ABSTRACT

Afloortrenchwithcontinuouscoversmaybeused,asshowninFig.12.4.However,forlargerpipesandcablesitmaybenecessarytoincreasethedepthofthe trenchandprovideaccessopeningsatintervals,asshowninFig.12.5.

Floortrenchesmaybeusedinternallyatgroundfloorlevelorexternally belowground.Whenusedexternally,theconcretecoverslabsshouldbebedded andjointedtogetherwithlimemortarandshouldoverlapthetrenchwallsso thatsurfacewatermaybedirectedclearofthewall.