Download - Engineering Surveyor

Buildings and structures: excavationsIf topsoil is to be removed before setting out the excavation, the site engineer should set out in two stages.Stage 1: Removal of topsoildetermine overall excavation dimensionsset out temporary pegs defining area for excavation – sprinkle sand along string line between pegs asguide.Stage 2: Main excavationOnce the area has had the soil removed, proceed as follows (refer to diagram opposite for clarification): set up stakes for corner profiles offset from structure lines by a convenient multiple of, say, 1 m set and level peg adjacent to each profile set profile boards to a level such that the height of traveller for excavation is a convenient multiple of, say,0.25 m (traveller preferably not more than 5 m high) check that clearance between profiles and excavation lines is sufficient for plant access set out structure lines by marking opposing profiles set out excavation lines from corner lines by distance needed to give clearance for formwork etc provide foreman/ganger with dimensioned sketch on a Site Information Sheet showing profiles, excavationlines, structure lines and traveller height.Structure linesShallow excavations: use theodolite or Total Station if sufficient formation is visible.Deep excavations set up piano wire between opposing profiles plumb down line as close to corners as practicable.LevelsExcavations 5m deep set up board across corner of excavation to a reduced level tape down to level peg at bottom of excavation set up temporary profiles within excavation set pegs for blinding by re-taping agree peg levels with the supervising authority or seek other independent check.CIRIA C70971