摘要
为揭示地上输料通道对浅圆仓仓壁和通道受力的影响,开展了不同高径比、不同偏心率的缩尺筒仓模型装卸料试验,并将测试结果与筒仓标准GB 50077—2017有关规定进行对比分析。装料试验结果表明,通道的存在影响了仓壁底部的侧压力分布,仓壁侧压力在通道高度范围内明显小于筒仓标准预测值。整个卸料过程可以归纳为一个倒锥不断下切的过程,倒锥的顶点位于卸料口的正上方。卸料试验中没有观测到超压系数随着卸料偏心率增大而增大的现象。高径比在0.69以下时,仓壁和通道上超压系数普遍较小;高径比接近1.0时,仓壁和通道上超压系数迅速上升。当通道依据标准GB 50077—2017判定为深埋时,通道压力预测值明显小于测试值,偏于不安全。主次通道顶壁及侧壁的静载压力依据本文提出的浅埋公式计算更加合理,其中贮料高度应取为通道计算点的实际贮料高度。建议浅圆仓设计时适当考虑通道的顶壁和侧壁超压系数,可取1.2~1.3。
In order to facilitate later maintenance,the underground conveying corridor is moved up to the inside of the squat silo.This process reform is bound to have an impact on the pressure distribution of the wall and corridor.In this study,the loading and discharge experiments of the reduced-scale silo models with different aspect ratios and eccentricity ratios were carried out.Three kinds of PMMA cylinders with different heights were used to simulate the wall.The outer diameter of the cylinder is 1000 mm,the wall thickness is 10 mm,and the height is 392 mm,642 mm,and 892 mm,respectively.Three different lengths of ground conveying corridors are made of 10 mm thick steel plate,which are one main corridor and two secondary corridors.The strip eccentricity of the main corridor is zero,and that of the two secondary corridors is 300 mm.In order to consider the influence of eccentricity ratios,five discharge openings are set on the top wall of the main corridor to simulate central and eccentric discharge.In order to explore the influence of aspect ratios,three silos with different aspect ratios(0.44,0.69,0.95)are used.The cylinder and the corridors are placed on the steel support.A total of three main and secondary corridors were placed in the silo model,and the manual loading mode was adopted.All the openings on the top wall of the corridors were blocked first,and then the stored material was loaded from the top of the model.When the stored material in the full state of the model was completely stable,the pressure data were recorded by the test system.The results of the loading tests showed that the lateral pressure at the bottom of the silo wall was affected by the corridors.The lateral pressure of the wall in the corridor height range is significantly smaller than the predicted value of the silo standard.The whole discharge process can be summed up as a process of continuous undercutting of the inverted cone,and the vertex of the inverted cone is always located directly above the discharge opening.The phenomenon that the
作者
孙巍巍
冯君
朱建平
张栩东
易建荣
王磊
Sun Weiwei;Feng Jun;Zhu Jianping;Zhang Xudong;Yi Jianrong;Wang Lei(Department of Civil Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;National Key Laboratory of Transient Physics,Nanjing University of Science and Technology,Nanjing 210094,China;Sinoma International Engineering Co.,Ltd.(Nanjing),Nanjing 211100,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2020年第16期259-266,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金(51308297,11902161)
南京市建设系统科研项目(Ks1717)。
关键词
筒仓
试验
压力
通道
超压系数
高径比
偏心率
silos
experiment
pressure
corridor
overpressure coefficient
aspect ratio
eccentricity ratio
