装配式地下粮仓钢板-混凝土组合仓壁轴压受力性能分析

为了研究装配式地下粮仓钢板-混凝土组合仓壁的轴压力学性能,该研究在仓壁试件轴压试验的基础上,对仓壁试件进行非线性有限元分析,模拟试件加载的全过程,进一步分析试件及其组件在加载过程中的受力性能及工作机理,并对钢板强度、混凝土强度、距厚比等不同的参数影响规律进行了分析。结果表明:有限元模拟结果与试验结果吻合较好,在最大试验载荷5 000 kN时模拟轴向压缩总变形与试验平均轴向压缩总变形相对差值为4.2%,建立的有限元模型适用;在弹性阶段仓壁预制块部位混凝土和接头部位止水钢板分别承担了79.7%和50.9%的荷载,峰值荷载主要由混凝土和传力钢板决定,达到峰值荷载后接头部位止水钢板承担更大的荷载,增强止水钢板可以改善试件的延性;相较钢板强度、距厚比和止水钢板厚度,混凝土强度对仓壁试件的初始刚度和峰值荷载影响最大,混凝土强度、钢板强度、距厚比和止水钢板厚度对峰值荷载回归得到的回归系数值分别为0.910、0.154、-0.005和0.301;止水钢板的强度和厚度较小时,试件易发生脆性破坏;结合设计参数分析中得到的荷载-变形曲线,提出2种荷载-变形模型曲线,进一步提出装配式钢板-混凝土组合仓壁轴压峰值荷载简化计算式,得到的计算峰值荷载与有限元峰值荷载相对差值均不超过9%,计算结果具有较高的精度。研究结果可为装配式地下粮仓仓壁的工程设计提供指导和参考。

Performance analysis of axial compressive behavior for precast steel plate-concrete composite silo wall of underground silo

An underground silo is essential to green grain storage, due to its low temperature, low land consumption, energy conservation, and environmental protection. A new underground silo was proposed in combination with the prefabricated technology and combined structure technology in the engineering practice. In this study, a finite element model of steel plate-concrete composite silo wall containing stud was established on the ABAQUS software, in order to explore the compressive properties of assembled underground silo using the full scale axial compression test. An nonlinear finite element model of silo wall specimen was also established, concurrently considering the plastic damage of concrete and the elastoplasticity of steel plate. A simulation was performed on the whole loading process of specimens, thereby to analyze the mechanical properties and working mechanism. Various parameters were determined, such as the steel plate strength, concrete strength, and distance thickness ratio. The results show that: The finite element simulation was in good agreement with the test. Moreover, the relative difference of axial deformation between the simulated and experimental value was 4.2% at 5 000 kN, indicating an applicable finite element model. The precast block concrete and the joint sealing-up steel plate can bear the load of 79.7%, and 50.9%, respectively, during the elastic stage. The peak load depended mainly on the precast concrete of silo wall and the load transfer of steel plates. There was more load in the sealing-up steel plate at the joint position after reaching the peak load. As such, to strengthen the sealing-up steel plate can be used to improve the ductility of the specimen. There was the greatest influence of concrete strength on the initial stiffness and the ultimate bearing capacity of specimens, compared with the strength of steel plate, the distance thickness ratio, and sealing-up steel plate thickness. The Beta values of concrete strength, steel plate strength, distance thickness ratio, and sealing-up steel plate thickness to peak load were 0.910, 0.154, -0.005, and 0.301, respectively. The specimens were prone to brittle failure, due to the small strength and thickness of sealing-up steel plate. Two curves of load-deformation model were proposed in combination with the load-deformation curves for the silo wall specimens with the assembled steel plate-concrete composite under the various parameters. Furthermore, the simplified formula was also proposed for the axial peak load of the assembled steel plate-concrete composite silo wall. The relative difference of peak loads that obtained by the calculation formula and the finite element method was not more than 9%, indicating a high accuracy of calculation. The research findings can provide a potential guidance for the engineering design of prefabricated underground silo wall.