砂雨法制备砂样的控制要素及均匀性分析

Controlling factors of sand pouring method in sand sample preparation and uniformity analysis

常规砂雨法能制备出中密、密实状态的砂样。为获得相对密实度范围更大的砂样,利用自主研发的撒砂装置,在讨论常规影响因素如流量、落距等的基础上,进一步研究了出砂头移动速度、路径、筛网等因素对砂样相对密实度的影响。通过改变这些因素制出了松散状态的砂样。分别通过不同大小的圆盒与CPT方法对砂样的均匀性进行检测,结果表明制备出的砂样均匀性较好。分析对比不同的均匀性检测方法表明,圆盒检测方法简单易操作,但检测结果误差较大,而CPT方法较为真实可靠。

Conventional sand pouring method can produce sand samples in medium and dense state. In order to produce sand samples with wider range of relative density, the self - developed sand pourer device was used. Aiming to the newly developed device, on the base of discussing conventional influential factors such as drop height, flow rate, etc, the influences of sand head moving rate and moving path, sieves, etc on relative density of sand samples were further studied. By changing these factors, the sand samples of loose state were produced. The uniformity of produced sand samples were tested by small boxes of different sizes and CPT method, which showed that the uniformity was good. By comparing these two uniformity test methods, it is demonstrated that the method of small boxes is easy to be operated, but the error is larger, and CPT method is credible and reliable.