ECISOLATED - Isolated Foundation Design

This part of user manual describes how to use ECISOLATED for the design of Isolated Foundations. ECPlus applications are designed as wizard type which is a step by step guided input procedure. If you are new to ECPlus applications, click here for general guidance.

Prerequisites: The user is expected to have a basic understanding of foundation design concepts.
The minimum input data required to use this application is as follows:

• ❶ Soil data such as Safe Bearing Capacity and ground water table.
• ❷ Allowable stability factors
• ❸ Concrete and Reinforcement Grades
• ❹ Pedestal Shape and Dimensions
• ❺ Foundation Loads

Following sections are presented with various input pages of ECISOLATED application with descriptions:

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Foundation

This page allows to provide the Isolated foundation details and analysis options.

Depth of the Foundation below GL - D_f

Enter the depth of the foundation below ground level.
↔ Range: 0 to 6000 mm

Depth of the Water Table below GL - D_wt

Enter the depth of the water table below ground level.
↔ Range: 0 to 5000 mm

Extend of Minimum Soil Cover - S_cve

▽ Nil: Select this option when there is no soil cover above pad.
▽ Full: Select this option when soil cover is up to ground level above pad.
▽ Partial: Select this option to enter the level of soil cover above pad.

Minimum Soil Cover above Pad - S_cv

Enter the minimum soil cover above pad, if extend of minimum partial cover is set to partial.

Pedestal and Pad

☉ Pedestal and Pad: Select this option to analyse and design both pedestal and pad.
☉ Pad only: Select this option to analyse pad alone.
☉ Pedestal only: Select this option to analyse pedestal alone.

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Pad

This page allows to provide dimension of the pad.

Length of the Pad (X - Dir) - L_f

Enter the length of the pad in X direction.
↔ Range: 300 to 100000 mm

Breadth of the Pad (Z - Dir) - B_f

Enter the breadth of the pad in z direction.
↔ Range: 300 to 100000 mm

Thickness of the Pad - T_f

Enter the thickness of the pad.
↔ Range: 100 to 5000 mm

Size of the pad can also be increased or decreased without affecting the pedestal position by changing the edge distance.

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Pedestal

This page allows to enter the pedestal dimension and it's location.

Type

▽ Pedestal: Select this option when pedestal load is applied at a height above the ground level such as pedestal supporting a steel column.
▽ Loaded Area: Select this option when pedestal load is applied at the top of the Pad such as a concrete column supporting roof beams.

Shape

Select the shape of the pedestal from the available options Rectangular, Square, Circle, Octagon or Wall.

Length (X - Dir) - L_c

Enter the length of the pedestal for the selected shape as defined in the picture.
↔ Range: 150 to 10000 mm

Breadth (Z - Dir) - B_c

Enter the breadth of the pedestal for the selected shape as defined in the picture.
↔ Range: 150 to 10000 mm

Diameter - D_c

Enter the diameter of the pedestal, in case of circular pedestal.
↔ Range: 150 to 10000 mm

Top of Pedestal above GL - TOG

Enter the height of the pedestal above Ground Level.
↔ Range: -5000 to 5000 mm

Eccentricity (X - Dir) - E_x

Enter the eccentricity for pedestal in X direction from centre of pad.
↔ Range: -600 to 600 mm

Eccentricity (Z - Dir) - E_z

Enter the eccentricity for pedestal in Z direction from centre of pad.
↔ Range: -600 to 600 mm

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Reinforcement

Cover

This page allows to provide the clear cover for pad and pedestal reinforcements.

Clear Cover for Pedestal - C_ped

Enter the clear cover for pedestal.
↔ Range: 15 to 150 mm

Clear Cover for Pad - C_pad

Enter the clear cover for pad.
↔ Range: 15 to 150 mm

Pad

This page allows to provide the reinforcement for pad.

Size

Enter or choose the size of the pad reinforcement in length (X direction) and breadth (Z direction) for both bottom and top layers.
↔ Range: 4 to 60 mm

Spacing

Enter the spacing of pad reinforcement for both bottom and top layers.
↔ Range: 20 to 450 mm

Area

Displays the area of the pad reinforcement based on size and spacing of bar given for both bottom and top layers.

%

Displays the percentage of pad reinforcement provided based on the details provided for both bottom and top layers.

Top reinforcement will not be considered, if minimum % value is provided as zero.

Pedestal

This page allows to provide the reinforcement for pedestal.

