Undergrounding construction unavoidably disturbs soil at the site, generating excess spoils that must be properly disposed of. These spoils must be handled according to specific requirements and often must be hauled off-site for processing, remediation, or disposal. Moving soils back and forth for processing and disposal between off-site locations that are often far from dig sites requires time and resources that could be spent elsewhere. This process is particularly costly in cases where distrubed soil contains hazardous materials.
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Problem
Labor required for digging tunnels and trenches, laying conduit and pulling and splicing cables drives the majority of undergrounding costs. While some innovation has been made in these areas, the methods and materials used have remained largely unchanged for years. Not only do novel materials and construction methods have the ability to drive down cost, but also to improve worker safety, shorten timelines and increase longevity of the system.
Desired properties
- Enable cost reductions for underground construction across variable terrain conditions
- Improvements in materials or methods (i.e., automation) that reduce the number of required splices and/or enclosures
- Innovative materials that circumvent supply chain challenges and reduce overall materials costs
Specifications
Category 2: Novel Materials / Construction Methods for Undergrounding
Problem statement
In large part, undergrounding relies on the same materials and construction methods that have been industry standard for years. While costs have come down over time, current methods and materials continue to drive the relatively high costs associated with undergrounding (~$3-5 million / mile), largely driven by:
- Construction methods employed for difficult terrain (e.g., granite) still rely on older technologies that make relatively slow progress at a high cost
- Cable splicing continues to be a manual process that is the primary source of failure for underground cables
- Tunneling often involves multiple sequential steps (boring, installing conduit, pulling cable, etc.) that extends timelines and increases costs
- Existing conduit materials and lubricants limit cable pulls and increase the number of enclosures and manual splices required on a section of underground line
- Many of the key components utilized in underground technology are manufactured from raw materials that are in high demand across the broader economy, challenging supply chains and ability to acquire sufficient inventories
- Materials used in undergrounding projects such as concrete and steel tend to be heavy and bulky, making them difficult and expensive to transport
Possible approaches
Potential solutions may span various aspects of the construction process, from trenching methods to automated splicing to novel techniques / materials to reduce the number of sequential steps required for underground construction. Solutions to combat high demand material procurement could include steel or concrete alternatives (e.g., fiberglass, polymers, and other novel materials) that could be utilized in undergrounding infrastructure. 3D printing could also be a viable alternative to sourcing in-demand materials to bypass supply chain issues.
| Industrywide Market Gap | Potential Solution Category |
|---|---|
| Today’s tunneling and trenching methods are time-consuming and costly | New methods that enable faster, more efficient digging in a diversity of terrains |
| Cable splicing is a manual process that requires a high degree of precision under adverse conditions | Automation of all / parts of the splicing process Technologies that reduce the number of required splices on a run of cable |
| Many materials utilized in underground distribution lines are bulky, heavy and in high demand across the broader economy | Novel materials that are lighter, cheaper and abundant across any key component On-site component production (e.g., trenching technology that creates conduit in situ) |
Known approaches not of interest
- Procedural / management solutions are not of interest.
- Software based solutions are not of interest.
Key success criteria
Required:
- Demonstrated improvement over current state-of-the-art technology
- 35% cost savings relative to current methods within same or shorter timeframe or 35% reduction in construction time at same or lesser cost
- Materials and methods that are well-suited to construction in remote areas with difficult terrain
Desired:
- Commercially deployable within 3 years