Where he [Osmanagic] saw concrete blocks and human intervention, I saw only perfectly natural sandstones and conglomerates that had broken into larger or smaller blocks due both to tectonic stresses and gravity slumping...
The rocks have been tilted and bent due to tectonic stresses. The tectonic forces plastically deformed the clays and mudstones, but the sandstones and conglomerates broke into semi-regularly shaped pieces that Osmanagic and his team have excavated in numerous places, interpreting them as “pavements,” “terraces,” “concrete blocks,” “foundation stones,”
and so forth.
As for the supposed "ancient inscriptions", Schoch had a much better explanation:
The much-touted “ancient inscriptions” seem not to be ancient at all. I was told by a reliable source that the inscriptions were not there when members of the “pyramid team” initially entered the tunnels less than two years ago. The “ancient inscriptions” had been added since,
perhaps non-maliciously, or perhaps as a downright hoax.
I applaud Osmanagic for allowing Schoch to visit, although I'm sure the good doctor's conclusions were not what Osmanagic wanted. Too often, the details of high profile discoveries are kept hidden, discussed by "experts" outside the fields of study actually required for critical analysis, but sold to an uncritical media as authentic - when that happens, rest assured someone let the skunk in the door and is trying to convince everyone that it's a kitten. Whenever an individual, group of people or organization is afraid to have qualified experts in appropriate fields evaluate their discoveries, or fail to offer detailed, well written reports on what was discovered, or fail to share their data with colleagues...well, you can bet something fraudulent is afoot.