Hydrovac Utility Locating

The act of locating utilities through hydrovac is becoming increasingly common. This is the safest way for workers to locate the underground utilities and it helps to minimize potential damage and downtime that would have occurred if the exact location was not known. By exposing them by hand, the utilities can be repaired, installed, and inspected more efficiently. By law in Alberta, hand exposure of underground utilities in an area where ground disturbances are intended, is a must.

Detection

Because there are so many different types of materials that are used to make and hide the underground lines, there are different detection and location methods. Electromagnetic locating equipment is used to detect metal pipes and conductive cables with help from a transmitter and receiver. For more traditional types of pipes, such as concrete or plastic, other types of radar detection is used, such as ground-penetrating radar or radiolocation.

What Could Be Encountered?

When excavating and tunnelling with hydrovac, these are some of the underground services that may be encountered:

• Water
• Sewage
• Oil
• Natural gas
• Cable lines
• Electric lines
• Electric energy
• Telephonic communications
• Chemicals

These may be hidden inside pipes, conduits, wires, cables, valves, manholes, catch basins, ducts, and other attachments. The starting steps for locating these things start with a surface study by another company that can correctly identify the exact location of them from the surface. The term “call before you dig”, and “One-Call” are some of the terms that are used to identify the proper third-party vendors that are available for use before the ground disturbances are done. They will then identify where the utilities are by using color-coded markings to show where they are.

APWA Uniform Color Codes

If you are driving down the road and happen to see bright colored spray paint on the ground, this was probably used in preparation for hydrovac excavation. These colors are part of a color code system to identify underground lines. Colored lines or flags mark the type of underground utility so that the workers know exactly what they are exposing. If there is a flag, this usually identifies the company or utility that the line belongs to. In Canada, the use of APWA Uniform Color Codes are used which includes;

• RED - Cables, conduit, lighting cables, and electric power lines.

• ORANGE - Telecommunications, signal lines, cables, conduit, or alarms.

• YELLOW - Oil, steam, petroleum, natural gas, or other flammable or gaseous materials.

• GREEN - Drain lines and sewers.

• BLUE - Drinking water

• PURPLE - Slurry lines, irrigation, and reclaimed water.

• PINK - Unknown or unidentified facilities and temporary survey markings.

• WHITE - Proposed excavation limits or route.

Once everything is properly located, the process of hydrovac will begin the ground removal process using the colored lines and flags as guidelines. As more of the material is removed, the utilities can safely be exposed and visually identified.

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Hydrovac Trenching

A very common requirement in new construction or in service of existing installations is the need for trenching.  A trench is considered an excavation where the depth exceeds the width. It is typically used for the safe burial of utilities, piping, or materials to span distances between two objects where these items are rarely accessed after installation and are covered with soil or other materials to keep them protected from frost, water, contact, and movement from surrounding forces. In many instances there are multiple items or services placed underground and the crossing or interaction of these services becomes complicated and congested while no longer visible to the naked eye. Trenching in open areas or virgin ground can often be done safely and efficiently with traditional methods such as mechanical excavators, trenching machines, even a shovel. Unfortunately, when there is a need for trenching where the possibility exists that there are existing utilities or services in the area, these traditional methods are no longer suitable as they cannot accurately identify the location of these buried items and will typically damage or destroy them immediately upon contact. As a result, a safer or more gentle approach is required. This is where a hydrovac can provide an excellent solution to not only excavate the required material to create the trench but can do so safely without damage. In addition, the hydrovac process will allow the operator to gently expose the underground utilities completely including under and around them in order to create a space for service or replacement of components if need be. This is often the process used to replace underground valves, connections, or splices as needed. Another distinct advantage of the hydrovac method is that a targeted or minimal amount of material can be removed to prevent ground shifting which can create collateral damage to nearby utilities even if direct contact is not made.  The added benefit is also less material required to back fill the trench and better compaction if less earth is removed from its original compacted state. The hydrovac process is ultimately controlled by the operator and by varying the water pressure or vacuum levels on the truck the sensitivity of the dig can be adjusted to suit the sensitivity of the service as it is uncovered. From super narrow slot trenching, (as narrow as 2 inches) to large open trenches, the hydrovac process will accomplish both with ease and as safely as digging with your bare hands. Another unique advantage of the hydrovac process over mechanical methods is the option of using remote hose to access any area that may not have any suitable access for larger machinery. The use of remote hose will allow access into existing structures, basements, or in extremely congested spaces where the only useable space may be room for the operator himself and these hoses.

