How to return an array using Laravel Eloquent select?

I have this class

<?php

namespace AppModelsTables;

use IlluminateDatabaseEloquentModel;
use IlluminateDatabaseQueryBuilder;
use IlluminateSupportFacadesDB;

class ZipCode extends Model
{
    protected $table      = 'zip';
    public    $timestamps = false;
    protected $fillable   = [
        'latitude',
        'longitude',
    ];

    public static function radiusSearch($lat, $lng)
    {
        $circle_radius = 3959;
        $subQuery      = '(SELECT *, (' . $circle_radius . ' * acos(cos(radians(' . $lat . ')) * cos(radians(latitude)) * cos(radians(longitude) - radians(' . $lng . ')) + sin(radians(' . $lat . ')) * sin(radians(latitude)))) AS distance FROM zip) AS distances';

        $result = ZipCode::select('*')
            ->from(ZipCode::raw($subQuery))
            ->limit(20);

        var_dump($result);

        return $result;
    }
}

when I call radiusSearch(...) I get a IlluminateDatabaseEloquentBuilder object and not the actual result

$result->get() doesn’t work, I get Object of class IlluminateDatabaseEloquentBuilder could not be converted to string

This generic query works just fine ZipCode::where('zip', '11111')->get() just not the above one

Any ideas?

EDIT: the $result returns something like this:

object(IlluminateDatabaseEloquentBuilder)[170]
  protected 'query' => 
    object(IlluminateDatabaseQueryBuilder)[164]
      public 'connection' => 
        object(IlluminateDatabaseMySqlConnection)[166]
          protected 'pdo' => 
            object(PDO)[175]
            ...
  protected 'model' => 
    object(AppModelsTablesZipCode)[171]
      protected 'table' => string 'zip' (length=9)
      public 'timestamps' => boolean false
      ...

If I do $result->getModel()->get()->toArray() this returns all results from the table

Answer

Here is the solution I came up with based on some other community answers

public static function getClosestCities($lat, $lng, $city, $distance = 20, $limit = 20)
{
    $coordinates = ['latitude' => $lat, 'longitude' => $lng];
    $cares       = self::scopeIsWithinMaxDistance(ZipCode::raw('select *'), $coordinates, $distance, $city)->limit($limit)->get();

    return $cares ? $cares->toArray() : null;
}


public static function scopeIsWithinMaxDistance($query, $coordinates, $radius = 5, $city)
{
    $haversine = "(3961 * acos(cos(radians(" . $coordinates['latitude'] . ")) 
                * cos(radians(`latitude`)) 
                * cos(radians(`longitude`) 
                - radians(" . $coordinates['longitude'] . ")) 
                + sin(radians(" . $coordinates['latitude'] . ")) 
                * sin(radians(`latitude`))))";

    return $query->select('*')
        ->selectRaw("{$haversine} AS distance")
        ->orderByRaw("{$haversine} asc")
        ->whereRaw("{$haversine} < ?", [$radius])
        ->groupBy("city");
}