Revealing Hidden Subsurface Structures

Understanding subsurface conditions is essential for the safe and efficient planning of tunnels and other infrastructure projects. However, geological structures, cavities and other potential risks are not always accessible through direct investigation alone. Geophysical methods provide valuable information on subsurface conditions without the need for extensive drilling or excavation.

Drilling a tunnel is challenging for many reasons. One major challenge is to define the route. But how do you explore the interior of a mountain or possible underground cavities that cannot be accessed by drilling?

Geophysics uses indirect methods to obtain information about structures and physical properties below the earth's surface. Among others, it uses gravimetric, seismic, (electro-)magnetic and electrical methods. These make it possible to non-destruc¬tively examine the substrate and the objects stored in it and to create an image of these structures. For example, geophysics observes the temperature, gravity or magnetic field of the earth, evaluates the seismic waves generated by earthquakes and other vibrations or determines the mass distri¬b¬u¬tion or conduc¬tiv¬ity in deep soil layers.

While physicists experiment under controlled conditions in the laboratory, geophysicists collect their data in the field and transfer this data with the help of sophisticated computer simulations and calculations into high-resolution models of the subsurface. Based on these models, geophysicists generate geological maps, site plans or profile sections in interdisciplinary cooperation with colleagues.

Our Services

CDM Smith provides the expertise you need to safely guide your project through every stage of planning and construction. Whether geoelectrics, ground-penetrating radar, (electro)magnetics or seismic methods – our long-standing experience enables us to select the most appropriate technique from a wide range of options, design the investigation accordingly, and deliver robust, well-founded results on subsurface conditions or existing structures – quickly, reliably and cost-effectively.

Versatile Applications

Accurate subsurface investigations typically require calibration against direct exposures, such as boreholes. Geophysics helps significantly reduce drilling efforts by enabling more targeted placement of boreholes. As a result, geophysical methods are used across a broad range of applications – from environmental and infrastructure projects to hydraulic engineering, mineral exploration and structural assessments. At CDM Smith, our areas of work include: