地震作用下散粮楼房仓仓壁动态侧压力分析

    Dynamic lateral pressure analysis of granular grain building warehouse walls under seismic effects

    • 摘要: 地震作用下贮料对仓壁产生的动态侧压力是影响散粮楼房仓结构安全的一个重要因素。为此,该研究设计制作了缩尺比例为1:25的三层楼房仓试验模型,进行了3条地震波下不同加载等级的振动台试验,分析获得了贮料地震反应特性、仓壁动态侧压力变化规律及超压系数,提出了仓壁动态侧压力计算方法。研究表明:不同楼层同一高度处仓壁动态侧压力达到峰值的时间不同步,沿楼房仓高度方向逐步滞后,且其均滞后于对应楼层仓壁加速度峰值时刻;各楼层仓壁动态侧压力逐层增大,每升高一层,增大约29%,且同一楼层的仓壁动态侧压力沿高度逐渐增大,仓壁上部、中部动态侧压力分别是下部的2.5倍、1.4倍;一、二、三层的超压系数最大值依次为2.9、3.4、4.1,且均位于每层仓壁上部位置;通过试验结果验证了所提出的仓壁动态侧压力计算方法的有效性;散粮楼房仓结构抗震设计,应考虑仓壁动态侧压力的影响与不同楼层的差异性。研究成果可为散粮楼房仓的抗震设计提供参考。

       

      Abstract: Granular grain can be stored into the warehouse in food industry. The high loading efficiency is often required to optimize the land use for the effective grain preservation. The crucial warehouse mode has emerged in the regions with limited land resources. The diverse grain varieties can be stored to promote the sustainable development. Currently, the granular grain warehouse normally employs a load-bearing system that constituted by a reinforced concrete frame structure. The vertical gravity load of the grain is supported by the well-beam floors and large-section frame columns, while the lateral pressure exerted by the grain is directly absorbed by reinforced concrete horizontal tie-up beams integrated within the warehouse walls. The structural integrity of granular grain warehouses can also depend on the dynamic lateral pressure exerted by the storage material on the warehouse wall during seismic events. In this study, a scaled-down 1:25 three-story warehouse was designed and then produced to explore the effect of granular grains on the dynamic lateral pressure. Shaking table tests were carried out to simulate the varying ground vibration levels under three seismic waves. The data was collected on the acceleration and the lateral pressure that exerted on its walls. Analysed the seismic response characteristics of the storage material. Furthermore, the overpressure coefficient was obtained from the patterns of dynamic lateral pressure on the walls. The dynamic lateral pressure on the warehouse walls was also calculated. Acorrelation analysis was conducted between the height of warehouse and the timing of the peak moment, when the dynamic lateral pressure was exerted on the warehouse walls. Specifically, there was a noticeable lag in the occurrence of this peak moment, as the height of the building increased. Moreover, the peak moment of dynamic lateral pressure on the warehouse wall was consistently lagged behind that of acceleration on the same wall, particularly with the elevation of the height. The dynamic lateral pressure on the warehouse walls escalated progressively with each ascending floor. In the given floor, this dynamic lateral pressure incrementally intensified along the vertical extent of the warehouse walls. Each floor was found with an average increase of approximately 29% per floor. The dynamic lateral pressure exerted on the upper and middle sections of the warehouse walls was 2.5 and 1.4 times greater than that on the lower sections within the same floor. Consequently, the structural design of granular grain warehouses should consider these variations across different floor levels. The overpressure coefficient of the warehouse wall increased with the elevation of the floor, indicating a higher overall overpressure at upper levels. Within a single floor, the overpressure coefficient peaks at the upper section of the warehouse wall, with the middle and lower sections exhibiting lower and closer. Specifically, the maximum overpressure coefficients were 2.9, 3.4, and 4.1, respectively, for the first, second, and third floors of the warehouse walls. The overpressure on the warehouse walls was of significant concern, when subjected to seismic activity. It is very necessary to consider the influence of the dynamic lateral pressure on the warehouse wall across various floors. The seismic response of the storage materials can be used to elucidate the distribution pattern of dynamic lateral pressure. The overpressure on the warehouse walls can be assessed to calculate the lateral pressure on these walls. The findings can offer a strong reference for the warehouses of granular grains under seismic conditions.

       

    /

    返回文章
    返回