大型直升机荷载下黄土场地模型箱试验研究

Strong impact loading is applied to the site during the landing process of large helicopter. The dynamic interaction between a large helicopter and the landing site is significantly dependent on the property of the landing site. The small-scale model test was carried out by modeling the impact loadings of two wheels belonging to one dual-wheel landing gear on the loess site using the new double hammer impact testing equipment, which was based on the fixed landing situation of a big helicopter. The settlement and dynamic vertical stress produced in the loess site are analyzed together with the effects of hammer spacing. It is found that the settlement in the shallow layer of the loess site shows the typical W type under the impact of double hammers. Single pulse characteristics can be observed in the time history curve of dynamic vertical stress, which is comparable in different positions. The magnitude of the settlement and peak vertical stress along the centerline of the drop hammer decreases with increasing depth. However, their decreasing rate is related to the depth and the largest decreasing rate is produced in the shallow layer of the loess site. The hammer spacing mainly affects the magnitude of the settlement and dynamic vertical stress, which has minor effects on the variation pattern of the settlement and dynamic vertical stress.