Earthbag Testing
An Amazing Experiment: If anyone had any doubts about the strength and integrity of this system of building, this experiment should allay those concerns. Earthbag building of this sort can be STRONG! 
Earth Architecture and Ceramics: The Sandbag/Superadobe/ Superblock Construction System by Nader Khalili (Cal-Earth Institute) and Phill Vittore (Structural Engineering Consultant),1998. An article outlining the chronology and results of testing done on Nader Khalili's superadobe system of building. 
Prism Testing of Polypropylene Earthbags A prism test was conducted on earthbags using three different types of fill: sand, rubble, and dirt. The tests gave us the failure stress of the bags with the different types of fill (43.06 psi, 57.84 psi, and 311 psi respectively), as well as providing deflection data on the earthbags. These tests were conducted at the West Point Military Academy Engineering Department.