Elastic telescopic tunnel steel arch

The invention discloses an elastic telescopic tunnel steel arch, and belongs to the technical field of construction in tunnel engineering.The elastic telescopic tunnel steel arch comprises upper arch bodies, lower arch bodies, outer sleeve boxes, inner insertion boxes, springs and a top arch body, the upper arch bodies are connected to the two ends of the bottom of the top arch body, and the inner insertion boxes are fixedly arranged at the bottoms of the upper arch bodies; an outer sleeve box is arranged at the top end of the lower arch frame, the outer sleeve box is hollow inside and open at the top, the size of an inner inserting box is matched with the inner outline of the outer sleeve box, the inner inserting box is inserted in the outer sleeve box, and a spring is arranged between the bottom face of the inner inserting box and the inner bottom of the outer sleeve box. By arranging the arch feet of the telescopic elastic structure, the arch feet can shrink along with shrinkage of the surrounding rock, so