The abovearticle Hydrovac Trenching is courtesy of Renegade Groups blog

Frozen Ground Excavation

As a company operating out of Northern Alberta, working in the winter months is inevitable. Typically in the Edmonton area we can experience up to 5-6 months where there is significant frost in the ground. While this frost will often completely prevent traditional methods of excavating with machinery like excavators, the frozen ground is no match for the Hydrovac process. Our trucks are equipped with one million BTU boilers to heat the water to cut through frozen ground making the hydrovac process possible twelve months a year. In the winter months Hydrovacing becomes the ONLY method to expose under ground utilities as hand exposing with shovel is not possible. In using a Hydrovac we can not only penetrate the frozen ground efficiently, but we can do it safely and prevent any unwanted damage to utilities that we encounter in the frozen ground. In addition to the obvious fact that the ground is nearly rock hard, frost causes significant movement in the ground due to the heaving and expansion caused when water freezes and thaws. Often this movement itself will put tremendous strain on underground utilities and cause faults or failures. Water main breaks are a common example and occur relatively frequently during the frost season. The Hydrovac process will allow us to expose these lines, open up sufficient access for repair and often thaw and remove standing water that can quickly form once the line is compromised. Hydrovac can also be used for the thawing of frozen lines, hydrants, and many other circumstances where frost or frozen water are encountered. In fact, we have specialty devices such as a jet nozzle that will attach to our dig hose and self feed a jet of hot water or steam as it propels itself forward through a frozen blockage in a line.

The post Frozen Ground Excavation is courtesy of Renegade Group Blog

Post and Pile Holes

Much like trenching, mechanical post and pile hole digging poses problems when working around today's busy underground infrastructure layout. Hydrovacing services becomes the solution to this problem as we can dig to any depth safely without damaging any utilities that may be present. Often the layout of these post/pile holes cover a matrix within the property or form a boundary around a property. In nearly all instances they will intersect underground utilities at some point. The typical methods of post/pile hole digging using an auger or excavator are unable to accurately locate these utilities and could cause significant damage to them during the excavation process. In fact, even ground disturbances in the area near a buried utility can cause failure or disruption. The gradual and gentle process of hydrovac allows for efficient removal of the necessary materials without damaging the underground utilities. Similar to an auger, the hydrovac will allow the operator to create a precise and accurate hole to any depth, but unlike the auger, it will not harm and utilitues that intersect or border the hole. Another key advantage to the use of hydrovac is that we can use a remote hose to access difficult to reach areas that typical mechanical devices cannot get to.

Post and Pile Holes is republished from renegadegroup.ca

Hydrovac Shoring

One of the services we offer is shoring. Shoring is the process of bracing the wall of a trench or excavation to prevent collapse and allow a safe environment for workers to enter and conduct repairs or complete installations of utilities or services. The process generally begins with the Hydrovac first exposing the underground service to confirm its location. Once the target is identified the shoring selection will be defined by the specifics of what needs to be done. If workers are required to go down into the trench or excavation, the shoring must have sufficient space to accommodate this. The shoring cage or box is then set up at grade, and the Hydrovac removes only the required material to sink the cage into the excavation and secure the walls. The result is a safe and cost effective way to create suitable access meeting regulatory standards and allow workers to access the utilities with minimal impact to the surrounding infrastructure and environment. Here is an example of a shoring cage in position for a worker to safely complete a repair on underground services without risk of trench collapse.

The abovearticle Hydrovac Shoring is courtesy of http://www.renegadegroup.ca/

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