Modelling a Reinforced Concrete Bund Wall & Base Slab in MasterSeries

Learn how to model, analyse and design a concrete bund storage structure or retaining structure using MasterSeries Finite Element Analysis (FEA) and Concrete Design modules. This tutorial demonstrates the core software workflow for generating finite element surfaces, applying hydrostatic loads, configuring foundation springs, and executing slab and wall design checks according to project specifications.

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Under Construction and Review

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Design File -

Step 1: Define Geometry & FE Surfaces

Open MasterFrame
Navigate to the 📄 Create Menu select 📄 Add Members . Draw the wireframe outer perimeter members for your structural layout

Select 📄 Add Slab, Wall, Ramp (FE Surface) .
Click along the perimeter boundaries to form closed loops generating FE Surface regions for both the raft foundation base slab and the vertical bund walls.

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Tip: Ensure all perimeter members form a closed, planar loop before creating an FE surface to prevent surface definition and meshing geometry errors.

Step 2: Assign Material Properties & Section Thickness

📄 Material/Thickness

Under FE Surface Properties, define the material properties, grade, and thickness for each surface element:

Material Type: Set to Concrete.
Base Raft Slab Thickness: (or per design).
Bund Wall Thickness: (or per design).
Concrete Grade: Minimum recommended class for retaining structures.
Concrete Density:

Step 3: Define Supports & Soil Springs

📄 Edge Restraints and Releases

Soil Spring Stiffness

Select the bottom surface (Raft FE Surface).
Go to Edge Restraints and Support Options tab.
Apply a vertical subgrade reaction spring () to model ground support (in this example - ).

Nodal Restraints for Lateral Stability

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Refer to Horizontal Restraint to Slabs section within Edge Restraints and Releases

Go to Nodal static supports and assign lateral static restraints to restrain the raft horizontally and prevent rigid body translation during FE matrix solution.

Step 4: Apply Hydrostatic Liquid Pressure & Loads

(Loads application and navigation in FE surfaces-Loading)

Hydrostatic loading varies linearly from zero at the maximum liquid level to maximum pressure at the wall base.

Navigate to Loading,

Wall Hydrostatic Loads (Full Height)

To apply a full-height triangular load distribution, enable the Varying Load option within the wall surface loading parameters.

Buffer Tank Walls: Apply a base hydrostatic pressure of .
Storage Tank Walls: Apply a base hydrostatic pressure of .

Partial Hydrostatic Loads (Submerged Level Below Top of Wall)

If the liquid level does not reach the top of the wall (e.g., freeboard below the top edge). Select Patch Loads and define the boundary load points to restrict the pressure zone strictly up to the liquid surface level.

Buffer Tank Walls (Partial): Apply a peak base hydrostatic load of .
Storage Tank Walls (Partial): Apply a peak base hydrostatic load of .

Base Slab Loads

Apply uniform area loads across the raft base slab surfaces to model self-weight, direct liquid head, or equipment/storage loading:

Buffer Tank Base Slab: Apply a uniform area load of .
Water Storage Tank Base Slab: Apply a uniform area load of .

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Loads and Load Combination Generation:

When designing a multi-compartment bund, multiple load patterns must be checked (e.g., Compartment 1 full / Compartment 2 empty, both full, or both empty during maintenance).

Separate Load Cases: Assign distinct load cases for each compartment's liquid loading—for example, assign Dead Load D2 for the Buffer Tank and Dead Load D3 for the Storage Tank. and use the same numbers for live, wind or any kinda load applied for the particular compartment.
Automatic Combination: Use📄 Auto-Generation of Load Cases to combine these separate load sets into all critical Ultimate Limit State and Serviceability Limit State load combinations required for the structural integrity and design.

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Under FE surfaces there would be tabs📄 Attached Beams and 📄 Openings. These options let the user define any attached beam or openings present in the selected FE surface.

Step 5: Generate Mesh & Run Static Analysis

Go to Analysis Menu > FE Surface Meshing
In the Finite Element Mesh Generation Options dialog, set the Default initial mesh size (e.g., or ).
In the Finite Element Mesh Generation Options dialog, set the Default initial mesh size (m) (e.g., 0.5 m or 1.0 m).
Select OK to automatically generate quadrilateral shell element meshes.
Run the static solver via Analysis > Static Analysis.

Step 6: Review Graphical Results & Deflections

Open the Graphical Analysis Output window.
Deflection Check: Select Deflected Shape to view 3D displacements under each critical SLS load case.
Surface Forces & Moments: Switch to Shell Elements and select force, displacement or stress outputs to render contour maps.
Support Reactions: Inspect ground spring reaction contours to ensure no localized tension/uplift occurs under asymmetrical fluid filling cases.

Step 7: Concrete Slab Design

Go to the Design menu and launch Concrete Slab Design
Define the defaults in the 📄 Default and Auto-Design Settings
Select a 📄 Basic Regions reinforcement set and select the surface you wish to design (e.g., selecting the Water Storage Tank Raft Slab).
Adjust the proposed top and bottom reinforcement layouts in both orthogonal directions (X and Z axes) and review the capacity .
in this example we have updated the slab depth to 400mm and provided a reinforcemtn of
- top X-16@200
- top z- 25@150
- Bottom x-25@150
- bottom z-20@150

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💡 Design Iteration Slab Depth Adjustments:

If the slab section is overstressed due to high bending moments or high shear forces, increasing rebar density alone may be insufficient or lead to congested rebar spacing. In these cases, return to Step 2 to revise the slab thickness before re-running the design.

In this worked example, the raft slab depth was increased from 200 mm to 400 mm to satisfy the design with the following reinforcement arrangement assigned:

Top Layer (X-dir): 16 dia bars @ 200 mm
Top Layer (Z-dir): 25 dia bars @ 150mm
Bottom Layer (X-dir): 25 dia bars @ 150mm
Bottom Layer (Z-dir): 20 dia bars @ 150mm

Step 8: Concrete Wall Design

Go to the Design menu and launch Concrete wall Design
Define the defaults in the Shear Wall Design Basic Data and Defaults
Select a Wall Pier Zone Design Sets and select the surface you wish to design (e.g., selecting the Water Tank wall 3 ).
Place a current pier zone and define the reinforcement and review the design results
Adjust the proposed vertical and horizontal reinforcement layouts on both inside and outside faces, then review the wall design.
The following reinforcement arrangement was assigned to the wall:
- Vertical Rebar (Each Face): 16 dia bars @ 150 mm
- Horizontal Rebar (Each Face): 12 dia bars @ 150 mm

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The Concrete Wall Design module evaluates the wall as a shear wall element and does not automatically calculate out-of-plane bending moments .

To verify out-of-plane flexure and crack width limits for fluid-retaining walls:

Extract the critical out-of-plane bending moments directly from the Shell Element Contour Plots in the Graphical Analysis Output (Step 6).
It is the engineers reaponsibility to perform a separate manual or section-design check against these moments to ensure a safe design.

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