4.14.5.35.1.7. ReeseStiffClayBelowWS

hystereticBackbone('ReeseStiffClayBelowWS', backboneTag, Esi, y50, As, Pc)

The backbone function is defined in this manual in page 328

backboneTag (int)

integer tag identifying the backbone function.

Esi (float)

see below

y50 (float)

see below

As (float)

see below

Pc (float)

see below
../_images/ReeseStiffClayBelowWS.png

4.14.5.35.1.7.1. Esi

\(Esi = k_sx\)

where ks is the k value for static load selected from the following table

The average shear strength should be computed from the shear strength of the soil to a depth of 5 pile diameters. It should be defined as half the total maximum principal stress difference in an unconsolidated undrained triaxial test.

Average Undrained Shear Strength (ton/ft^2)

0.5-1

1-2

2-4

\(k_s`\) (Static) \(lb/in^3\)

500

1000

2000

4.14.5.35.1.7.2. y50

\(y_{50} = \varepsilon_{50} b\)

Use an appropriate value of \(\varepsilon_{50}\) from results of laboratory tests or, in the absence of laboratory tests, from the following table.

Average Undrained Shear Strength (ton/ft^2)

0.5-1

1-2

2-4

\(\varepsilon_{50}`\) \(in/in\)

0.007

0.005

0.004

4.14.5.35.1.7.3. As

Choose the appropriate value of As from the following figure for the particular nondimensional depth.

../_images/Figure3.7.png

4.14.5.35.1.7.4. Pc

Compute the ultimate soil resistance per unit length of pile, using the smaller of the values given by the equations below

\[ \begin{align}\begin{aligned}p_{ct} = 2c_ab+\gamma'bx+2.83c_ax\\p_{cd} = 11cb\end{aligned}\end{align} \]

where

1. Obtain values for undrained soil shear strength \(c\), soil submerged unit weight \(\gamma'\), and pile diameter \(b\) 2. Compute the average undrained soil shear strength \(c_a\) over the depth \(x\).