三轴重塑样均匀性研究及改进装置

Study on Uniformity of Triaxial Remolded Samples and Introduction of an Improved Device

在研究静、动力作用下路基土湿化变形特性的试验中,三轴样的均匀性对于试验结果的精度有着极为明显的影响。由于冲击等影响,传统的整体击样法与单向分层击样法造成土样在含水量及干密度等方面都存在一定的不均匀性。通过对比分析制备过程中土样受力的差异,提出了一套分层压实成样装置。从试验结果可以得出,在压实过程中,该装置不会对上层土样产生冲击力,故对下层土样的扰动较小;进一步对下层土进行压缩试验,结果表明,上层土样在压实过程中几乎不会引起下层土样产生塑性变形。因此,该方法可有效保证土样的均匀性,且具有操作简便等优点。

In the test to study wetting deformation characteristics of subgrade soil under static and dynamic,the uniformity of the triaxial specimen has an obvious effect on the results precision. Due to the impact force,soil samples prepared by unidirectional holistic bumping method and layered bumping method are not uniform in water content and dry density. Thus,a set of layered pressing device is proposed after analyzing the stress characteristics of samples during the preparation. It can be seen from the test results that the device cannot produce impact force on the upper soil in the process of compaction,resulting in little disturbance to lower soil. Further,a compression test was performed on the lower soil,the results show that plastic deformation does not appear in the lower soil when the upper soil is being compacted. To conclude,this instrument saves time and labor force,that is simple,high precision,doable and satisfies the needs of preparing triaxial samples.