基于透明土的4种锚杆拔出对比模型试验

发布时间：2018-07-22 11:45

【摘要】：采用透明土材料和粒子图像测速法(PIV)技术,通过物理模型试验研究锚杆拔出机理。在试验中采用普通圆柱型和手榴弹型、糖葫芦型和圣诞树型3种异型共4种不同形状锚固段锚杆,测试获得各锚杆随锚杆锚固段上移对周围土体的扰动规律、锚杆位移与锚固力变化曲线,分析各锚杆锚固段的极限承载力与锚固段破坏机理。试验结果分析表明:在本文试验条件下,在锚杆拔出破坏前,除了手榴弹型锚杆外,各种形状锚杆对土体水平位移影响相对于竖向位移均较小,糖葫芦型和圣诞树型锚杆对土体的竖向位移影响范围最大,达到6.0倍锚杆半径,比普通圆柱型锚杆对土体竖向位移影响范围大1.5倍;异形锚杆可以很有效的提高锚杆极限承载力,比普通圆柱型锚杆可提高66%~91%,其中圣诞树型锚杆的极限承载力最大;锚杆锚固段的有效长度、有效横截面积、有效直径对其极限承载力有直接影响;锚杆极限承载力值是发生在锚杆锚固段与土体接触的界面开始破坏到完全破坏之间,锚杆锚固段与土体接触界面发生破坏,是从锚杆自由段部位开始逐渐往锚杆底部发展,以A型锚杆为例,当破坏发展到距锚杆底部1/3的位置时,锚杆极限承载力达到峰值。
[Abstract]:The mechanism of bolt pull-out was studied by means of physical model test by using transparent soil and particle image velocimetry (PIV) technique. In the experiment, four kinds of anchors with different shapes were adopted, such as ordinary cylinder type and grenade type, Tomatoes on sticks type and Christmas tree type. The disturbance law of each anchor rod moving up with anchor bolt segment on surrounding soil was obtained. The ultimate bearing capacity and failure mechanism of anchoring section are analyzed. The analysis of the test results shows that, before the bolt is pulled out and destroyed, the influence of various shape anchors on the horizontal displacement of soil is smaller than that on the vertical displacement, except for the grenade bolt. The vertical displacement of soil is influenced by Tomatoes on sticks type and Christmas tree type anchor, reaching 6.0-fold radius, which is 1.5 times larger than that of ordinary cylindrical anchor. Special-shaped anchors can effectively improve the ultimate bearing capacity of anchors, which can be increased by 66% and 91% compared with ordinary cylindrical anchors, in which the ultimate bearing capacity of Christmas tree anchors is the largest, the effective length of anchoring section, the effective cross section area, The effective diameter has a direct effect on the ultimate bearing capacity, the ultimate bearing capacity of the bolt occurs between the interface between the anchoring section and the soil, and the contact interface between the anchor and the soil is destroyed. The ultimate bearing capacity of the anchoring rod reaches its peak when the failure develops to a third of the bottom of the anchor rod when the failure occurs to a third of the bottom of the anchor rod, starting from the free section of the anchor rod and gradually moving to the bottom of the anchor rod.
【作者单位】：武汉理工大学土木工程与建筑学院;华威大学工程学院;
【基金】：国家自然科学基金面上项目(51374163)
【分类号】：TU476

【相似文献】