We recognise, observe and foresee problems by analysing the land deep-down, including physical perturbations, monitoring and observing values and indicators that can help prevent them. In order to do so we have converged different fields of competence, from geology to engineering, geophysics and geotechnics, integrating an approach that respects nature, ecosystems and infrastructures, thanks to non-invasive technologies. This has culminated in profound knowledge, combined with the ability to anticipate and monitor criticalities of sites, areas and human works.
In the past, obtaining such information required expensive machinery, lengthy time periods and highly invasive, polluting and expensive procedures. Today, we are able to acquire complex information from actions as simple as the beating of a sledgehammer, which informs our technological devices of structures and elements that lie deep down, with considerable energy savings and more comprehensive protection of sites and areas.
The gravimetric method consists of the detailed analysis of deformations of the land’s gravitational field, caused by anomalies and heterogeneities present in the subsoil. Gravimetry (and microgravimetry in particular) is a geophysical method used to map rock density and to search for natural and artificial cavities in the subsoil.
Electromagnetic investigations, both in the time domain (TDEM) and in the frequency domain (FDEM), involve the generation of an artificial magnetic impulse (the primary field), which induces a secondary field within the land. Electromagnetic investigations in the time domain (TDEM) involve reconstructing true resistivity distribution in the subsoil. The FDEM investigation method (in the frequency dominion) enables the mapping of phase variation and secondary electromagnetic field amplitude values with respect to the induced primary field. This type of investigation is carried out above all to identify buried metal objects, in archaeological research, investigations in waste disposal plants, the identification of cavities and buried debris, environmental investigations and the identification of underground ducts in non-urbanised areas.
Enables the passive measurement of electromagnetic fields of the subsoil generated by natural external sources, providing a geoelectric stratigraphy with investigation depths ranging from 100-200 m, to several thousand metres. Thanks to high reachable depths and the small size of on site equipment, it enables the rapid assessment, at a relatively low cost, of deep-down geological models for mining applications, the design of deep tunnels, hydrological and geothermal research.
Enable the calculation of stress a structure is subjected to, through the measurement of vibrations. Special equipment is fitted to the structure, to measure deformations induced by internal or external stress. Reference standard: UNI9916:2004
Each building or structure has its own natural resonance frequencies. Modal analysis, through accelerometers and velocimeters, enables the identification of natural frequencies, damping and the modal forms of a structure. With the application of a mechanical impulse of a known force (using a sledgehammer), induced excitation can be correlated with the structure’s response. The intensity of excitation is measured using accelometric sensors positioned in the body of the sledgehammer. A calibration factor correlates acceleration with exerted force, insofar as the mass of the instrument is known. The structure’s response is measured using accelerometers installed in it. The application of the impulse to different points of the structure, and the variation of the response acquisition point, enables the reconstruction of the modal forms of the structure under investigation. The purpose of modal analysis is to create a modal model of the structure, with frequencies, damping and modal forms, in order to obtain a comparison with numerical analysis, or as the basis for analysing the sensitivity of a structure’s forced response.
Dynamic monitoring is a type of geophysical investigation that verifies the structural health and response of large structures, like dams, historic buildings, bridges, railway lines, platforms, etc. The aim is to dynamically characterise the structure under investigation, by identifying its eigenmodes, natural vibration frequencies and relative damping. Indeed dynamic monitoring enables the measurement of accelerations and shifts a structure is subjected to during natural or anthropic events that take place in close proximity. Such surveying can be carried out using accelerometers or velocimeters positioned at different points around the structure, which acquire data continuously or during a single event. The recording of a structure’s natural frequency requires continuous reading, whereas the measurement of vibrations or accelerations usually requires the recording of a single event.
Such measurements are obtained to evaluate the thermal conduction characteristics of lands and rocks. Thermal resistivity is the specific parameter measured here, or inversely, thermal conductibility. A knowledge of this parameter is fundamental when designing underground cable ducts, as it enables the evaluation of induced temperatures inside conductors, or heat dispersion in the tubes of geothermal plants.
The measurement system involves taking readings with a probe that contains both a heating wire and a temperature sensor. The land’s response to a heating cycle is measured for a few minutes; with this procedure it is possible to calculate the thermal resistivity and/or conductibility of land or rock.
Georadar, or GPR (Ground Penetrating Radar) is a non-invasive system for surveying the subsoil, suitable for modest depths and based on the reflection of electromagnetic waves. This technique is mostly used in underground utility investigations, including manholes and pipes, for the identification and mapping of existing installations, the identification of the geometric structure of foundations, and the identification of masonry structures and cavities. Short electromagnetic impulses of varying frequencies are emitted, which upon meeting surfaces with different physical characteristics (different dielectric constant or electrical conductivity), are partly reflected (so they return to the receiving antenna) and partly transmitted in the subsoil. Maximum depth and the consequent degree of obtainable detail varies according to the frequency used. A low frequency enables information to be collected at grater depths, whereas high frequencies are desirable when aiming for better resolution for surface targets.
The antenna is made to slide along a previously defined straight line (usually a rectangular grill is created), to obtain a real-time radargram in digital format on a PC monitor, which is successively elaborated and interpreted using specific software.
This type of investigation method is applied to underground utilities like electric cables, metal pipes, to prevent risks before undertaking any excavation operations. The radiodetector method enables the identification of metal pipes or electric cables at depths of up to 3-4 metres in the subsoil of the site under investigation, with a good degree of precision and detail. In some conditions, it also enables the discernment of different types of identified tubes and the complete reconstruction of any underground utility networks present.
Radiodetector investigations do not directly detect the presence of cables and pipes, rather they identify cylindrical magnetic fields wrapped around them, generated by AC which flows inside underground utility installations, thus enabling the identification of position and depth. f electric current does not pass through underground utilities, the magnetic field can be induced, using a special transmitter. This type of investigation often accompanies and completes georadar investigations.
Topographic surveying is always a necessary integration for geophysical and geotechnical investigations and consists of the planimetric determination of the positioning of various surveying equipment, with reference to significant points or known cartographic elements within the area of interest. Topographic information is fundamental for the georeferentiation of investigations, can be processed using GIS software and most important of all, is used to make necessary corrections to geophysical and geotechnical data processing. Topographic survey coordinates are entered in a system of general project coordinates supplied by the Client. If unavailable, the survey is provided using relative coordinates.