爆破动荷载作用下边坡锚杆加固效果分析  

Analysis of Reinforcement Effect of Slope Bolt under Blasting Dynamic Load

作　　者：石洪超[1] 邹新宽[1] 张继春[1] 王中达 

机构地区：[1]西南交通大学土木工程,成都610031 [2]青岛岩土工程勘察研究院,青岛266033

出　　处：《爆破》2016年第2期6-11,共6页Blasting

基　　金：国家自然科学基金项目(41272321)

摘　　要：岩质基坑边坡的加固措施常采用全长粘结式锚杆。为了研究在爆破动荷载作用下的锚杆加固效果,根据南溪长江大桥北岸锚碇基坑北侧边坡的爆破开挖情况,采用FLAC3D对基坑边坡加设锚杆前后的动力响应进行了计算。应用Bishop-拟静力法计算基坑边坡的动力稳定性系数。通过分析计算结果得出以下主要结论:加设锚杆后可以改善边坡的应力分布,减弱边坡坡脚处的应力集中现象,防止由于应力集中而导致的局部破坏;在爆破动力作用下,锚杆的轴力和砂浆剪应力均随时间的增加而增大,且增大的速率基本相同;加设锚杆后边坡的动力稳定性系数由0.98提高到1.33,提升幅度为36%。The full-length bonding bolt was used to reinforce the rock foundation pit slope. In order to study the reinforcement effect of bolt under the blasting dynamic load,the dynamic responses of foundation pit slope before and after adding bolt were calculated by the FLAC3 D according to the situation of excavation blasting in north side slope of north anchor pit slope of Nanxi Yangtze River Bridge. The dynamic stability of the foundation pit slope coefficient was calculated by Bishop-pseudo-static method. Results show that the additional bolt improved the stress distribution of slope,and reduced the stress concentration phenomenon of the slope foot,and prevented local failure due to the stress concentration. Under blasting dynamic loading,the axial force of bolt and mortar shear stress increased with the time,and the increase rate kept constant. By setting up the additional bolt,the dynamic stability of the foundation pit slope coefficient increased from 0. 98 to 1. 33 and the increase rate reached up to 36%.

关 键 词：基坑边坡 锚杆 爆破动力 动力稳定性 

分 类 号：TD235.3[矿业工程—矿井建设]