use strict;
use warnings;
use Storable qw(dclone);
use Data::Dumper;

# define @aoa1 w/ anonymous AoA
#
my @aoa1 = map { [qw(- - -)] } 0..2;  

# deep clone @aoa1 to create @aoa2
#
my @aoa2 = @{dclone(\@aoa1)};

# modify @aoa2
#
$aoa2[1][1] = '@';

# display structures
#
print Dumper(\@aoa1);
print Dumper(\@aoa2);