FoundationDesign 0.0.1

A python module for structural analysis and design of different foundation type in accordance to the Eurocodes

FoundationDesign

FoundationDesign is a python module to be used for the design and analysis of different foundation types in accordance to the Eurocode 2. This project is an attempt to have a free standalone python package that can be used to analyse and design foundations with results as good as paid softwares. This module will be useful in determining:

• The critical bending moments in the foundation
• Critical shear force in the foundation
• Transverse shear check of the foundation
• Sliding checks
• Crack width checks
• Reinforcement provisions
• Punching shear checks etc

The project is based mainly on instructions contained in the Eurocode 2 alongside python packages like numpy,plotly,scipy and IndeterminateBeam package. Comprehensive examples are contained in the examples folder

Project Purpose

1. Create a free python package that can analyse and design pad foundation,combined footing foundation, pile foundation and/or raft foundation design.

2. Create the web version of this module on Civils.ai platform an open source website for civil engineering calculations.

Functionality and usage

For now this package is limited to only concentric and eccentric pad foundation and combined footing foundation types. A typical use case of the pad foundation class contained in the FoundationDesign module includes

• Create a PadFoundation object to help analyse
• Assign foundation_loads to the PadFoundation
• Assign column_axial_loads to the PadFoundation
• Assign column_horizontal_loads_xdir to the PadFoundation
• Assign column_horizontal_loads_xdir to the PadFoundation
• Assign column_moments_xdir to the PadFoundation
• Assign column_moments_ydir to the PadFoundation
• Check the minimum_area_required for the PadFoundation
• Check the bearing_pressure_check_sls on the PadFoundation
• Create a PadFoundationDesign object to help design the foundation
• Plot the Bending moment and shear force diagrams
• Check the area of steel required and provided in x and y direction
• Check the adequacy of the transverse shear along both column_axial_loads
• Check for punching_shear_column_face on the PadFoundationDesign object
• Check for punching_shear_check_1d on the PadFoundationDesign object
• Check for punching_shear_check_2d on the PadFoundationDesign object

Creating a Pad Foundation

The creation of a PadFoundation instance involves the input of the following:

1. Foundation Length in mm

2. Foundation Width in mm

3. Column Length in mm

4. Column Width in mm

5. The position of the column along x direction from the origin in mm

6. The position of the column along y direction from the origin in mm

7. The soil bearing capacity in kN/mm2

    from foundationdesign import PadFoundation,padFoundationDesign
    fdn = PadFoundation(foundation_length=2500,foundation_width=2500,column_length=400,column_width=400,col_pos_xdir=1250,col_pos_ydir=1250,soil_bearing_capacity=200)
   

Assigning Foundation Loads

Soil self weight and concrete self weight can be added to the Foundation by specifying the Foundation thickness in mm and the soil depth above the Foundation in mm. A default value of 18kN/mm³ and 24kN/mm³ has been specified for soil unit weight and concrete unit weight respectively

fdn.foundation_loads(foundation_thickness=650,soil_depth_abv_foundation=0,soil_unit_weight=18,concrete_unit_weight=24)

Assigning Column Loads

Axial loads, horizontal loads in x and y direction, moments in x and y direction can all be added to the pad foundation for permanent,imposed and wind load cases.

fdn.column_axial_loads(permanent_axial_load=800,imposed_axial_load=300)

Designing a pad foundation

To design the foundation the PadFoundation must first be created as done above this would then be included when creating the padFoundationDesign object The creation of this object includes the following:

1. PadFoundation object created

2. Characteristic compressive cylinder strength in N/mm2. Accepted range of values [16,20,25,30,32,35,37,40,45,55]

3. Characteristic yield strength of reinforcement in N/mm2

4. Nominal cover to foundation in mm

5. Initial assumed bar diameter of the foundation in the x direction in mm. Accepted range of values [8,10,12,16,20,25,32,40] used to calculate depth to tension reinforcement along the x direction

6. Initial assumed bar diameter of the foundation in the y direction in mm Accepted range of values [8,10,12,16,20,25,32,40] used to calculate depth to tension reinforcement along the y direction

    fdn_design = padFoundationDesign(fdn, fck=30, fyk=500, concrete_cover=40, bar_diameterX=16, bar_diameterY=16)
   

Plotting Foundation forces

Lots of checks can be done on the Foundation which can be found in the notebooks contained in the examples folder To show the bending moment of the Foundation. The plot_bending_moment_X() can be called this figure will show the bending moment values at the critical location along the Foundation length or width.

fdn_design.plot_bending_moment_X()
fdn_design.plot_shear_force_X()

This outputs the bending moment plot with the design bending moment shown at the face of the column The shear force plot is also displayed with critical shearforce showing at 1d from column the face

Future Works

The following are areas that will be implemented in future:

• Adding a method to calculate crack width
• PDF report generation
• User documentation
• Creating a web application interface to be hosted on Civils.ai