Seismic Tomography provides high-resolution 2D or 3D images of seismic velocities between boreholes. The method is used to delineate geological structures, to map cavities and weak zones and to specify mechanical soil and rock properties. Geophysicists and engineers apply methods to investigate the foundation and underlying rock of buildings and bridges in order to characterize the subsurface before infrastructure is built and it image time-dependent processes.
* Applications: Disaggregation zone, sinkholes, karst structures, deep tomography and etc.
* Suitable Geophones:
The cross-hole test provides a depth profile of shear wave velocities and compressional wave velocities between boreholes at a high vertical resolution. The method is used to determine soil dynamic parameters, such as shear modulus, Poisson ratio and Yong’s modulus. Engineers use these key parameters to predict the response of soils to dynamic loading.
* Applications: Determination of elastic soil parameters.
* Suitable Geophones:
The downhole test provides shear wave velocities and compressional wave velocities for geological layers along a single borehole. Soil dynamic parameters, such as shear modulus, Poisson Ration and Young’s modulus can be determined to evaluate the soil’s response to dynamic loading. The downhole test has a lower vertical resolution than the crosshole test.
* Applications: Determination of elastic soil parameters.
* Suitable Geophones:
Refraction seismic utilizes seismic waves being refracted on geological layers. The method is used to image velocity contrasts of the subsurface. Changes in lithology and the degree of fracturing can be mapped and geological structures, such as faults and cavities can be identified. The methods are used for detailed subsurface characterization in a variety of engineering site investigations.
The MASW(Multichannel analysis of surface waves) utilize the dispersion of seismic surface waves. The method provides 1D or 2D depth profiles of shear wave velocities. The S-wave velocity is closely related to soil stiffness. The method is commonly used for various types of geotechnical engineering purposes related to foundation design.
* Applications: Site classification according to EC8 and DIN4149, strength characterization of dykes and dams.
* Suitable Geophones:
Description: The main purpose of seismic reflection is to acquire a 2D or 3D image of S-wave reflections as a function of depth. The acquired data can be used for the evaluation of the lateral continuity of geological layers, which will be associated with reflectors. Reflections and diffractions usually occur at other geological structures as well, such as volcanic craters and fault or marine-controlled deposition centres.
* Applications: Layer Boundaries.
* Suitable Geophones:
* References: https://www.geotomographie.de/methods/
