  It is recent that the emergence of topological insulators in condensed matter
physics has inspired analogous wave phenomena in mechanical systems, mostly in
the setting of discrete lattice models. Here we report a numerical and
experimental demonstration of topological waveguiding in a continuum plate. We
take a ubiquitous design of a bolted elastic plate and show that such a design
allows us to invoke the pseudo-spin Hall effect at remarkably low frequencies.
We harness the complex interaction of the bolts and the plate to show the
existence of a pair of double Dirac cones near the resonant frequency of the
bolt. The manipulation of bolted patterns results in the opening of multiple
topological bandgaps, including a complete bandgap that forbids all plate
modes. We demonstrate that inside this bandgap, the interface between two
topologically distinct zones can guide flexural waves crisply around sharp
bends.
