Input Parameters

 

Input parameters pane specifies the dimensions, properties of the pile, soil, and load cases.  These are entered in their respective tabs. 

 

 

Pile Dimensions Tab

 

Pile Dimensions tab defines the pile type, cross-section of the pile and the dimensions of the pile for the foundation.  It also displays a pictorial view of the pile along with the layers of soil.    

 

 

Pile Type

 

Select the pile type (method of construction) used for the project in the pile dimensions tab.  The choices for pile types are

 

a)     Driven

b)    Bored (Bored cast-insitu)

c)     CFA (Continuous flight auger)

d)    Driven Cast-insitu

 

The method of construction along with the pile cross-section and pile material is used to determine the default values for 'k earth pressure coefficient' for sand layers.  It is also used in calculation of pile capacity estimation. 

 

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Table 1 below describes the practical choices for pile method of construction, pile cross-section and material used.  The application may give warnings (which may be ignored by the user) if the selections don’t adhere to the table below. 

 

Table 1 Pile type, cross-section, material compatibility matrix

Pile Type

Driven

Bored

CFA

Driven Cast-insitu

Pile Cross-section

Hollow Circular

H-Section

Square

Rectangular

Hollow Circular

Full Circular

Full Circular

Full Circular

Construction material

Steel

Concrete

Concrete

Concrete

Concrete

 

 

Pile Cross-Section

 

Select the pile cross-section to be used for the project in the pile dimensions tab.  The choices for pile cross-section are

 

a)     Full circular pile

b)    Square pile

c)     Rectangular pile

d)    Hollow circular pile

e)    H Section pile

 

Based on the cross-section of the pile, define the parameters of the pile in the adjacent pile dimensions pane.

 

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The application may give warnings (which may be ignored by user) if the selections don’t adhere to the Table 1 Pile type, cross-section, material compatibility matrix described in 'Pile Type' section. 

 

 

Table 2 Summary of parameters to be specified for the different pile cross sections.

 

Full Circular pile

Square pile

Rectangular pile

Hollow Circular pile

H Section pile

Pile length

Pile length above ground

Optional

Optional

Optional

Optional

Optional

Number of elements

Pile diameter

 

 

 

Diameter of base

Optional

 

 

 

 

Pile wall thickness

 

 

 

 

Sectional breadth

 

 

Sectional depth

 

 

 

Sectional area

 

 

 

 

Moment of inertia about x-axis

 

 

 

 

Moment of inertia about y-axis

 

 

 

 

Direction of loading

 

 

 

 


Pile length

 

Specify the pile length here in the units chosen.  After selecting the pile cross-section, this should be the first item to be entered on this page.  This field is mandatory for all pile cross-sections.

 

 

Note: For TRIAL version, Pile length is restricted to 6m (19.6ft)

 

Pile length above ground

 

Specify the length of the pile length above the ground here in the units chosen.  This field is optional and applicable for all pile cross-sections.

 

 

Number of elements

 

This is the guidance of number of elements used in the finite element calculation.  The program may adjust this number based on the other input data to carry out the analysis.  A higher number of elements will improve granularity but may result in some loss of fidelity.  The default value of 50 elements is recommended. 

 

 

Use the slider to select the number of elements. A minimum of 20 elements and a maximum of 100 elements are permitted. This field is applicable for all pile cross-sections.

 

Pile diameter

 

Specify the external diameter of the pile here in the units specified.    This field is mandatory for Full circular pile and Hollow Circular Pile.

 

 

Diameter of base

 

Specify the diameter of base of the pile here in the units specified if different from the pile diameter.  This is usually required for piles with enlarged bases. This field is optional and can be specified only for full circular pile.

 

 

Pile thickness

 

Specify the pile wall thickness of the pile in the units specified.  This field is mandatory and applicable for hollow circular pile.

 

 

Sectional breadth

 

Specify the sectional breadth the pile here in the units specified.    This field is mandatory for Square pile, Rectangular pile and H Section pile. 

 

 

Sectional depth

 

Specify the sectional depth the pile here in the units specified.    This field is mandatory for Rectangular pile and H Section Pile. 

 

 

Square Pile

Rectangular Pile

H Section Pile

 

Sectional area

 

Specify the sectional area the pile here in the units specified. This field is mandatory for H Section pile.  The default value displayed here is calculated for a H-section pile with a 1” thickness.

 

 

Direction of loading (Required only for lateral pile analysis)

 

Use the radio button to select the direction of loading of the pile.  The choices are x-axis and y-axis.  This field is applicable only for Rectangular pile and H-Section piles.  The default value is taken as x-axis.  The diagram below shows the axis conventions used.  The direction of loading will also reflect in the loading diagrams.

 

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Rectangular Pile

H Section Pile

 

Moment of inertia about X-axis

 

Specify the moment of inertia of the pile about X-axis here in the units specified. This field is mandatory for H Section Pile. 

 

 

Moment of inertia about Y-axis

 

Specify the moment of inertia of the pile in Y-axis here in the units specified.    This field is mandatory for H Section Pile. 

 

 

Pile Diagram

 

The pile diagram displays the pile along with all the layers of soil.  Different scales are used for the depth axis and horizontal axis.  The pile length in the diagram is 20 m.  This diagram shows the perspective view of the pile along with the different layers of soil, scour and depth of water table.

 

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Pile Properties Tab

 

Pile properties tab is used for specifying the properties of the pile material, pile head boundary conditions, self-weight inputs. 

 

 

Pile Material Properties

 

Use the dropdown menu to select the material used for the pile.  The elastic modulus of the pile along with the unit weight is updated based on the selection.

 

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Table 3 Elastic modulus of pile

Pile Material

Elastic Modulus

(kN/m3)

(kips/ft3)

Steel

 

 

ASTMA36

2.0*108

4.173 * 106

Concrete

 

 

M20

3.0 * 107

6.26 * 105

M25

3.1 * 107

6.47 * 105

M30

3.3 * 107

6.68 * 105

M35

3.4 * 107

7.10 * 105

M40

3.5 * 107

7.31 * 105

M45

3.6 * 107

7.52 * 105

M50

3.7 * 107

7.73 * 105

 

 

Select the “User Defined” option to enter values for the elastic modulus and unit weight of the pile material. 

 

Elastic modulus of pile

 

The elastic modulus of pile is shown here based on the material specified.  If “User Defined” material is selected, the elastic modulus of the pile can be edited and entered here. 

 

 

Unit weight of material

 

The unit weight of pile material of pile is shown here based on the material specified.  If “User Defined” material is selected, the ‘unit weight of material’ can be edited and entered here.

 

 

Self-weight inputs

 

The self-weight properties could be taken into account for axial analysis of the pile.  The values of self-weight are auto-calculated based on the pile dimensions and soil properties or they could be user-defined. 

 

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Effective pile weight

 

The automatically calculated ‘Effective pile weight’ is shown here as default value. Effective pile weight accounts for the reduction in pile weight due to buoyancy effect of water. This will be used for ‘self-weight’ analysis if required. To enter a user defined value of ‘effective pile weight’, select the checkbox adjacent to this and enter the user defined value in the ‘text field’ next to it.   

