Abstract
Dynamic compaction (DC) is one of the most popular methods for ground improvement. To solve the problem of the factors affecting the sandy soil improvement effect and estimate the effective improvement range under DC, the influences of drop number, drop energy, tamping distance, tamper radius, and drop momentum on the relative degree of improvement were investigated. Three normalized indicators △δz,i, △δA,i, and △δU,i were derived to evaluate the weak zone and corresponding improvement effect. For multipoint tamping, it is found that the improvement depth and the improvement of the weak zone are highly correlated with drop energy and drop momentum, while the influence of the drop number and tamper radius is relatively smaller. The improvement of the weak zone and the improvement depth decrease with tamping distance, whereas the improvement area increases with tamping distance. The soil compacted by the previous impact point will be improved to a lesser extent with impact at subsequent impact points. It is also noted that drop energy had better not exceed the saturated drop energy in DC design. Based on the parametric study, a formula considering the various factors of DC was put forward, with the validation by two field cases of DC.
Highlights
Dynamic compaction (DC) is a commonly used method to improve the bearing capacity of various kinds of soils [1,2,3,4,5]
A significant amount of numerical studies [9,10,11,12], physical model tests [13,14], and field tests [1,15,16,17,18] have been reported on the improvement depth of DC; the majority of these works mainly focused on the improvement range below the tamper and only dealt with the soil response by single-point tamping
In terms of multipoint tamping, Chow et al [19] proposed an empirical method for assessing the compaction effect between impact points, which is based on the relationship between normalized friction angle and dimensionless distance by single-point tamping
Summary
Dynamic compaction (DC) is a commonly used method to improve the bearing capacity of various kinds of soils [1,2,3,4,5]. Several sandy field tests have shown5that the triangular grid patterns are more efficient than the rectangular grid patterns in the case of small areas of DC treatment [23,24,25,26] Those field investigations aim to come up with the DCof construction based on some specific project cases, may be assumption asymmetryparameters in a compacted zone around the centerline of thewhich impact point not suitable for other. Several sandy from field the published literature, the influences of drop energy, drop number, tamper radius, tests have shown that the triangular grid patterns are more efficient than the rectangular tamping distance, well as drop momentum on the relative of improvement, grid patterns in the as case of small areas of DC treatment [23,24,25,26]. A three-dimensional finite element analysis with an improved cap soil model was conducted toDC simulate the single-point and the multipoint tamping on dry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
