trench Excavation & Timbering

LOng, narrow trenches in firm soil may be excavated to the full depth by mechanism excavators , enabling the support timbering to be placed in one continuous operation .

weak and waterlogged ground must be supported before excavation commences by driving timber runners ot steel trench sheeting to a position below the formation level , or by a drive and dig procedure .

In the drive and dig procedure , the runners can be driven to a reasonable depth of approximately 1.5 m followed by an excavation cut of 1.2 m and then the operation repeated until the required level has been reached ; this will make the driving of the runners easier and enable a smeller drving appliance to be used .