摘要
基于多个工程的实测数据,研究了扩大头锚杆的力学机制,指出其力学过程可分为3个阶段:第一阶段为静止土压力阶段;第二阶段为过渡阶段,其特征是位移曲线出现有一个拐点;第三阶段为塑性区压密—扩张阶段,其特征是随着土体的压密强化,扩大头的锚固力得到提高。文中给出了符合上述力学过程的多个实例。根据摩尔强度理论推导出了扩大头锚杆的抗拔力计算公式;分析了扩大头埋深、土体黏聚力、内摩擦角等因素对抗拔力的影响,指出了现行规范中计算方法的缺陷。给出了一个工程实例,采用文中的方法和现行规范中的方法分别进行计算对比,表明文中的方法计算结果以试验结果对比显著的合理,用于工程实践取得了良好的技术经济效果。
Based on the measured data of several projects,the mechanical mechanism of the bit expanded anchor rod has been studied.It is pointed out that the mechanical process can be divided into three stages.The first stage is of earth pressure at rest.The second stage is of the transition phase,which is characterized by the displacement curve that has an inflection point.The third stage is of plastic zone compaction-expansion stage,which is characterized by the soil compaction body to strengthen and expand the head improved anchorage force.In this paper,several instances consistent with the above-mentioned mechanical process are given.According to Mohr-Coulomb strength theory,the calculation formula of anti-pullforce of the bit expanded anchor rod are deduced;and the expansion the first burial depth,soil cohesion,internal friction angle and other factors against the pulling force are analysed;and it is pointed out the shortcomings of the calculation method in current industry standard.Finally,an engineering example is given,and compared with the method of the text and the existing norms.It is shown that the results of the proposed method is more reasonable compared with experimental results.For engineering practice,it has achieved good technical and economic effects.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2010年第5期1359-1367,共9页
Rock and Soil Mechanics
关键词
锚杆
扩大头
摩尔强度理论
力学机制
计算方法
anchor
bit expanded anchor rod
Mohr-Coulomb strength theory
mechanical mechanism
calculation method
