If there’s one thing clear about the National Transportation Safety Board’s recent release of documents on last year’s Florida International University bridge collapse, it’s that the spin machines have been running at full speed. As expected, contractor MCM and engineer FIGG Bridge Engineers, the pedestrian bridge’s contractor-led design-build team, have accused each other of being at fault.

NTSB将于10月22日进行演示关于灾难的最终报告。如果除了评估原因外，董事会可以做工程和建设，这是一个很大的青睐，它定义了两个关键行业概念，这些概念是MCM-FIGG崩溃论点的中心。

The first is constructibility, as it relates to the bridge design’s independent peer review.

在佛罗里达州运输部的同行评审范围中阐明了所需的构造性。

路易斯·伯杰集团（Louis Berger Group）与FIGG合同进行了61,000美元的合同，该审查已成为一个闪点。

伯杰（Berger）签订了制定有限元模型，确定每个桥梁元素所需的内容，以及审查基础，子结构和上层建筑计划。当将异常的混凝土桁架结构插入到位时，合同未指定扭曲负载的审查，审查也不包括节点和连接所需的所有计算。

Berger certified that the peer review was conducted according to state rules, but FIGG now claims that “Louis Berger, unbeknownst to FIGG, completely failed in their role” by not analyzing loads when the bridge was moved and not reviewing truss connections in greater detail.

为什么在项目期间或经过几个月的同行评审后都没有出现。NTSB需要阐明谁负责有限的审查范围。

A more important concept is redundancy in the bridge design. A U.S. Labor Dept. OSHA report on the disaster released in June criticized FIGG for producing a bridge design that is non-redundant.

The report defined redundancy as multiple load paths that would prevent total collapse if one structural component or system failed.

FIGG argues that there are two other types of redundancy in addition to load paths. One is internal redundancy, in which a member is composed of multiple parallel elements. Another is a different type of structural redundancy, the engineer says, “due to static indeterminacy such as structures continuous over support.”

该公司表示，它为行人桥设计提供了冗余功能，其中包括多个平行的加固条和/或预应力肌腱以及完成后连续的上层建筑。

FIGG还说，没有与混凝土桥的冗余有关的州或联邦法规规定。

NTSB澄清和验证这些论点的努力将有助于行业同行从佛罗里达悲剧中汲取重要的教训，以及现在的后果。