Mechanical behaviour of carbonate sands

According to studies undertaken by Coop (1990) and Coop and Airey (2003) the specific properties of carbonate sands result in  

Coop and Airey (2003) have proposed a framework to describe the mechanical behaviour of carbonate sands that shows many similarities to the Critical State framework used for clayey soils. Some basic concepts of the critical state soil mechanics like the normal compression line (NCL) and critical state line (CSL) are used in the following sections. Detailed references to geotechnical literature can be found in appendix D. 

For more detailed information reference is made to the paper of Coop and Airey. Note that so far only a limited number of papers has been published on this subject. More research in the future may be required to fully understand the mechanical behaviour of carbonate sands. 

Coop and Airey (2003) conclude that the compressibility cannot be described by a unique bulk modulus, but will depend on stress level, initial (depositional) void ratio and previous loading history. 

This conclusion has its implications for sampling and testing of carbonate sands originating from both the borrow area and the fill itself Because a better graded sand usually produces a NCL with a smaller gradient X it is important to test a sample that is representative of the fill in the reclamation area. This sample may have a grading that, as a result of dredging, hydraulic transport and deposition, differs from the fill encountered in the borrow area. 

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