沉管节段接头剪力键结构形式合理性  

Structure reasonableness of segmental joint shear keys on immersed tunnel

作　　者：胡指南[1] 谢永利[1] 张宏光[1] 岳夏冰[1] 徐国平[2] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]中交公路规划设计院有限公司,北京100088

出　　处：《长安大学学报（自然科学版）》2015年第3期103-109,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：国家科技支撑计划项目(2011BAG07B01)

摘　　要：为了优化剪力键结构,改善剪力键受力,采用三维数值模拟软件对沉管节段接头剪力键的受力特性进行了分析,并将结果与大比例尺模型试验剪力键受力特征及破坏状态进行比较,得出了剪力键端角处局部压应力较大,剪力键与衬砌衔接处局部拉应力较大的受力特点。针对上述受力特点,提出了在剪力键与节段衔接处增设受拉钢筋,对剪力键的结构形式进行了3种改变的建议,并将改变后的剪力键与工程原型进行局部三维数值模拟对比研究。研究结果表明:相比工程原型,增大剪力键端头倾角有利于剪力键受力,但效果并不显著;端角处采用圆角设计,能够明显改善剪力键受力,其端角处的局部应力较工程原型降低了27.2%;在端角处采用倒角设计,剪力键局部应力集中最显著,不利于剪力键受力,应避免采用。In order to optimize the structure of shear keys and improve their stress performance, the 3-D numerical simulation software was adopted. In addition, the mechanical characteristics of segmental joint shear keys on immersed tunnel were analysed and these results were compared to the mechanical characteristics and failure conditions in large scale model tests. The result that local compression stress on shear key tips and local tension stress on the link part between shear keys and segments were large was obtained. Furthermore, based on these mechanical characteristics, the advice that setting up tensile reinforcement on the link part was put forward. Besides, three structure changes on shear key tips were proposed and they were studied by local 3-D numerical simulations, whose results were compared to those of engineering prototype. The results show that, comparing to the prototype, increasing horizontal inclination of shear keys has benefits to the stress distribution of shear keys, but its effect is not so notable. The circular angle design can improve the stress performance of shear keys significantly, and its local stress can decrease 27.2 % than that of engineering prototype. However, the concentration of chamfer angle design has no advantage to the stress performance of shear keys, which should be avoided. 2 tabs, 20 figs, 16 refs.

关 键 词：隧道工程 沉管隧道 剪力键 结构形式 数值模拟 模型试验 

分 类 号：U459.5[建筑科学—桥梁与隧道工程]