Seismic Datalogger Shallow Seismic Refraction Reflection Surface Waves Seismic Recorder Exploration Seismographwith Geophone Seismic methods measure the speed and direction of seismic waves through the earth, using instruments including seismographs and geophones.
This is done by sending an energy pulse into the ground - using a hammer and plate,a drop weight, specialised airguns, or small controlled explosives at surface level.
An array of geophones is used to detect the seismic energy when it 'bounces back' and returns to the ground surface.
The design of a survey includes many settings like geophone spacing and locations, energy source type and power and frequency, 'shot' locations and choice of recording seismograph. The most commonly used seismic measuring techniques are:
1. depth of bedrock,
2.not weathered, solid rockmass of granite, limestone, dolomite etc.,
3.interfaces separating zones/layers of varying degrees of weathering,
4.effectiveness of backfilling of voids and cracks zones in shallow mining areas,
5.rippability of rocks in open pit mines,
6.faults, fracture and weak zones, anisotrophy in jointed rock masses,
7.postmining: voids, caverns, sinkholes, collapses, inactive shafts & foreshafts, galleries, adits,
8.groundwater tables,
9.landslide zones - especially the spatial mapping the depth and shape of slip surfaces,
10.geomechanical parameters like dynamic elastic modules: Young Emax, shear Gmax, bulk Kmax, dynamic Poisson's ratio,
11.length of concrete piles, gravel columns, depth and continuity of DSM, CDMM diaphragms,
12.rock mass geomechanical classes for tunnel construction.