预制装配式足尺RC锥形独立基础下压变形特性试验研究

Experimental study on compressive deformation characteristics of prefabricated full-scale RC conical independent foundation

由于变电站建筑基础相对尺寸及质量较大,0 m以下基础的模块化装配率较低,为此提出了一种110 kV变电站气体绝缘开关设备(GIS)建筑钢筋混凝土(RC)锥形独立基础,按照装配式要求提出该基础的模块化及装配式方案,并进行装配模块ZK 1和FK 1尺寸、剪力键及配筋设计;同时,开展足尺模块化基础浇筑及装配试验。以装配预应力钢棒的预紧力大小为参数,开展小立柱加载的下压试验,考察装配式基础底板下压变形及装配缝张开变形的变化特点;分析装配用钢棒预紧力大小对下压变形、张开变形及残余变形的影响规律,探讨合理预紧力取值。测试并对比剪力键及剪力槽钢筋应变的发展及变化特点,探讨下压荷载下剪力键及剪力槽的设计要点。结果表明:当下压荷载为380 kN时,预制装配式RC锥形独立基础没有发生任何失效破坏现象,装配剪力键及剪力槽均没有发生破坏现象;装配式基础的装配预紧力为2.00 F t时,可以满足刚度及挠度要求。本文研究成果可为装配式RC锥形独立基础的装配式方案设计、预紧力取值以及剪力键设计提供依据。

Due to the relatively large size and mass of the substation building foundation,the modular assembly rate of the foundation below 0 m is low.The reinforced concrete(RC)conical independent foundation of geographic information system(GIS)building in 110 kV substation was studied in this paper,and the relative modular solutions and assembly solutions were given.Based on the solutions,the designs of dimension,shear connector and reinforcement of modules ZK-1 and FK-1 were performed,and the full-scale modular pouring and assembly tests were carried out.The column downward compressive test was carried out with assembly preload as the parameter to investigate the changing characteristics of the downward compressive deformation of foundation base plate and the opening deformation of assembly seam,and the influence caused by assembly preload on downward compressive deformation,openings deformation,and residual deformation was studied.Based on these,the reasonable value for preload was discussed.In addition,the developing and changing characteristics of strain on the reinforcement of shear connector and shear groove were tested and compared to investigate the design focus of shear connector and shear groove under the downward compressive load.It revealed that when the compressive load was 380 kN,the prefabricated RC conical independent foundation had no failure,and the shear connector and shear groove also had no failure.When the assembly preload of prefabricated foundation was 2.00 F t,the requirements of rigidity and deflection could be satisfied.The results of this paper can be used as a reference in the design of assembly solution of prefabricated RC conical independent foundation,the determination of preload and the design of shear connector.