Hamilton County in rural Indiana, just north of Indianapolis, was going through a review and redesign of 4 of their bridge structures due to the increased growth in the area. They wanted to provide consistence with style and design with an upgrade to aesthetics. There were several factors to be considered, one was budget and the other was quick turnaround.

Working with Reading Rock and local rep Jill Fouts, they learned about the benefits of a Geosynthetic Reinforced Soil – Integrated Bridge System (GRS-IBS). This system met all of their design and budget requirements, and three bridges were replaced within weeks of starting.

The last bridge was in the town of Sheridan, IN and again the final outcome was praised for saving the county thousands of dollars and completed in weeks. Designed by Infrastructure Engineering and installed by White Construction using the AB Vertical INDOT block, the project was built and awarded the contractors their Allan Block Certification with the product.

The project was a success, the results spoke for themselves. We encourage you to learn more about the project’s entirety in the full case study.

One of the most notable concerns with the design of any foundation in colder climates is the need to account for blocks buried below frost depth. This is due to something called frost heaving. As water freezes, it expands by approximately 9% in volume and can cause the soil to move around, leading to disturbed foundations in winters. Therefore, different states and territories have differing minimum frost depths, dependent upon their individual climates. The figure below provides an example of average frost depth ranges across North America.

The values shown are the minimum depth in inches that a foundation must be buried to be past frost depth. We know what you’re thinking: “What are Allan Block’s requirements?”

Due to the flexible nature of our mortarless Retaining Wall Blocks that allows for slight shifting and moving during the winter months, there is no need to bury your wall’s base foundation below frost depth. The blocks then return to their original position when the ground thaws.

However, there are many details to consider with construction during winter months in colder climates. Just because the worry of frost heave is minimized due to the movability of SRW’s, does not mean it doesn’t need to be considered at all. We have plenty of resources to ensure you take proper steps and preventative measures through the design process to understand what you’re working with for soils, existing site conditions and grading.

For full details see our the AB Tech Sheet #620, and reach out to us at Allan Block on 1-800-899-5309 for any further questions you may have, we’re always here to help you out.

What is the AB Layout Tool?

The AB Layout Tool is a specialized free software designed to simplify the early stages of retaining wall design. It allows you to trace plans directly from PDF files or images, accurately calculate overall lengths, and manage station points. With these capabilities, you can quickly generate a detailed layout that can be seamlessly transferred to other Allan Block tools such as AB Walls.

How the AB Layout Tool Enhances Your Workflow

• Streamlined Design Process: By automating tasks like plan tracing and length calculation, the AB Layout Tool significantly reduces the time required to create an initial layout. This streamlined process allows you to focus on refining your design rather than getting bogged down in manual calculations.
• Improved Accuracy: Manual calculation can lead to errors that compromise the integrity of your design. The AB Layout Tool's precise tracing and automatic calculation features minimize these risks, leading to more accurate and reliable designs.
• Seamless Data Transfer: The ability to transfer layout data directly into other Allan Block tools means that you can maintain continuity throughout the design process. This seamless data transfer eliminates the need for redundant data entry and ensures that all aspects of the design are aligned.
• Versatility Across Projects: Whether you’re working on a small residential project or a large commercial development, the AB Layout Tool adapts to your needs. Its flexibility and powerful features make it suitable for a wide range of retaining wall designs.

The AB Layout Tool is an indispensable resource for design professionals involved in retaining wall projects. Its ability to trace plans, calculate lengths, and manage station points, combined with seamless integration with other Allan Block tools, makes it a powerful asset in your design arsenal. By incorporating the AB Layout Tool into your workflow, you’ll not only improve the accuracy and efficiency of your designs but also ensure that your projects are built on a solid foundation from the very start. If you have any questions or want a tutorial, reach out to the AB Engineering Team at engineering@allanblock.com or call 800-899-5309 ext.3.

When constructing a retaining wall, the strength of the foundation is highly important. You can't build anything reliable on a weak foundation, and in the case of retaining walls, proper compaction is the key to ensuring stability and longevity. Without it, even the most well-designed structures are at risk of failure.

No matter the size of the project, if sufficient compaction is not achieved within the base and consolidation zone, differential settlement can occur over time, causing both structural and aesthetic concerns. Ensure that compaction testing procedures and requirements are supplied and followed by the installation team. Communication is key to a successful project. Refer to Allan Block’s Best Practices Chapter 6 for Compaction Guidelines and Responsibilities. A few key takeaways are:

• A plate compactor should be used for compaction on site.
• The base and consolidation zone should be compacted to 95% of the Standard Proctor or per engineer specification, in 8-inch (200 mm) lifts, maximum.
• When running the compactor, compaction should be directly on top of the blocks starting on the second course to the top of the wall.
• Compaction at every course in parallel paths behind the wall is crucial.

The Allan Block Best Practices for SRW Design, Allan Block Spec Book, and Commercial Installation Manual for Allan Block Retaining Wallsdives deeper into the proper procedures, each of them having a section covering proper compaction.

If you have any questions or want to learn more, send the Allan Block Engineering Team an email at engineering@allanblock.com or call at 800-899-5309 x3.

Our Allan Block Engineering Department fields multiple questions everyday from our AB Walls Design Software to design solutions for a project. A common question we have received lately is: How do you design a modular retaining wall that adjoins an existing structure?

Be it a building foundation, an existing concrete wall or even another segmental retaining wall (SRW) there are a few things to consider:

• How are the walls abutting? Perpendicular or in-line?
• The setback/batter of the walls – do they match?
• How will they connect?

An SRW can abut an existing structure perpendicularly on its face with little concern beyond aesthetic but for wall abutting in-line, the concern of how the setback of the wall(s) will align come into consideration.

If the existing structure has no setback its thickness and height are factors that will affect the layout of the SRW. Sometimes the amount of setback could result in exposing the soil behind an existing retaining wall, which will require returns, either at the top or bottom of the SRW, to enclose the exposed soil.

It is not recommended to mechanically connect SRWs to existing structures for many reasons, as listed below.

• SRWs are meant to move with soil movement and if they are connected to a rigid structure, the connection points will be subject to loading that was not designed for, resulting in damage to both structures.
• If the existing structure is another SRW, the block heights and setbacks may not be the same which could lead to issues if the walls are to be weaved together. A solution would be to place a column between the 2 walls for a vertical transition.

If you have a SRW that is to adjoin with an existing structure, give the Allan Block engineering department a call (800-899-5309 x 3) or email engineering@allanblock.com for assistance.