中美标准锅炉大板梁分段设计方法对比

Comparison on Design Methods for Large Plate Girder Segmentation of Boiler Steel Structure Between Chinese and American Standards

为降低运输成本、满足吊装及运输条件,660 MW及以上锅炉大板梁一般需要在高度方向和长度方向采用分段设计,形成分段式叠梁,高度方向和长度方向的连接均采用高强度螺栓连接。结合贵州某660 MW锅炉具体工程实例,给出了锅炉分段式叠梁运用中国GB 50017—2017《钢结构设计标准》和美国ANSI/AISC 360-16 Specification for Structural Steel Buildings(LRFD方法)的翼缘拼接、腹板拼接、叠合面翼缘拼接的设计方法。对于分段连接所用的高强度螺栓,美国规范计算得到的单颗螺栓承载力较大,螺栓数的需求较少,中国标准偏于安全。对于分段连接处板材,采用美国规范计算的应力系数低于采用中国标准计算的应力系数。对于大板梁分段设计,中美规范的安全水准基本一致,中国规范略偏保守。研究结果为锅炉分段式叠梁的连接设计提供了参考。

In order to reduce the transportation costs and meet the requirements of hoisting assembly and transportation,the large plate girders of 660 MW and above boilers generally need to be designed in blocks manner in height and length directions to form a segmented superposed beam,while high-strength bolts are applied to the connection in height and length directions.Taking a specific engineering of a 660 MW boiler in Guizhou Province as the research example,based on GB 50017—2017 Standard for Design of Steel Structures in China and ANSI/AISC 360-16 Specification for Structural Steel Buildings(LRFD method)in America,design methods for the flange splicing,web splicing,and laminated surface splicing connections of the segmented superposed beam were presented.For high-strength bolts used in segmented connections,the single bolt bearing capacity calculated by American standard is relatively greater,and there is less demand for the number of bolts,while Chinese standard tends to be more safe.For the plates used for segmented connections,the stress coefficients calculated by American standard are lower than those calculated by Chinese standard.For the design of large plate girder segmentation,the safety levels of above two standards are basically the same,while the Chinese standard is slightly more conservative.Research results provide a reference for the connection design of segmented superposed beam of boiler steel structures.