I went with half inch clear gravel. Was super easy to work with. Costlier but less maintenance & more longevity.How much connection to the ground do containers need. In transport they are usually just held in place by straps or chains. If you're using your shipping container on flat ground and there's nothing nearby that it could damage or nothing connected to it that could be damaged and it moves a little bit during an earthquake it may not be a problem. If the container could fall down a hill during an earthquake then you have a different problem. If you live in an area where strong winds, tornadoes and hurricanes might happen then you have a different set of problems. Also depending on what's stored inside the container some things are more easily damaged or dangerous. There may be many additional things to consider depending on the use and situation.