Ultimate hor. soil reaction [RH]

Calculations of Ultimate horizontal soil reaction

The soil range of importance for the Ultimate horizontal soil reaction is from ground level to the bottom of the pipeline.

NEN3650-1992

For the NEN3650-1992 calculation methodology two formula's are given, one for sandy soil types and one for clayey/peaty soil types.

Sandy:
Formula_RH_sandy

Clayey/peaty:
Formula_RH_clayey2

Qhor

Ultimate horizontal soil reaction

Kq

Function of φ and H*/D 1 (for sandy soil types)

σk

Vertical grain pressure at pipeline axis (see General parameters)

α

constant: 0.6

Kc

Function of φ and H*/D 2 (for clayey/peaty soil types)

cu

Undrained cohesion (averaged over range from ground level to the bottom of the pipeline)

φ

Angle of internal friction (averaged over range from ground level to the bottom of the pipeline)

H*

Height of soil coverage from ground level to pipeline axis

D

Outer diameter of pipeline

NEN3650-1:2012

The formula for sandy soil types is not changed in the NEN3650-1:2012 calculation methodology. For clay/peat soil types the NEN3650-1:2012 calculation methodology distinguishes slow and fast deformation. The formula's for clay are:

Clayey/peaty, slow deformation:
Formula_RVS_clayey_slow

Clayey/peaty, fast deformation:
Formula_RH_clayey_fast

Qhor

Ultimate horizontal soil reaction

Kq

Function of φ and H*/D 1

σk

Vertical grain pressure at pipeline axis (see General parameters)

α

constant: 0.6 for installation method trench and 1.0 for non-trench installation method. A trench installation is either 1)Trench uncompressed fill or 2)Trench compressed fill and a non-trench installation is either 3)Boring or 4)HDD.

Kcu

Formula_Kcu

Kc

Function of φ and H*/D 2

cu

Undrained cohesion (averaged over range from ground level to the bottom of the pipeline)

φ

Effective angle of internal friction (averaged over range from ground level to the bottom of the pipeline, using the Effective Young's modulus of soil for the same range with a depth as at bottom of pipe)

H*

Height of soil coverage from ground level to pipeline axis

D

Outer diameter of pipeline

 

1The function Kq is defined as:

Formula_Kq

Where:

Formula_Kq0

Kq

Formula_KqUnl

αq

Formula_alphaQ

H*

Height of soil coverage from ground level to pipeline axis

D

Outer diameter of pipeline

Nc

Function of φ 3

dc

Function of φ 4

 

2The function Kc is defined as:

Formula_Kc

Where:

Formula_Kc0

Kc

Formula_KcUnl

αc

Formula_alphaC

Nc

Function of φ 3

dc

Function of φ 4

H*

Height of soil coverage from ground level to pipeline axis

D

Outer diameter of pipeline

 

3The function Nc is defined as:

Formula_Nc

 

4The function dc is defined as:

Formula_dcUnl


Last changed: 20/10/2016