岩石群锚杆基础界限间距与群锚效率估算方法

Limit Distance and the Estimating Efficiency Factor of Rock Group Anchor

岩石群锚杆基础是一种材料用量少、机械化程度高、主要发挥抗拔力、应用较为广泛的抗拔基础型式。在竖向荷载作用下,岩石群锚杆基础承载过程受到岩体抗剪强度、锚杆设计施工参数、锚杆-岩体协同工作等复杂因素的影响,其抗拔破坏机理和群锚杆相互作用等问题尚未揭示,使得现行规范在确定锚杆间距、群锚杆承载力等关键设计参数时需要依靠较多原位试验。应用弹性力学和岩石锚杆竖向抗拔传力规律,建立了岩石群锚杆基础的单根锚杆间无相互影响的界限间距近似计算方法以及岩石群锚杆群锚效率估算方法,理论计算结果与试验结果比较接近,可以满足岩石群锚杆基础初步设计要求。

Rock anchors foundation is a kind of foundation who is low material consumption,high mechanization,mainly subject to pullout resistance and it is widely used.Under vertical loading,the bearing process of rock group anchor foundation is influenced by the complicated factors,such as shear strength of rock mass,design and construction parameters of anchor and the collaborative work of rod-rock mass,so the mechanism of uplift failure and the interaction of anchors foundation has not been revealed.In the relevant codes,the anchor distance and the bearing capacity of anchors are put out according to some field testing results Used elastic mechanics and the vertical pulling force law of a rock anchor,the calculating method of the limit distance of anchors and the estimating method of efficiency factor of anchors were put out.These calculations were close to the test results,so the calculating method of limit distance of anchors and the estimating method of efficiency factor of anchors would be fit for the initial design of rock anchor foundation.