METHODOLOGIES

Soil Thermal Resistivity Testing

Soil thermal resistivity testing measures the capacity of the ground to conduct or dissipate heat. A correct understanding of the thermal properties of a soil or layer of made ground is important for the design and installation of underground pipelines and transmission cables, to avoid premature failures. The heat produced by current flowing through an underground power cable must be properly dissipated.

The thermal resistivity of a soil will determine whether a buried power cable remains cool or overheats. A build-up of heat around the cable can reduce transmission efficiency, or in the worst cases cause the cable to melt. Potential problems can be identified by measuring the thermal resistivity of an in-situ soil. Remedial measures include changing the capacity and insulation of the cables or installing corrective thermal backfills in the cable trench.

Above : In-situ thermal resistivity testing with a needle probe.

Typical Applications

Assists the design and layout of underground pipelines
Prevents occurrence of heat build-up around power transmission cables
Measures the ground's heat dissipation properties for a pipeline installation
Calculates the optimum cable specifications for the local ground conditions
Determines if in-situ ground must be replaced by cable bedding thermal back-fill

Survey Operation

Soil thermal resistivity testing is normally carried out before a cable is actually laid out. Ideally the testing should be done at the proposed cover depth of the installation. Transient line heat source methods have been used to measure the thermal resistivity of porous materials for many years. Typically, a handheld device is used comprising a needle with heater and temperature sensor inside, which conforms to specifications outlined in IEEE 442 and ASTM 5334.

The probe is inserted into the ground to a specified depth and a current passed through the heater. The system monitors the temperature of the sensor over a period of time. Analysis of the sensor temperature determines the soil thermal resistivity of the material surrounding the probe. Heating times are kept as short as possible, to minimise thermally induced water movement and reduce reading times. Temperatures can be measured to an accuracy of one thousandth of a degree. The final results are given in units of: C.m/W, where C = degrees Centigrade and W = Watts.

How accurate is SUMO's underground utility survey and what types of utilities can it locate?

Using cutting-edge technologies like electro-magnetics, signal induced threading, and Ground-Penetrating Radar (GPR), our underground utility surveys accurately detect a wide array of buried utilities including metal and plastic pipes, drainage systems, electricity cables, telecoms, and fiber optic cables. The methodology ensures high accuracy without the need for invasive trial holes.
What is the turnaround time for obtaining results with SUMO's Underground Utility Detection service?

SUMO’s service is built for rapid response. Contractors can receive immediate results onsite. Our equipment provides real-time information, and once we leave the site, the detected utilities are visibly marked on the ground surface for quick reference.
Does SUMO provide detailed mapping of the detected utilities for permanent records or construction purposes?

Absolutely, SUMO not only marks the detected utilities on-site but also offers high-quality, color-coded survey drawings. These drawings can include topographic features and a comprehensive record of the utility detection survey, ensuring it meets the client’s needs for future reference or pre-construction design works.
Topographical and Geophysical survey

In addition to mapping out utilities, our experience team can accurately survey the land, creating topographical drawings for use. With our state-of-the-art aerial technology, nothing is missed.
What additional information can be included in the underground utility mapping service provided by SUMO?

In addition to topographic features, SUMO’s mapping service can include fixed surface utility features such as inspection chambers, valve boxes, and telegraph poles. It can also incorporate key topographic details like building lines, fence lines, kerb lines, street furniture, street names, building names, and house numbers, facilitating easy site location.
Does the utility mapping service by SUMO include standard referencing and compatibility with existing survey data?

Yes, SUMO ensures the utility mapping references the ordnance survey grid and level datum as standard. Additionally, the drawings can be supplied to a specified grid and level datum and can overlay an existing topographical survey, making it a versatile and adaptable service for various project needs.
What sets SUMO Services apart from other survey providers?

SUMO stands out due to our impeccable level of service with nationwide coverage, state-of-the-art equipment, and our commitment to delivering top-quality, detailed colour-coded survey drawings in both hard and electronic formats.
How do I request a survey quotation from SUMO Services?

Requesting a quotation is easy. Just click on the "Request a Survey Quotation" button on this page, and our team will get in touch with you promptly.
Can I book a SUMO Survey online?

Yes, you can! Simply click on the "Book a SUMO Survey" button on this page, and you can schedule your survey with us at your convenience.
What type of survey is suitable for my project or site?

Our experienced team will work with you to determine the most appropriate survey for your specific needs. Contact us, and we'll assist you in making the right choice.
Can I obtain both digital and hard copies of survey drawings?

Absolutely. We offer the convenience of electronic copies for digital use and hard copies for your records. Just let us know your preference.
Do you provide custom survey solutions for unique projects?

Yes, we understand that every project is unique. Our team is highly adaptable and can tailor our surveying services to meet your specific requirements.
How do I get in touch with SUMO Services for further questions?

For any additional questions or inquiries, feel free to contact us through the contact form, and our dedicated team will assist you promptly.