 

 

Plug weight

 

The automatically calculated plug weight is shown here. The automatic calculation is based on the different soil layers and the inner diameter of the bottom segment of the pile.  This is only relevant for driven hollow piles.  A 0.9 reduction factor is used in calculating the plug weight.  This will be used for ‘self-weight’ analysis if required.  To enter a user defined value of plug-weight, select the checkbox adjacent to this and enter the user defined values in the ‘text field’ next to it.  

 

 

 

Pile Head Boundary Conditions

 

The boundary conditions pertain to only for lateral analysis of pile and are applied at the pile head. 

 

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Lateral Displacement

 

Select the checkbox ‘Lateral displacement’ to set the lateral ‘pile head’ displacement.  Enter the lateral displacement value in the field provided. 

 

 

Note: Lateral displacement can be specified only if there are no lateral loads applied at the pile head. This also includes distributed lateral loads starting at the pile head. 

 

Rotation

 

Select the checkbox ‘Rotation’ to set the ‘pile head’ rotation.  Enter the rotation value (radians) in the field provided. 

 

 

Note: Rotation can be specified only if there are no lateral moments applied at the pile head.

 

Rotational spring

 

Select the checkbox ‘Rotational spring’ to set the ‘pile head’ rotational spring value.  Enter the rotational spring value in the field provided. 

 


 

Soil Properties Tab

 

 

Soil properties tab is used to enter the details of soil layers, and standard penetration test (SPT) data.  The tab is further subdivided into 2 tabs (on right hand side)

·      Soil Layers

·      SPT

 

Soil Properties Tab > Soil Layers Tab

 

Soil Properties Tab is used to enter the data about the site condition, sub-soil layers and properties of each soil layer.  It is divided into 3 panes

 

·      Site Condition

·      Soil Layer Table

·      Soil Layer Properties

 

This tab is mandatory for ‘Pile Capacity Estimation’, ‘Laterally Loaded Pile Analysis’ and ‘Axially Loaded Pile Analysis’.      

 

Soil Properties Tab > Soil Layers Tab > Site Condition

 

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Scour depth

 

This field is not mandatory. Specify the local scour around the pile at the site.  Enter the ‘scour’ value in the field. 

 

Some restrictions on the scour depth:

·      Scour depth can extend up to the first three layers of soil

·      Scour depth should be less than 2.5 times of diameter of the pile

·      Scour cannot extend into a rock layer.

 

Depth of water table

 

This field is not mandatory. Specify the depth of water table at the site in the field provided. 

 

If no value is specified, it is assumed the water table lies below all the layers of soil specified.  For water table at ground level, set it as 0. 

 

Zeta (z)

 

Specify the value of ‘zeta (z)’ in the field provided.

 

Zeta (z) is required for Axial load analysis by ‘Elastic method’ and is based on the parameter proposed by (Randolph and Wroth 1978) as where rm is the radial extent of the influenced zone in the soil layer due to axil load and ro is the radius of the pile.

 

Min value: 3

Max value: 5

Default value: 4

 

Critical depth ratio (Zc)

 

Specify the value of ‘Critical depth ratio’ (zc/d) in the field provided.

Zc is the ratio of depth to diameter of pile beyond which the vertical and lateral effective stresses are considered to remain constant up to the pile base. The usual values are  Zc = 15 for loose sand and 20 for dense sand.

 

Critical depth ratio’ is required for Pile capacity estimation in ‘Sand soil’ when the limiting side friction and base resistance are determined by the values computed at the critical depth. This method is followed in IS-2911 (IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010). The software also adopts this method for limiting base resistance determined by ‘Nq - Berezantev – Zc’ method. The table below summarizes the scenarios under which Zc is required.

 

Analysis Module:

a)     Pile capacity analysis

b)    Axially loaded pile analysis

 

Table 4 Scenarios where ‘critical depth ratio’ is required

 

Method for maximum base resistance

Nq - qlim method

(API-2011, API-2000)

Nq-Zc method

(IS-2911)

Nq -Berezantev - Zc method

Meyerhoff SPT method (IS-2911)

Meyerhoff SPT method for silty sand (IS-2911)

Method for maximum side friction

β method (API-2011)

 

 

 

K - δ method (API-2000)

 

 

 

K - δ - Zc method (IS-2911)

Meyerhoff SPT method (IS-2911)

 

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

 

 

 

Min value: 15

Max value: 20

Default value: 15

 

Unit weight of water

 

Specify the unit weight of water in the field provided.  This parameter is a mandatory field.

 

Min value: 9.5 kN/m3 or 0.062 kips/ft3

Max value: 10.5 kN/m3 or 0.067 kips/ft3

Default value: 9.8 kN/m3 or 0.063 kips/ft3

 

Soil Properties Tab > Soil Layers Tab > Soil Layer Table

 

The ‘Soil Layer Table’ is used to define the type of soil and the thickness of each layer of soil. The properties of the soil layer selected is entered in the adjacent ‘Soil Layer Properties’ pane. 

 

 

 

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Number of soil layers

First select the number of soil layers using the up/down arrow.  This will set the number of rows in the table to populate

 

Up 50 soil layers can be specified.

Note: For TRIAL version, number of soil layers is restricted to 3.

 

Table: Double-click on the table cells to edit the content of the cells.

 

The table consists of four columns – Layer, Soil type, Starting depth and Layer thickness.  The ‘Layer’ column and the ‘Starting depth’ columns cannot be edited. 

 

To enter the Soil type, click on the cell in this column and select the type of soil from the ‘drop down’ menu for each segment.

 

Permissible soil types currently are – Soft Clay, Stiff Clay, Sand, Weak Rock, and Hard Rock.    

You can use ‘Sand’ to represent silt, silty sand, and gravel as well.

 

Layer thickness Column – This defines the thickness of each layer of soil.

 

Starting depth Column – This column is auto calculated based on the thickness of soil layers entered. 

 

The pile diagram in the pile dimensions tab will graphically show the values entered in this table. 

 

Note: Soil layers should extend up to pile depth below ground + n * effective diameter

n = 3 for pile terminating in soil

n = 1 for pile terminating in rock.

 

Soil Properties Tab > Soil Layers Tab > Soil Layer Properties

 

Select a layer in the ‘Soil layer table’ to display the soil properties associated with it in this pane. 

 

Note: Mandatory fields have a () adjacent to them depending on the choices made for capacity estimation, axial pile analysis and lateral pile analysis.

 

Note: The soil layer properties need to be arrived at from the soil investigation report.  The application populates median recommended values for each property.  These values need to be updated with actual values from the soil investigation report or values chosen by the user.

 

Common properties for all soil types:

 

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Soil type: Shows the type of soil in this layer.  (Field cannot be edited)

 

Unit weight of soil (γ): The unit weight to be given as data is the total unit weight of soil in the layer that is the moist unit weight above the water table and saturated unit weight below the water table. If required one may choose to divide the layer in to two halves one above water table and the other below the water table having different unit weights.