Size

Enter or choose the size of the pedestal reinforcement for corner, depth and width bars.
↔ Range: 4 to 100 mm

Nos

Number of corner bars will be fixed (4 Nos) in rectangular or square shape. Additional number of bars can be added in width and depth side.
↔ Range: 0 to 10
↔ Range: 6 to 14 for circular section

Area

Displays the area of reinforcement provided based on size and number of reinforcement provided in the section.

%

Displays the percentage of reinforcement provided based on size and number of reinforcement provided in the section.

Diameter of Bar - D_s

Enter the diameter of ties.
↔ Range: 4 to 60 mm

Spacing between Bars - S_s

Enter the spacing between the bars.
↔ Range: 20 to 450 mm

Additional Legs in X Direction - N_x

Select the number of additional legs provided in X direction.

Additional Legs in Z Direction - N_z

Select the number of additional legs provided in Z direction.

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Design Loads

SLS

This page allows to enter the Serviceability limit state (SLS) load details.

Load Factor for Selfweight and Soil - F_DS1

Enter the load factor for self weight and soil loads.
↔ Range: 0 to 5

Axial Load - P_S1

Enter the axial load.
↔ Range: -10000 to 10000 kN

Horizontal Load (X - Dir) - F_XS1

Enter the horizontal load in X direction.
↔ Range: -10000 to 10000 kN

Horizontal Load (Z - Dir) - F_ZS1

Enter the horizontal load in Z direction.
↔ Range: -10000 to 10000 kN

Moment about X Direction - M_XS1

Enter the moment in X direction.
↔ Range: -10000 to 10000kNm

Moment about Z Direction - M_ZX1

Enter the moment in Z direction.
↔ Range: -10000 to 10000 kNm

ULS

This page allows to enter the Ultimate limit state (ULS) load details.

Load Factor for Selfweight and Soil - F_DU1

Enter the load factor for self weight and soil loads.
↔ Range: 0 to 5

Axial Load - P_U1

Enter the axial load.
↔ Range: -10000 to 10000 kN

Horizontal Load (X - Dir) - F_XU1

Enter the horizontal load in X direction.
↔ Range: -10000 to 10000 kN

Horizontal Load (Z - Dir) - F_ZU1

Enter the horizontal load in Z direction.
↔ Range: -10000 to 10000 kN

Moment about X Direction - M_XU1

Enter the moment in X direction.
↔ Range: -10000 to 10000kNm

Moment about Z Direction - M_ZU1

Enter the moment in Z direction.
↔ Range: -10000 to 10000 kNm

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Design Setting

Setting for various Design Data such as Soil, Concrete, Safety Factors and Crack Width are presented in this section. This setting pop-up can be accessed by clicking the bottom panel below the left navigation.

Soil

Allowable Net Bearing Pressure - SBC

↔ Range: 50 to 300 kN/m²

Density of Soil - γ_soil

↔ Range: 16 to 30 kN/m³

Density of Ground Water - γ_w

↔ Range: 5 to 15 kN/m³

Angle of Internal Friction - Φ

↔ Range: 0 to 60 deg

Coefficient of Friction - μ

↔ Range: 0 to 1

Concrete

Density of Concrete - γ_conc

↔ Range: 16 to 30 kN/m³

Unit Weight of Steel - γ_steel

↔ Range: 50 to 100 kN/m³

Concrete Grade @ 28 days - f_cu

↔ Range: 15 to 100 N/mm²

Main / Shear Reinforcement Grade - f_y / f_yv

↔ Range: 200 to 600 N/mm²

Modulus Elasticity of Steel - E_s

↔ Range: 50 to 300 kN/mm²

Factors

Concrete in Flexure / Compression / Shear - γ_mc / γ_mcs

↔ Range: 1 to 2

Reinforcement - γ_ms

↔ Range: 1 to 2

F.O.S against Sliding / Overturning / Uplift - γ_Slide / γ_Over / γ_UP

↔ Range: 1 to 5

Crack Width

☐   Check for Crack Width
Check this option to include crack width check in the design.

Allowable Crack Width - W_c

Enter the allowable crack width value.
↔ Range: 0 to 0.4 mm

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Error Handling

Errors and Warnings are generated to prevent any inadvertent error in the input data. This section describes how to handle the errors and warnings. These errors are displayed at the bottom of the input page when the data in one or more input fields invalidate each other.