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Armor Grading (based on CIRIA C683 or Latham et al, 2022)

cmorgh

Geotechnical
Dec 17, 2002
35
Hello all,

I have a question (geotechnical engineering) regarding Armor grading based on CIRIA C683. I'm involved in some armor grading issues (as an example 60 to 300 Kg).
The grading is done based on weighing around 250 samples. It seems that M50 is calculated as the average weight of all samples greater than 30 Kgs. The percent of <30 kg is around 1.

My questions:
1- Is it the right way to calculate M50 as the average of all weights (and for rocks with mass>30 kg)?

2- Mem min (Memll) is 120 Kg and Mem max (Memul) is 190 kg. I calculate the ratios M50/Memll and M50/Memul) using CIRIA C683 formula (3.16, 3.17 or 3.18 based on the reliability of each formula that is discussed in CIRIA). Then I calculate max and min acceptable values of M50 having 120 kg and 190 kg stated above times the ratios calculated from formula above. If the M50 calculated in item 1 above ok, then it shall be between the min and max M5o values calculated in item 2 above.


Thanks for your comments.

Cmorgh
 

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