 

Starting depth: Displays the starting depth of the layer. (Field cannot be edited)

 

Layer thickness: Displays the thickness of the selected layer.  (Field cannot be edited)

 

 

Properties for Clay soil

 

Pile capacity estimation of clay soil

 

Method for maximum side friction: The table below details the options available for Soft Clay and Stiff Clay soil. 

 

Table 5 Details of ‘Method for maximum side friction’ for clay soil

Method for maximum side friction

Notes

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

a method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Semple & Ridgen (1984)

(Semple and Rigden 1984)

Kolk & Van Der Velde (1996)

(Kolk and van der Velde 1996)

 

The maximum unit shaft friction  of clay soil layers is based on the equation

 

Where α is a multiplier and is the undrained cohesion of the soil. Methods of estimating the α multiplier by the following four methods are available in the software:

 

1)    API RP GEO 2011

In this 

 

 

2)    α method (IS 2911)

Curve relating the   given in the Standard is made use of.

 

3)    Semple & Rigden (1984)

 

 

4)    Kolk& van der Velde (1996)

 

 

Base resistance in cohesive soil layers

 

The unit base resistance is given by

 

 

 

Properties for Soft Clay soil

 

 

Pile capacity estimation of soft clay soil

 

Method for maximum side friction: Select the method for maximum side friction from the dropdown list.  This parameter is mandatory for Axial pile capacity calculation and Axial loaded pile analysis. 

 

Table 6 Details of ‘Method for maximum side friction’ for soft clay soil

Method for maximum side friction

Notes

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

a method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Semple & Ridgen (1984)

(Semple and Rigden 1984)

Kolk & Van Der Velde (1996)

(Kolk and van der Velde 1996)

 

For more details on the methods, refer to the section on 'Method for maximum side friction' under 'Clay Soil'.

 

Table 7 Required properties for ‘pile capacity estimation’ for soft clay soil.

Method for maximum side friction

Cohesion at top

Cohesion at bottom

API-2011

α method (IS-2911)

Semple Rigden

Kolk & Van der Velde

 

 

Axial analysis method: Select the ‘Axial analysis method’ using the ‘drop down menu’ for axial load analysis.

 

Table 8 Axial analysis method details for Soft Clay

Axial analysis method

Method details

API-2000

(API 2000 RP2A-WSD 2000)

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

Elastic method

Based on elastic properties of soil.

 

Table 9 Required properties for ‘axial pile analysis’ for soft clay soil.

Axial analysis method

Cohesion at top

Cohesion at bottom

R factor

Elastic modulus

Poisson ratio

API-2011

API-2000

Elastic Code

 

 

Lateral analysis method: Select the ‘Lateral analysis method’ using the ‘drop down menu’ for lateral load analysis. 

 

Table 10 Lateral analysis method details for Soft Clay

Lateral analysis method

Method details

API-2011

(API 2000 RP2A-WSD 2000)

kh Based Horizontal Subgrade Modulus

Lateral spring of constant stiffness based on kh

 

IS-2911 recommends use of kh based horizontal subgrade modulus method for lateral analysis of pile. (IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

nh Based Horizontal Subgrade Modulus Variation

Lateral spring of stiffness proportional to depth based on nh

 

IS-2911 recommends use of nh based horizontal subgrade modulus variation method for lateral analysis of pile.  (IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

 

1.     API 2011 recommends nonlinear p-y models for static and cyclic loading. .The parameters used in the model are undrained cohesion cu, ε50 strain at 50% maximum lateral stress pu and a factor J.

 

2.     kh based method on Horizontal Subgrade Modulus

IS 2911 has provided recommended values for use in this method

3.     Linear elastic spring model based on nh.

In this approach the lateral soil resistance is proportional to depth given by p/y = nh x z where z is the depth.

 

Recommended values of nh (Davisson 1970) are :

Soft normally-consolidated clays: 350 to700 kN/m3

Soft organic silts: 150kN/ m3. The input required for this method is the value of nh for the soil layer.

 

IS-2911 has provided recommended values for use in this method

 

Table 11 Required properties for lateral pile analysis for soft clay soil.

Lateral analysis method

Cohesion at top

Cohesion at bottom

J constant

ε 50

Horizontal subgrade modulus

Linear variable subgrade modulus

API-2011

 

kh Based Horizontal Subgrade Modulus

 

 

 

 

 

nh Based Horizontal Subgrade Modulus Variation

 

 

 

 

 

 

 

Table 12 Soil property details for soft clay soil

Soil property

Units

Min value

Max value

Notes

Elastic modulus of soil

kN/m2

1750

5000

 

kips/ft2

36.54

104.4

Poisson Ratio

 

0.1

0.5

Default value: 0.5

Cohesion at top

kN/m2

0

100

Value of 0 is only permissible for the first soil layer.

kips/ft2

0

2.09

Cohesion at bottom

kN/m2

> 0

100

 

kips/ft2

> 0

2.09

J Constant

 

0.25

0.5

Default value: 0.5

e 50

 

> 0

0.025

Default value: 0.01

R factor

 

0.5

1.0

Default value: 0.9

Horizontal subgrade modulus

kN/m3

> 500

 

 

kips/ft3

> 10

 

Horizontal  subgrade modulus variation

kN/m3

> 10

1000

 

kips/ft3

> 0.25

21

 

 

Properties for Stiff Clay soil

 

 

 

Pile capacity estimation of stiff clay

 

Method for maximum side friction: Select the method for maximum side friction from the dropdown list.  This parameter is mandatory for Axial pile capacity calculation and Axial loaded pile analysis. 

 

Table 13 Details of ‘Method for maximum side friction’ for stiff clay soil

Method for maximum side friction

Notes

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

a method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Semple & Ridgen (1984)

(Semple and Rigden 1984)

Kolk & Van Der Velde (1996)

(Kolk and van der Velde 1996)

 

For more details, refer to the section on 'Method for maximum side friction' under 'Clay Soil'.

 

Table 14 Required properties for ‘pile capacity estimation’ for stiff clay soil.

Method for maximum side friction

Cohesion at top

Cohesion at bottom

API-2011

α method (IS-2911)

Semple Rigden

Kolk & Van der Velde

 

 

Axial analysis method: Select the ‘Axial analysis method’ using the ‘drop down menu’ for axial load analysis.

 

Table 15 Axial analysis method details for stiff clay

Axial analysis method

Method details

API-2000

(API 2000 RP2A-WSD 2000)

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

Elastic method

Based on elastic properties of soil.

 

Table 16 Required properties for ‘axial pile analysis’ for stiff clay soil.

Axial analysis method

Cohesion at top

Cohesion at bottom

R factor

Elastic modulus

Poisson ratio

API-2011

API-2000

Elastic Code

 

 

Lateral analysis method: Select the ‘Lateral analysis method’ using the ‘drop down menu’ for lateral load analysis. 

