模拟月壤的抗剪强度特性试验

Test Research on Shear Strength Properties of Simulant Lunar Soil

对火山玄武岩破碎后形成的6个粒组区间的试样依规范进行直剪试验,得出不同相对密度下的内聚力和内摩擦角试验数据;根据抗剪强度参数的统计结果,按Chauvenet法剔除粗差数据,并评价变异性,以提高数据的准确性和可靠度。对试样在不同的相对密度下和不同粒组区间的力学规律进行对比、研究分析后得出：模拟月壤的内聚力为0.33～5.5kPa,内摩擦角为29.1°～35.65°;抗剪强度参数与颗粒粒径、密度具有较好的线性关系;颗粒粒径决定了密度的变化范围,这导致了抗剪强度参数在密度的一定的范围内随之变化,而总的变化趋势却是由粒径来控制的。根据以上结论,按一定颗粒级配研制模拟月壤混合样,其内聚力为0.16～1.59kPa,内摩擦角为34.8°～45.5°,符合真实月壤的实际情况。可为后续的模拟月壤研制和性能评估提供参考。

The rebuilt volcanic basalt samples consist of smashed basalt particles,grouped by six grain diameters.They were studied by direct shear experiments following standard to acquire the data of cohesion and internal friction under different relative densities.To improve accuracy and reliability of the data,gross error data were rejected by applying the Chauvenet method and the variability was assessed according to the statistical results of shear strength parameters.The results are acquired after the research on the mechanical theorem of samples under different relative densities and particle groups.When water content is ignored,the following results are obtained.The cohesion range is 0.33-5.5kPa and the internal friction range is 29.1°-35.65°.There is better relationship among particle size,density and direct shear strength parameters.The particle size decides the range of the density so that the parameters vary with density in a certain range,while the total varying trend is controlled by the particle size.Finally,according to the above conclusion,the cohesion and internal friction range of mixed samples are 0.16-1.59 kPa and34.8°-45.5°,which are developed in a certain grain composition based on the single samples,proving to be in the range of the lunar soil.The achievement could provide reference and basis for the subsequent development and assessment of the simulant lunar soils.