基于缩尺模型试验的浮力折减计算方法研究

Research on Alculation Method of Buoyancy Reduction Based on Scale Model Test

浮力计算是地下粮仓抗浮设计的关键,而回填土中浮力是否折减存在不确定性,以某新建地下粮仓为研究对象,考虑实际工况中灰土的回填,制作3个直径分别为400mm、500mm、600mm地下粮仓模型筒。采用注水上浮的试验方法对它们进行室内缩尺模型试验。试验中用位移计和压力传感器监测模型筒上浮时位移和上部约束反力,通过位移和约束反力分析整个上浮过程中位移和约束反力的变化情况,并由位移和约束反力确定模型筒的起浮水位。通过试验数据和理论受力分析计算得出灰土中地下粮仓浮力折减系数为0.86,试验及计算分析结果对今后地下粮仓抗浮设计具有一定的参考意义。

This paper takes three new underground granaries as research objects,and produces three model cylinders with diameters of 400mm,500mm and 600mm respectively.Taking the idea of water injection to make the model cylinder float,the three model cylinders were placed in the lime soil for the scale model test.The displacement gauge and the pressure reaction are used to monitor the floating displacement and the restraining reaction force of the model cylinder.The displacement and the restraining reaction force are used to analyze the change of the whole cylinder during the floating process.According to the analysis of the bearing capacity,the buoyancy reduction coefficient of the underground granary model cylinder in the lime soil is 0.86.The test and calculation analysis results have certain reference significance for the anti-floating design of the underground granary.