 

Table 17 Lateral analysis method details for stiff clay

Lateral analysis method

Method details

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

REESE

(Reese and Cox, Field Testing and Analysis of Laterally Loaded Piles in Stiff Clay April 1975)

kh Based Horizontal Subgrade Modulus

Lateral spring of constant stiffness based on kh

 

IS-2911 recommends use of kh based horizontal subgrade modulus method for lateral analysis of pile. (IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

 

1.     API-2011 recommends nonlinear p-y models for static and cyclic loading. The parameters used in the model are undrained cohesion cu, ε50 strain at 50% maximum lateral stress pu  and a factor J.

 

2.     Reese model

This is also a non-linear p-y model for static and cyclic loading (Reese,Cox,Koop-1975). The soil parameters needed are cu, e50 strain at 50% maximum lateral stress pu .The model is applicable to only layers below water table.

 

3.     Method based on horizontal subgrade modulus kh of the soil layer.

This is a linear spring model and the kh should include the correction ( division by 1.5) for use in piles. In SI units the value should be for 1m x 1m and in American units for 1ft x 1ft of pile The values kh recommended by Terzaghi (1955) for pile width are given Table 18 & Table 19 below.

Table 18 kh values for 1ft width & 1ft  length of pile (Terzaghi, 1955)

Consistency

Stiff

Very stiff

Hard

qu(tsf)

1 -2

2-4

>4

Kh(tcf)

50

100

>200

 

The values in SI units after width correction for 1m are given below:

 

Table 19 Modified Terzaghi values of kh for 1 m width & 1m length of pile in SI units

Consistency

Stiff

Very stiff

Hard

qu (kPa)

100-200

200-400

>400

kh(kN/m3)

5300

10500

>21000

 

IS-2911 also has given recommendations for  values.

 

Modified Vesic’s equation for piles (Bowels 1968)

 

 

Table 20 Required properties for laterally loaded pile analysis for stiff clay soil

Lateral analysis method

Cohesion at top

Cohesion at bottom

J constant

ε 50

Horizontal subgrade modulus

API-2011

REESE

 

 

kh based Horizontal Subgrade Modulus

 

 

 

 

 

 

Table 21 Soil property details for stiff clay soil

Soil property

Units

Min value

Max value

Notes

Elastic modulus of soil

kN/m2

4000

10000

 

kips/ft2

83.5

208.8

Poisson Ratio

 

0.1

0.5

Recommended value

Below water table: 0.5

Above water table: 0.4

Cohesion at top

kN/m2

100

 

For the top layer, a value from 0 can be used.

kips/ft2

2.09

 

Cohesion at bottom

kN/m2

100

 

 

kips/ft2

2.09

 

J Constant

 

0.25

0.5

Default value: 0.25

e 50

 

> 0

0.025

Default value: 0.005

R factor

 

0.5

1.0

Default value: 0.9

Horizontal subgrade modulus

kN/m3

> 1000

 

 

kips/ft3

> 21

 

 

 

Properties for Sand soil

 

 

Pile capacity estimation of sand

 

Method for maximum side friction: Select the method for maximum side friction from the dropdown list.  This parameter is mandatory for Pile capacity estimation calculation and Axial loaded pile analysis.  The table below details the options available for Sand soil. 

 

Table 22 Details of ‘Method for maximum side friction’ for sand

Method for maximum side friction

Notes

β method (API-2011)

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

K - δ method (API-2000)

(API 2000 RP2A-WSD 2000)

K - δ - Zc method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Meyerhoff SPT method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Meyerhoff SPT method for silty sand (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

 

1)    The β - fmax method (API-2011)

In this method   is given by the equation in which β depends on the density of the sand layer and pv’ is the vertical effective stress. β values recommended by API range from 0.29 for medium dense sand to 0.56 for very dense sand. User defined value β could also be specified. This method requires also a value of flim which is the limiting value for tmax. API proposes flim values ranging from 67 kPa for medium dense sand to 115 kPa for very dense sand. User defined value of flim could also be prescribed.

 

2)    K - δ - flim method (API-2000)

In this method   is given by the equation in which K is lateral earth pressure coefficient,  is the angle of friction between the pile surface and soil and  is the vertical effective stress. The values of K and δ need to be specified by the user after due consideration of type of soil, pile and method of installation.  Some guidance values in this regard are given in the appendix. API recommends a K value of 0.8 for open ended pipe piles and 1.0 for closed ended piles. The recommended δ values range from 15 degrees for very loose sand to 35 degrees for very dense sand. Standards and literature would be of help in choosing the appropriate values of K and δ. K and δ displayed in the software are those recommended by the code for driven tubular piles.

 

3)    K - δ - Zc method (IS 2911)

In this method  is given by the equation .The maximum vertical effective stress   is limited to the value at the critical depth Zc.   Zc /D ratio is specified ranging from 15 for φ’ to 20 for φ’. There is provision for user defined values of δ, K and Zc

 

4)    Meyerhoff SPT method (IS 2911)

In this method  for sand and  for silty sand where  is the average N value for the layer.


 

Table 23 Required properties for ’Pile Capacity Estimation’ - ‘method for maximum side friction’ for sand

Method for maximum side friction

Friction angle

Shaft friction factor (β)

Angle of shaft friction (δ)

K Earth pressure coefficient

Limiting shaft friction (flim)

Standard penetration test, average value in layer

Elastic modulus

Poisson ratio

β method (API-2011)

 

 

 

K - δ method (API-2000)

 

 

 

K - δ - Zc method (IS-2911)

 

 

 

 

 

Meyerhoff SPT method (IS-2911)

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

 


Method for maximum base resistance: Select the method for maximum base resistance from the dropdown list.  This parameter is mandatory for Pile capacity estimation and Axially loaded pile analysis.  The table below details the options available for Sand soil. 

 

Table 24 Details of 'Method for maximum base resistance' for sand

Method for maximum base resistance

Notes

Nq - qlim method (API-2011, API-2000)

(API 2000 RP2A-WSD 2000)

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

Nq - Zc method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Nq - Berezantsev - Zc method

 

Meyerhoff SPT method (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Meyerhoff SPT method for silty sand (IS-2911)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

 

1)    Nq - qlim  method. (API-2011, API-2000)

In API recommended values of Nq and qlim are automatically displayed in the software. User may also specify values of Nq and qlim

 

2)    Nq - Zc method (IS 2911)  

In this method the software automatically gets the value of Nq for the φ value from the curve given in IS 2911. This value is used together with the specified value of Zc/D ratio  to get the  limiting value of qmax. A default value of  Zc/D = 15  is used for  in the software. The user has option to prescribe other value of Zc/D up to 20.

 

3)    Nq – Berezantsev - Zc method

In this method Nq is obtained from Berezantsev’s curve using the value of φ specified. This value is used together with the limiting value of qmax using the value of Zc/D  specified.

 

4)    Meyerhoff - SPT method (IS 2911)

In this method  where is the average N value at the pile tip. Lb is the pile penetration in this embedment layer and D is the pile diameter.  is limited to to 400 . In silty sand  and is limited to 300N.

