基于FTA-BIM的市政桥梁

钢围堰施工风险评估

王子豪

摘要

近年来我国水上市政桥梁工程建设不断发展，钢围堰由于良好的稳定性及防水挡土性能等诸多优势，已经成为最常见的水上基础支护类型之一。随着建设环境的不断复杂化，钢围堰施工的风险也不断增加。为了减少钢围堰施工可能造成的损失，本文结合支持向量机（SVM）、故障树分析法（FTA）、BIM技术等相关理论，对水上市政桥梁钢围堰施工风险评估展开了综合性的计算与分析。主要研究内容如下：

（1）综合考虑天气预报、邻近水系等影响因素，建立复杂水文地质环境下符合工程实际需求的中短期尺度水位预测，并结合工程实例构建样本集进行SVM训练测试与计算分析；

（2）针对水位变化的动态性、钢围堰施工风险的复杂性以及传统风险评估方法的不足，本文以SVM水位预测为关键支持技术，通过更新取证动态刻画水位因素的影响，然后结合FTA在定性定量分析、BIM在数据集成与可视化等方面的优势，提出基于FTA-BIM的钢围堰施工风险评估模型，并阐述模型的总体框架及应用流程，实现钢围堰施工的水文数据动态更新、风险评估可视化；

（3）以武汉市新河桥钢围堰施工为例，运用FTA-BIM模型重点研究发生钢围堰发生管涌渗水的风险。首先构建钢围堰结构、地质、水文、进度等相应的BIM模型、SVM水位预测更新模型、FTA模型；然后对FTA模型进行定性定量的计算分析；最后进行风险可视化表达与风险控制。

本文结合实际工程案例，对于FTA-BIM钢围堰施工风险评估模型的适用性及可靠性进行了综合分析与验证，为市政桥梁工程施工风险评估提供了新的思路与参考。

关键词：市政桥梁; 钢围堰施工；支持向量机；风险评估；故障树；BIM

Abstract

In recent years, China's water municipal bridge construction has been continuously developed. Steel cofferdams have become one of the most common types of water foundation support due to their many advantages such as good stability and waterproof retaining performance. As the construction environment continues to be complicated, the risk of steel cofferdam construction continues to rise. Therefore, in order to reduce the casualties and losses caused by steel cofferdam construction, this thesis combined support vector machine (SVM), fault tree analysis (FTA), BIM technology and other related theories to systematically analyze the risk assessment of steel cofferdam construction on water. The main contents are as follows:

(1) Combined with the influencing factors such as weather forecast and adjacent water system, the medium and short-term water level prediction in complex hydrogeological environment was established from the perspective of engineering actual demand, and the sample set was combined with engineering examples to carry out SVM training test and calculation analysis;

(2) In view of the dynamics of water level change, the complexity of steel cofferdam construction risk and the shortcomings of traditional risk assessment methods, this thesis took SVM water level prediction as the key support technology, dynamically depicts the influence of water level factors through update forensics, and then combined FTA with Qualitative and quantitative analysis, the advantages of BIM in data integration and visualization, the risk assessment model of steel cofferdam construction based on FTA-BIM was proposed, and the overall framework and application process of the model were expounded to realize the dynamic update of hydrological data of steel cofferdam construction and visualization of risk assessment;

(3) By taking a caisson of Xinhe Bridge in Wuhan as an example, the FTA-BIM model was used to study the risk of pipe seepage. Firstly, the BIM model of steel cofferdam structure and hydrogeology was constructed, and the FTA model was constructed by risk identification. Secondly, the fault tree was used to calculate and analyze the model qualitatively and quantitatively. Finally, the risk visualization and response were carried out.

Based on the actual engineering case, this thesis comprehensively analyzed and verified the applicability and reliability of FTA-BIM steel cofferdam construction risk assessment model, and provided new ideas and references for municipal bridge engineering construction risk assessment.

Key words: municipal bridge; steel cofferdam construction; support vector machine; risk assessment; fault tree; BIM