Actually and very telling that's quite hard packable sand in anutami's pics as you can see the many previous vehicle tire tracks showing and their detail. Also showing is lots of pebble media and underlying and nearby dead vegetation debris and there has to be feeder roots from the many close side bushes which means there's ample water or moisture underneath the very top layer that packs/hardens/firms and supports weight or the so much vegetation shown wouldn't be green and growing!
As an example of some of the very different kinds of sand and beach sand:
Our beach sand and lots of the sand areas in our state is totally different as if you drove off the pavement or gravel roads, "hi frame, meet sand!" and you won't be able to move at all even with only 10 PSI in all tires. Walking barefoot on the beach or in many woods in it and you will usually sink almost to your ankles in the dry sand unless you have size 14 feet! Gunboats! Need wide sole flat bottom shoes or sandals. The sand also sings with a music like sound as you take steps in it because it's 97% pure quartz sand granules all the same size without fine grit between or hardly any foreign particles in it. Pure clean sand! That's why it's called "singing sand". That's what we call "sand" and "beach sand" Look it up! In most of the S.E. USA, what they call sand, we call clay as it's slimy when wet. In Florida, you can drive with regular OEM tire at full inflation on most beaches as it's mostly ground coral, shell, fragments mixed in with some quartz sand.
We could and do drive our TC rig on it here in our state also when it's sand like shown in California etc as it's more like a forest road here which are there for fire fighting access in our masses of our woods/forests/meadows.