A track clamp assembly for supporting or splicing tracks of I-shaped cross-section formed by a vertical web with horizontal parallel flanges at the opposite ends of the web and having a pair of oppositely facing grooves formed in the flanges on each side of the web. The track clamp assembly comprises upper and lower clamp members respectively having upper and lower edges insertable in a pair of track grooves, and having interengageable ramp surfaces disposed between the upper and lower edges and extending obliquely thereto. Outwardly projecting tabs on the clamp members are engageable by a connecting bolt which when tightened moves the ramp surfaces into interengagement, increasing the dimension between the upper and lower edges and forcing the clamp members into locking engagement with the track.