【作者】 金叔阳；

【导师】 张文献；

【作者基本信息】 东北大学 ， 结构工程， 2009， 硕士

【摘要】 中、小桥涵,中、短隧道,以及一般构造物的位置应服从路线走向[41]。近年来,新建中小跨径的斜交桥梁很多,而超斜铰接板桥(斜交角大于45°)也相应增加,其横向分布规律的简化计算及受力特点,亟待做深入研究,以便使设计更趋合理。本文研究超斜铰接板桥的荷载横向分布规律,以期找出有别于正交板的受力特点。文中从以往铰接斜板桥的已研究成果入手,提出了利用经验公式求超斜铰接板荷载横向分布影响线的方法。首先利用MIDAS/Civil有限元软件对8板、45°斜交角的某桥进行了分析。用剪力柔性梁格法,多次调整虚拟横梁截面形式、材料参数以及拟定铰接、支撑等边界条件,建立了可靠的有限元数值模型。为验证数值模型的合理性,制作了有机玻璃试验模型。为使试验模型尽量贴近原型,采用不完全铰的形式代替铰接缝,利用橡胶块粘结一端、另一端不粘结做为固定、滑动支座；采用量纲分析法计算,得出了相似判据。加载试验数据与数值模拟结果耦合很好,表明数值模型可靠。这种数值建模方法,可对多角度斜交桥做进一步数值分析。为了验证不同的宽跨比、抗扭刚度、抗弯刚度等是否影响耦合效果,又建立了正交铰接板桥的数值模型。通过改变宽跨比、板的抗扭刚度、抗弯刚度,施加半波正弦荷载进行横向分布规律的分析,并与成熟理论计算结果比对,相对误差很小,再次验证了数值建模可靠。文中采用剪力-柔性梁格法,对不同板块、不同斜交角的共56个铰接板桥进行了数值模拟,揭示了超斜铰接板桥中内力随斜交角变化的规律。给出的荷载横向分布影响线随斜交角变化的经验公式,经过理论解求算,证明经验公式计算的数值可靠。超斜铰接板桥的最大弯矩随斜交角增大而减小,可利用正桥的最大弯矩,通过经验公式求算。文中还给出了超斜铰接板桥主梁弯矩异于正桥的特点,可为此类桥的设计提供参考。更多还原

【Abstract】 The positions of Medium and small bridges, culverts, tunnels or general structures should obey the road line shapes. In recent years, many medium or small skew bridges had been built, and large-angle hinged skew slab bridges increase monotonically at the same time. In order to making bridge designing be more reasonable, transverse load distribution and mechanical characteristics of large-angle hinged skew slab bridges should be studied in deeply.Transverse load distribution of large-angle hinged skew slab bridges will be studied in this paper. And mechanical characteristics which are unlike to the ones of right bridge are expected to be discovered.According to the previous research results of hinged skew slab bridges, the method of calculating influence line of transverse load distribution by using empirical formula is put forward in this paper.Firstly, one bridge with 8 slabs,45°skew angle is studied with using FEA software-MIDAS/Civil. In order to establish a reliable numerical model, shear-flexible grillage method is adopted, section types and material parameters of virtual crossbeam are adjusted, and boundary conditions such as hinge joint, support condition are determined.Organic glass model is made for verifying the reasonableness of numerical model. In order to make the test model be as close as possible to the prototype model, using the form of incomplete hinged joints to replace real hinge joints, rubber blocks be bonded on one end as fixed bearings, the other side not bonded as sliding bearings. Then, similarity criterion is calculated with using dimensional analysis method. And the results of organic glass model has good coupling to numerical model, so numerical model can be considered as correct. This numerical modeling method can be used to analysis other hinged skew slab bridges with different angles.In order to verify if width-span ratio, torsional rigidity, flexural rigidity will impact the coupling effect, right bridge’s numerical model is established to be analysised. By changing slab’s width-span ratio, torsional rigidity and flexural rigidity, half-wave sinusoidal load loading on slabs, influence line of transverse load distribution is calculated. The results are compared with the theoretical calculation results. And the results of the two methods have small relative error, so numerical model can be considered as correct.There are 56 numerical models of hinged skew slab bridges with different slabs, different skew angles are established by shear-flexible grillage method, which reveal the relationships of internal force and skew angles. Empirical formulas of influence line of transverse load distribution with the skew angle coincide with theoretical calculation, so the empirical formulas are reliable.The maximum bending moments of large-angle hinged skew slab bridges decrease as the increasing of skew angle. It can be calculated with using empirical formulas on the base of having calculating right bridges’maximum bending moments.The characteristics of large-angle hinged skew slab bridges’bending moments which different with the right bridges are shown in this paper. It can give reference for designing other large-angle hinged skew slab bridges.更多还原