Chek Lap Kok Airport (Hong Kong)	Palm Deira (Dubai)

The high energy and relatively large depth of influence of the Landpac ground improvement equipment makes it an effective mechanism of improving the engineering properties of deep in-situ fills and weak natural soils. Improvements can typically be achieved in such in-situ materials to depths of up to 2m to 4m depending on the material type and moisture regime. This deep in-situ ground improvement can thus eliminate the need for costly excavation and the replacement and compaction in thin layers associated with improving such in-situ materials utilising conventional compaction equipment.

In-situ ground improvement using the Landpac high energy compaction and monitoring technologies comprises the improvement of the engineering properties of in-place ground materials at depth, both above and below the ground water level. Material strength is increased and compressibility and future settlements are decreased as a result of the densification process. The primary objective of this Landpac in-situ ground improvement process is to convert a heterogeneous material into one that has more uniform and better engineering properties.

In addition to improving the engineering properties of the existing in-situ materials, the Landpac high energy compaction process acts as a proof roller and is able to identify pockets of soft material or excessively weak materials that are unsuitable for improvement by compaction. Such pockets can then be remediated either by additional compaction, if appropriate, or by removal and replacement with more suitable materials.

The degree of improvement of engineering properties of in-situ materials depends largely upon the total amount of compaction energy applied to the material i.e. the more energy input to the material, the greater the degree of improvement. The result of in-situ material treatment using Landpac high energy compaction is dramatic and immediate. Induced settlement is typically 5% to 10% of the depth of material being treated whilst the strength and density of the material, as measured by in-situ testing, are typically improved by a factor of between 2 to 6 times.

The depth of influence of the Landpac high energy in-situ ground improvement process is related to the specific Landpac equipment rating with improvement depths of 2m to 4m being commonly recorded by cone penetration and dynamic probe testing. The depth of influence is also dependant on other factors including the material type and stratigraphic features, efficiency and energy loss of the compaction process on soft surfaces, the surface contact pressure of the Landpac high energy compactor drums and the method of application of the compaction energy (i.e. drum configuration).