Surveying Projects

ENVIRONMENTAL GEOPHYSICS: GPR as Part of a Phase 2 Environmental Site Assessment (ESA)
PROJECT: GPR survey for Geotechnical Engineering firm
LOCATION: Spokane, Washington
DESCRIPTION:
A project that employed the capabilities of our two firms, ECA Geophysics and Environmental Compliance Associates (ECA)

The client was required to have a Phase 2 environmental site assessment (ESA) that comprised subsurface soil sampling to address concerns regarding potential petroleum / chemical contamination associated with suspected buried solvent / fuel storage tanks (USTs). The geophysical survey (Ground-Penetrating Radar – GPR) was initially performed, to determine whether or not USTs exist at the Site. Findings from the GPR survey determined that no USTs were located onsite, thereby greatly simplifying the drilling program and most importantly, making the strong argument that contamination SOURCES do not exist. Favorable findings deemed the Site to be “clean” and classified as an “unrestricted property”.

When you hire ECA / ECA Geophysics, you reap the benefits of this “integrated approach” that can significantly reduce your site characterization (ESA) costs!

GEOTECHNICAL GEOPHYSICS: ReMi™ Surveys for New Construction in downtown Waikiki
PROJECT: Refraction Microtremor (ReMi™) surveys for Geotechnical Engineering firm
LOCATION: Waikiki, Oahu, Hawai’i
DESCRIPTION: Designed and acquired ReMi™ survey data at 6 predetermined locations within and around the footprint for a previously razed multi-story building, in order to passively measure microtremors within the upper 100 feet (30 meters) of the subsurface.
The primary goal of this interesting investigation was to identify potential low-velocity (less indurated or rock-like) subsurface zones representative of corraline deposits, instaed of the desired crytalline igneous bedrock upon which high-rise buildings prefer to rest. This information confirmed what the geotechnical design engineers suspected as the cause of a nearby building collapse.

GEOTECHNICAL GEOPHYSICS: ReMi™ Surveys for US Army
PROJECT: ReMi™ surveys for Geotechnical Engineering firm
LOCATION: Southeast of Boise, Idaho
DESCRIPTION: Designed and acquired ReMi™ survey data at predetermined locations within the United States Army’s Mobile Tank Training Area located near Boise, Idaho.
The goal of this interesting investigation was to determine the depth to weathered and “fresh” (competent) basalt bedrock, the rippability of the weathered basalt and the depth to the competent basalt bedrock at 12 proposed construction locations. The ReMi™ data correlated nicely with test pit “ground truth”, as well as coincident electrical resistivity data.

GEOTECHNICAL GEOPHYSICS: ReMi™ Surveys for New Construction
PROJECT: ReMi™ surveys for Geotechnical Engineering firm
LOCATION: Idaho
DESCRIPTION: Designed and performed ReMi™ Surveys for proposed construction at vacant and existing land to passively measure microtremors within the upper 100 feet (30 meters) of the subsurface, in order to acquire Vs, the average shear-wave velocity required to ascertain the proper NEHRP / IBC site class.
This information provided an ACCURATE (vs asumed) seismic site classification from which to design the safest and most cost-effective building foundation.

ENVIRONMENTAL GEOPHYSICS: ReMi™ Survey at a Hazardous Waste Landfill
PROJECT: ReMi™ surveys at a closed waste disposal site
LOCATION: The Dalles, Oregon
DESCRIPTION: Designed and performed ReMi™ Surveys at a closed 8-acre waste disposal site to passively measure microtremors within the upper 55 feet of the subsurface, in order to determine the depth to competent (non-rippable) basalt bedrock.