滑坡锚杆锚固力时间效应试验研究

Experimental study on time effect of pull-out characteristic for anchor in slope

为研究陕南千枚岩边坡锚杆锚固效果,通过不同的加载方式进行了锚杆拉拔试验,对锚杆应力变化与位移的对应关系及锚杆应力的长期变化进行了总结。结果认为,采用逐级加载方式予以加载时,潜在滑面处应力增加滞后于锚头处应力值;采用瞬时加载至极限抗拉强度方式予以加载时,孔中滑面处钢筋计应力对外荷载不敏感。采用逐级加载方式予以拉拔后,锚杆锚头及潜在滑面处应力均需要经过约一年时间调整,同步达到稳定状态;采用瞬时加载至极限抗拉强度进行拉拔后,孔口应力调整需要较长时间,远长于潜在滑面处应力调整至稳定值的时间。

Different loading tests for studying pull-out characteristic for anchor were did for getting anchoring force in phyllite area of south Shan＇xi province,long-term changes for stress and corresponding relationship between stress and displacement were summarized.As the results exposed that stress increasing in the potential sliding surface of the anchor lags behind with which in the head of the anchor when took the level-load mode.While took the instantaneous load to the ultimate tensile strength mode,stress from sliding surface in hole was not sensitive to the external load.Stress from the head of the anchor and the potential sliding surface took about one year to simultaneously reach steady state under the level-load mode.And stress in the hole took a long time to adjust reaching the steady state,longer than the time took by stress from the potential sliding surface under the instantaneous load mode.