construction and refurbishment of earthen irrigation channel banks

AdvantagesCost – instrument relatively cheap topurchase.Robustness – The instrument issturdy. It is suitable to be carriedaround in the back of a utility.Ease of Use – testing method issimple, requiring little training ofusers.Time consumed in testing is minimal.Speed of Results – very fewcalculations are required with thisdevice. Once calibrated, an indicationof density could be given.DisadvantagesCannot be directly related to density or relativedensity.Using the Australian Standard method the conepenetrates a 150mm layer of material in 2 to 3blows. This does not give enough informationto correlate the results to actual density.Inconsistency of results - Readings from thetest are influenced by variations in moisturecontent.OH&S concerns• With a one metre shaft, it was found thatthe 9kg weight would have to be lifted up to1.6 metres above ground level, which washard for some shorter operators.• The tester may also have difficulty carryingapparatus long distances due to the weightof the 9kg hammer as well as the shaft.Table 16-3Dynamic Cone Penetrometer – Advantages & Disadvantages16.14 Testing and ReportingTo assess whether the specified requirements are being achieved, inspection and testing atregular and appropriate intervals is required having due regard to the nature of the workand the specification. Such inspections should be carried out by personnel experiencedand knowledgeable in earthworks.16.14.1 Sampling16.14.1.1 Borrow Pit SamplesWhen samples are taken from potential borrow pits (refer Section 15, MaterialSelection and Testing) enough of each sample can also be taken to determine thefield moisture content, Optimum Moisture Content and Maximum Dry Density ofthe material. This will give an indication before construction commences of whatmoisture conditioning the material may require, and give an indication of whatoptimum moisture content and maximum dry density will occur duringcompaction testing of the channel bank.16.14.1.2 Compacted Channel Bank samplesSamples should be cut with an auger to a depth of at least 150mm (depth of layer)and sealed in a plastic bag. The bag should be marked and the sample recordedon a log sheet. Refer toFigure 16.4. Test results can then be recorded on the same log sheet.Construction and Refurbishment of Earthen Channel Banks August 2002 - Edition 1.0 16-28