  We investigate the possibility of testing supergravity unified models with
scalar masses in the range 50-100 TeV and much lighter gaugino masses at the
Large Hadron Collider. The analysis is carried out under the constraints that
models produce the Higgs boson mass consistent with experiment and also produce
dark matter consistent with WMAP and PLANCK experiments. A set of benchmarks in
the supergravity parameter space are investigated using a combination of signal
regions which are optimized for the model set. It is found that some of the
models with scalar masses in the 50-100 TeV mass range are discoverable with as
little as 100 fb$^{-1}$ of integrated luminosity and should be accessible at
the LHC RUN II. The remaining benchmark models are found to be discoverable
with less than 1000 fb$^{-1}$ of integrated luminosity and thus testable in the
high luminosity era of the LHC, i.e., at HL-LHC. It is shown that scalar masses
in the 50-100 TeV range but gaugino masses much lower in mass produce
unification of gauge coupling constants, consistent with experimental data at
low scale, with as good an accuracy (and sometimes even better) as models with
low ($\mathcal{O}(1)$ TeV) weak scale supersymmetry. Decay of the gravitinos
for the supergravity model benchmarks are investigated and it is shown that
they decay before the Big Bang Nucleosynthesis (BBN). Further, we investigate
the non-thermal production of neutralinos from gravitino decay and it is found
that the non-thermal contribution to the dark matter relic density is
negligible relative to that from the thermal production of neutralinos for
reheat temperature after inflation up to $10^9$ GeV. An analysis of the direct
detection of dark matter for SUGRA models with high scalar masses is also
discussed.
