基于Kelvin解的CFRP锚杆锚固段的力学分析

Mechanical analysis of bonded segment of CFRP anchor based on Kelvin solution

为研究压力型CFRP锚杆锚固段在土体介质中的应力应变分布规律,将锚杆的受力状态视为无限体内部一点受集中力作用的弹性问题,运用Kelvin解进行位移分析,推导了锚杆锚固段在土体介质中的轴向应力和剪应力及轴向应变的理论公式,结合现场CFRP锚杆抗拔试验,将场地土层参数代入理论公式,绘出了锚固段轴向应力和剪应力的分布曲线,并将计算值与现场实测的轴向应变值进行对比分析。研究结果表明:土层弹性模量是压力型CFRP锚杆锚固段应力的大小及分布形态的关键参数。锚固段理论轴向应变值与实测轴向应变值的对比结果表明,实测值与计算值相近,其变化趋势反映了合理的规律,由此验证了理论公式的可行性。

In order to investigate the stress and strain distribution of the bonded segment of CFRP anchor, a mechanical analysis of an anchor in soil was assumed as an elastic calculation on a point load inside an infinite body. Displacement analysis and distribution equation of axial and shear stresses and axial strain of the anchorage segment could be derived from Kelvin solution. Based on the CFRP anchor pullout test, in-situ soil parameters were put into the formula to draw the distributional curves of axial stress and shear stress of the anchorage segment, and to make a comparison between the calculated values of axial strain and its measured values. The results showed that the elastic modulus of the soil was the key parameter to the value and distribution of stress of bonded segment of CFRP anchor. The comparison between the calculated values of axial strain and its measured values suggested that the two values were close, and the change of statistical trend of measured values re- flected the rationality of the theoretical rules, which could prove the feasibility of the formulas.