$re = '/.+?\]\]/m';
$str = 'Floor_Live_Patterened_SpanPairs_1: [[-3, 0, 0, 5.5], [-3, 5.5, 0, .5]]
Floor_Live_Patterened_SpanPairs_2: [[-3, 0, 0, 5.5], [-3, 9.5, 0, 13.5]]
Floor_Live_Patterened_SpanPairs_3: [[-3, 5.5, 0, 9.5], [-3, 9.5, 0, 13.5]]';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php