If the clips are on separate tracks, perhaps you could Tracks > Align Tracks > Align End to End, Tracks > Mix and Render to put them in one track, then search for a plugin to suit your purpose.
If the clips are of equal length, you could try Regular interval audio splitter.
If there are silences at the end or start of the clips, you could try Extend Silences.
Those are both Nyquist plugins - see here for how to install Nyquist plugins: http://manual.audacityteam.org/o/man/effect_menu.html#nyquist_effects.
Gale