【作者】 张婷婷；

【导师】 项贻强；

【作者基本信息】 浙江大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 桥梁工程的基本特点是投资巨大、技术复杂、工程涉及面广、工程寿命周期长、一旦发生事故又影响重大。桥梁工程从立项到长期运营过程中都存在着各种难以预料的因素,工程建设中发生失败、失策对经济建设都将会带来不可估量的损失。建立桥梁工程风险评估体制,研究其风险评估理论、方法和管理规程,并对工程项目的各阶段展开风险评估,将有助于完善桥梁建设管理体制,制定应对桥梁风险的有效措施,以期达到以最小的成本获得工程最大的安全保障。本文以台缙高速东延段灵江大桥建设工程为背景,分析桥梁从建设方案论证阶段到运营期间各典型风险事态的风险因素组成,利用定性方法进行风险识别,列出风险清单。对识别后的风险做进一步分析,采用定性和定量两类方法,利用模糊综合评价方法,建立风险损失模型和风险概率模型。提出风险概率等级标准、风险损失等级标准以及风险评价矩阵。通过风险概率和风险损失的计算获得对桥梁风险事态的估计。在成桥前期阶段,桥梁方案设计的选择受到桥梁所处位置自然环境、经济性以及施工工艺复杂程度等因素的影响,其风险也是不同的。因此,通过灵江大桥的设计风险分析,从预应力混凝土连续梁桥、矮塔斜拉桥和独塔斜拉桥三个方案中选取了结构设计合理、风险相对合理的矮塔斜拉桥方案。在此基础上,对其投资风险进行了分析,并提出设计风险和投资风险的控制措施。在施工阶段,下部结构施工方案的选择受到施工现场的通航、地质水文、气候及施工条件等因素的影响。本文拟定双壁钢围堰结合混凝土拌合船和搭设栈桥两种下部结构的施工方案,对其各自的施工风险进行识别和分析,选定施工风险相对较小、费用稍高、结构稳固、施工抵御台风及抗潮汐能力强的栈桥施工方案。在运营阶段,考虑到灵江船运比较繁忙的通航状况,着重分析比较目前使用比较广泛的几个船撞桥的模型,提出采用AASHTO模型来对灵江大桥进行船撞风险分析,结果表明尽管船撞的风险较低,但还是应该采取降低船撞风险的措施加以改进。论文还在最后综合概括桥梁工程建设风险管理的目标、内容、策略、流程等基础上,初步编制提出了桥梁工程建设风险管理的规程,可供有关部门参考。更多还原

【Abstract】 The bridge engineering has long project life cycle, needs huge investment and complex technology, involves wide ranges, and once an accident happens, the impact is significant. From project establishment to long-term operational process, the bridge engineering possesses various factors that are difficult to predict, which will bring immeasurable loss to economic development if the failure of construction occurs. Building risk assessment system, studying the theory, method and management regulation of risk assessment of the bridge engineering and carrying out risk assessment in all stages of the project will help to improve the building management system of bridges, develop effective measures to deal with the risk of bridges and finally gain the greatest security with the minimum cost.The background of this paper focused on the building of Lingjiang Bridge of the eastern extension segment of TaiJin Highway. We analyzed the composition of the risk factors of the typical risk situation, used the qualitative method to identify the risks and listed the risks. To analyze risks after identifying, we used the qualitative and quantitative methods and the Fuzzy Comprehensive Evaluation to establish the Loss Model and the Probability Model of the risks. We put forward the grading standards of the probability and the loss of the risks and the risk assessment matrix. We obtained the estimate of the bridge risk events through calculating the probability and the loss of the risks.During the design stages, the bridge design programs are affected by the factors including the environment of a bridge location, cost and the complexity of construction technology, etc. The risk of each design is different. Therefore, after analyzing the design risk of Lingjiang Bridge, we chose the cable-stayed bridge with low towers from the three options including prestressed concrete continuous girder bridge, cable-stayed bridge with low towers and cable-stayed bridge with one tower for its reasonable structural design and risk. On this basis, we analyzed the invest risk and then proposed the control measures of design risk and investment risk. During the construction stage, the choice of the substructure construction plan is affected by the factors of navigation, geology, hydrology, climate and construction con-dition, etc. We proposed two construction programs of substructure-double-wall steel cofferdam and construction site. We identified and analyzed their construction risk and then chose the construction site construction program for its less risk, structural stability, withstand strong typhoons and tidal resistance though the fee is higher.During the operational stage, considering busy navigation of Lingjiang, we analyzed several ship collision models that commonly used at present and then proposed the AASHTO Model to evaluate the ship collision risk of Lingjiang Bridge. The results showed that though the ship collision risk was low, it still should take measures to reduce the risk of ship collision.Finally, we draw up the management regulation of building risks of bridge engineering on the basis of generalizing the objective, content, strategy and process of the management regulation of building risks of bridge engineering.更多还原