不等五跨刚构-连续梁桥长期下挠影响参数分析

Analysis on Parameters Influencing Long-Term Downwarp of Unequal Five-Span Rigid-Frame Continuous Beam Bridge

摘要:

为探究桥梁工程中连续刚构跨中长期下挠的影响因素，采用数值模拟计算的方式，以某不等五跨刚构-连续梁桥为例，系统评估了纵向预应力损失、环境湿度变化、桥面铺装超重及底板混凝土超方等因素对跨中下挠的影响。研究结果显示：上述参数均会不同程度地导致跨中下挠，且其引起的挠度增长主要集中在前十年内；跨径越大，各参数变化对下挠的影响也越显著，其中预应力损失是引起跨中下挠的最主要因素，调平层超重的影响最为微弱，参数敏感性排序为预应力损失＞底板超方＞环境湿度。

Abstract:

To explore the factors influencing the continuous rigid-frame mid-span long-term downwarp in the bridge engineering, the numerical simulation and calculation method is used to systematically evaluate the factors, such as longitudinal prestress loss, environmental humidity variation, deck paving overweight and over-cubic concrete in bottom slab, influencing the mid-span downwarp based on an unequal five-span rigid-frame continuous beam bridge. The results indicate that all these factors contribute to varying degrees of mid-span downwarp, and its caused deflection growth is mainly concentrated within the first ten years. The larger the span length, the more significant the influence of each parameter change on downwarp, in which the prestress loss is the most main factor causing the mid-span downwarp, and the impact of overweight in the leveling layer is the weakest. The parameter sensitivity ranking is prestress loss > over-cubic concrete in bottom slab concrete > environmental humidity.