- 摘 要
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（1 江蘇省蘇科建設(shè)技術(shù)發(fā)展有限公司， 南京 210008；
2 江蘇省建筑科學(xué)研究院有限公司， 南京 210008）
［摘要］基于結(jié)構(gòu)的動力特性，針對某超長大跨網(wǎng)架結(jié)構(gòu)的初步設(shè)計方案的合理性進行了研究。初步方案中網(wǎng)架采用橫向桁架體系，擱置在下部獨立鋼柱上，網(wǎng)架內(nèi)部橫向桁架之間僅存在縱向水平連系桿，整體結(jié)構(gòu)低階自振模態(tài)為水平橫向的半波振動，不同于一般網(wǎng)架結(jié)構(gòu)的豎向振動，且基本周期達到0.62s，說明其整體剛度較弱，且剛度不合理。為改善結(jié)構(gòu)自振模態(tài)，加強結(jié)構(gòu)整體性，采取多種優(yōu)化措施，包括增設(shè)橫向和縱向的水平剪刀撐、縱向斜腹桿以及下部支承結(jié)構(gòu)的連系梁，增加支承結(jié)構(gòu)抗側(cè)剛度等。研究表明這些措施所起的作用是不同的，針對超長大跨網(wǎng)架結(jié)構(gòu)，要綜合考慮屋蓋和下部支承剛度才能保證結(jié)構(gòu)整體剛度的合理性。
［關(guān)鍵詞］網(wǎng)架； 模態(tài)分析； 剛度； 優(yōu)化
中圖分類號： TU242.5 文獻標識碼： A文章編號： 1002-848X(2016)S2-0391-05
Modal analysis and stiffness optimization of over-long and large-span lattice grid
structure
Dong Weidong 1,2
（1 Jiangsu Suke Construction Technology Co．， Ltd．， Nanjing 210008, China；
2 Jiangsu Research Institute of Building Science Co．， Ltd．， Nanjing 210008, China）
Abstract: Based on the dynamic characteristics of structure, the rationality of the preliminary design scheme of over-long and large-span lattice grid structure is researched. The lattice grid composed of transverse trusses lay on the under independent steel columns, there are only longitudinal horizontal tie bar between transverse trusses in lattice grid′s interior, the low-order mode is horizontal transverse half-wave which is different from vertical vibration of the general lattice grid, and the basic period is 0.62s, that is to say, structural global stiffness is weak. So that, several measures are adopted to improve mode and strengthen structural stiffness, including adding transverse and longitudinal horizontal bridging, longitudinal web member, tie girders between steel columns, lateral force resistance of under bearing. Results indicate the effect of these measures is different, considering stiffness of the roof and under bearing at the same time can insure the rationality of the structural global stiffness during designing over-long and large-span gird structure.
Keywords: lattice grid； modal analysis； stiffness； optimization
作者簡介： 董衛(wèi)東，碩士，工程師，Email:dwd83@163.com。
