Understanding soil conditions is critical for safe and efficient construction and agricultural operations. Poor soil trafficability can lead to equipment failure, safety hazards, and costly delays.
Measuring soil penetration resistance provides essential insights into soil strength, compaction, and moisture levels—helping professionals make informed decisions before and during fieldwork.
For civil engineering, it is important that the soil is well-compacted, so that buildings, machines, and people have a stable surface. For agriculture, it’s the opposite: there, compaction is becoming an issue. Machinery used by farmers are getting heavier and create a lot of pressure on the soil. This compaction hinders water retention and root growth.
Penetration resistance is a measure to determine the load-bearing capacity and root penetration of the soil. This resistance is a mechanical property, which, at a given texture, depends on variable parameters such as
In cohesive soils like clay and loam, moisture plays a significant role in resistance. In sandy soils, resistance readings are more directly related to compaction levels.
In construction, penetration resistance is used to evaluate trafficability—the ability of vehicles and personnel to safely move across a site. The quality of the top layer, the load-bearing capacity of the (ground) surface and the types of vehicles used are of great importance to the trafficability of a construction site. The capacity table drawn up by the manufacturer of the machines specifies the maximum expected soil pressure per m² in the most unfavourable situation.
A construction site with sufficient load-bearing capacity are important for trafficability and walkability. The condition of the construction site has a direct influence on the stability of the equipment, but also on the working conditions of the personnel as slippery or soggy soil can cause workers to slip or sink. For optimal workability, the top layer must consist of clean sand with adequate water permeability.
The inspection of a construction site begins with a visual inspection: is the soil dry and even, and is the site flat. Then, further inspection takes place through soundings or penetration resistance tests.
For the determination of the trafficability of construction sites for persons and vehicles, we look at the pressure that is exercised on the ground by the person or vehicle. This pressure is called the Vehicle Cone Index (VCI). The Vehicle Cone Index is related to the Cone Index (CI), or the resistance that the soil can offer. A comparison is then made between the soil number CI and the vehicle number VCI. If the CI exceeds the VCI, the site is considered safe. If not, mitigation strategies must be implemented to avoid accidents and equipment damage.
Soil compaction is a form of soil degradation, in which the soil structure is lost because the soil is compressed. This global problem is still underestimated and causes problems for agriculture, nature, and climate. If farmers have an overly compacted soil, they have to make sure that they loosen that compacted layer and restore the balance between the pores and the soil fauna.
Regular resistance measurements help detect damage to soil structure, determine problem areas in the soil and prevent long-term deterioration.
Soil compaction reduces soil life, permeability to water and air, and the possibilities for plant growth. If a soil is compacted, water and oxygen can no longer enter the soil, and as a result nothing grows. It is a widespread, but sadly often underestimated issue. It reduces:
A soil with good physical properties is composed in such a way that both small and large pores are present in the soil. The moisture is retained in the small pores, and the large pores ensure an adequate supply of air and the removal of excess water. Through ploughing, or treading by humans or animals or use of heavy machinery, these pores can become compressed and lose their function, and the structure of the soil is damaged.
Moist soils are much more sensitive to compaction than dry soils. Tillage under wet conditions is therefore very unfavourable for the soil structure.
The Penetrologger PRO by Royal Eijkelkamp is a state-of-the-art device designed for accurate and efficient in situ measurement of the resistance to penetration of the soil. Key features include:
With the PenetroPROviewer software, users can easily analyze and export data for reporting and decision-making.
The penetrologger comprises an accurate internal GPS-system to determine the exact measuring point. The coordinates saved in the penetrologger can be linked to a place or map using software (or less accurately via Internet).
Optionally, a soil moisture sensor can be connected to the Penetrologger PRO to make a one point measurement and record the soil moisture percentage at the measuring point (applying the Frequency Domain technique). The soil moisture data is stored together with the coordinates and the measured resistance to penetration.
The Penetrologger is a great tool for soil compaction insights for construction and civil engineering as well as agriculture.
In construction, it helps to establish in advance whether the site is safe for man and machine. This helps make sure that you don’t run the risk of damaging the material or equipment you use because of problems with the soil. The Penetrologger is more often used for measurements in autumn than in summer. The reason for this is that the soil is wetter in autumn than it is in summer, meaning the construction pits are wetter and weaker.
In addition to determining the trafficability and load-bearing capacity of soil, the penetrologger is also used for the laying of cables and pipes. Once cables and pipes have been laid, the trench in which they are located must be recompacted. During the compaction process, the penetrologger can be used to measure directly whether the sand is sufficiently compacted.
In agriculture, the Penetrologger PRO helps identify soil compaction zones that hinder root growth and water movement. Farmers use it to optimize tillage, improve crop performance, and maintain soil health.
One measurement is as good as no measurement - to get a reliable result, you always need to perform a number of repeated measurements. A single measurement produces a value that does not necessarily apply to the entire measurement area as soil is not homogeneous in composition. To get a reliable and representative value, several measurements need to be taken. The Penetrologger PRO is a user-friendly device that lets you take repeated measurements quickly, all linked to a location, thus creating a grid of measurements.
Measuring soil penetration resistance is essential for modern construction and farming. The Penetrologger PRO empowers professionals with reliable data to enhance safety, efficiency, and sustainability. Whether you're building infrastructure or growing crops, understanding your soil starts with the right tools.
