Utah Strong Motion Network Site Location Guide

Siting Specifications:

In general, urban strong-motion reference instruments should be located in small housings, on grade, and not at subsurface locations or in large buildings, so that the motion recorded corresponds to that on the ground in the surrounding area.

Location Strategy:

Urban strong-motion reference stations should be located to record representative ground motion in the vicinity of significant business districts or groups of structures where possible. Locations should be chosen with site geology representative of the area and preferably within 1 km of a significant business district or structure grouping. Additional stations may be required in areas with unique geologies or expected to experience altered shaking due to other factors (e.g., topography, distance to fault, soil-structure interaction).

Station Housing:

Small building, without significant basement; 1-2 story light structure, wood frame preferable but reinforced masonry acceptable; building generally less than ~4000 sq. ft. in plan.

Station Housing Foundation:

Concrete pad (6 in. or less), on grade, without piles or piers. If a special, light instrument hut is used, the pad should be approximately 4 ft. square, with 6 in. x 18 in. piers to ensure effective coupling, especially in soft soils.

Nearby Structures:

Stations should be sited away from structures likely to cause significant soil-structure interaction effects that may be recorded in the data. A distance of at least one major structure dimension away from all large/massive structures in the vicinity should be maintained where possible.

Site Conditions:

Stations should be sited to avoid highly localized characteristics of the geology or nearby topography unless special documentation is performed.

Site Geology Documentation:

Site geology at stations should be characterized through on-site geologic inspection or special investigations.