Geotechnical Design (Construction) Projects

ECA Geophysics has performed dozens of seismic Refraction Microtremor (ReMi™) surveys for Geotechnical and Construction firms throughout Idaho’s Treasure Valley and elsewhere in the United States. ReMi™ surveys are equivalent to MASW surveys, in that both provide reliable and confirmable International Building Code (IBC) site classifications that assist in the safe and effective design of building foundations. ReMi™ surveys effectively reduce the amount of drilling, while simultaneously expanding subsurface information laterally and vertically, thereby providing reliable information from which to calculate the IBC Site Class.

We charge a reasonable fee for this service that augments drilling programs, while also reducing otherwise expensive drilling budgets!

Some typical ReMi™ surveying projects performed by ECA Geophysics are listed below:

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, to noninvasively 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, instead of the desired crystalline 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 at US Army Facility
PROJECT: ReMi™ surveys for Geotechnical Engineering design
LOCATION: Southeast of Boise, Idaho
DESCRIPTION: Designed and acquired ReMi™ survey data at predetermined locations within the United States Army’s 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 design
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, 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.