 

Note on average N Value:

For pile capacity estimation at various depths: Average N value at a given depth is computed using N values between -2D to +3D.  If no SPT points are present in this range then the average or weighted average of the two closest points around this depth will be used.  If only one SPT point is present in the entire sand layer, then the N value of this point will be used for the entire layer. 

 

For pile capacity at the pile tip: For calculating Average N value at the pile tip, only points in the range of -2D to +3D will be used.  If no points are present in this range then validation will fail. 

 

Table 25 Required properties for ‘Pile Capacity Estimation’ - ‘method for maximum base resistance’ for sand

Method for maximum base resistance

Friction angle (f)

Limiting end bearing (qlim)

Bearing capacity factor (Nq)

Standard penetration test, value at pile base

Nq - qlim method (API-2011, API-2000)

 

Nq - Zc method (IS-2911)

 

Nq - Berezantev - Zc method

 

 

 

Meyerhoff SPT method (IS-2911)

Meyerhoff SPT method for silty sand (IS-2911)

 

 

Axial analysis method: Select the ‘Axial analysis method’ using the ‘drop down menu’ for axial load analysis.

 

Table 26 Axial analysis method details for sand

Axial analysis method

Method details

API-2000

(API 2000 RP2A-WSD 2000)

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

Elastic method

Based on elastic properties of soil.


Table 27 Required properties for ‘Axially loaded pile analysis’ and ‘method for maximum side friction’ for sand

Axial analysis method

Method for maximum side friction

Friction angle (f)

Shaft friction factor (β)

Angle of shaft friction (δ)

K Earth pressure coefficient

Limiting shaft friction (flim)

Standard penetration test, average value in layer

Elastic modulus

Poisson ratio

API-2011

β method (API-2011)

 

 

 

K - δ method (API-2000)

 

 

 

K - δ - Zc method (IS-2911)

 

 

 

 

 

Meyerhoff SPT method (IS-2911)

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

API-2000

β method (API-2011)

 

 

 

K - δ method (API-2000)

 

 

 

 

 

K - δ - Zc method (IS-2911)

 

 

 

Meyerhoff SPT method (IS-2911)

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

Elastic Code

β method (API-2011)

 

K - δ method (API-2000)

 

 

 

K - δ - Zc method (IS-2911)

 

Meyerhoff SPT method (IS-2911)

Meyerhoff SPT method for silty sand (IS-2911)

 


 

Table 28 Required properties  for ‘Axially loaded pile analysis’ and ‘maximum base resistance’ for sand

Axial analysis method

Method for maximum base resistance

Friction angle (f)

Limiting end bearing (qlim)

Bearing capacity factor (NQ)

Standard penetration test, value at pile base

Elastic modulus

Poisson ratio

API-2011

Nq - qlim method (API-2011, API-2000)

 

 

 

Nq - Zc method (IS-2911)

 

 

 

Nq - Berezantev - Zc method

 

 

 

 

 

Meyerhoff SPT method (IS-2911)

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

API-2000

Nq - qlim method (API-2011, API-2000)

 

 

 

Nq - Zc method (IS-2911)

 

 

 

 

 

Nq - Berezantev - Zc method

 

 

 

Meyerhoff SPT method (IS-2911)

 

 

Meyerhoff SPT method for silty sand (IS-2911)

 

 

Elastic Code

Nq - qlim method (API-2011, API-2000)

 

Nq - Zc method (IS-2911)

 

 

 

Nq - Berezantev - Zc method

 

Meyerhoff SPT method (IS-2911)

Meyerhoff SPT method for silty sand (IS-2911)

 

 


Lateral analysis method: Select the ‘Lateral analysis method’ using the ‘drop down menu’ for lateral load analysis.  The table below details the ‘Lateral analysis methods’ for the various soil types. Only the relevant recommended practices are displayed based on the soil type selected in the layer.

 

Table 29 Lateral analysis method details for sand

Lateral analysis method

Method details

API-2011

(API 2011 Geotechnical and Foundation Design Considerations April 2011, Addendum 1, 2014)

nh Based Horizontal Subgrade Modulus Variation

Lateral spring of stiffness proportional to depth based on nh

 

IS-2911 recommends use of nh based horizontal subgrade modulus variation method for lateral analysis of pile for sand layers. (IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Hybrid model for liquefied sand (Based on φ)

 

This model is based on the paper (Franke and Kyle 2013). This model makes use of the friction angle (φ) of layer

 

Hybrid model for liquefied sand (based on SPT)

 

This model is based on the paper (Franke and Kyle 2013). This model makes use of the average SPT of the layer.

 

 

1)    API-2011

Recommends a non-linear p-y model for static and cyclic loading. The parameters needed are angle of internal friction φ and the value horizontal subgrade modulus. If not provided by the use the subgrade modulus will be generated internally by the software as per API.

 

2)   Linear elastic spring model based on  

In this approach the lateral soil resistance is proportional to depth given by  p/y = x z where z is the depth. Values of recommended by Terzaghi (1955) are given below

Table 30 Terzaghi  values of nh for sand

Terzaghi  values of nh for sand(t/ft3)

Density

       Loose

Medium

Dense

Dry

7

21

56

Submerged

4

14

34

Terzaghi  values of nh for sand(kN/m3)

Density

       Loose

Medium

Dense

Dry

2420

7300

19400

Submerged

1400

4800

11800

 

We may get nh values from the linear segments of p-y curves recommended by API 2011. These values are given in the table below:

 

Table 31 API-2011 recommendations for nh

φ′

kN/m3

kips/ft3

25°

5400

35

30°

11000

70

35°

22000

140

40°

45000

285

 

 

Table 32 IS-2911 recommendations for nh (clause -2.1, 2.31)

Soil Type

N

(Blows / foot)

Range of nh

 (kN/m3)

 

 

Dry

Submerged

Very loose sand

0 - 4

< 400

< 200

Loose sand

4 - 10

400 - 2500

200 - 1400

Medium sand

10 - 35

2500 - 7500

1400 - 5000

Dense sand

> 35

7500 - 20000

5000 - 12000

 

 

The input required for this model is the nh value for the sand layer in the units adopted.

 

3)    Hybrid model for liquefied sand.

Hybrid model for liquified sand can be used for modelling laterally loaded pile behaviour in sand layers due to liquefaction after an earthquake.

a)     Hybrid model based on angle of friction (f) for the layer

b)    Hybrid model based on average SPT value for the layer

 

Note: The hybrid models are available only with SI unit system. 

 

Table 33 Required properties for lateral pile analysis for sand.

Lateral analysis method

Friction angle (f)

K subgrade

Linear variable subgrade modulus

Fines (%)

Standard penetration test, average value in layer

API-2011

Optional

 

 

nh Based Horizontal Subgrade Modulus Variation

 

 

 

 

Hybrid model for liquefied sand (based on f)

 

 

 

Hybrid model for liquefied sand (based on SPT)

 

 

 

 

 

Relative density:  Select the relative density of the sand soil from the dropdown menu.  The choices are ‘Very Loose’, ‘Loose’, ‘Medium’, ‘Dense’ and ‘Very Dense’ sand.  Based on the relative density selection and the ‘Axial analysis method’ selected, the application populates the recommended values for the below parameters.  For API-2011 and API-2000 these are based on the appropriate ‘API recommended’ practices.  These values can be replaced by user preferred values.

