渐变大,但应力变化速率逐渐减小,有必要采取工程措施,以便防止随着时间的延长岩体流变量逐渐增长,从而使岩壁吊车梁锚杆发生屈服。
[Abstract]:Rheology is the inherent mechanical property of rock mass and has great influence on the safety and stability of excavation and operation of underground powerhouse. However, in the design of rock wall crane beam, the rigid body limit equilibrium method, which only considers the load of the rock wall crane beam itself, is adopted, and the influence of the surrounding rock deformation, especially the rock mass rheological deformation, is neglected. Therefore, the finite element model of underground powerhouse system is established based on the Drucker-Prager elastoplastic constitutive relation of rock mass and the equivalent rheological principle considering time hardening. The influence of rock mass rheology on the stress of rock wall crane beam is studied in the excavation process of underground powerhouse and after 10 years of normal operation. The results show that, after 10 years of normal operation of underground powerhouse, the stress value of the first row of tension anchor at the top of downstream reaches 317.83 MPA at 6.72m in length. With the extension of operation time of underground powerhouse, the stress value of rock wall crane beam is gradually increased. However, the rate of stress change gradually decreases, so it is necessary to take engineering measures in order to prevent the rock mass flow variables from gradually increasing with time, thus making the rock wall crane beam anchor rod yield.
【作者单位】：河海大学水利水电学院;
【基金】：国家自然科学基金项目(51509079)
【分类号】：TV731.6

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