  Magnetohydrodynamic (MHD) instabilities allow energy to be released from
stressed magnetic fields, commonly modelled in cylindrical flux tubes linking
parallel planes, but, more recently, also in curved arcades containing flux
tubes with both footpoints in the same photospheric plane. Uncurved cylindrical
flux tubes containing multiple individual threads have been shown to be capable
of sustaining an MHD avalanche, whereby a single unstable thread can
destabilise many. We examine the properties of multi-threaded coronal loops,
wherein each thread is created by photospheric driving in a realistic, curved
coronal arcade structure (with both footpoints of each thread in the same
plane). We use three-dimensional MHD simulations to study the evolution of
single- and multi-threaded coronal loops, which become unstable and reconnect,
while varying the driving velocity of individual threads. Experiments
containing a single thread destabilise in a manner indicative of an ideal MHD
instability and consistent with previous examples in the literature. The
introduction of additional threads modifies this picture, with aspects of the
model geometry and relative driving speeds of individual threads affecting the
ability of any thread to destabilise others. In both single- and multi-threaded
cases, continuous driving of the remnants of disrupted threads produces
secondary, aperiodic bursts of energetic release.
