跨座式单轨刚构体系钢轨道梁的墩梁固结构造研究

墩梁固结构造是刚构体系钢轨道梁桥的关键部位。通过比较焊接连接、嵌套式连接、预应力锚栓连接三种墩梁固结构造方案,创新性地提出传力机理可靠、疲劳性能优越、可实施性好的预应力锚栓连接方案,并在此基础上进行锚固构造的锚固能力及预应力锚栓受力验算,以及锚固构造稳定性计算,锚固构造的应力计算,以此指导此类桥梁的设计工作。

设缝双肢墩曲线刚构桥抗震性能研究

双肢墩和整体式桥墩在刚构桥上使用较多,但整体墩多用于高墩,双肢墩柔性好但布置较为复杂。介绍了一种新型设缝双肢墩,并通过建立ANSYS有限元模型,分析比较4种结构形式:连续曲线梁桥、设缝双肢墩曲线刚构桥、双肢墩曲线刚构桥、整体墩曲线刚构桥的动力特性,并通过反应谱法对其进行抗震性能评估。结果表明:4种结构形式的低阶振型主要是桥墩变形,桥墩是较为薄弱的构件;采用设缝双肢墩与双肢墩的刚构桥自振频率和振型结果较为接近;两者的墩底剪力均略大于连续梁,远小于整体墩刚构桥。可见,设缝双肢墩的抗震性能与双肢墩接近,但外观上更简洁美观,适合用于曲线刚构桥上。

Simulation research on the energy dissipation and shock absorption performance of a swing column device based on fuzzy control

Double-column bridge piers are prone to local damage during earthquakes,leading to the destruction of bridges.To improve the earthquake resistance of double-column bridge piers,a novel swing column device(SCD),consisting of a magnetorheological(MR)damper,a current controller,and a swing column,was designed for the present work.To verify the seismic energy dissipation ability of the SCD,a lumped mass model for a double-column bridge pier with the SCD was established according to the low-order modeling method proposed by Steo.Furthermore,the motion equation of the double-column bridge pier with the SCD was established based on the D′Alembert principle and solved with the use of computational programming.It was found that the displacement response of the double-column bridge pier was effectively controlled by the SCD.However,due to rough current selection and a time delay,there is a significant overshoot of the bridge acceleration using SCD.Hence,to solve the overshoot phenomenon,a current controller was designed based on fuzzy logic theory.It was found that the SCD design based on fuzzy control provided an ideal shock absorption effect,while reducing the displacement and acceleration of the bridge pier by 36.43%‒40.63%and 30.06%‒33.6%,respectively.

蒙内铁路圆端形桥墩托盘、顶帽裂缝分析与加固

在铁路桥圆端形桥墩设计中,托盘受力较为复杂,针对蒙内铁路桥梁部分墩台出现裂缝的情况,对铁路桥墩托盘顶帽建立实体模型并进行力学分析。对比分析在不同工况及加固方案下,桥墩托盘的受力分析结果。研究表明:采用CFRP材料对托盘裂缝处进行加固处理后,托盘的应力明显减小。此研究结果对托盘裂缝处理有一定的实际指导意义。

不同参数对连续刚构桥抗震性能的影响分析

为了解地震多发区发生地震时对连续刚构桥的影响,以某连续刚构桥为例,采用MIDAS/Civil有限元软件,对不同墩高比、支座摩擦力和梁台间隙对连续刚构桥抗震性能的影响进行了模拟分析,为该类桥梁的抗震设计提供了科学依据,为中西部地区桥梁的抗震设计提供了有益的借鉴。

罕遇地震作用下钢筋混凝土框架-剪力墙结构的耗能机制分析

为了确定钢筋混凝土框架-剪力墙结构在强震作用下的合理耗能机制,对多个结构算例进行多条强震记录作用下的弹塑性时程分析。通过分析总累积耗能在各类构件中的分配和各类构件耗能沿结构高度方向的分布模式,研究结构的典型耗能机制类型,讨论耗能机制与结构参数的关系,并对不同的耗能机制进行评价。结果表明,"强墙肢弱连梁"整体型耗能机制使结构具有良好的抗震性能,应作为结构耗能机制设计的目标,"强连梁弱墙肢"耗能机制则应予以避免;连梁与墙肢的相对刚度关系是影响结构耗能机制的关键因素,框架和剪力墙相对数量的改变则不会明显影响结构耗能机制。对具有小跨高比连梁的结构,建议采用连梁水平分缝措施引导结构形成"强墙肢弱连梁"耗能机制,并通过算例分析验证了该措施的有效性。