砂性地层中自进式中空注浆锚杆承载特征试验研究及应用

Experimental research on load bearing characteristics of self-drilling hollow grouting anchor in sandy strata and its application

自进式中空注浆锚杆是一种新型的多功能锚杆,应用在软弱、破碎、松散的岩层及边坡支护中有较好的效果。基于沿海地区砂性地层高透水性的特点,在桩锚边坡支护中采用自进式中空注浆锚杆,有效解决了此类工程中塌孔、流砂、注浆不饱满等难题。通过3根中空注浆锚杆的现场拉拔试验,研究了砂性地层中自进式中注浆锚杆的承载性能和变形特性。试验结果表明,锚杆的极限抗拔承载力达到210 k N,远大于设计承载力80 k N,位移均小于9 mm,能够满足工程需要。施工过程中,锚杆注浆压力可达1.9 MPa左右,注浆量比普通注浆锚杆稍大。

The self-drilling hollow grouting anchor is a new type multi-functional anchor,it has good effect in weak,broken,loose rock and slope supporting. Based on the characteristics of high water permeability of sandy strata in coastal areas,the adoption of the hollow grouting anchor in the slope pile anchor support can effectively solve such problems in the project,like hole collapse,quicksand and low rate of grouting etc. Through the field pull-out test of three self-drilling hollow grouting anchors,the bearing capacity and deformation characteristics of the selfdrilling hollow grouting anchor in sandy strata were studied. The experiment results show that,the ultimate pull-out bearing capacity of anchor reaches 210 k N,which is far more than the designed capacity 80 k N,the displacement is all smaller than 9 mm,and the engineering requirements can be satisfied. During the construction process,the anchor grouting pressure can be up to 1. 9 MPa,and the grouting quantity is slightly bigger than that of the normal grouting bolt..