研究目的:边坡工程中常用的全长粘结型锚杆,能够利用被加固体地层(滑体或潜在滑动体)孔壁粘 结强度而具有-定的自锚作用,但因其应力分布不均而作用有限;预应力锚索未利用被加固体地层 孔壁粘结强度而无自锚作用,需等外锚结构物和注浆体达到-定强度而张拉锁定后才能发挥锚固效 用。针对这种情况,研发了可充分利用被加固体地层孔壁粘结强度的递控式锚杆新结构 (ZL201120477930.8)。本次试验的目的,就是通过递控式锚杆与全长粘结型锚杆室内模型对比试验 ,研究递控式锚杆被加固体地层段的受力变形特性及其作用效果。
研究结论:(1)根据试验数据分析得出,递控式锚杆由于在被加固体地层段分段交替设置了粘结段和 无粘结段,因而受力过程中其应力峰值呈错峰交替出现,应力分布较均匀,充分利用了被加固体地 层的孔壁粘结强度,具有较好的自锚作用,从而很好地改善了锚杆的受力性能;(2)由两种不同锚杆 锚头位移曲线图可以看出,递控式锚杆位移较小,能够更好地限制坡体变形,从而体现了递控式锚 杆新结构的优越性。(3)该研究成果对锚杆自由段的有效利用可具有-定的指导和借鉴意义。
Research purposes : The common anchor used in slope engineering is fully grouted anchor, which uses the solid strata ( sliding body or potential landslide sliding body) adhesive strength between mortar and soil or rock and have a certain self — anchoring effect, however, because of the uneven stress distribution the reinforced effect of anchor is limited. Prestressed anchor can not make use of adhesive strength and without self — anchoring effect, it is need outer anchorage structure and grouting anchor body reaches a certain strength that apply a post - tensioned locking force,then can reflect anchoring effect. For this situation, a new structure of delivery controlled anchor ( ZL201120477930. 8 ) is researched and invented, which can take full advantage of the adhesive strength between mortar and soil or rock of reinforced ground. The purpose of this experiment is through indoor model test to compare delivery controlled anchor with fully grouted anchor,research the mechanical behavior and effects of delivery controlled anchor.
Research conclusions : It is concluded from the study that :(1) According to the test results of data analysis,due to the unbonded segments are arranged alternately at the free section on the new structure of delivery controlled anchor, peak values of anchor stress appear alternately along the free section during the loading process,and the stress distribution is relatively unifoml,which takes full use of the self-anchoring effects of the free section,SO the mechanical behavior of the anchor is well improved.(2)Viewing from the displacement of two different anchors,it Call be seen that the displacements of delivery controlled anchor is smaller than that of fully grouted anchor,and the slope deformation Call be restricted much better,which reflects the superiority of delivery controlled anchor.(3)The research results Call provide guidance and reference to the efficient use of anchor free section.