Example 9.2 · Elastic settlement

Example 9.2 of Das & Sivakugan (2017), Principles of Foundation Engineering, solved in Rischio: settlement at the centre, beside the source's answers.

Source: Das, B. M., & Sivakugan, N. (2017). Principles of Foundation Engineering, SI edition, 9th ed. Cengage Learning. Example 9.2.
ID: das-pfe9-9-2

Open in the studioA copy, in your account

The model as the editor draws it, with what governs its result.

Source vs Rischio

	Source	Rischio	Difference
Settlement at the centre	12.4 mm	12.6 mm	+1.6 %

The book interpolates Steinbrenner's F₁ and F₂ in its tables; Rischio computes them with his formulas.

Every check

What the engine checks in this model, against Rischio's default limits.

Bearing capacityPasses	$\mathrm{FS} = 8.07$	$\ge 3.0$	Passes
Eccentricity along the widthPasses	$e_B = 0.00\,\mathrm{m}$	$\le 0.167\,\mathrm{m}$	Passes
Eccentricity along the lengthPasses	$e_L = 0.00\,\mathrm{m}$	$\le 0.333\,\mathrm{m}$	Passes
SettlementPasses	$S = 0.01\,\mathrm{m}$	$\le 0.025\,\mathrm{m}$	Passes

The model

The example's data, element by element, as the model holds it.

FootingFooting · Rectangular

Width $B$: 1 m
Embedment depth $D$: 1 m
Length $L$: 2 m

LoadLoad · on the footing

Vertical load $V$: 300 kN
Horizontal load $H$: 0 kN
Moment along the width $M_B$: 0 kN·m
Moment along the length $M_L$: 0 kN·m

Upper layerStratum

Thickness $t$: 3 m
Unit weight $\gamma$: 16 kN/m³
Cohesion $c'$: 0 kPa
Friction angle $\varphi'$: 35 °
Elastic modulus $E$: 10000 kPa
Poisson's ratio $\nu$: 0.3

Middle layerStratum

Thickness $t$: 1 m
Unit weight $\gamma$: 16 kN/m³
Cohesion $c'$: 0 kPa
Friction angle $\varphi'$: 35 °
Elastic modulus $E$: 8000 kPa
Poisson's ratio $\nu$: 0.3

Lower layerStratum

Thickness $t$: 2 m
Unit weight $\gamma$: 16 kN/m³
Cohesion $c'$: 0 kPa
Friction angle $\varphi'$: 35 °
Elastic modulus $E$: 12000 kPa
Poisson's ratio $\nu$: 0.3

Example 9.2 · Elastic settlement

Source vs Rischio

Every check

The model

How it's calculated