摘要
由于锚杆加固稳定性决定岩土高陡边坡抗倾覆性能,影响边坡工程质量,因此提出岩土高陡边坡锚杆加固稳定性及抗倾覆安全系数分析。根据锚杆加固作用机制,分析锚杆对岩土层间抗剪强度加固效果,获取锚杆处于压缩-剪切或者拉伸-剪切综合作用下的屈服强度以及全部锚杆抗剪强度之和。分析岩土高陡边坡弯曲倾覆破坏时形成的滑移区、叠加倾覆区和悬臂倾覆区,得出保障岩土高陡边坡稳定性,锚杆加固初始位置应在叠加倾覆区最后一层岩土层之下,充足数量和强度的锚杆加固促使悬臂倾覆区消失,达到边坡稳定。锚杆加固后岩土高陡边坡抗倾覆安全系数计算方法为重心稳定力矩总和与倾覆力矩总和比值。实验结果表明:岩土高陡边坡抗倾覆安全系数随锚杆预应力增加而增大,基于工程应用经济性、安全性原则,施加的最佳锚杆预应力为110 k N;锚杆加固初始位置应处于边坡叠加倾覆区,锚杆加固初始位置越靠近悬臂倾覆区,边坡抗倾覆安全系数数值越小,当锚杆加固初始位置位于悬臂倾覆区时,锚杆加固未起到边坡稳定性提升作用;锚杆加固区域横跨叠加倾覆区和悬臂倾覆区时边坡抗倾覆安全系数最高,边坡锚杆加固效果最好,稳定性最佳。
Because the stability of rock bolt reinforcement determines the anti overturning performance of rock soil high steep slope and affects the quality of slope engineering, the stability of rock soil high steep slope reinforcement and anti overturning safety factor analysis are proposed. According to the mechanism of bolt reinforcement, the effect of bolt on the shear strength of rock soil layer is analyzed, and the yield strength of bolt under the combined action of compression shear or tension shear and the sum of shear strength of all bolts are obtained. Based on the analysis of the slip area, superposition overturning area and cantilever overturning area, it is concluded that the initial position of anchor bolt reinforcement should be under the last layer of rock soil layer in superposition overturning area, and sufficient quantity and strength of anchor bolt reinforcement can promote the disappearance of cantilever overturning area and achieve slope stability. The calculation method of anti overturning safety factor of rock and soil high and steep slope after bolt reinforcement is the ratio of the sum of center of gravity stability moment and overturning moment. The experimental results show that the anti overturning safety factor increases with the increase of anchor prestress. Based on the principle of economy and safety in engineering application, the best anchor prestress is 110 kn. The initial position of anchor reinforcement should be in the slope superposition overturning area. The closer the initial position of anchor reinforcement is to the cantilever overturning area,the smaller the anti overturning safety factor of the slope is. When the initial fixing position is in the cantilever overturning area, the anchor bolt reinforcement does not play a role in improving the slope stability;when the anchor bolt reinforcement area crosses the superposition overturning area and the cantilever overturning area, the slope anti overturning safety coefficient is the highest, the slope anchor bolt reinforcement effect is the best, and the stability is the best.
作者
封永梅
张楠
FENG Yong-mei;ZHANG Nan(Chengdu Polytechnic,Chengdu 610041,China;Beijing Jiaotong University,Beijing 100044,China)
出处
《山东农业大学学报（自然科学版）》
北大核心
2020年第2期335-339,共5页
Journal of Shandong Agricultural University：Natural Science Edition
基金
国家自然科学基金(C15A200010)
成都职业技术学院院级项目(19CAYG002)。
关键词
岩土边坡
稳定性
安全系数
Rock-soil slope
stability
safety factor
