【作者】 张敏；

【导师】 宁晓骏；

【作者基本信息】 昆明理工大学 ， 建筑与土木工程（专业学位）， 2018， 硕士

【摘要】 连续刚构桥兼具连续梁桥和T型刚构桥的受力特点,其受力合理、外形简洁美观、具备良好的行车条件、抗震性能良好,同时其造价较低、施工方法成熟、具有较大的跨越能力、对地形地质条件适应性较好,因此连续刚构桥在实际工程中得到了广泛的应用。但是目前连续刚构桥的设计多以经验为主,辅以计算,这样的设计往往过于保守,还会存在设计缺陷的遗传性。为了使连续刚构桥的设计更加科学经济,很有必要在现有设计经验的基础上,对连续刚构桥的设计参数进行动力响应优化。而目前连续刚构桥的优化研究中,存在着优化变量选择不全面、优化目标不明确、优化目标过于单一、优化算法的选取具有随意性问题,并且对于正交试验下的优化结果没有进行相应的对比验证,以及上下部设计参数统筹考虑下优化结果是否优于仅考虑下部设计参数时的情况。针对上述存在的问题,本文主要完成以下几个方面工作:(1)根据不同设计参数对连续刚构桥受力影响,确定了优化时的设计变量和设计常量。连续刚构桥的下部设计参数中,双肢薄壁墩墩间距、薄壁墩墩厚、薄壁墩墩壁厚度以及横系梁个数为设计变量,其余设计参数均视为设计常量。连续刚构桥的上部设计参数中,边中跨比为设计变量,其余设计参数均视为设计常量。连续刚构桥上下部参数统筹考虑下,双肢薄壁墩墩间距、薄壁墩墩厚、薄壁墩墩壁厚度、横系梁支数以及边中跨比为设计变量,其余设计参数均视为设计常量。(2)对于连续刚构桥的优化目标,在地震作用下以实际作用效应和允许作用效应之比最小和疲劳损伤系数最小为优化目标。(3)对目前国内外已建成的连续刚构桥参数进行归纳整理,得出相应的使用范围。对于连续刚构桥的优化目标,在地震作用下,根据不同的地震响应情况,提出了基于E1弹性时程作用下墩底抗弯能力需求比最小和E2弹塑性时程作用下墩底延性转角需求比最小、疲劳损伤系数最小及墩底延性转角需求比和疲劳损伤系数统筹考虑下多目标函数值最小的四类优化目标。(4)在进行优化算法的选取上,本文根据多目标函数下同时取最优解的情况,采用了评价函数方法中极小距离理想点法进行多目标优化。(5)运用动力时程分析方法,对正交试验下的下部参数组合试验模型进行计算分析,得出地震响应下最优试验组合和不同设计参数对试验的影响程度。(6)基于Java语言下随机组合的筛选,进行动力时程分析计算,得出最优试验组合与正交试验下的最优组合对比。(7)统筹考虑上下部设计参数,进行动力时程分析,得出正交试验下的最优试验组合和不同设计参数对地震响应的影响,与仅考虑下部设计参数下的最优组合进行对比。更多还原

【Abstract】 The continuous rigid frame bridge has the mechanical characteristics of the continuous beam bridge and the T-shaped rigid frame bridge.Its force is reasonable,its appearance is simple and beautiful,it has good driving conditions,and its seismic performance is good.At the same time,its construction cost is low and the construction method is mature.Large spanning capacity and adaptability to terrain and geological conditions are good,so continuous rigid frame bridges have been widely used in practical projects.However,the design of continuous rigid-frame bridges is mostly based on experience and supplemented by calculations.Such designs are often too conservative and there is also the inheritance of design flaws.In order to make the design of the continuous rigid frame bridge more scientific and economic,it is necessary to optimize the dynamic response of the design parameters of the continuous rigid frame bridge based on the existing design experience.However,in the current optimization study of continuous rigid frame bridges,there are problems such as incomplete selection of optimization variables,unclear optimization objectives,over-optimized optimization goals,and the selection of optimization algorithms,and there are no corresponding results for the optimization results under orthogonal test.The comparison verification,and whether the optimization results of the upper and lower design parameters are considered better than when only the lower design parameters are considered.In response to the above problems,this paper mainly completes the following aspects of work:(1)According to the influence of different design parameters on the force of the continuous rigid frame bridge,the design variables and design constants during optimization are determined.In the design parameters of the continuous rigid frame bridge,the distance between the thin-wall piers,the thickness of the thin-walled piers,the thickness of the thin-wall piers and the number of horizontal beams are the design variables.The rest of the design parameters are regarded as design constants.In the upper design parameters of the continuous rigid frame bridge,the mid-span ratio is the design variable,and the rest of the design parameters are considered as design constants.Under the consideration of the overall parameters of the continuous rigid frame bridge,the distance between the thin-walled piers,the thickness of the thin-walled piers,the thickness of the thin-walled piers,the number of the horizontal beam,and the mid-span ratio are the design variables.The rest of the design parameters are As a design constant.(2)For the optimization goal of continuous rigid frame bridges,the objective of optimization is to minimize the ratio of actual effect and allowable effect and to minimize the fatigue damage factor under earthquake.(3)Summarize the parameters of the continuous rigid frame bridges that have been built at home and abroad,and draw the corresponding scope of use.For the optimization goal of the continuous rigid frame bridge,under the action of earthquake,according to different seismic response conditions,the ductility corner of the pier bottom under the effect of the E1 elastic time history and the minimum requirement of the flexural capacity of the pier bottom and the E2elastic-plastic time course are proposed.There are four types of optimization objectives with the smallest demand ratio,the smallest fatigue damage coefficient,the required ratio of ductile corners,and the fatigue damage coefficient.(4)In the selection of the optimization algorithm,this paper adopts the minimum distance ideal point method in the evaluation function method to perform multi-objective optimization according to the situation that the multi-objective function simultaneously takes the optimal solution.(5)Using the dynamic time history analysis method,the lower parameter combination test model under orthogonal test is calculated and analyzed,and the degree of influence of the optimal test combination and different design parameters on the test under seismic response is obtained.(6)Based on the selection of random combinations in the Java language,dynamic time history analysis is performed to obtain the optimal combination comparison between the optimal test set and the orthogonal test.(7)Overall consideration of the design parameters of the upper and lower parts,and dynamic time history analysis,to obtain the influence of the optimal test combination and different design parameters under orthogonal test on the seismic response,compared with the optimal combination considering only the lower design parameters.更多还原