Splitting post loop with array chunk, WordPress.

array_chunk_post_loop.php

<?php 
	$args = array(
		'post_type' => array('post'),
		'posts_per_page' => 16	
	);
?>
<?php
/**
 * https://developer.wordpress.org/reference/functions/get_posts/
 * https://codex.wordpress.org/Template_Tags/get_posts
 */
  $posts = get_posts( $args );
	if ( !empty($posts) ) :
?>
<section class="main-section">

	<?php foreach (array_chunk($posts, 4, true) as $posts) : ?>

	<div class="chunk-wrapper">

		<?php foreach( $posts as $post ) : setup_postdata($post); ?>

		<div class="post-item">
			<?php the_title('<h3>','</h3>'); ?>
			<?php echo wpautop(wp_trim_words( get_the_content(), $num_words = 20, $more = null )); ?>
		</div><!-- /.post-item -->

		<?php endforeach; // foreach( $posts as $post ) : setup_postdata($post); ?>

	</div><!-- /.chunk-wrapper -->

	<?php endforeach; // foreach (array_chunk($posts, 4, true) as $posts) :
	wp_reset_postdata(); ?>

</section><!-- /.main-section -->
  
<?php endif; // if ( !empty($posts) ) : ?>