桥梁单锥孔夹片式预应力锚具握裹力分析  

Analysis on Gripping Force of Single-cone-hole Wedge-type Prestressed Anchorage for Bridges

作　　者：董昊 吴建芳 顾俊钢 张守龙 林颀栋 DONG Hao;WU Jianfang;GU Jungang;ZHANG Shoulong;LINQidong

机构地区：[1]重庆交通大学土木工程学院,重庆市400074 [2]宁波市交通建设工程试验检测中心有限公司,浙江宁波315124

出　　处：《城市道桥与防洪》2023年第6期230-233,M0022,共5页Urban Roads Bridges & Flood Control

基　　金：宁波市交通运输科技项目(202014)。

摘　　要：反拉法以测试曲线的拐点来判断锚下有效预应力,是当前最为广泛的锚下有效预应力检测手段。近年,众多学者发现测试曲线拐点处存在荷载骤降的情况。因此,针对反拉法测试曲线的突变段成因进行了探讨,提出了反拉荷载在夹片拉脱过程中需克服锚具握裹力从而导致突变段产生的观点。其中,锚具握裹力主要由锚圈与夹片的摩阻力和锚圈与夹片的机械咬合力构成。同时,为了得到握裹力的影响因素,建立了单锥孔夹片式锚具握裹力分析的有限元模型,设计并阐述了有限元模型的握裹力提取方法。通过有限元模型得到了影响锚具握裹力的3项影响因素——控制张拉力、摩擦系数、锥孔数量,并拟合了控制张拉力、摩擦系数与握裹力的关系曲线,得出了控制张拉力、摩擦系数与握裹力正相关的结论。The reverse-pull method is currently the most widely used method for detecting the effective prestress under the anchor.The inflection point of the test curve is used to determine the effective prestress under the anchor.In recent years,many scholars have found that there is a sudden load drop at the inflection point of the test curve.Therefore,the causes of the sudden change segment in the test curve of the reverse-pull method are discussed.The viewpoint is proposed that the reverse pull load needs to overcome the anchorage grip force during the clamping piece pulling-out process,which leads to the generation of the sudden change segment.The gripping force of anchorage is mainly composed of the friction resistance of the anchor ring and the clamping piece and the mechanical bite force of the anchor ring and the clamping piece.At the same time,in order to obtain the influencing factors of the gripping force,a finite element model is established to analyze the gripping force of the single-cone-hole wedge-type anchorage.The method for extracting the gripping force of the finite element model is designed and expounded.Through the finite element model,three factors of control tension force,friction coefficient and tapered-hole amount are obtain to affect the gripping force of anchorage are obtained.And the correlation curve of the control tension force and friction coefficient with the gripping force is fitted.It is concluded that the control tension force and friction coefficient are positively correlated with the gripping force.

关 键 词：反拉法检测 锚下有效预应力 夹片式锚具 握裹力 有限元分析 

分 类 号：U446[建筑科学—桥梁与隧道工程]