泥岩地层抗浮锚杆试验研究

Experimental Reasearch on Anti-floating Anchor of Mudstone Stratum

为探讨泥岩地层全黏结抗浮锚杆荷载传递机理和承载性能,基于陕西安康地区泥岩地层抗浮锚杆现场进行了基本试验和锚杆杆体的轴力测试,试验结果表明:锚杆杆体的轴力分布是不均匀的,从锚杆顶面向深部逐渐减小,且超过一定的长度后不再受力;同时表明锚杆受力时,沿锚固端全长的黏结应力分布也是不均匀的,其有效发挥黏结应力的分布长度有一定限度;确定了该地区泥岩地层中直径为150 mm抗浮锚杆的有效锚固长度、极限黏结强度标准值及8 m长锚固段对黏结强度的影响系数等,为类似泥岩地层抗浮锚杆的设计提供依据。

In order to study the load transfer mechanism and the bearing capacity of the fully bonded anti floating anchor in the mudstone stratum,the field test and the axial force of the anchor rod were carried out for the anti-floating anchor in the mudstone stratum of Ankang area,Shaanxi Province.The test results show that the axial force distribution of the anchor body is not uniform,and it gradually decreases from the top of the bolt to the bottom,and it will not be stressed after it exceeds a certain length.At the same time,the bond stress distribution along the whole length of the anchorage end is also uneven when the bolt is stressed,and there is a limit to the distribution length of the effective bond stress.The effective anchorage length,the standard value of ultimate bond strength for the anti-floating anchor rod with a diameter of 150 mm,and the influence coefficient of 8 m long anchorage segment on the bond strength were determined in the mudstone stratum in this area,which provided the basis for the design of anti-floating anchor in similar mudstone stratum.