Bowser-Morner provides extensive geotechnical investigation services to its clients, including shear-wave velocity testing. The shear-wave velocity, once obtained, can be used for several purposes:
- Seismic site classification
- Liquefaction susceptibility analysis
- Subsurface mapping and subgrade strength estimation
Sites for schools, hospitals, power plants, water and waste-water treatment plants, police and fire stations, and others require seismic site classifications. The test can also be used to determine caves or mine voids for mined lands in the design of landfill facilities, and for the study of sand and gravel mining operations. We have also used this test method to assess the integrity of a clay isolation layer beneath a landfill in northeast Ohio.
Primarily, Bowser-Morner performs this test to determine the shear-wave velocity for seismic site classification for project sites, including:
- Multiple coke plants in Ohio and Kentucky
- GE Aviation EPISCENTER at the University of Dayton
- Dayton Children’s Hospital Patient Bed Tower
- Helix Innovation Center–Emerson Climate at the University of Dayton
- Hobart Arena Addition, City of Troy, OH
- Fire Station, City of Norwalk, OH
- CertainTeed Roofing complex expansion, Milan, OH
The shear-wave tests are performed using the SeisOpt® ReMiTM Vs30 Method, which is a non-destructive method with conventional geophones. This method can use both ambient seismic noise (microtremors) and induced signals as a source. This versatility means that the shear-wave measurement can be performed on active construction sites, other noisy urban areas, and in quiet, rural areas.
The ReMiTM (Refraction Microtremor) method has several advantages over other seismic testing methods. This method tests a much larger volume of the subgrade compared to borehole measurements using the down-hole methods. Our equipment is capable of determining the average shear wave velocity over distances up to 300 feet and down to depths of 100 feet. No permits are required to use this test method, since it is non-invasive and non-destructive. The equipment (the seismic lines and geophones) can be set up and the test can be run without interrupting road traffic or construction activity, if testing is performed in active areas. The test takes little time – set-up through breakdown usually takes less than two hours. All of these advantages save substantial amounts of time and cost.