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混凝土梁桥施工期与使用期安全评估
Safety Assessment for Concrete Beam Bridge during Construction and Service Life
【作者】 李凯;
【导师】 王春生;
【作者基本信息】 长安大学 , 桥梁与隧道工程, 2012, 硕士
【摘要】 混凝土梁式桥由于其结构简单、施工方便且具有良好的受力特性,因此在我国的大中型桥梁中普遍使用。国内外针对混凝土梁式桥的安全评估开展过大量的研究工作,但对于施工期结构构件的安全评估较少。本文以实际工程为背景,对广泛存在于我国的混凝土梁式桥进行桥梁施工期与使用期的安全评估。本文首先研究了国内外混凝土梁桥全寿命周期的安全评估方法、指标研究现状调查分析,掌握目前的最新研究成果,并分析成果中的不足;其次以承朝高速混凝土梁式桥为工程背景,通过分析混凝土梁桥的受力特点,提出了混凝土梁式桥在桥梁施工过程中结构可能面临的安全问题。第三,本文中通过对混凝土梁桥安全评估方法的比选,最终采用层次分析法(The analytic hierarchy process, AHP)对混凝土梁桥的施工期风险进行了定性与定量的评价,通过评定,对混凝土梁式桥施工过程中的风险在宏观上有所把握,并且筛选出其中的主要风险因素。以此为基础,对施工过程中的混凝土梁式桥进行结构安全定量评价,对结构可能出现的风险进行分析评定,并且对混凝土梁式桥的主要风险因素进行了有针对性的研究。最终,通过分析比对结构可靠度的实用计算方法,采用一次二阶矩法对施工期混凝土梁桥主梁构件在关键施工阶段承受运梁车、混凝土罐车等特殊施工荷载时的可靠度进行了计算,通过比对评价指标进行主梁的安全评估。通过对混凝土梁式桥使用阶段的调查研究,分析总结梁式桥在正常使用极限状态下结构构件的安全性。经过分析,决定针对正常使用阶段的挠度进行了安全评价,得出正常使用极限状态下混凝土梁式桥主梁构件的挠度可靠指标。最后,对结构体系可靠度进行了研究,通过对梁式桥结构体系可靠度概念、影响因素以及计算方法的总结分析,针对混凝土梁式桥主梁体系可靠指标,采用窄界限法等进行了相关的计算,得出相应梁式桥结构体系的可靠指标。
【Abstract】 Due to the simple structure form and easy construction, concrete girder bridge was used a lot inlarge and medium-sized bridges in China. A lot of work have been done about the safety assessment forconcrete beam bridge at home and abroad, but less study exist for the safety assessment of the structuralelements of the construction period. Based on the practical engineering, this paper conducts safetyassessment for concrete beam bridge in construction and service life.Firstly, this paper studies safety assessment methods in the full life cycle of the domestic andinternational concrete girder bridge, indicators of investigation and analysis, to master the latest researchresults, and analyze the shortage of the achievements. Secondly, this paper analysis the working stage ofconcrete girder bridge, and put forward the security problems of the concrete beam bridge structure in thebridge construction process basing on the Chengde City, Hebei Province engineering. Third, evaluationmethods were compared, using the analytic hierarchy process for the construction period concrete beambridge the risk carried out for the qualitative evaluation ultimately. The main risks factors were filtered outthrough the assessment of beam bridge construction process risks at the macro level.Analysis the safety assessment of concrete beam bridge, the paper evaluates the possible risks andstudies the major risk factor for concrete beam bridge. In the end, through the analysis of the practicalcalculation method of structural reliability, the FOSM method was choose for the calculation of the typicalconcrete beam bridge. The paper calculates the degree of reliability of the typical concrete beam bridge atthe Construction Stage when the concrete beam born the loading of transporting girder vehicle, concretetank trucks. Through the comparison the safety of the main beam was evaluated.This paper research the security of the structural components of the beam bridge in the serviceabilitylimit state. After analysis, we decide to evaluate the deflection during normal use stage. At last, the papercalculate the reliable indicator of the deflection about the concrete girder bridges.Finally, this paper studies the reliability of the structural system, and introduces the concept ofthe structural system reliability, the influence factor and the method of calculation. After that, the law of thenarrow limits was used to calculate the corresponding beam bridge structure system.
【Key words】 concrete beam bridge; element reliability; AHP; first order second moment; construction load; system reliability;
- 【网络出版投稿人】 长安大学 【网络出版年期】2013年 07期
- 【分类号】U448.34;U447
- 【被引频次】2
- 【下载频次】202