📺Retaining Wall Design to EuroCode 7
Posted on November 7th, 2018 in Webinars
Summary
The Master Series Retaining Walls software, which is produced by a company that has been operating for over 30 years, is available as a standalone program or as part of several product suites.
Master Series Product Overview
The Master Series includes three main product ranges: the building design suite, the PowerPad light suite, and a custom system.
• Building Design Suite: Does not include the retaining walls module by default, but it can be added.
• PowerPad Light Suite: Contains a light version of the retaining walls module.
• Custom System: Recommended if the user only requires the retaining walls module.
The retaining walls module is available either as a standalone program or as part of the PowerPad system.
General Design Workflow and Features
The software supports design according to EC7 2004 (for soils) and EC2 2004 (for concrete). The interface uses several input tabs for adjusting parameters, including wall data, soil properties, loading, and reinforcement.
Success and Failure Indication: The program uses unity values to indicate design status; anything above 1 signifies a failure. The successful status of a design is usually indicated when the screen elements are "white". If a design fails, the background may turn blue or red, and clicking on the associated word will explain the reason for the failure.
Wall Geometry and Stability Checks: Users define various geometric aspects, such as wall thickness, projection height, toe height, heel length, and back soil slope. Features include:
• Projections: A projection above the wall can be included, primarily to account for the additional self-weight of that section.
• Water Table: The water table height can be specified.
• Nibs: Nibs are straightforward to input, but the speaker advises that incorporating them can cause issues with the design by adding active pressure against passive pressure, potentially creating a "losing scenario" according to the codes.
• Density: The density default for concrete is 24.
• Stability: If a wall has a sliding problem (often caused by sloping soil), remedies include lengthening the base or using a prop.
• Cohesion: If building onto clay, users can input cohesion (e.g., 10 kilonewtons per meter square) to help satisfy stability checks.
Loading and Props: Standard default loading is 10 kilonewtons per meter. The software handles various complex loading conditions:
• Surcharges: Users can apply additional surcharge and horizontal surcharge loads.
• Point Loads: Point loads can be designated as live or dead loads and can be eccentric (out on the air side).
• Layered Soil: The full version of the software allows for layered soil modeling, including sloping layers.
• Highway Loading: The software can design walls to highway loading standards, including additional loading combinations, and offers options for bridge abutment loads.
• Props and Ties: The full version supports props at multiple levels, which is useful for basement designs. Props can be modeled as static or by applying a spring stiffness (measured in kilonewtons per meter). Ties are also available, which can be applied at an angle down the wall and possess an ultimate limit state force. The PowerPad version is limited to only having a prop at base.
Reinforcement Design: The design process involves setting the desired concrete grade (e.g., C28/35) and reinforcement grade (e.g., 500B). To meet design requirements, engineers adjust rebar sizes and spacing (e.g., using 16s at 200 centres). The preferred spacing is often 200 centres as it allows for easier fabrication. While reinforcement is needed on the top and bottom of the base, it is usually not required on the outer face of the wall.
Reinforced Masonry and Steepock Walls
The software supports reinforced masonry design, a feature not available in the PowerPad version (which only supports plain masonry).
For reinforced masonry:
• Cavity Steel: The software recognizes when cavity steel is necessary.
• Compression Zone: When working with masonry, the strength of the outer leaf bricks or blocks is highly critical, as they form the compression zone (the "concrete zone") of the cantilever beam.
• Stepping: The software allows for wall stepping.
The program has specific configurations for Steepock walls, which are special types of hollow block masonry walls often made by Anderton. Key characteristics of Steepock walls include:
• Construction: They are built without horizontal mortar joints.
• Design: Special notches hold the distribution steel and the main steel in location.
• Finish: They provide a "lovely fair-faced wall finish".
• Sizes: They come in three sizes: 200, 256, and 325, all designed to weigh less than 20 kilograms.
• Configuration: The correct rebar distances, spacing, mesh spacing, and covers are automatically set. These Steepock configurations are available as library files within the software.
Customization and National Annexes
Users have the ability to customize several design parameters:
• Reinforcement Strength: Users can add their own steel grades (e.g., the old 250R) by accessing the utilities and customisation menu.
• Concrete Grades: New concrete grades can be added based on standard cube strengths, and the software automatically calculates the corresponding FCKs.
• Design Codes/National Annexes: The software is designed for use in multiple countries using the Eurocode. Users can copy existing national annexes (like the Euro Norm or UK values) and create custom versions (e.g., a "Japanese version") to modify factors such as epsilon or the partial safety factor for steel ($\gamma_S$).
Exporting and Learning
The retaining walls design can be exported into DXF format.
• DXF Output: The export provides a full detailed version of the wall, including the cross-section, elevation, and plan view.
• Schedule: A matching schedule in DXF format is also generated, providing details on bar weight, dimensions (e.g., 7.9 metres for an 8-metre length, allowing for 50 mm cover), and shapes used (straights and U-bars).
• Master RC: The design data can also be pushed to Master RC.
