Measure out the entire area that will be used for the concrete sections. Drive a wooden stake in the ground at each corner. Rope off the area by connecting the stakes with twine.
Excavate the site. Remove all dirt and sod with a shovel to a depth of six inches.
Lay out a framework of 2-by-4 lumber along the interior perimeter of the hole. Place the 2-by-4 pieces against the wall. Add a wooden stake between the 2-by-4 lumber and the wall of the hole. Drill the 2-by-4 into the wooden stake. Add these wooden stakes every two feet.
Divide the excavated space into smaller sections. Run new 2-by-4 lumber from the top and bottom of the original 2-by-4 framework. The placement of the 2-by-4 lumber depends on how many sections you want and how large you want the sections to be. If you place two 2-by-4 pieces running from top to bottom, you will have three sections. Drill the new 2-by-4 pieces into the framework.
Add two inches of gravel to each section. Tamp down the gravel with a shovel to pack it and even out the area.
Place two-inch-thick bricks on top of the gravel in each section. Add a couple bricks to the center of each section and some on the sides.
Place metal reinforcement screens on top of the bricks in each section.
Mix concrete and then pour it into each section. Make sure the concrete completely covers each reinforcement screen.
Level out the wet concrete by dragging a 2-by-4 over the area. Smooth out the concrete with a trowel.
Cover each section with a burlap sheet. Spray the areas with a hose. Keep the sheet on the sections for five to seven days. Lightly spray the area with water over the next week until the sections have cured and dried.