 

Note: For ‘Very Loose’ and ‘Loose’ sand, t-z/Q-z API-2011 code doesn’t recommend any values for ‘Shaft friction factor’, ‘Limiting shaft friction (flim), Limiting end bearing (qlim) and Bearing capacity factor (Nq).  These need to be prescribed by the user based on soil investigation reports.

 

Properties for Sandy soil

 

 

Table 34 Soil property details for sand

Soil property

Units

Min value

Max value

Notes

Elastic modulus of soil

kN/m2

11000

200000

Default values for the particular 'relative density' will be populated when the ‘axial analysis method’ is set as ‘Elastic method’

kips/ft2

229.68

4176

Poisson Ratio

 

0.1

0.5

Default value: 0.2

Friction angle (f)

Deg

25

45

The value is not changed based on selection of ‘relative density of soil’

Shaft friction factor (b)

 

0.10

1.0

 

Angle of shaft friction (d)

Deg

5

45

Details in Table 19 Values for interface friction angle δ

K Earth pressure coefficient

 

0.25

2.0

Details in Table 20 Guidance values for lateral earth pressure coefficient K

Limiting shaft friction (flim)

kN/m2

0

400

 

kips/ft2

0

8.35

Limiting end bearing (qlim)

kN/m2

0

15000

 

kips/ft2

0

313.2

Bearing capacity factor (Nq)

 

1.5

320

 

Horizontal subgrade modulus

 

> 0

 

K-subgrade may be specified if available.  Otherwise, the program calculates the values based on the friction angle provided.  Set the value as – to enable auto calculation.

Linear variable subgrade modulus

kN/m3

500

60000

 

kips/ft3

10

1250

Fines

%

0

75

Percentage of fine particle sand

Standard penetration test, average value in layer

Blows/ft

> 0

 

This value is automatically calculated from the SPT table in the SPT tab.  The values of 'N values' in the layer are averaged.

Standard penetration test, value at pile base

Blows/ft

> 0

 

This value is automatically calculated from the SPT table in the SPT tab.  This is the average 'N value' - 2D above pile tip and 3D below pile tip.

 

 

Table 35 Values for interface friction angle δ

Type of soil

Angle of pile soil friction  δ (degrees)

Reference

Granular soil

Tan δ range

0.7 to 1.0

Fleming et al

Granular soil

Constant volume  friction angle φcv

Fleming et al

Tomlinson et al

Very loose sand

Loose sand silt

Medium silt

15

API 2000

Loose sand

Medium sand-silt

Dense silt

20

Medium sand

Dense sand silt

25

Dense sand

Very dense sand silt

30

Dense gravel

Very dense sand

35

 

 

Table 36 Guidance values for lateral earth pressure coefficient K

Pile Type

K

Reference

Driven hollow Tubular steel piles

0.8

(API 2000 RP2A-WSD 2000)

Driven cast –insitu piles

1.2 dry concrete

Fleming et al

 

1.0  wet concrete

Conventional bored piles in sand

0.7

Bored cast insitu concrete

0.7

Continuous flight augur in sand

0.9

Continuous flight augur in silty sand and silt

0.6

Precast concrete driven 

1.0-2.0 (φ = 30o to 40o)

(IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3) 2010)

Driven cast –insitu piles

1.0-2.0 (φ = 30o to 40o)

Bored cast insitu concrete

1.0-1.5 (φ = 30o to 40o)


 

Properties for Weak Rock

 

Graphical user interface

Description automatically generated

 

Pile capacity estimation in weak rock

 

Shaft friction estimate in weak and strong rock strata.

 

The maximum unit shaft friction  is estimated using the equation

 

 

Where α is multiplier and  is the unconfined compressive strength. Default value of α in the appropriate system of units gets shown in the software however user may also specify value of α.

 

Base resistance in weak and strong rock strata

 

The maximum unit base resistance qmax is estimated using the expression

 

 

A default value of β = 1 is used in the software. Other values between 0.5 and 3 may be adopted based on rock discontinuities and local experience.

 

Table 37 Required properties for pile capacity estimation for weak rock

Pile capacity estimation

Unconfined compressive strength

α factor

Base resistance factor

Elastic Method

 

 

Axial analysis method: Select the ‘Axial analysis method’ using the ‘drop down menu’ for axial load analysis.

 

Table 38 Axial analysis method details for weak rock

Axial analysis method

Method details

Elastic method

Based on elastic properties of rock.

 

 

Table 39 Required properties for Axially loaded pile analysis for weak rock

Axial analysis method

Unconfined compressive strength

α factor

Base resistance factor

Elastic modulus

Poisson ratio

Elastic Method

 

 

Lateral analysis method: Select the ‘Lateral analysis method’ using the ‘drop down menu’ for lateral load analysis. 

 

Table 40 Lateral analysis method details for weak rock

Lateral analysis method

Method details

REESE

(L. Reese, Analysis of Laterally Loaded Piles in Weak Rock 1997)

kh Based Horizontal Subgrade Modulus

Lateral spring of constant stiffness based on kh

 

1)    Based on the model proposed by Reese(1997)

The p-y relationship in this model is non-linear comprising an initial linear segment, a curvilinear segment in the middle followed by a horizontal segment. The rock parameters required for this model are:

qu = unconfined compressive strength

RQD = rock quality designation expressed in percentage

Km = empirical dimensionless parameter

E = elastic modulus of the rock mass in the layer.

 

2)    kh based Subgrade reaction approach.

This is a linear spring model based on kh. The input required is kh value in appropriate unit. 

 

Table 41 Required properties for laterally loaded pile analysis for weak rock

Lateral analysis method

Unconfined compressive strength

Rock quality designation

KRML Constant

Elastic modulus

Poisson ratio

Horizontal subgrade modulus

REESE

 

kh Based Horizontal Subgrade Modulus

 

 

 

 

 

 

 

Table 42 Soil property details for weak rock

Property

Units

Min value

Max value

Notes

Elastic modulus of soil

kN/m2

106

2*107

 

kips/ft2

20880

417600

Poisson Ratio

 

0.1

0.5

Default value: 0.2

Unconfined compressive strength

kN/m2

1000

20000

 

kips/ft2

20.88

417.6

a factor

(kN/m2)1/2

3

20

(Focht Jr. 1973)

(kips/ft2)1/2

0.433

2.88

Base resistance factor

 

0.5

3

(e. a. Reese 1984)

Rock quality designation

%

0

100

 

KRML constant

 

0.00005

0.0005

 

Horizontal subgrade modulus

kN/m3

6.5 * 105

1.3*107

 

kips/ft3

1.4 * 104

2.7 * 105

 

 

Properties for Hard rock

 

Graphical user interface

Description automatically generated with medium confidence

 

Pile capacity estimation for hard rock

 

Shaft friction estimate in hard rock strata.

