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Project Details

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Project Information Sheet 2004-09

Predicted responses of unconsolidated materials throughout Indiana to seismically induced ground shaking

Funding Source:	State Emergency Management Association
Period of Contract:	6 Apr 2003 to 1 Apr 2004
Status:	completed — Definition of status type
Project Director:	John Hill

Issue

The seismic hazard for any locale is a function of geologic materials present, depth to bedrock, shear wave velocities of the bedrock and unconsolidated materials, and the thickness of unconsolidated materials. More than 40 downhole shear wave velocities have been measured throughout Indiana to begin the process of characterizing site amplification effects on ground shaking as a function of unconsolidated-material thickness and local geology.

Objective

Measure shear-wave velocities in the major types of unconsolidated materials that exist in Indiana and construct a first-phase National Earthquake Hazards Reduction Program (NEHRP) classification map for the state.

Approach

Using a downhole triaxial geophone and Geode portable seismic recorder, shear-wave velocities are determined in cased boreholes, many of which terminate on the bedrock surface.

Products

This research will result in the creation of a geographic information system (GIS) with layers illustrating generalized surficial geology, boring locations, and NEHRP classes throughout Indiana at a scale of 1:500,000.

Benefits

The National Earthquake Hazards Reduction Program classification layer of the GIS will be used by the Indiana State Emergency Management Association as a basis for running the risk assessment software, HAZUS, in all 92 Indiana counties.

Locations Affected:

state

Information Updated January 31, 2007

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