Dynamic compaction techniques

Common dynamic compaction techniques include the Dynamic Compaction (or Heavy Tamping) method, the Rapid Impact Compaction (RIC) and the High Energy Impact Compaction (HEIC) techniques. 

Dynamic Compaction tends to disturb and loosen the top layers even though it compacts the deeper layers. Often different passes are required to compact the deeper layers with heavy impact on a wide grid, followed by lower impact in a narrower grid to improve layers closer to the surface. 

The response of granular and cohesive soils when subjected to high-energy impacts is fundamentally different. Dynamic compaction literally squeezes water out of the soil to effectively pre-load the ground (Moseley et al, 2004). Granular and dry cohesive fills respond well to dynamic compaction. The response of clays, however, is more complex than that of granular soils. Therefore care must be exercised in the treatment of weak natural clayey soils or clay fills below the water table. Their low permeability will prevent pore water to escape from the soil mass. Nevertheless, claims have been made that, in particular, HEIC may be effective in clayey soils as well (Chu et al, 2009). 

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Dynamic compaction techniques dynamic compaction Granular material From the surface up to 8-12 m... 

Fig. 50. a SFM picture of an indentation of the letter T on PMMA with a nickel tip. Force used for the imaging was 10"6N. b Profile along the line drawn in (a). Reproduced from [416]. c HEUREKA written with the dynamic ploughing technique on a compact disc (CD) of polycarbonate. The holes are information pits in the disc. The letter height is 700 nm, and the indentation depth is 10 nm. Reproduced from [464]... 

One of the objective of this research is to fabricate diamond- gradually dispersed cermets by the combination technique of SHS for short time processing and following dynamic compaction for densification. The other is to support for the fabrication by the calculation of residual stress based on graded structure of diamond in the matrix. 

Synthesis and dynamic compaction of ceramic nano powders by techniques based on electric pulsed power. Nanostruct. Materials. Vol. 6, No 1-4, pp. 287 - 290. 

Techniques that affect adjacent structures e.g., dynamic compaction with large drop weights in the immediate vicinity of existing structures (e.g. quay walls) and infrastructure (e.g. pipelines) may induce esthetical or structural damage. 

Compaction by means of vibroflotation can generally not be applied, since the vibroflotation probe is not capable to penetrate the rock fill. Dynamic compaction is the only possible compaction technique. 

Dynamic compaction by a heavy weight. Compaction causes subsurface voids to collapse. This technique does not necessarily eliminate further development of sinkholes. 

The formation of a compact structure accompanying the complexation of PMMA with PEO and the lower flexibility of the PMMA chain in the complex than that of the PAA chain have been confirmed by viscometry [ 16], membrane contraction [2], and polarized luminescence techniques [3]. In addition, comparison of the dynamic light-scattering behavior of PMAA/PEO and PMAA/PEO" in solution shows that the pyrene label, which acts as a hydrophobic species, allows the labeled PEO to aggregate intermolecularly much faster than unlabeled PEO does [30]. 

It is assumed that the limited proteolysis phenomenon derives from the fact that a specific polypeptide chain segment of the compact, folded protein substrate is exposed and flexible so that it can fit the active site of the appropriate peptidase for an efficient and selective limited hydrolysis. There is no doubt that enhanced chain flexibility or segment mobility is the key feature of the site of peptide bond hydrolysis demonstrated by a clear-cut correlation between sites of proteolytic attack and sites of enhanced chain flexibility. The present availability of automatic, efficient and sensitive techniques of protein sequencing and, particularly, the recent dramatic advances of mass spectrometry 361 in the analysis of peptides and proteins, allows a more systematic use of the limited proteolysis approach as a simple first step in the elucidation of structure-dynamics-function relationships for novel proteins which are only available in minute amounts. 

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