为探讨港工高桩码头结构为提高桩身竖向抗拔承载力而日渐采用的桩内嵌岩锚杆技术的复杂受力特点,基于锚杆锚固体-周围岩体相互作用的剪胀机理,建立适合于桩内嵌岩锚杆的荷载传递函数,并由此推导出锚杆临界锚固长度的解析解。然后,基于所获得的解答提出了可近似考虑多种影响桩内嵌岩锚杆承载特性因素的综合影响系数δ值,并由此探讨了桩内嵌岩锚杆锚固段轴力、相对位移与摩阻力等沿锚固长度的分布规律:δ值越大,轴力沿锚固段衰减越快,锚固体与周围岩土体之间的相对位移和摩阻力分布越趋不均匀,且临界锚固长度越小。最后,结合某工程实例的实测数据进行了应用,对比分析结果表明,两者吻合较好。
In order to discuss the behavior of rock-socketed anchoring blots under the pile toe of high-pile wharf, a new kind of load transferring function was set up based on the dilatancy effect between the anchorage-body and surrounding rock, and an analytical solution to determine the critical anchorage length is obtained as well. Then, based on the obtained analytical solution, a parameter δ is introduced to consider the comprehensive influencing effect by various factors on the bearing behavior approximatively. In addition, distribution rules of axial force, relative displacement between the anchorage-body and surrounding rock, and frictional resistance along the anchorage length are discussed in detail. The analysis result shows that, with the increase of δ, an obvious quicker decline of axial force, uneven distributions of relative displacement and frictional resistance with a smaller critical anchorage length are observed. Lastly, the present method is applied in an engineering example with a good agreement between the calculated values and the measured data, which shows that rock-socketed anchoring bolts under the pile toe may increase the vertical pulling resistance of piles obviously and economically.