筒仓散体储料空间静压力试验研究

发布时间：2018-12-11 16:24

【摘要】：筒仓是我国目前广泛使用的大型储料仓储建筑,它具有节省空间,储藏空间大,便于机械化操作等优势。近年来筒仓倒塌,崩裂事故时有发生,引发人员伤亡和经济损失。本文针对筒仓散体储料空间静压力问题,结合试验,理论和数值模拟,进行了以下研究并取得相应结论:1)以河南小麦作为试验样本,对其物理特性进行试验研究,测得试验用小麦的含水率,容重,比重,孔隙率等物理特性参数值,分析了小麦的含水率,容重,比重,孔隙率等之间的相关关系;通过分析小麦样本的应力—应变关系,得出小麦内摩擦角,外摩擦角,摩擦系数等,为筒仓小麦储料空间静压力问题的研究提供了相应的计算参数。2)利用筒仓模型,进行了缩尺筒仓散体储料仓底压应力试验,测量了仓底压应力大小,分布情况以及仓壁侧压力和摩阻力的变化趋势;使用PFC3D模拟筒仓内散粒体对仓底的压力;将试验结果与传统Coulomb公式,规范深仓竖向压力值,PFC3D模拟值比较分析,发现筒仓内散体储料底部压应力随堆载高度增加呈现非线性变化;仓壁摩擦力与小麦堆载高度呈线性分布;将试验数据与深仓计算公式,Coulomb公式进行比对发现实测值介于规范公式与Coulomb公式区间内;PFC3D模拟值与试验数据规律一致且略大于试验值。3)利用筒仓模型,进行了缩尺筒仓散体储料仓壁侧压力试验,测量试验过程中仓壁侧压力值,仓底压应力,仓壁摩阻力值及变化趋势,并将仓壁侧压力与取不同k值的Janssen理论值比较,发现筒仓内散体储料侧压力试验虽大于理论值,但与Jassen理论变化趋势相同;PFC3D模拟值侧压力值与试验数据、Jassen理论值规律一致,但在筒仓不同高度趋近于不同k值的Janssen理论值;托盘下降过程中底部各环压应力值由中环向外变化幅度逐渐增大,但整体呈平稳趋势;土压力盒测量结果发现在与距料面距离中间范围内误差较小。
[Abstract]:Silo is a large storage building widely used in our country at present. It has the advantages of saving space, large storage space and convenient mechanization operation. In recent years, silos collapse, crack accidents occur from time to time, causing casualties and economic losses. In this paper, according to the static pressure problem of silo bulk storage space, combined with experiment, theory and numerical simulation, the following research is carried out and the corresponding conclusions are obtained: 1) taking Henan wheat as test sample, the physical properties of wheat are studied experimentally. The physical parameters such as water content, bulk density, specific gravity and porosity of wheat were measured, and the correlation among water content, bulk density, specific gravity and porosity of wheat were analyzed. By analyzing the stress-strain relationship of wheat samples, the internal friction angle, external friction angle, friction coefficient and so on are obtained, which provide the corresponding calculation parameters for the study of the static pressure problem of silo wheat storage space. 2) the silo model is used. The pressure stress test on the bottom of the bulk silo was carried out, and the pressure stress and distribution of the silo bottom were measured, as well as the variation trend of the lateral pressure and friction resistance of the silo wall. PFC3D is used to simulate the pressure of granular particles on the bottom of silo. By comparing the test results with the traditional Coulomb formula, the vertical pressure values of the deep silo and the simulated values of PFC3D, it is found that the compressive stress at the bottom of the bulk material in the silo shows a nonlinear variation with the increase of the heap-load height. The friction of silo wall was linearly distributed with the height of heaped wheat, and the experimental data were compared with the formula of deep warehouse and Coulomb formula, and the measured values were found to be in the range between the standard formula and the Coulomb formula. The PFC3D simulation value is consistent with the test data and is slightly larger than the experimental data. 3) the sidewall pressure of the silo bulk storage silo is tested by the silos model, and the lateral pressure values of the silo wall and the pressure stress at the bottom of the silo are measured during the test. The friction resistance of silo wall and its variation trend are compared with the Janssen theoretical values of different k values. It is found that the lateral pressure test of bulk material storage in silo is larger than the theoretical value, but the trend is the same as that of Jassen theory. The lateral pressure value of PFC3D simulation value is consistent with the experimental data, the Jassen theory value is consistent, but the Janssen theory value of different height approaches to different k value in silo. The pressure stress of each ring at the bottom of the tray increases gradually from the ring to the outside, but the whole pressure box shows a steady trend, and the measurement results of the earth pressure box show that the error is small in the middle range of the distance from the surface to the material.
【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S379.3;TU317

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