To require the removal of all obstructions from sidewalks, curbstones, gutters, streets and street crossings, at the expense of the owners or occupiers of the ground fronting thereon, or at the expense of the person or persons placing the same there; and to regulate the planting and protection of shade trees in the streets, the building of cellar and basement ways and other excavations through or under the sidewalks in said city.
53 P.S. § 23115