 

The maximum unit shaft friction  is estimated using the equation

 

 

Where α is multiplier and  is the unconfined compressive strength. Default value of α in the appropriate system of units gets shown in the software however user may also specify value of α.

 

Base resistance in hard rock strata

 

The maximum unit base resistance qmax is estimated using the expression

 

 

A default value of β = 1 is used in the software. Other values between 0.5 and 3 may be adopted based on rock discontinuities and local experience.

 

Table 43 Required properties for pile capacity estimation for hard rock

Pile capacity estimation

Unconfined compressive strength

α factor

Base resistance factor

Elastic Method

 

 

Axial analysis method: Select the ‘Axial analysis method’ using the ‘drop down menu’ for axial load analysis.

 

Table 44 Axial analysis method details for hard rock

Axial analysis method

Method details

Elastic method

Based on elastic properties of rock.

 

 

Table 45 Required properties for axially loaded pile analysis for hard rock

Axial analysis method

Unconfined compressive strength

α factor

Base resistance factor

Elastic modulus

Poisson ratio

Elastic Method

 

 

Lateral analysis method: Select the ‘Lateral analysis method’ using the ‘drop down menu’ for lateral load analysis. 

 

Table 46 Lateral analysis method details for hard rock

Lateral analysis method

Method details

TURNER (2006)

(Turner 2006)

kh Based Horizontal Subgrade Modulus

Lateral spring of constant stiffness based on kh

 

 

1)    Approach proposed by Turner (2006).

The p-y relationship in this model is non-linear comprising three linear segments. The slope of the first linear segment is 1000qu up to p=0.4qu and thereafter 50qu up to p=0.5qu after which the line remains horizontal

 

2)    Subgrade reaction based approach.

This is a linear spring model based on kh. The input required is kh value in appropriate unit. 

 

Table 47 Required properties for lateral loaded pile Analysis for hard rock.

Lateral analysis method

Unconfined compressive strength

Horizontal subgrade modulus

TURNER (2006)

 

kh Based Horizontal Subgrade Modulus

 

 

 

Table 48 Property details for hard rock

Rock Property

Units

Min value

Max value

Notes

Elastic modulus of soil

kN/m2

1.5*107

108

 

kips/ft2

313200

2088000

Poisson Ratio

 

0.1

0.5

Default value: 0.25

Unconfined compressive strength

kN/m2

10000

100000

 

kips/ft2

208.8

2088

 

a factor

 

3

20

 

Base resistance factor

 

0.2

3

 

Horizontal subgrade modulus

kN/m3

9.8 * 106

6.5 * 107

 

kips/ft3

2.1 * 105

1.35 * 106

 

 

Soil Properties Tab > Standard Penetration Test (SPT)

 

SPT tab is used to define the standard penetration test results. 

 

 

The data in this tab is required for pile capacity estimation and axial load analysis for sand soil layer when ‘Meyerhoff SPT method (IS2911)’ is selected as the 'Method for maximum side friction' or as the 'Method for maximum base resistance'.

 

 

This data is also required for lateral load analysis for sand soil layer when ‘Hybrid model for liquified sand (based on SPT)’ is selected.

 

 

For sand layers, the 'standard penetration test avg value in layer' is calculated by averaging the values in the layer and displayed in the soil layer tab in the ' Soil Layer Properties ' pane.  This value is used when the 'method for maximum side friction' is set as one of 'Meyerhoff SPT method (IS2911)'.  This data is also used for lateral load analysis for sand soil layer when ‘Hybrid model for liquified sand (based on SPT)’ is selected

 

Graphical user interface

Description automatically generated with low confidence

 

When the pile terminates in the sand layer, the 'standard penetration test value at pile base' is calculated by averaging the values from pile tip – 2D and pile tip + 3D and displayed in the soil layer tab in the 'Soil Layer Properties' pane (D is the effective Diameter of the pile). This value is used when one of 'Meyerhoff SPT method (IS2911)' is selected as the ' method for maximum base resistance '.

 

SPT Table:

 

The ‘SPT Table’ contains the corrected data from the SPT test performed. 

 

Table

Description automatically generated

 

Use the (+) and (-) buttons at the top of the table to add / delete rows to the SPT table. 

[Organize] button can be used to sort the values in ascending order of depth and to clean up empty entries in the table. 

 

Up to 100 SPT points can be specified in the table.

 

Table:

Double-click on the table cells to edit the content of the cells.

 

The table consists of three columns: No., Depth, N Value. 

‘No.’ column cannot be edited and displays the entry index. 

 

Depth Column – Contains the depth at which the test is done.

 

N Value Column – Contains the corrected 'N' value of the test and specified as number of blows per foot

 

Right click on the table to bring-up the context menu to insert / delete rows in the table, cut, copy, delete and paste contents into the table.  It is also possible to copy the table from excel and paste the contents into this table.  Ensure adequate number of empty rows are added to the table prior to pasting contents from an excel table.

 

 

SPT Graph:

The SPT graph plots the data in the ‘SPT table’. 

 

Chart, line chart

Description automatically generated

 

 

Load Cases Tab

 

The ‘Load Cases’ tab is used to enter details of the loading on the pile.

 

It is important to first specify the ‘Number of load-cases’ in the ‘Project Properties Pane’.  This will setup the appropriate number of tabs under the ‘Load Cases Tab’ for specifying the details of each load case. 

 

Each load-case should be entered in a separate tab (on the right-hand side).  Each load case tab consists of details of the load applied on the pile along with a loading diagram that graphically represents the same.

 

 

Load Case Description

 

Enter the description of the load case for your reference.  This is an editable text field. 

 

 

Load at Pile Head

 

A close-up of a check

Description automatically generated with medium confidence

 

Axial load

 

Specify the axial load applied on the pile at the pile head.  Compressive loads (+ve) values act downward while tensile loads (-ve) values act upwards. 

 

Lateral load

 

Specify the lateral load applied on the pile head.

 

For Circular and Square cross-section piles, the load acts along the X direction. 

For Rectangular and H-Section piles, depending on the ‘Direction of loading’ selected in the ‘Pile Dimensions’ tab, load may act along the X or Y direction.  

 

Moment

 

Specify the moment load applied at the pile head.

Note: that counterclockwise moment is +ve.  If clockwise moment is to be applied, then prefix a –ve sign to the value. 

 

For Circular and Square cross-section piles, the moment acts around the Y direction. 

For Rectangular and H-Section piles, depending on the ‘Direction of loading’ selected in the ‘Pile Dimensions’ tab, moments may act around the X or Y direction. 

 

A picture containing text, diagram, screenshot, line

Description automatically generated

 

The figure above shows an axial load of 1000kN, lateral load of 100kN and a lateral moment of 20kNm applied at the pile head.

 

Include ‘self-weight’ in analysis

 

Select this checkbox if the weight of the pile is to be included in the analysis.  The weight of the pile is used in axial analysis only.  It is not taken into consideration for lateral analysis 

 

 

The “self-weight” of the pile consists of pile weight and plug weight and is taken from the ‘Self weight inputs’ pane in the ‘Pile Properties’ tab

 

Loading type

 

Loading type can either be static loading or cyclic loading.  Use the radio button to select the option.  Cyclic loading is used to simulate long term effects of wave action on a long pile.

