锚固体应力分布演化规律及其影响因素研究

Research of stress distribution evolution law and influencing factors

通过室内试验与细观颗粒流模拟相结合的方法,研究了锚固段应力分布演化规律及其影响因素。锚固体的拉拔破坏过程可以分为3个阶段:黏弹阶段、黏脱阶段和破坏阶段。在黏弹阶段,剪应力呈先增后减的分布形式,峰值点靠近拉拔端孔口处;在黏脱阶段,拉拔端处的界面黏结首先失效,并向内部扩展,在此阶段,剪应力的峰值点随之向锚固段内部移动。锚杆和锚固剂弹性模量影响锚杆轴力和界面剪应力的分布形式,锚杆弹性模量越大,锚固剂弹性模量越小,剪应力在锚固段拉拔端的集中程度越小。

With laboratory tests and particle flow simulation, stress distribution evolution law and influencing factors along anchorage segment are studied. The failure process of anchor system can be divided into three stages： viscoelastic stage, de-viscosity stage and failure stage. In the viscoelastic stage, the shear stress first increases and then decreases along the anchorage segment, and the peak point is close to the pull end. In the de-viscosity stage, the bond at the pull end first fails, and then expands to the internal layer. The shear stress peak point also moves inward. Elastic modulus of anchor and anchor agent influences the stress distribution. With the increase of anchor＇s modulus and decrease of anchor agent＇s modulus, the intensity of stress at pull end weakens.