Transportation Geotechnics ( IF 5.3 ) Pub Date : 2020-10-06 , DOI: 10.1016/j.trgeo.2020.100451 Md. Zillal Hossain , Md. Zoynul Abedin , Md. Rejwanur Rahman , Md. Nafiul Haque , Rowshon Jadid
This paper investigates the effectiveness of Sand Compaction Pile (SCP) in improving the density characteristics of cohesionless soil. The performance of SCP for different pile spacing, pile arrangement such as triangular and square, and coarseness of bed materials on the degree of soil improvement is studied in a better-controlled laboratory environment rather than more variable field environment. A SCP miniature device and a miniature dynamic cone penetrometer (DCP) were designed and fabricated in the laboratory. Sand beds containing loose cohesionless soil were prepared in a fabricated tank by sand raining from the pre-calibrated height. The SCPs were installed using the miniature device on the sand bed by displacing soil in the lateral direction in order to densify the bed prior to pouring sand in the displacement holes. The data of DCP in terms of penetration index and field density were measured at various depths to obtain correlation parameters between DCP and relative density of soil. This correlation was used to determine the relative density of improved soil beds due to the installation of SCPs. The improved soil condition was measured in terms of a decrease in penetration index or an increase in the relative density of bed materials. Some of the major findings include: the rate of increase of relative density due to installment of SCP is similar irrespective of the coarseness of bed materials; smaller pile spacing compared to an optimum spacing causes insignificant soil improvement; the triangular pattern shows better soil improvement compared to the square pattern for a given pile spacing.
中文翻译:
压实桩在疏松无粘性土中的有效性
本文研究了压实桩(SCP)在改善无粘性土的密度特性方面的有效性。在更好控制的实验室环境而不是更多可变的田间环境中研究了SCP在不同桩距,桩排列(如三角形和正方形)以及床料的粗度对土壤改良程度方面的性能。在实验室中设计并制造了一个SCP微型设备和一个微型动态锥状渗透仪(DCP)。在预制的水箱中,从预先校准的高度开始下雨,准备了一个包含松散的无粘性土壤的沙床。通过使用微型设备将SCP固定在沙床上,方法是在侧向移动土壤,以便在将沙子倒入排水孔之前进行致密化。在不同深度下测量DCP数据的渗透指数和场密度,得到DCP与土壤相对密度之间的相关参数。该相关性用于确定由于安装了SCP而导致的改良土壤床的相对密度。根据渗透指数的降低或床料相对密度的增加来衡量土壤条件的改善。一些主要发现包括:由于安装了SCP而引起的相对密度的增加速率是相似的,而与床身材料的粗糙程度无关。与最佳间距相比,桩间距更小,土壤改良效果不明显;在给定的桩距下,与正方形模式相比,三角形模式显示出更好的土壤改良效果。