  Radiatively-driven natural SUSY (RNS) models enjoy electroweak naturalness at
the $10\%$ level while respecting LHC sparticle and Higgs mass constraints.
Gluino and top squark masses can range up to several TeV (with other squarks
even heavier) but a set of light Higgsinos are required with mass not too far
above $m_h\sim 125$ GeV. Within the RNS framework, gluinos dominantly decay via
${\tilde g} \to t{\tilde t}_1^{*},\ \bar{t}{\tilde t}_1 \to t\bar{t}{\widetilde
Z}_{1,2}$ or $t\bar{b}{\widetilde W}_1^-+c.c.$, where the decay products of the
higgsino-like ${\widetilde W}_1$ and ${\widetilde Z}_2$ are very soft. Gluino
pair production is, therefore, signalled by events with up to four hard
$b$-jets and large ${\not\!\!{E_T}}$. We devise a set of cuts to isolate a
relatively pure gluino sample at the (high luminosity) LHC and show that in the
RNS model with very heavy squarks, the gluino signal will be accessible for
$m_{{\tilde g}} < 2400 \ (2800)$ GeV for an integrated luminosity of 300 (3000)
fb$^{-1}$. We also show that the measurement of the rate of gluino events in
the clean sample mentioned above allows for a determination of $m_{{\tilde g}}$
with a statistical precision of $2.5-5\%$ (depending on the integrated
luminosity and the gluino mass) over the range of gluino masses where a
$5\sigma$ discovery is possible at the LHC.
