Underground Detection
We often think that the construction of a building works upwards. We just see the building grow taller day by day. We just see the process happening above the ground and towards the sky. There is a lot that happens below the ground. It begins deep under the ground level. Even before laying the pile, the ground is thoroughly surveyed. Most importantly, underground detection is done at the beginning as a preparation for the construction. So, let us read more about this critical process which we seldom hear about. This article thoroughly explains the underground detection process and the facts about it.
What is Underground Detection?
Underground Detection is the process of identifying the utilities and contraptions present below the ground that is about to be constructed upon. Underground Detection is considered one of the most important processes in surveying. Before constructing a structure, one should know what is present under that particular ground, so that nothing could come up in the later stages of the construction. If so, it is very difficult to correct at such an advanced stage of construction. So, underground detection must be done thoroughly to avoid such instances.
Underground Utilities
We read about Underground Detection. But what are the things that could be detected from under the ground? This is an important question. Several utilities lie under the ground. They have to be thoroughly analyzed and the construction should be planned according to those utilities present underground. The most common utilities that are found underneath the surface are,
• Electrical Wiring
• Plumbing lines
• Digital cables
• Sewage pipes
• Gas lines
Utility Mapping
Utility Mapping is the process of creating a map that displays the utilities under the ground. Utility Mapping shows the various pipes, cables, wiring and lines that are present underneath the ground. These utilities may have been installed for purposes like
• Communication
• Electricity
• Cable TV
• Gas
• Sewage
Utility mapping helps prevent dangerous and untoward accidents from occurring to the people working in the construction or to the people who live nearby or pass through the area. It helps avoid causing damages to these utilities while constructing the building.
Utility Maps
Utility maps are colour coded according to the type of utility found underground. The following are the different colours present in a utility map and the various utilities they represent.
• Purple – Telecom Cable
• Green – Gas Line
• Red – Electrical wire
• Orange – Water Piping
Utility maps must be devised during the planning stages. It is a process that cannot be omitted.
Why is Underground Detection a must?
Underground Detection is necessary to avoid many dangerous circumstances during the construction or years after the building is constructed. Some of the reasons why Underground Detection is done are listed below.
• Breakage of the Gas line due to impact from the excavating machinery.
• Rupturing of electrical wires that may carry high voltage of electricity. This might cause the electrocution of the workers and other people.
• Leakage of water if pipes for freshwater are laid underground. Any damage to these pipes causes wastage of freshwater that is quite difficult to obtain.
• Breaking of sewage lines causes dirty and toxic wastewater to overflow and run on the streets or seep into the building.
• If water seeps into the building even years after construction, it could compromise the structure and cause cracks and breakage in the building.
Even more, underground detection has to be done promptly and correctly to avoid fatal accidents causing death and injury of personnel. There are numerous incidents where improper underground detection had led to many incidents where workers and the public had lost lives or were injured badly. This is the most important reason why underground detection is necessary during surveying and excavation processes.
Underground Detection Equipment
Underground detection can be done using specialized equipment designed exclusively for the purpose. We saw the reasons to do proper underground detection. Now, let us see how to do it. Some of the instruments used for underground detection are,
- Ground Penetrating Radar (GPR)
This is the most sought-after method of underground detection because it needs no literal digging of the land. Underground utilities are identified by the pulses emitted by the radar. It can identify metal and PVC piping, fibre optic cables, plastic and clay, water lines, gas lines, etc. the only flip side of the GPR is that if there is too much clay soil and the depth of the utilities is very much, they might interfere with the pulses of the radar.
- Electromagnetic Locator
The Electromagnetic Locator uses electromagnetic waves that are sent through a transmitter and received by a receiver. It is considered the best for identifying conductive materials like metal underground. They help in identifying gas lines, water lines, etc. however, they do not identify non-conductive materials.
- Magnetometers
- Radio Frequency Cable Locators
This is used especially to locate telecommunication cables like telephone wires and other cables underground. The cable locator identifies the frequencies present beneath the soil. It is also used to detect electric cables.
- Acoustic Locator
This is an exclusive pipe locator. It locates metallic, plastic and PVC pipes. It can identify and locate large pipes as well as smaller pipes that cater for households. This is done by sending audio pulses underground and are received by a receiver.
- Vacuum Excavation
This uses high power suction to excavate the soil. This process does the actual digging to identify the utilities below.
- Hydro Power Potholing
This method uses hydropower suction to excavate the ground and locate the utilities physically.
Both the above methods are done by digging many holes in the plot.
How to choose a good brand for Underground Detection Equipment?
The GPR or the Ground Penetrating Radar proves to be the most useful as it locates most of the utilities underground. Choosing the brand that provides many accessories and other pointers like the warranty they provide, etc. have to be taken into account. To summarize, underground detection equipment is a must for surveying land.
