Transactions of the American Society of Civil Engineers, vol. LXXII, June, 1911 : Experiments on retaining walls and pressures on tunnels

In this landmark 1911 civil‑engineering paper, the author presents the most extensive series of laboratory tests ever conducted on retaining walls and the pressures exerted on tunnels. By carefully measuring the behavior of both full‑scale walls and small rotating boards, the study reveals where established theories succeed and where they fall short. Listeners will hear a step‑by‑step reconstruction of the experimental setup, the observations recorded, and the surprising gaps that prompted a deeper look into the forces at work.

The core of the investigation centers on the role of cohesion, a factor often omitted from practical design formulas. Through clear geometric constructions and simple calculations, the paper shows how cohesion becomes significant for low‑height boards but diminishes as walls grow taller, restoring confidence in the sliding‑prism theory that underpins modern retaining‑wall design. Engineers and students alike will gain insight into the logical reasoning that bridges laboratory data with the engineering methods still taught today.