新型抗浮复合锚杆承载性状试验研究

Experimental Study on Bearing Properties of New-type Anti-floating Composite Anchor

本文提出一种新型抗浮复合锚杆,用于解决工程抗浮问题。这种复合锚杆具有造价低、承载力高、施工速度快的优点。为了研究新型复合锚杆的承载性状,进行了现场试验。试验分成两组:其一为粘结锚固试验,研究复合锚杆构件内部荷载传递机理;其二为带有自由段的复合锚杆基本试验,用于分析复合锚杆内部受力机理。试验结果表明:钢绞线与注浆体的粘结力与钢绞线根数和锚固长度有关,钢管与混凝土的粘结力与钢管直径和锚固长度有关;有自由段的复合锚杆杆身混凝土在自由段受压,在锚固段部分受拉。相对于无自由段的普通锚杆,新型复合锚杆的极限拉应力明显变小。根据以上两组试验的相关结论,在保证复合锚杆粘结锚固可靠的前提下,可考虑减少锚固段长度,合理利用混凝土材料的受压特性,可以达到优化设计的目的。

A new type of anti-floating composite anchor is put forward to solve the problem of engineering antifloating. This kind of composite anchor has the advantage of low cost,high bearing capacity,rapid construction speed. In order to study new composite anchor bearing character,the field test is carried out. This experiment is divided into two groups： the first group is the bond anchorage test,which is to study the composite anchor load transfer mechanism of component; the second group is the basic test of the composite anchor with free period,which is applied to analyze the composite anchor mechanism of the internal stress. The results show that： the cohesive force of steel strand and grouting body relates to the number of steel strand and anchorage length,the cohesive force of steel and concrete and steel tube relates to diameter and anchorage length. The concrete of composite anchor with a free period is pressed in the free period,and partly stretched in the anchoring. Compared with the ordinary anchor without free period,the ultimate tensile stress of the composite anchor decreases significantly. According to the conclusion of the above two groups experiment,on the premise of guarantee of the composite anchor bonding anchorage,it can achieve the goal of optimization design by reducing the anchoring length,which can make reasonable use of the compressive behaviour of concrete material.