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楠竹加筋复合锚杆已经应用于中国西北丝绸之路上留存的古代土遗址保护加固工程中。该锚杆截面积大,可以获得足够大的锚固力。针对现场拉拔试验中钢绞线从内黏结剂中拔出的破坏形式,设计了专门的试件及夹具,试验研究了钢绞线与内黏结剂间的力学行为。试验结果表明,钢绞线与内黏结剂的黏结滑移分为指数上升阶段、软化下降阶段和残余应力阶段3个阶段,可以用简化模型和精确模型描述。试验还表明,钢绞线与内黏结剂接触界面上应力分布不均匀,靠近加载端的应力较大,且有应力峰,应力峰随荷载的逐渐增大向远离加载端的方向移动;钢绞线与内黏结剂间平均剪切应力随锚杆的长度增大呈指数衰减。通过理论分析,给出了界面黏结滑移微分方程及相关曲线,结果表明,钢绞线轴力及界面相对滑移沿钢绞线均呈不均匀分布,且随着距加载端的距离增加其值急剧下降,该规律可以指导锚杆设计及工程应用。
Nanzhu reinforced composite anchor has been used in the protection of the ancient soil sites preserved in the Northwest China Silk Road project. The anchor cross-sectional area, can get enough anchorage force. Aiming at the damage form of steel strands pulled out from the internal cement in the spot drawing test, special specimens and fixtures were designed. The mechanical behavior between strand and internal binder was studied. The test results show that the bond slip between the strand and the internal bond is divided into three stages: exponential rise stage, softening descent stage and residual stress stage, which can be described by simplified model and exact model. The test also shows that the stress distribution on the contact interface between the strand and the inner adhesive is not uniform, the stress near the loading end is larger and the stress peak is larger, and the stress peak moves away from the loading end gradually as the load increases. The average shear stress within the binder increases exponentially with the length of the anchor. Through theoretical analysis, the interface slip equation and the correlation curve are given. The results show that the axial force and the relative slip of the steel strand are all unevenly distributed along the strand, and its value increases sharply with the distance from the loading end Decline, the law can guide the design of bolts and engineering applications.