Question

The vertical strain ∈z due to triaxial load (σz,σr,σt=σr) under the center of plate is _________

(a) \(∈_z=\frac{1}{E}[σ_z-μ(σ_r)]\)

(b) \(∈_z=\frac{1}{E}[σ_z-2μ(σ_r)]\)

(c) \(∈_z=\frac{1}{E}[σ_z-23μ(σ_r)]\)

(d) \(∈_z=\frac{1}{E}[σ_z-0.43μ(σ_r)]\)

I got this question in exam.

I would like to ask this question from Stresses in Flexible Pavements in section Design of Flexible & Rigid Pavement of Geotechnical Engineering II

Answer 1

Right answer is (b) \(∈_z=\frac{1}{E}[σ_z-2μ(σ_r)]\)

Explanation: The vertical strain ∈z due to triaxial load (σz,σr,σt=σr) under the center of plate is given by,

\(∈_z=\frac{1}{E}[σ_z-2μ(σ_r)],\)

where,

σz=vertical stress

E=elastic modulus

μ= Poisson’s ratio.