摘要
某酒店工程在两座塔楼间设置高空双层钢桁架连廊,跨度69.5 m,总质量3485 t,采用Q420GJC箱型截面构件。受场地限制(仅20 m×70 m作业面)及机械成本控制,选用钢柱支撑平台拼装滑移工艺,累积滑移3次后整体提升。通过分阶段拼装滑移和整体提升过程分析,并结合施工过程监测来确保结构安全。将桁架结构分为4个滑移单元(单元1~4),采用“累积滑移安装”的方式进行安装。根据滑移流程建立滑移分析模型,首先只施加自重荷载提取各支点反力,换算成摩擦力并施加至滑移分析模型。计算结果表明,滑移过程中桁架最大竖向位移均为-4.8mm,最大应力比0.112,结构滑移过程中强度和刚度均满足要求。根据滑移过程的分析结果提取支点反力和摩擦力并施加于滑移梁分析模型,结果表明,竖向位移最大值出现在边缘滑移梁,最大竖向位移为-7.3 mm,支撑构件的最大应力比为0.789,滑移梁的位移和应力比均小于限值。根据分析结果,在桁架和滑移梁滑移过程中应力和位移较大位置设置监测点,监测结果表明滑移过程中各测点的应力和位移均小于计算结果。滑移至设计位置下方后进行同步提升施工阶段,利用周边塔楼结构柱设置提升支架,安装提升设备作为提升上吊点,在桁架结构上弦上设置下吊点,并在下吊点处设置加强杆件。吊点微调处理对结构进行调平后开始正式提升,提升过程中每提升5 m暂停并进行结构姿态调整,直至提升至设计位置。根据提升工艺和结构布置建立提升过程分析模型和提升支架分析模型。结果表明在提升过程中只要保证不同步提升值不大于25 mm,即可忽略不同步效应对结构安全的影响。结构最大位移发生于跨中部位,最大竖向位移为20.8 mm,提升桁架最大应力比0.269,加固杆件最大应力比0.723,提升支架最大竖向位移和最大应力比分别为-7.2 mm和0.783,提升结构及支架的强度和刚度均满足要求。根据分析结果,在桁架和提升支架提升过程中应力和位移较大位置设置监测点,监测结果表明提升过程中各测点的应力和位移均小于计算结果。
A certain hotel project has set up a high-altitude double-layer steel truss corridor between two towers,with a span of 69.5 m and a total mass of 3485 t,using Q420GJC box-section components.Due to site limitations(only a 20 m×70 m working surface)and cost control for machinery,a steel column support platform assembly sliding technology was selected.The overall lifting was achieved after accumulating three sliding cycles.By analyzing the phased assembly sliding and overall lifting processes,and combined with construction process monitoring,the structural safety was ensured.The truss structure was divided into four sliding units,namely Unit 1,Unit 2,Unit 3,and Unit 4,and they were installed using the"cumulative sliding installation"method.A slip analysis model was established based on the slip process.Firstly,only the self-weight load was applied to extract the reaction force at each fulcrum,which was converted into frictional force and applied to the slip analysis model.The calculation results showed that the maximum vertical displacement of the truss during the sliding process was-4.8 mm,and the maximum stress ratio was 0.112.The strength and stiffness of the structure during the sliding process met the requirements.Based on the analysis results of the sliding process,the fulcrum reaction force and friction force were extracted and applied to the sliding beam analysis model.The results showed that the maximum vertical displacement occurred at the edge sliding beam,with a maximum vertical displacement of-7.3 mm.The maximum stress ratio of the supporting component was 0.789,and both the displacement and stress ratio of the sliding beam were below the limit.According to the analysis results,monitoring points were set up at locations with high stress and displacement during the sliding process of the truss and sliding beam.The monitoring results showed that the stress and displacement at each measuring point during the sliding process were lower than the calculated results.After sliding to the design position below,the synchronous lifting construction phase was carried out.This involved utilizing the surrounding tower structural columns to set up lifting brackets and install lifting equipment to serve as lifting points.Lower lifting points were established on the upper chord of the truss structure,which were then reinforced with stiffening members.After the suspension points were fine-tuned to level the structure,the formal lifting process commenced.The process was paused every 5 meters to adjust the structural alignment until it reached the design position.The lifting process analysis model and the lifting bracket analysis model were established based on the lifting process and structural layout.The results indicated that as long as the asynchronous lifting value was guaranteed not to exceed 25 mm during the lifting process,the impact of asynchronous effects on structural safety could be neglected.The maximum displacement of the structure occurred at the mid-span location,with a maximum vertical displacement of 20.8 mm.The lifting truss exhibited a maximum stress ratio of 0.269,while the stiffening members showed a maximum stress ratio of 0.723.The maximum vertical displacement and maximum stress ratio of the lifting brackets were-7.2 mm and 0.783,respectively.Both the strength and stiffness of the lifted structure and brackets met the specified requirements.According to the analysis results,monitoring points were set up at locations experiencing high stress and displacement on the truss and lifting brackets.The monitoring results showed that the stress and displacement at each measuring point during the lifting process were lower than the calculated values.
作者
高辉
王钢
周霞菊
唐威
赵才其
Hui Gao;Gang Wang;Xiaju Zhou;Wei Tang;Caiqi Zhao(Shanghai Baoye Group Corp.,Ltd.,Shanghai 201900,China;School of Civil Engineering,Southeast University,Nanjing 210096,China)
出处
《钢结构(中英文)》
2025年第8期51-62,共12页
Steel Construction(Chinese & English)
关键词
高空双层钢桁架
累积滑移
同步提升
过程分析
施工监测
high-altitude double-layer steel truss
cumulative sliding
synchronous lifting
process analysis
construction monitoring
