荷兰Venlo型温室结构抗震性能分析

为了研究地震作用对依据荷兰规范设计的Venlo温室结构安全性的影响，该研究以荷兰公司设计的山东某Venlo型温室为例，利用有限元软件MIDAS Gen，采用振型分解反应谱法对设防烈度分别为7度（0.10 g）、7度（0.15 g）、8度（0.20 g）和8度（0.30 g）的温室整体结构进行模拟计算，对结构的周期、振型、应力和位移进行了分析探讨。结果显示，温室整体的最长自振周期为1.75 s，表现为较柔性的结构体系，前2阶振型分别为Y、X向的平动，在2个主轴方向上具有相近的抗震性能。不同设防烈度下，结构的承载力最大值均为216.96 MPa，由风荷载控制，最大应力小于构件屈服强度。当设防烈度为8度（0.30 g）时，X向地震作用对构件的拉、压应力最大，分别为211.95和196.02 MPa。无地震参与的荷载组合中X向风荷载产生的位移最大，达到31.80 mm。在地震参与的荷载组合中，柱顶最大位移为61.84 mm，结构变形主要受地震荷载的影响，Y向地震作用超过同工况下X向地震作用约11.6%。结论表明，引进的荷兰温室在地震设防烈度不高于8度（0.30 g）时，构件始终处于弹性范围内，满足规范要求，但最大变形超过了中国建筑抗震设计对弹性层间位移角1/250的要求。最后，该文对中国农业温室结构设计标准的编制提出了一些建议。

Seismic performance analysis of Dutch Venlo greenhouse structure

A Venlo-type greenhouse has widely been introduced from Netherland for modern agriculture in China at present. This type of greenhouse is also the largest, most commonly-used, and state-of-the-art glass structure with advanced equipment and control systems for super greenhouses in the world. However, few national standards are released for the structure design of modern agricultural greenhouse, although most industry or group standards in China. Furthermore, the combination of earthquake load other than wind load cannot be usually considered for the structure design in most studies, due to the light-weight components and covering materials in the greenhouse structure. If the greenhouse that designed by the Netherlands was directly introduced to adopt the Dutch structural standards in China, there is a safety hazard of seismic action for the damage of main structure, particularly for nearly half of land areas in high-level zones of seismic intensity in China, even above 7 degrees. Taking a Venlo-type greenhousedesigned by a Dutch company in Shandong province as an example, this study aims to explore the impact of seismic action on structural safety according to the Dutch code, considering the stress diaphragm of covering material on the structural stiffness. A finite element software MIDAS Gen with the response spectrum modal was also selected to simulate the whole structure of the greenhouse with the seismic precautionary intensity of 7 (0.10g), 7 (0.15g), 8 (0.20g), and 8 degrees (0.30g). A systematic analysis was made on the mode periods, vibration patterns, the maximum stresses, and displacements for the structure. The results showed that the longest period of natural vibration was 1.75 s in the greenhouse structure, indicating a relatively flexible performance of the structural system. The first and second vibration patterns were the flat motion in Y and X -direction, especially a similar seismic performance in the 2 principal axes. Additionally, the maximum bearing capacity of the structure was 216.96 MPa for different seismic precautionary intensities under the wind load. The maximum stress was still less than the yield strength of components. When the seismic precautionary intensity exceeded 8 degrees (0.30g), the maximum tensile and compressive stresses of components were 211.95 and 196.02 MPa for the X-directional seismic action, respectively. In addition, the maximum displacement was 31.80 mm under the X-directional wind load without considering seismic action. The structural deformation was also mainly influenced by the seismic load. Specifically, the Y-directional seismic action was about 11.6% than that in the X-direction under the same load combination. Consequently, the greenhouse structure introduced from Netherland can always be expected to fully meet the code requirements within the elastic range of components, when the seismic intensity was lower than 8 degrees (0.30g). Nevertheless, the maximum deformation exceeded the standard requirement of 1/250 of the elastic inter-story displacement angle, according to the code for seismic design of buildings in China.