Question

The earth pressure distribution on braced sheeting is based on

• A. Rankine's theory
• B. Coulomb's theory
• C. Brinch Hansen's theory
• D. Empirical pressure diagrams inferred from experimental observations

Hint:

Braced excavations are commonly designed using \[ \boxed{\text{Peck's Apparent Earth Pressure Diagrams}} \] which are based on field observations rather than classical earth pressure theories.

Answer 1

The Correct Option is D

Step 1: Why classical theories fall short here.
Rankine's and Coulomb's theories both assume a wall that rotates or translates freely about its base, letting a full active or passive wedge develop. A braced excavation is held by struts at several levels instead, so it barely moves and its deflection pattern looks nothing like a free retaining wall.
Step 2: What engineers actually rely on.
Because the real pressure distribution on strutted sheeting is governed by how much each strut level deflects and by the construction sequence, engineers instead use apparent pressure diagrams built up from years of measured strut loads on actual excavations, most famously the Peck diagrams for sand and clay.
Step 3: Concluding the basis of design.
This makes the design basis for braced sheeting an empirical one, drawn from field observations rather than a closed form theory.
\[ \boxed{\text{Empirical pressure diagrams inferred from experimental observations}} \]