基于传统预应力张拉工艺的箱梁桥腹板开裂风险概率分析  

Analysis on Probability of Web Cracking Risk of Box Girder Bridge Based on Traditional Prestress Tensioning Technology

作　　者：陈强[1] 

机构地区：[1]湖南城市学院,湖南益阳413000

出　　处：《公路交通科技》2014年第8期91-95,112,共6页Journal of Highway and Transportation Research and Development

基　　金：湖南省教育厅科技计划项目(2012GK3066)

摘　　要：建立了采用传统竖向预应力技术的箱梁桥腹板主拉应力随时间变化模型,考虑混凝土强度、螺纹钢强度等参数的时变性和随机性,以腹板内主拉应力达到容许应力限值为极限状态,发展了采用传统预应力张拉工艺的箱梁桥腹板开裂概率模型。基于Monte-Carlo模拟方法,计算了服役期内腹板开裂风险,并对相关参数进行敏感性分析。研究表明在本文设计参数条件下,设计使用年限内的腹板最大开裂风险概率为1.49%;敏感性分析表明精轧螺纹钢筋纵向间距和锚具变形与钢筋回缩对腹板开裂影响最大;安装偏差角度次之;箍筋数量对腹板开裂风险影响最小。The model of principle tensile stress in webs of box girder bridge varying with time using traditional vertical prestressing technology is developed. Considering the randomness and time variation of the strengths of concrete and reinforcement, the allowance stress of principle tensile stress in webs is taken as limit state, a probabilistie model of web cracking of box girder bridge is developed using traditional prestressing technology. Based on Monte-Carlo simulation method, the cracking risk of webs over service time is calculated, and the relative parametric sensibility is analysed. It is found that （ 1 ） based on the design parameters, the maximum probability of cracking of webs in designed service time is 1.49%. The sensibility analysis shows that the longitudinal spacing of finishing reinforcement, the anchorage deformation and the reinforcement shrinkage have a maximum influence on cracking of web, the influence of assembling deviation angle is second, and the quantities of stirrups have a lowest influence on web cracking of box girder bridge.

关 键 词：桥梁工程 腹板开裂 MONTE-CARLO方法 竖向预应力损失 敏感性分析 

分 类 号：U447[建筑科学—桥梁与隧道工程]