For users needing assistance, the Master Series offers a learning centre with videos on various aspects of the software, including specific guides on using Steepock walls. Technical support is available from the department headed by George Brown. The sales team is headed by Tommy White, whose email address is tommy@masterseries.com .
Summary with Timestamps
The following table provides a summary of the Master Series Retaining Walls software features, design procedures, and available modules, segmented by time stamps from the source recording.
Time Range | Summary / Topic | Citation |
00:00:00,880 – 00:00:24,080 | Introduction and Personnel | |
00:00:00,880 – 00:00:24,080 | Welcome to the webinar on Master Series Retaining Walls. Presenters are Tommy White (head of the sales team) and George Brown (head of the technical support department). | |
00:00:28,160 – 00:00:33,520 | The Master Series company has been operating for over 30 years and offers three product ranges. | |
00:00:34,160 – 00:01:45,920 | Product Ranges and Module Availability | |
00:00:34,160 – 00:00:44,160 | The three product ranges are the building design suite, the PowerPad light suite, and the custom system. | |
00:00:46,320 – 00:01:05,200 | The building design suite does not include retaining walls by default but they can be added. The PowerPad suite has a light version of the retaining walls module. The custom suite is recommended if retaining walls are the only module needed. | |
00:01:15,480 – 00:01:45,920 | Retaining Walls is available as a standalone program or as part of the PowerPad system. The demonstration uses a 2018 version of the software. | |
00:02:43,280 – 00:04:03,840 | Interface, Codes, and Status | |
00:02:43,280 – 00:03:06,320 | The screen displays graphics and bending moments. The capacity line is constant if the wall is not tapered or stepped. | |
00:03:13,680 – 00:03:30,000 | Users can define a water table height (e.g., 1200 mm up). Projections above the wall can be included to account for additional self-weight. | |
00:03:30,560 – 00:03:43,280 | The design uses EC7 2004 for soils and EC2 2004 for concrete. | |
00:03:56,880 – 00:04:03,840 | The program works with unity values; anything above 1 is a failure. | |
00:04:06,720 – 00:05:47,280 | Wall Geometry and Nibs | |
00:04:06,720 – 00:04:22,680 | Input tabs allow setting wall data, including thickness, projection height, toe height, heel length, and back soil slope. | |
00:04:43,080 – 00:04:57,440 | The software uses an overdig of 10% or 500 mm as required by the code. | |
00:05:10,560 – 00:05:47,280 | Nibs are straightforward to input, but the speaker suggests avoiding them as they can cause design havoc by introducing active pressure against passive pressure, potentially creating a "losing scenario" under the codes. | |
00:05:50,880 – 00:06:14,960 | Concrete density is defaulted to 24. A successful design is indicated when screen elements are "white". Users typically adjust footing, heel, and toe values to manage pressure. | |
00:06:25,240 – 00:08:22,640 | Soil, Loading, and Stability Checks | |
00:06:25,240 – 00:06:49,600 | Front and back soil pressure can be checked differently. The full version supports layered soil, including sloping layers. | |
00:07:05,440 – 00:07:12,560 | Default loading is 10 kilonewtons per meter. | |
00:07:13,680 – 00:07:37,880 | Additional surcharge loads (e.g., 5 kN, resulting in 15 kN total) can be applied, and the factored surcharge is displayed. | |
00:07:52,320 – 00:08:22,640 | If a prop at the base is turned off, a bearing pressure problem may arise, which can be resolved by changing the base geometry. | |
00:10:19,280 – 00:10:37,760 | A sloping soil condition can cause a sliding problem, which requires either a longer base or a prop to remedy . | |
00:11:04,720 – 00:11:34,080 | Sliding issues can be resolved by inputting soil cohesion (e.g., 10 kilonewtons per meter square) if building onto clay . | |
00:08:33,640 – 00:10:10,720 | Reinforcement Design | |
00:08:33,640 – 00:09:01,200 | Users define concrete grade (e.g., C28/35) and reinforcement grade (e.g., 500B). Cover can be adjusted (e.g., 50 mm). Inner steel failure can occur if the rebar size is too small (e.g., 12s). | |
00:09:19,680 – 00:09:37,440 | Failures can be resolved by adjusting spacing (e.g., 12s at 100) or size (e.g., 16s at 200 centres), with 200 centres often preferred for easier fabrication . | |
00:09:51,680 – 00:10:10,720 | Reinforcement is generally not needed on the outer face of the wall, but it is necessary on both the top and bottom of the base . | |
00:11:41,760 – 00:17:42,880 | Reinforced Masonry and Stepping | |
00:11:41,760 – 00:12:01,520 | The design shifts to Reinforced Masonry . (Note: The PowerPad version only supports plain masonry) . | |
00:12:59,640 – 00:13:47,200 | The software supports wall stepping (e.g., stepping on the inside by 450 down and 225 out) . | |
00:14:03,840 – 00:14:35,760 | For reinforced masonry walls with a cavity, the software recognizes the need for cavity steel . The outer leaf bricks/blocks form the compression zone (the "concrete zone") of the cantilever beam and are critical . | |
