某多跨空腹式箱形拱桥倒塌成因分析

摘要

In this paper, a box-shaped multi-span arch bridge collapsed fasting accident, for example, ana-lyze the causes of its collapse. First, the bridge collapse accident scene investigation, proved a bit of geologi-cal bridge pier foundation and Conditions; secondly, according to the findings of the arch structure was seized count;moreover, considering the effect of cutting down on the pile bearing capacity of the river bed;the results show that under the riverbed leads to the bridge substructure cut transition from low pile platform for high pile caps, this time the stakes withstand compressive stress is greater than its carrying capacity, the stakes can not bear the weight of the upper structure, leading to the occurrence of arch collapsed.%本文以某多跨空腹式箱形拱桥倒塌事故为例，对其倒塌成因进行了分析。首先，对桥梁倒塌事故现场进行了调查，探明了桥墩基础及桥位地质条件情况；其次，根据调查结果对拱桥结构进行了检算；此外，考虑了河床下切对桩基承载力的影响；分析结果表明，河床下切导致该桥下部结构从低桩承台转变为高桩承台，此时木桩承受的压应力大于其承载能力，木桩已经不能承担上部结构自重的作用，导致拱桥发生倒塌。