Page 97 - Water Standards

6 Theri g idbod ylimite q uilibriummethodandthefiniteel-
ementmethodma ybeusedforthestabilit ydesi g nofrockbolt
su pp ortedcranebeam.Theri g idbod ylimite q uilibriummethod
forrockboltsu pp ortedcranebeamisseeninAnnexE.
7 Full yg routedboltsorp re-stressedboltsma ybeusedas
tensileboltsforrockboltsu pp ortedcranebeam.Whenfull y
g routedrockboltsareused, theadverseimp actofsurroundin g
rockdeformationduetoexcavationbelowontheforcecarr y in g
ca p acit yofboltsshallbefull yconsideredandenou g hsafet yallo-
wenceshallbemadefororreinforcin gmeasuresshallbetaken.
p
Whenp re-stressedboltsareused,artiall yp re-stressedorfull y
p re-stressedstructurema ybeado p tedandthere q uirementsfor
secondtensionin gshallbemet.
8 Thedesi g nofboltsforrockboltsu pp ortedcranebeam
shallmeetGB50086, SL377andSL212.Thesectionoftensile
boltsfromrockwallsurfacetocertainde p thintorocksshouldbe
ke p tfree.
9 Thestructuraldesi g nofcranebeamshallbeinaccord-
ancewiththerelevantsti p ulationsforwallt yp econtinuouscor-
belinSL191.
10 Rockboltsu pp ortedcranebeamma ynothaveex p an-
sionj oints , butshallbep rovidedwithex p ansionj ointsincorre-
s p ondin glocationswheretherockwallhei g htandg eolo g icalcon-
ditionsvar yg reatl yorthestructuralformofbeamchan g es.The
tensileboltsforrockboltsu pp ortedcranebeamonbothsidesof
ex p ansionj ointsshallbeintensified.
11 Constructionj ointsshallbesetonrockboltsu pp orted
cranebeamandshouldbes p acedat8 15m.Thej ointfaceshall
bep rovidedwithke y wa y sandbetreatedintorou g henedface.
Thelon g itudinalreinforcementofcranebeamshallcrossthe

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