00:15:04,560 – 00:17:10,359 | Adjusting the masonry design by increasing the outer leaf (e.g., to 215) can help . Block strength is highly critical (e.g., 10.4s must be used, 2.9s will fail) . | |
00:17:58,160 – 00:23:22,640 | Advanced Loading and Features | |
00:18:05,920 – 00:18:39,760 | Piers can be modeled, including reinforcement and shear links, though the speaker prefers reinforced masonry . | |
00:18:49,400 – 00:19:26,560 | The full version allows for layered soil modeling, where layers can be sloping (e.g., 5-degree angle) . | |
00:19:34,880 – 00:20:55,360 | Point loads can be applied at specific heights, designated as live or dead loads (permanent), and can be eccentric (out on the air side/outside) . | |
00:21:09,840 – 00:21:37,280 | Additional surcharge and horizontal surcharge loads can be applied (e.g., modeling a barrier or "tanker engines at 850 up") . | |
00:21:59,960 – 00:23:22,640 | The software can design using highway loading standards, which introduces additional loading combinations and factors . It also includes options for bridge abutment loads (e.g., applying a 50-ton HA load horizontally) . | |
00:23:25,640 – 00:29:32,320 | Steepock Walls | |
00:23:25,640 – 00:24:50,400 | Steepock walls are special types of masonry walls, typically manufactured by Anderton . They are built without horizontal mortar joints and use internal notches to hold the distribution and main steel in location . | |
00:24:50,880 – 00:25:00,480 | Steepock blocks come in three sizes: 200, 256, and 325, all designed to be less than 20 kilograms . | |
00:25:01,200 – 00:25:35,920 | Steepock walls have configurations available where the correct rebar distances, spacing, mesh spacing, and covers are automatically set . | |
00:25:39,760 – 00:26:47,200 | These Steepock files are available as sample files/technical notes on the company website and are now built into recent software versions . | |
00:28:44,920 – 00:29:17,120 | The standard Steepock walls are set to "sweet spots," such as the small 200 wall working up to 2 metres, and the 325 wall working up to approximately 4.35 metres . | |
00:30:00,720 – 00:31:49,760 | Failure Indicators and PowerPad Limitations | |
00:30:04,560 – 00:30:14,400 | Failures are indicated when the background turns blue or red . Users can click on the word indicating failure to find out why (e.g., soil pressure needs longer base) . | |
00:30:42,560 – 00:31:49,760 | The highways feature is part of the full version . PowerPad limitations include: only prop at base (not multi-level props), no layered soils, and only reinforced concrete (not reinforced masonry, meaning no Steepock walls) . PowerPad does support additional and horizontal surcharge . | |
00:32:10,920 – 00:34:49,280 | Basements, Props, and Ties | |
00:32:19,360 – 00:32:52,720 | Basements can be modeled with multiple props (e.g., a double basement with props at 3 metres and 6 metres up) . Construction stages should be considered . | |
00:33:01,440 – 00:34:07,520 | Props are static by default but can be modeled using a spring stiffness (measured in kilonewtons per meter) . High values (e.g., 10 million) are needed for springs to effectively resist movement . | |
00:34:11,840 – 00:34:49,280 | Ties can be modeled, which are the opposite of a prop and can be applied at an angle down the wall . A tie must have an ultimate limit state force defined . | |
00:35:40,640 – 00:40:14,280 | Customization and National Annexes | |
00:35:40,640 – 00:36:16,320 | Users can create their own reinforcement grades (e.g., the old 250R) by accessing the utilities and customisation menu . | |
00:37:00,720 – 00:37:06,800 | Users can add their own concrete grades based on standard cube strengths, and the software automatically calculates the corresponding FCKs . | |
00:37:21,440 – 00:38:21,360 | The software supports multiple countries using the Eurocode. UK and Euro Norm default values are built in . The UK annex modifies factors, such as changing 1.35 down to 1.25 in certain instances . | |
00:38:21,360 – 00:39:37,240 | Users can create custom national annexes (e.g., a "Japanese version") by copying existing norms and modifying factors, such as epsilon or the partial safety factor for steel ($\gamma_S$) . | |
00:40:17,800 – 00:42:36,600 | Exporting and Detailing | |
00:40:17,800 – 00:41:41,240 | The design can be exported into DXF format . The export provides a full detailed cross-section, elevation, and plan view of the wall (e.g., 50m wall exported in 8m lengths) . | |
00:41:43,480 – 00:42:32,840 | A matching schedule is also generated in DXF format, detailing bar weight, dimensions (e.g., 7.9m length accounts for 50mm cover), and shapes used (straights and U-bars) . | |
00:41:14,280 – 00:42:36,600 | Design data can be pushed to Master RC . | |
00:42:37,320 – 00:43:45,000 | Learning and Support | |
00:42:40,520 – 00:43:10,600 | The company provides a learning centre with videos on various aspects of the software, including specific guides on how to use Steepock walls . | |
00:43:32,680 – 00:43:40,120 | Tommy White's email address is tommy@masterseries.com . |