摘要
根据模型相似准则,采用低强度混凝土模拟中风化泥砂岩,制作预应力岩体锚固基础缩尺模型,进行疲劳试验和抗拔试验研究。试验对无差别模型分别施加不同的预应力和循环荷载,通过采集锚杆应变,并根据材料试验数据,分析锚杆受力和界面损伤情况。研究发现:在低应力水平循环荷载作用下,预应力岩体锚固基础具有较高的抗疲劳性能,模型循环加载400万次后虽未发生破坏,但不同锚杆间界面疲劳损伤不均,受力响应出现分化。锚杆应变减小主要发生在加载的最初阶段,在循环荷载作用下,锚杆应变呈线性减小,初始预应力越大,减小量越大,增加振幅和频率,锚杆应变减小量有增大趋势。经过400万次循环荷载锚杆极限抗拔承载力降低,且初始应力越大,降低幅度越明显。
According to the model similarity criterion, low-strength concrete is used to simulate the weathered argillaceous sandstone. The scaled model of the prestressed rock mass anchorage foundation was made, and the fatigue test and pullout test were carried out. Different prestressing and cyclic loads were applied to the undifferentiated model.By collecting the strain of the bolt and analyzing the stress and interface damage of the bolt according to the material test data. It is found that under the action of low stress horizontal cyclic load, the prestressed rock mass anchorage foundation has high fatigue resistance. Although the model was not damaged after 4 million cycles of loading, the fatigue damage of the interface between different anchors was uneven, and the force response was differentiated. The bolt strain reduction mainly occurs in the initial stage of loading. Under the action of cyclic load, the bolt strain decreases linearly, and the greater the initial prestress, the greater the decrease. With the increase of amplitude and frequency, the decrease of bolt strain has an increasing trend. After 4 million cyclic loads, the ultimate pull-out bearing capacity of the anchor decreases,and the greater the initial stress, the more obvious the decrease.
作者
杨龙
陈健云
苑晨阳
YANG Long;CHEN Jianyun;YUAN Chenyang(China United Engineering Co.,Ltd.,Hangzhou 310052,China;Dalian University of Technology,Dalian 116024,China;North China University of Water Resources and Electric Power,Zhengzhou 450046,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期2136-2141,共6页
Building Structure
基金
河南省重点研发与推广专项(212102310269)
关键词
预应力
岩体锚固基础
模拟岩体
疲劳试验
prestress
rock mass anchorage foundation
simulated rock mass
fatigue test
