📺Domestic House Extension using only PowerPad Plus | UK

Posted on March 13th, 2018 in Webinars

Summary

This video demonstrates the MasterSeries PowerPad software, a tool for structural engineers to design building extensions efficiently. The tutorial showcases how to import an AutoCAD drawing, which serves as the foundational outline for a house extension, and then meticulously refine the structural model by adjusting nodal positions and adding essential components like columns and supports. A significant portion of the demonstration focuses on applying various loading conditions, including area loads for floors and roofs, and line loads for walls, before moving on to steel member and connection design. Finally, the video illustrates how to design pad foundations and generate comprehensive reports, including an addendum for wind analysis, all within a remarkably short timeframe.

Key Points

• Project Overview
• Structural Analysis
• Connection Design
• Foundation Design
• Report Generation

Description

The provided source details a worked example of a small house extension project using MasterSeries PowerPad 2018, demonstrating its capabilities for structural engineering tasks from import to reporting, including the new features introduced in the 2018 version.

Here's a summary of the key steps and features demonstrated:

• Project Setup and Import from AutoCAD:

    ◦ The project started with an AutoCAD DXF drawing of a house extension, with structural members drawn on an isolated layer.

    ◦ This DXF file was imported into MasterSeries 2017/2018 using the PowerPad licence.

    ◦ Only the "master series" layer was imported, bringing in lines and polylines.

• Frame Tidying and Definition:

    ◦ Initial imported geometry required tidying up using X and Z axis alignment tools to correct misaligned nodes.

    ◦ Columns were added, defined as 100x100x3.6 square hollow sections, 2.5 meters high, and assigned to a member design group called "columns" (a new "Pro feature" in PowerPad 2018).

    ◦ Existing static supports were deleted, and new fully fixed supports were added at the column bases.

    ◦ End releases (pins) were applied to specific beam ends to simulate simple connections.

    ◦ The "explode" member split function was used to break down continuous members into individual segments where required, e.g., at intersecting nodes.

    ◦ The "quick merge" function was used to join members, if necessary.

    ◦ An additional 152 UC beam was created and inserted where a member was initially forgotten.

• Preliminary Analysis (Self-Weight):

    ◦ Initial material properties were set for beams (152 UBs) and columns (as defined).

    ◦ A quick analysis based on self-weight was performed to check frame stability and identify any initial issues, such as unstable nodes or members pinned at both ends lacking torsional restraint. Torsional restraints were then adjusted.

• Area Loading (New Feature):

    ◦ A significant new feature for PowerPad 2018 is area loading, replacing the traditional member-by-member load input.

    ◦ Default dead (0.45 kN/m²) and live (1.5 kN/m²) loads were set for internal areas.

    ◦ Dummy members were inserted to facilitate panel creation, especially for areas like roof overhangs or wall supports.

    ◦ Two distinct area load panels were created: "inside" with standard domestic loads and "outside" with heavier dead (0.6 kN/m²) and lighter live (0.75 kN/m²) loads for a tiled roof.

    ◦ The direction of load spanning (e.g., shortest span) could be changed or overridden for panels.

    ◦ Static supports were added to dummy members to stabilise them for load transfer.

    ◦ Line loads were applied for walls above, including a 10 kN dead load and a 15 kN dead load with 4 kN live load for a wall and roof section.

    ◦ Loading cases for ultimate (1.35 Dead + 1.5 Live) and serviceability (1.0 Dead + 1.0 Live) were automatically generated.

• Design Groups and Steel Member Design:

    ◦ Design groups (another "Pro feature" in PowerPad 2018) were created for different member types (e.g., "small walls," "big walls," "front members," "ties").

    ◦ These groups allowed pre-setting design parameters such as effective length factors (e.g., 1.5L for columns), restraint conditions (e.g., fully restrained, restrained at incoming members), deflection limits (e.g., L/360, L/250), and maximum depth.

    ◦ Steel member design was performed, initially showing failures with the default 152 UB sections.

    ◦ The "lightest on auto size" function was used to find appropriate sections, revealing the need for larger sections (e.g., 203 UB) due to deflection and destabilising load considerations (e.g., eccentricity of 150mm).

    ◦ Section filters were used to enforce minimum wall thicknesses for hollow sections (e.g., 5mm), guiding the auto-sizing to suitable sections (e.g., 100x6 or 120x5 SHS for columns).

    ◦ The design process allowed for scanning failures and re-analysing if self-weight changed.

• Connection Design:

    ◦ Connection groups were created for different joint types: "beam to beam flexible," "base plate," and "beam to column fin".

    ◦ Base plate design for the columns was demonstrated, adjusting plate size (e.g., 300x300mm), thickness (e.g., 10mm), and bolt edge distances.

    ◦ Beam-to-beam flexible connections required adjusting notch depth to zero and increasing the number of bolt rows due to failures.

    ◦ Fin plate to column connections for small beams proved challenging due to limited space for bolts and integrity issues. Adjustments were made to plate depth (e.g., 120mm), bolt vertical centres (e.g., 50mm), and bolt diameters (e.g., 20mm), with the option to turn off 'tying forces' for domestic single-storey applications.

• Pad Foundation Design:

    ◦ Pad foundations were designed using assumed soil properties (e.g., working pressure 100 kN/m², no cohesion, zero passive resistance).

    ◦ The software automatically defaulted to reinforced concrete pads (e.g., 750x300mm), and the most critical pad required a larger size (e.g., 950mm, rounded to 1 meter).

    ◦ The option to use mass concrete pads was also shown, where the projection and depth could be adjusted (e.g., 350mm deep for 750x350mm pad).

• Reporting and Output:

    ◦ Two reporting methods were presented: direct printing of graphics and the report generator.

    ◦ The report generator allows users to build custom reports with selected outputs (e.g., joint summaries, graphic output for bending moments, deflections).

    ◦ Snapshots feature records specific screen display settings (e.g., 3D sections, 3D wireframe, black and white) for inclusion in reports.

    ◦ Reports can include summary and detailed steel design checks, connections, and concrete design outputs.

    ◦ The final report is generated as a PDF, showing drawings, loading diagrams, bending moments, deflections, summary results, detailed member design, and connection designs.

• Wind Analysis (Addendum):

    ◦ PowerPad 2018 includes wind analysis for frames up to 100 members.

    ◦ Users can define wind directions (all four considered), use MasterKey wind analysis, and specify site data from UK/Irish maps or grid references.

    ◦ Wind panels can be defined manually or automatically detected by the program.

    ◦ Panels can be set to span horizontally, vertically, or two ways.

    ◦ The system calculates and displays external and internal wind pressures and suctions for each wind direction, identifying areas like parapets with higher loads.

• Availability: A 14-day free trial of PowerPad is available, as is a free student edition (with non-commercial file compatibility).