PC薄壁宽幅空心板纵向开裂原因分析及加固措施

发布时间：2018-06-15 03:26

本文选题：板梁桥 + 薄壁宽幅空心板　；参考：《世界桥梁》2017年02期

【摘要】：针对目前预应力薄壁宽幅空心板桥普遍发生的底板纵向开裂现象,以某高速公路薄壁宽幅空心板桥为背景,分别采用弹性地基梁比拟法、有限元法和足尺模型扭转试验法分析该桥空心板底板开裂原因。该薄壁宽幅空心板桥上部构造均为20m后张法预应力混凝土宽幅空心板(混凝土为C40),每跨横向各设8片空心板。理论和有限元计算得出最大扭矩作用下空心板最大横向拉应力分别为2.23MPa、2.35MPa(角隅处),大于C40混凝土抗拉强度设计值。基于荷载叠加原理进行了空心板足尺扭转试验,试验值与计算值趋势一致,进一步表明畸变效应是导致纵向开裂的主要原因。根据纵向裂缝的特征及其原因,提出采用粘贴钢板法对板梁进行加固,并运用有限元程序ANSYS计算了加固后板梁的横向拉应力,验证了加固方案的可行性。
[Abstract]:Aiming at the phenomenon of longitudinal cracking of bottom slab of prestressed thin-walled wide hollow slab bridge, the elastic foundation beam analogy method is adopted in this paper, taking the thin-walled and wide-width hollow slab bridge of a highway as the background. Finite element method and full-scale model torsion test method are used to analyze the cracking reason of hollow slab floor of the bridge. The superstructure of the thin-walled wide hollow slab bridge is 20 m later, the Zhang Fa prestressed concrete wide hollow slab (concrete is C40), each span is divided into 8 hollow slabs. Theoretical and finite element calculations show that the maximum transverse tensile stress of hollow slabs subjected to maximum torque is 2.23 MPA / 2. 35 MPa (corner / corner), which is larger than the design value of C40 concrete tensile strength. Based on the principle of load superposition, the full-scale torsion test of hollow slabs is carried out. The experimental values are consistent with the calculated values, which further indicates that the distortion effect is the main cause of longitudinal cracking. According to the characteristics of longitudinal cracks and their causes, the method of sticking steel plate is put forward to reinforce the slab beam, and the transverse tensile stress of the strengthened slab beam is calculated by the finite element program ANSYS, which verifies the feasibility of the strengthening scheme.
【作者单位】：江西赣粤高速公路股份有限公司;江西省交通科学研究院;
【基金】：江西省交通运输厅科技计划项目(2014C0001)
【分类号】：U445.72

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