Push array into array in Javascript (jQuery)

I've been trying to get the push() method on a loop to build a structure as follows:

var locations2 = [
    ['User', position.coords.latitude, position.coords.longitude, 1],
    ['Bondi Beach', -33.890542, 151.274856, 2],
    ['Coogee Beach', -33.923036, 151.259052, 3],
    ['Cronulla Beach', -34.028249, 151.157507, 4],
    ['Manly Beach', -33.80010128657071, 151.28747820854187, 5],
    ['Maroubra Beach', -33.950198, 151.259302, 6]
];

This is my code:

var locations = [];

$.ajax({
    type: "POST",
    url: "/ajax/map.php",
    data: "name=test",
    dataType: "json",
    cache: false,
    success: function(data){
        $.each(data.points, function(i,item){
            array_push = ["test", parseFloat(item.origem_lat), parseFloat(item.origem_lng), i];
            locations.push(array_push);
        });               
    }
});  

However, the Javascript console.log for locations shows an empty array.

I have tried to use push() in many different ways, but I cannot get the same structure as locations2. The biggest problem here is that I do not know how many arrays are going to be inside the locations array before the loop, so I can't initialize it beforehand.

Any thoughts?