考虑桩土效应的波纹钢腹板连续刚构桥的地震响应研究

发布时间：2018-01-30 22:56

本文关键词： 波纹钢腹板连续刚构桥桩土效应有限元方法动力特性地震响应　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：波纹钢腹板连续刚构桥作为近年来逐渐兴起的新型桥梁,其在构造、受力性能和经济效益等方面,与一般的混凝土腹板连续刚构桥相比都具有较大的优势。国内对该类桥的研究还主要集中在静力性能方面,对于其在考虑桩土效应的地震响应研究较少,也较为单一。因此,以小砂沟波纹钢腹板连续刚构桥为工程背景,建立多种桩土效应分析模型,着重研究了桩土效应对波纹钢腹板连续刚构桥动力特性及地震响应的影响,以及合理考虑桩土效应后,与等效的混凝土腹板连续刚构桥相比,其动力特性与动力响应的差别。主要工作及结论如下：(1)建立直接嵌固、等效嵌固、六弹簧及m法四种不同的桩土效应分析模型进行动力特性的对比研究。结果表明：同阶模态对应的自振频率按直接嵌固模型、等效嵌固模型、六弹簧模型、m法模型依次减小,这说明桩土效应使桥梁结构刚度降低,延长了自振周期。(2)采用多振型反应谱法对四种桩土效应分析模型在E1地震作用下的地震响应进行对比研究。结果表明：各模型的位移响应按直接嵌固模型、等效嵌固模型、六弹簧模型、m法模型依次增大；直接嵌固模型与m法模型内力响应的差别,说明考虑桩土效应后,桥梁下部结构的地震响应减小,但整体的地震响应结果并不总偏于安全,由此论证考虑桩土效应的必要性；等效嵌固模型的内力响应与m法模型相差不大,总体上要略大于m法模型；六弹簧模型的内力响应与m法模型的差距都在5%以内,略小于m法模型。由此确立m法模型相对能更好地模拟桩土效应。(3)根据嵌固深度H的不同,建立3D嵌固模型、H嵌固模型及5D嵌固模型探究嵌固深度H对等效嵌固模型动力特性及动力响应的影响。结果表明：随着嵌固深度H的增大,等效嵌固模型的各向刚度减小,自振周期增大,地震响应增大。(4)对采用m法考虑了桩土效应的波纹钢腹板连续刚构桥和普通腹板连续刚构桥进行动力特性的对比研究。结果表明：二者低阶自振频率相差很小,高阶频率相差较大,且波纹钢腹板连续刚构桥的自振频率总体上小于混凝土腹板连续刚构桥。(5)采用动态时程分析法对两种连续刚构桥在E2地震作用下的地震响应进行对比研究。结果表明：考虑桩土效应后,波纹钢腹板连续刚构桥在相同地震作用下的地震响应比普通混凝土腹板连续刚构桥小,具有较好的抗震性能。
[Abstract]:Corrugated steel web continuous rigid frame bridge, as a new type of bridge, has been developed in recent years. Compared with the common concrete web continuous rigid frame bridge, the research of this kind of bridge is mainly focused on static performance, and the seismic response of the bridge considering pile-soil effect is less. Therefore, taking the continuous rigid frame bridge with corrugated steel web as the engineering background, a variety of pile-soil effect analysis models are established. The influence of pile-soil effect on the dynamic characteristics and seismic response of corrugated steel web continuous rigid frame bridge is emphatically studied, and compared with the equivalent concrete web continuous rigid frame bridge after considering the pile-soil effect reasonably. The main work and conclusions are as follows: 1) establishing direct and equivalent inlay. The dynamic characteristics of four different pile-soil effect analysis models of six spring and m method are compared and studied. The results show that the natural vibration frequency corresponding to the same mode is directly embedded model, equivalent embedded model, six spring model. The m-method model decreases in turn, which indicates that the pile-soil effect reduces the stiffness of the bridge structure. The period of natural vibration is prolonged. The seismic response of four kinds of pile-soil effect analysis models under E1 earthquake is studied by using multi-mode response spectrum method. The results show that the displacement response of each model is directly embedded model. The equivalent inlay model, the six-spring model and the m method model increase in turn. The difference between the internal force response of the direct embedded model and the m method model shows that the seismic response of the bridge substructure decreases after considering the pile-soil effect, but the overall seismic response results are not always safe. The necessity of considering pile-soil effect is demonstrated. The internal force response of the equivalent embedded model is not different from that of the m-method model, and is slightly larger than that of the m-method model as a whole. The internal force response of the six-spring model is within 5%, which is slightly smaller than that of the m-method model. Thus, the m-method model can be used to simulate pile-soil effect better than the m-method model.) according to the difference of the embedded depth H, the m-method model can be used to simulate the pile-soil effect. The dynamic characteristics and dynamic response of the equivalent embedded model were investigated by establishing the 3D and 5D embedded models. The results show that the effect of the embedded depth H on the dynamic characteristics and the dynamic response of the equivalent embedded model increases with the increase of the embedded depth H. The stiffness of each direction of the model decreases and the natural vibration period increases. Increased seismic response. The dynamic characteristics of corrugated steel web continuous rigid frame bridge and ordinary web continuous rigid frame bridge are studied by m method. The results show that the difference of low order natural vibration frequency between them is very small. The difference of high-order frequency is large. The natural vibration frequency of corrugated steel web continuous rigid frame bridge is generally smaller than that of concrete web continuous rigid frame bridge. The seismic responses of two kinds of continuous rigid frame bridges under E2 earthquake are studied by dynamic time history analysis. The results show that the pile-soil effect is taken into account. The seismic response of corrugated steel web continuous rigid frame bridge under the same earthquake is smaller than that of ordinary concrete web continuous rigid frame bridge.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.23;U442.55

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