Abstract With the development of the three-dimensional traffic network, there are tunnels being constructed un? derneath airport runways and aprons, and it is necessary to study the effects of the moving load of an aircraft on the underlying tunnel structure to guarantee stability. Using the Beijing Capital Airport MRT as an example, the effects of the aircraft's moving load upon a tunnel structure are studied by comparing two response results of simplified aircraft moving loads (node dynamic load and surface load) by FEM. The results indicate that: 1) the variation laws of tunnel′s vertical displacement under the two simplified aircraft loads are similar, but the vertical displacement is slightly larger under the node dynamic load; 2) variation of the relative position of the aircraft′s landing and the tunnel has little effect on the vertical displacement variation law of the tunnel structure; 3) the dynamic influence on the tunnel structure is obvious when the plane is within the scope of a runway that measures triple the tunnel diameter and is located right above the tunnel—not only does it cause apparent vertical displacement of the tunnel structure,but it also results in a significant increase of the pressure on the surrounding rock; and 4) the pressure on the surrounding rock and the vertical displacement at the center of the tunnel crown are the highest, and therefore require much attention.
Abstract：
With the development of the three-dimensional traffic network, there are tunnels being constructed un? derneath airport runways and aprons, and it is necessary to study the effects of the moving load of an aircraft on the underlying tunnel structure to guarantee stability. Using the Beijing Capital Airport MRT as an example, the effects of the aircraft's moving load upon a tunnel structure are studied by comparing two response results of simplified aircraft moving loads (node dynamic load and surface load) by FEM. The results indicate that: 1) the variation laws of tunnel′s vertical displacement under the two simplified aircraft loads are similar, but the vertical displacement is slightly larger under the node dynamic load; 2) variation of the relative position of the aircraft′s landing and the tunnel has little effect on the vertical displacement variation law of the tunnel structure; 3) the dynamic influence on the tunnel structure is obvious when the plane is within the scope of a runway that measures triple the tunnel diameter and is located right above the tunnel—not only does it cause apparent vertical displacement of the tunnel structure,but it also results in a significant increase of the pressure on the surrounding rock; and 4) the pressure on the surrounding rock and the vertical displacement at the center of the tunnel crown are the highest, and therefore require much attention.
2018, Vol. 55 