Another advantage of using thick-lift layer works is the reduction in cost of the placement of the any given volume of material due to the reduction in levelling works. Typically, one thick-lift layer that can be compacted using Landpac ground improvement equipment would equate to 3 to 4 thin-lift layers that would be required for compaction using conventional compaction equipment. This obviously reduces the amount of time and equipment (e.g. Bulldozers, graders etc) that would need to be utilised for layer levelling by a factor of between 3 to 4 times for any given volume of material.

A less obvious, but equally valuable advantage of using thick-lift layer works, is that the maximum particle size of the material being placed for compaction can be far greater for thick-lift layer works than for the thin-lift layer works. As a rule of thumb, the major dimension of any one particle within a layer may be up to two-thirds the dimension of the layer thickness. Particles within a thick lift layer that can be compacted using Landpac ground improvement equipment can thus have a major dimension of 3 to 4 times that of particles within a thin-lift layer associated with compaction using conventional compaction equipment. This means that costs associated with the breakdown and screening of material being placed in layers can be massively reduced if the material is to be placed and compacted in thick-lifts. This is of particular value when compacting rock fill layers where the breakdown and screening costs tend to be extremely high.

Another less obvious advantage of thick layer works is a vast reduction in the amount of material left exposed to the elements upon placement. This in turn means that the risk associated with drying out of the material in arid climates is reduced whilst the risk associated with the material becoming excessively moist due to exposure to rain in wet climates is also reduced.

Yet anothet less obvious advantage of thick layerworks is that by placing material in thicker lifts, it is possible to place a far greater volume of material in a reduced area. This is particularly useful when working in confined sites.

Quality Assurance Advantages

The Landpac CIR and CIS technologies allow for constant “in process” monitoring of the thick-lift layer works compaction. This allows for the following advantages:
- Monitoring of 100% of the material being compacted.
- Recording of the relative compaction and strength of the entire area of each layer being compacted.
- Identification of focussed areas for conventional testing. This allows for a reduction in the number of conventional tests required. Furthermore, by ensuring that the relatively weakest areas comply to specification, the certainty of the entire fill complying with specification can be greatly improved compared to the extremely limited certainty provided by the “random point testing” associated with the typical thin-lift layer works compaction using conventional compaction equipment.

The relatively high compaction loads imparted to the fill layer works by the Landpac ground improvement equipment ensure that the material is pre-stressed to a far higher level than that achievable using conventional compaction equipment. This leads to the maximisation of plastic deformation of the fill material during the construction phase, thus minimising the potential for future plastic deformation of the fill under service conditions. Most importantly, this high level of pre-stressing of the fill material leads to a reduction in future differential settlement of the constructed fill.