摘要
为研究充气锚杆的变形特性及其对承载力的影响,通过建立室内模型,基于模型压力与体积的关系,测定橡胶膜在加压作用下变形的形状与大小;在此基础上,根据抗拔试验,获得典型荷载-位移曲线,探讨充气锚杆的锚固机理与承载特性。研究结果表明:充气锚杆橡胶膜膨胀体呈圆柱状,可以应用圆孔扩张理论计算充气压力与膨胀体积的关系,预测极限充气压力;充气锚杆在压力作用下形成较大的膨胀体,可获得较大的端阻力;随着充气压力的增加,橡胶膜侧向土体应力转化为第一主应力并达到极限压力,同时对周边的砂土产生压缩挤密作用,提高了砂土的强度,侧阻力提高幅度较大,与一般锚杆相比充气锚杆具有较大的承载能力。
In order to analyze the deformation characteristics of inflatable anchor and its influence on the bearing capacity, the deformation of membrane was measured during inflating according to the relationship between pressure and volume based on the laboratory model test. The typical load-displacement curves of inflatable anchor were obtained through the pullout test, and its anchoring mechanism and bearing features were discussed. The results show that the shape of the inflatable membrane is approximately cylindrical and the relationship among inflated pressure and volume and ultimate inflatable pressure can be calculated in advance using the cavity expansion theory. A large tip resistance is obtained from the expander body of inflatable anchor. As the lateral pressure of the soil changes into the first principal stress and the compact effect on the soil during the inflating of inflatable anchor, the shaft resistance of the inflatable anchor is greatly improved. The inflatable anchors have a higher bearing capacity than common anchors.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第5期1369-1374,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(50878212)
关键词
充气锚杆
变形特性
圆孔扩张
承载特性
抗拔试验
inflatable anchor
deformation characteristics
cavity expansion
bearing features
pullout test
