甬江铁路混合梁斜拉桥钢混结合段关键施工技术

钢箱梁与混凝土箱梁的连接是混合梁斜拉桥的关键点,为混合梁关键传力结构。在甬江铁路混合梁斜拉桥钢混结合段施工中,钢混结合段采用模块组拼法施工。详细介绍了钢混结合段模块吊装、滑移、定位等组拼技术,BIM模拟PBL剪力键及预应力筋定位技术,以及补偿收缩混凝土分区浇筑技术,并总结了钢混结合段施工控制要点。     

Sensor placement for structural damage detection with modal data

A new method is presented for prioritizing sensor locations for structural health monitoring (SHM). In view of the needs of SHM and damage detection,sensor locations are optimized for the purpose of both sensitivity for local damages and independence of the target mode. However,the two different optimization criterions lead to an inconsistency of the optimal result. Considering the structural response changes that result from damage,the relationship between the structural response and damage is deduced from the structural motion equation by a quasi-analytical mode. Based on the harmony between damage identifiability and mode observability,an object function is set up,including the information of mode independence and damage sensitivity. Utilizing the technique of singular value decomposition,an interior algorithm for the optimum sensor placement is proposed with the multiple objective criterions of minimizing the condition number of coefficient matrix and maximizing the fisher information matrix. A numerical example shows that this approach can effectively avoid the contradiction between the two different optimization criterions. Comparing with the result of single object,the result of damage detection from the optical sensor locations is much more accurate.     

独塔单索面部分斜拉桥非对称施工技术

依托余姚中山路斜拉桥项目,针对独塔单索面部分斜拉桥的结构特点,并结合该桥的周围环境,主桥主梁采用支架现浇和悬臂浇筑结合的非对称施工方法.根据悬臂现浇对称性施工原则和力学原理,建立不利条件下一侧挂篮一侧支架法现浇施工的新工艺,在支架侧先行施工一个节段,为菱形挂篮提供配重,经过体内预应力和体外斜拉索张拉,可有效保证结构安全...     

下承式钢管混凝土拱桥拱肋施工支架安全性研究

某主跨２００ｍ的下承式钢管混凝土拱桥的钢管拱肋拟采用支架法进行原位拼装架设，而支架法鲜有应用于大跨径拱桥拱肋原位拼装施工的案例，为保证该拱肋施工支架的安全性，采用桥梁工程软件ＭＩＤＡＳ／Ｃｉｖｉｌ建立了该施工支架在施工期最不利受力状态下的三维有限元模型，进行了静力分析和空间稳定性分析计算支架在自重和横桥向风荷载作用下的应力、位移和弹性稳定系数。结果表明:支架的强度、刚度和稳定性均满足规范和设计要求，且支架横向稳定性的控制荷载为支架和拱肋自重，横桥向风荷载影响不大，验证了该施工支架的安全性。