Trenchless Manhole Installation with Hydro Excavation

In order to keep cities functional, municipal professionals must have a reliable entry point to underground structures to perform inspections, maintenance and repairs. Using Monoform HEX™, HK Solution's manhole rehabilitation contractors can perform new manhole installations to give utility workers access to underground infrastructure.

When working in these sensitive areas, our experts use vacuum excavation, specifically hydro excavation, as the preferred trenchless manhole installation technique because of its precise and limited disruption to the surrounding areas.

What is vacuum excavation?

Vacuum excavation is a method of excavation which utilizes blasts of water or air to rupture large materials and debris, such as soil or other underground materials. Once the area is no longer compacted, a vacuum is used to remove all loose material, leaving an access point for contractors to perform their work. Vacuum excavation is often used for trenchless utilities installation because it is safer and less disruptive to the surrounding land than excavation with digging.

What is Hydro Excavation?

Hydro excavation is a form of vacuum excavation using pressurized water and a vacuum to move and remove soil for workers to locate underground utilities. HK Solution Group's experts prefer hydro excavation over air excavation because it is a more efficient process.

How Hydro Excavation can be used for New Manhole Installation

Hydro excavation allows for reduced risk and advanced precision when working around delicate subsurface utilities. Combining both Monoform™ and hydro excavation, Monoform HEX™ allows us to place a new manhole without disrupting the surrounding area.

What is Monoform™?

Monoform™ is a no-dig manhole rehabilitation solution, which creates a new, fully structural manhole within the existing structure. Monoform™ is an ideal solution for leaking, cracking and deteriorating manholes, as it is a trenchless construction method and has a longer design life than all other manhole repair options.

HK has since developed two additional fabricated manhole lining solutions: Monoform PLUS™ for corrosion resistant manhole rehabilitation and Monoform HEX™ for new manhole installation. HK's Monoform HEX trenchless manhole installation solution combines the proven process of Monoform™ with the power of hydro excavation to create a brand new, fully structural manhole, without disturbing surrounding land and sensitive subsurface infrastructure and utilities.

The Monoform HEX™ Manhole Installation Process for Trenchless Utilities Access

Before municipal contractors can perform maintenance underground, they must have entry to the problem areas. Utilizing Monoform HEX™ as our new manhole installation process ensures access for contractors to perform trenchless utility maintenance.

Manhole Installation Prep & Utility Locating

The HK team begins by surveying the buried pipeline with a camera and utility locator to determine the exact location and depth. Then, our team fabricates the exterior fiberglass form segments to accommodate the appropriate depth of the underground utility.

Excavation of the Area and Trenchless Manhole Installation

Because it relies on hydro excavation, the Monoform HEX™ process is a safe and efficient trenchless construction method for new manhole installation. Learn more and see a step-by-step breakdown of the trenchless construction process in our video:

Step 1: Vacuum Excavation of the Pilot Hole

HK performs vacuum excavation of the pilot hole to loosen material and remove debris that is preventing access to underground utilities. Our manhole rehabilitation contractors then vacuum out the substance.

Step 2: Confirm Location of Pipeline

Our crews confirm they have found the pipeline and identify that they are at the precise location needed to install the access manhole.

Step 3: Place Manhole Outer Forms

Before placing this form, the crew will ensure a level starting pad. The outer form is then placed within the excavated area. These outer forms will serve as the outline for the manhole and ensure the concrete sets in the right position.

picture of new manhole installation.

Step 4: Perform Hydro Excavation Within the Outer Form

After placing the outer form, hydro excavation is performed within the structure to keep the process contained. A second outer form is then placed and hydro excavation continues until the collector piping is exposed. When this point is reached, it is time to begin the Monoform™ manhole forming process.

Step 5: New Manhole Construction

The manhole base concrete is poured and the flow channel is formed. After the manhole base form is placed, the interior manhole wall is formed via two concrete pours. Next, forms are placed for the exterior section of the manhole and more concrete is poured. Finally, the prefabricated flat top and manhole cover are placed and installed. The HK team wraps up the project by performing soil stabilization grouting around the exterior of the newly installed access manhole and minor landscaping to clean up the surrounding area.

Applications for Monoform HEX™ Manhole Installation Solution

Monoform HEX is an ideal solution for installing access manholes in areas that are sensitive to open excavations, such as:

  • Levees
  • Rail yards
  • Power plants
  • Heavy industrial facilities
  • And more

Frozen ground is no problem when it comes to the Monoform HEX™ process. Our manhole installation experts are prepared for manhole installation all year round.

Contact HK to learn more about Monoform HEX™ manhole installation.

For more information about HK's trenchless manhole installation using hydro excavation, Monoform HEX™, reach out to our team of manhole rehabilitation contractors. Explore our other service offerings or reach out to our team - check us out online or give us a call at (515) 283-0500. Our team is ready to help.