预应力混凝土简支梁桥锚下有效预应力分析

Research on Anchorage Effective Prestress Detection of Prestressed Concrete Simply Supported Beam Bridge

为了确定预应力混凝土简支梁桥在施工张拉与运营养护全寿命过程中结构锚固端锚下有效预应力值,基于梁挠曲变形理论与简支梁受力特性,推导出简支梁桥锚下有效预应力计算公式,并提出了一种预应力混凝土简支梁桥下有效预应力简便检测方法.以某40 m预制简支T梁桥为依托工程,通过对不同工况下简支梁桥跨中挠度值与锚固端有效预应力值进行测量,计算了不同工况下简支梁桥锚下有效预应力值,并与实测值进行了比较.研究结果表明:本文所提简支梁桥锚下有效预应力计算公式能较准确预测锚固端有效预应力值,依托工程简支梁桥锚下有效预应力公式计算值与实测值相对误差最大仅为4.83%,计算精度满足工程需求;所提出的预应力混凝土简支梁桥锚下有效预应力简便检测方法可为桥梁全寿命预测提供指导与借鉴.

To determine effective under-anchor prestress value of the anchorage end of the prestressed concrete simply supported beam bridge in the whole life processes of the construction and the operation maintenance prestressed value,based on the beam deflection theory and the mechanical characteristics of the simply supported beam,the formula of the effective under-anchor prestress of the beam bridge is deduced.A simple detection method is proposed to determine the effective prestress of the prestressed concrete simply-supported beam bridge.Based on a 40 m prefabricated simply-supported T-girder bridge,the effective prestress under the anchor of the simply-supported girder bridge under different working conditions is calculated through measuring the mid-span deflection and the effective prestress at the anchorage end of the simply-supported girder bridge,and compared with the measured values.The results show that the proposed formula for the effective under-anchor prestress of the simply supported beam bridge can accurately predict the effective prestress at the anchor end.The maximum relative error between the calculated value and the measured value is only 4.83%,and the calculation accuracy meets the engineering requirements.The proposed simple detection method of effective under-anchor prestress can provide guidance and reference for the whole life prediction of the bridge.