SURFACE FAULT HAZARD ZONING: METHODS FOR REGIONAL PLANNING AND FOR SPECIFIC SITE INVESTIGATIONS

Heavy damage attributed to surface fault rupture accompanied the Managua, Nicaragua earthquake of December 23, 1972, demonstrating that surface fault rupture is a significant hazard there. Methods were developed in Managua to identify areas of potential surface fault damage, including general hazard zoning for regional planning, as well as site-specific methods for design and construction. The faults and lineaments were given a preliminary hazard ranking. The Nicaraguan government then established five categories for classifying buildings and structures based on the risk to life, size of investment, and the need for the structure to survive a natural disaster. From preliminary geologic study, five hazard zone categories were established: Major faults, minor faults, postulated faults, areas of concern, and areas with no apparent evidence of faulting. The classifications for structures and for faults were matched on a planning matrix. The characteristics of the faulting were investigated along many of the faults and lineaments by trenching. This provided a basis for establishing the width of postulated hazard zones and determining the construction hazards associated with the various classes of faults and lineaments. A preliminary hazard zone map, based on the limited geologic data, was then compiled for use with the planning matrix. These were the preliminary tools for land-use planning by the local government. A second type of hazard zone classification based mainly on detailed subsurface investigations by trenching was developed for use at specific sites. These zone classifications attempt to describe the local hazards in terms of surface faulting, warping, tilting and soil failure. This detailed work is the basis for determining the type and precise location of structures at a specific site. It also helps to establish site-specific design criteria for earthquake-resistant structures. The methods developed in Managua recognize the need for general land-use planning data on a regional basis, as well as design- oriented data for a specific site.

  • Supplemental Notes:
    • This article is an excerpt from the Proceedings of the Fourteenth Annual Engineering Geology and Soils Engineering Symposium that was sponsored by Idaho Transportation Department, Division of Highways; University of Idaho, Department of Geology and Department of Civil Engineering; Idaho State University, Department of Geology and Department of Engineering; and Boise State University, Department of Geology, and Department of Physical Science and Engineering. This symposium was held at the Rodeway Inn, Boise, Idaho, and was hosted by Boise State University.
  • Corporate Authors:

    Idaho Department of Highways

    P.O Box 7129
    Boise, ID  United States  83707
  • Authors:
    • Cluff, L S
    • Niccum, M R
    • Brogan, G E
    • Cline, K M
  • Publication Date: 1976-4-9

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Filing Info

  • Accession Number: 00142672
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Feb 1 1977 12:00AM