Puoi usare DB::raw() per fare questo:
DB::table('table')->insert([
'field' => DB::raw("SPECIAL_FUNC(X)"),
]);
Esempi:http://dev.mysql.com /doc/refman/4.1/en/point-property-functions.html http://dev.mysql.com/doc /refman/5.0/en/poulating-spatial-columns.html