 

 

 

Additional Loads

 

Along with the load applied at the pile head, concentrated loads (axial load, lateral load, lateral moment) can be applied along the length of the pile.  In addition, a distributed lateral load can also be applied.   These can be useful for modelling wave action, water currents, piers, loads applied on single buoy mooring piles. 

 

Distributed Lateral Load

 

The distributed lateral load can be used to model distributed loads along the length of the pile.  The loads can be triangular, uniform, or trapezoidal.  This is especially useful for modelling the effects of wave actions and water currents on the pile.

 

A picture containing text, screenshot, font, line

Description automatically generated

 

For Circular and Square cross-section piles, the load acts along the X direction. 

For Rectangular and H-Section piles, depending on the ‘Direction of loading’ selected in the ‘Pile Dimensions’ tab, load may act along the X or Y directions  

 

Specify the starting depth, ending depth along with the load at the starting depth and load at the ending depth.  If any of the values are left blank, then it is assumed that no distributed load is being applied. 

 

A drawing of a cylinder

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The figure above shows a trapezoidal load of 20kNm to 30kNm applied from a depth of 2m to 5m on the pile. 

 

Concentrated Load Table

 

This table is used to specify the additional concentrated loads and moments applied on the pile along its length. 

 

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The example above shows a pile with 30kN tensile and 30kNm lateral load applied at 6m depth. 

 

Use the (+) and (-) buttons at the top of the table to add / delete rows to the Concentrated Load Table'. 

[Organize] button can be used to sort the values in ascending order of ‘depth’ and to clean up empty entries in the table. 

 

Table Columns:

 

Depth: Specify the depth where the load is applied.

 

Note: A total of 20 unique depths with axial loads can be specified for axial analysis across load cases.

 

Axial load: Specify the axial load applied at the point.  Compressive loads (+ve) values act downward while tensile loads (-ve) values act upwards. 

 

Note: Only the axial load applied at the pile head is included in the calculation of beam-column effect for lateral load analysis. 

 

Lateral load: Specify the lateral load applied at the point.

For Circular and Square cross-section piles, the load acts along the X direction. 

For Rectangular and H-Section piles, depending on the ‘Direction of loading’ selected in the ‘Pile Dimensions’ tab, load may act along the X or Y direction.  

 

Moment: Specify the moment applied at the point. 

Note: that counterclockwise moment is +ve.  If clockwise moment is to be applied, then prefix a –ve sign to the value. 

 

For Circular and Square cross-section piles, the moment acts around the Y direction. 

For Rectangular and H-Section piles, depending on the ‘Direction of loading’ selected in the ‘Pile Dimensions’ tab, moments may act around the X or Y direction. 

 

Right click on the table to bring-up the context menu to insert / delete rows in the middle of the table, cut, copy, delete and paste contents into the table.  It is also possible to copy the table from excel and paste the contents into this table.  Ensure adequate number of empty rows are added to the table prior to pasting contents from an excel table.

 

Loading Diagram

 

The loading diagram represents the axial load, lateral load, and a distributed lateral load (trapezoidal) applied on the pile for a load case.

 

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Bibliography

Reese, et al. “Analysis of a Pile Group under Lateral Loading, Laterally Loaded Deep Foundations: Analysis and Performance.” ASTM, STP 835, 1984: 56-71.

Reese, L.C., and W.R. Cox. “Field Testing and Analysis of Laterally Loaded Piles in Stiff Clay.” 5th Annual Offshore Technology Conference. Houston, Texas, April 1975.

“API 2000 RP2A-WSD.” American Petroleum Institute WSD, 2000.

Fleming, K, A Weltman, M Randolph, and K Elson. Piling Engineering. Third. London: Taylor & Francis, 2009.

Terzaghi, K., R. B. Peck, and G. Mesri. Soil Mechanics in Engineering Practice. Third Edition. New York: John Wiley, n.d.

Tomlinson, M., and J. Woodward. Pile Design and Construction Practice. Fifth Edition. London: Taylor and Francis, n.d.

Reese, L. C., W. R. Cox, and F. D. Koop. “Analysis of laterally loaded piles in sand.” Proceedings of the offshore technology conference (OTC 2080). Houston, 1974.

Poulos, H. G., and E. H. Davis. Pile Foundation Analysis and Design. 1980, n.d.

Turner, J. Rock-Socketed Shafts for Highway Structure Foundations. In:Program, N.C.H.R (Ed) A Synthesis of Highway Practice, Transportation Research Board of the National Academies, 2006.

“API 2011 Geotechnical and Foundation Design Considerations.” ANSI/API RP2GEO, April 2011, Addendum 1, 2014.

Focht Jr., John A. Koch, Kenneth. J. “Rational Analysis of the Lateral Performance of Offshore Pile Groups.” Offshore Technology Conference. 1973. Paper No 1896.

Reese, L.C. “Analysis of Laterally Loaded Piles in Weak Rock.” Journal of Geotechnical and Geoenvironmental Engineering 123 (1997): 1010-1017.

Terzaghi, K. “Estimation of coefficient of subgrade reaction.” Geotechnique Vol.5, no. No. 4 (1955): 41-50.

Semple, R. M., and W. J. Rigden. “Shaft capacity of driven piles in clay.” Proc. ASCE National Convention. San Francisco, 1984.

Kolk, H. J., and E. van der Velde. “A reliable method to determine friction capacity of piles driven into clay.” Proc. Offshore technology conf. OTC 7993. Houston, 1996.

Randolph, M. F., and C. P. Wroth. “Analysis of deformation of vertically loaded piles.” ASCE, Geotech Eng Div. 104(GT12) (1978): 1465-1488.

“IS 2911 Design and construction of pile foundations - Code of Practice (Part 1. Sections - 1,2&3).” 2010.

Franke, Kevin W, and Rollins M Kyle. “Simplified hybrid p-y spring model for liquified soils.” Geotechnical and Geo-environmental Eng., no. 139(4) (2013): 564-576.

Matlock, H. “Correlations for design of laterally-loaded piles in soft clay.” 2nd Annual Offshore Technology Conference. Richardson, Texas, 1970. 577-594.

Rollins, K. M., T. M. Gerber, J. D. Lane, and S. Ashford. “Lateral resistance of a full-scale pile group in liquefied sand.” Geotech. Geoenviron. Engg, no. 131(1) (2005): 115-125.

Peck, R. B., W. E. Hanson, and T. H. Thornburn. Foundation Engineering. New York: Wiley, 1974.

Seed, R. B., and L. F. Harder. “SPT based analysis of cyclic pore pressure generation and undrained residual strength.” H. Bolton Seed Memorial Symp. Richmond, BC, Canada: Bitech, 1990. 351-376.

Rollins, K. M., L. J. Hales, J. D. Lane, and W. M. Camp. “p-y curves for large diameter shafts in liquefied sand for blast liquefaction tests.” Seismic performance and simulation of pile. 2005b.