Deformation control of long span high precision fair-faced concrete wind tunnel by post-tensioning prestressAnd regulation technology research
后张法预应力对大跨度高精度清水混凝土风洞洞体的变形控制与调节技术研究

摘要

大型低速风洞洞体结构的变形控制要求远高于一般混凝土构件的挠度限值，常规设计措施和施工方法难以保证如此高的完成精度，为保证项目设计方法的可靠性，施工建造的可行性，同时兼顾投资成本的经济性，开展结构模型试验研究，指导后续设计及建造工作。试验以风洞跨度最大的稳定段为研究对象，制作原尺寸试验模型，采用后张法预应力方法对大跨度高精度清水混凝土洞体的变形进行控制与调节。经现场综合检测，各测点实测变形与结构理论计算值十分接近，且远小于限制，满足高精度风洞洞体的各项指标要求。模型制作采用钢结构内核支撑体系，其强度、变形和整体稳定性满足试验精度需求。后续将持续优化模架支撑等技术方案，力争在项目洞体施工措施费计划资金3065万元的基础上，达到优化节省资金10%的目标。

Abstract

Because the deformation control requirements of large-scale low-speed wind tunnel structures are much higher than the deflection limit of general concrete components, conventional design measures and construction methods can hardly guarantee such high completion accuracy. To ensure the reliability of project design methods and the feasibility of construction,and take into account the investment costs at the same time.We conduct structural model experiments to guide follow-up design and construction.The experiments takes the stable section of the largest wind tunnel span as the research object,and the test model of original size is made. The post-tensioning prestress method is used to control and adjust the deformation of the large-span high-precision general concrete tunnel body.After the comprehensive inspection on the spot,we find that the measured deformation at each measuring point is very close to the theoretical calculation value of the structure, and is far less than the limit figure, the result satisfies the index requirements of the wind tunnel with high precision. The model is made of steel structure core support system, so its strength, deformation and overall stability meet the test precision requirements. Technical solutions such as mold frame support will continue to be optimized, and efforts will be made to achieve the goal of optimizing the savings of 10% of the funds on the basis of 30.65 million yuan planned for the construction measures of the project.