Accession Number:

ADA030949

Title:

Surface Gravity Effects of Subterranean Tunnels

Descriptive Note:

Contract rept.

Corporate Author:

ANALYTIC SCIENCES CORP READING MA

Personal Author(s):

Report Date:

1976-07-16

Pagination or Media Count:

102.0

Abstract:

This report determines the change of six components of the symmetric second order tensor associated with the earths gravity field as a result of the following mass changes and conditions 1 A tunnel 16 km long is excavated 6m below the earths surface 2 A vehicle traveling at a constant speed crosses the tunnel at the earths surface 3 The resulting tensor component changes are computed and plotted 4 The computations are repeated for tunnel depths of 30 and 90 m and 5 The problem may be inverted from one of subsurface mass removal to one of mass addition above the earths surface. The results of the report determine that 1 gradiometric detection of large tunnels to a depth of 30 m is feasible, 2 reliable detection of large tunnels deeper than 30 m imposes moderately sophisticated data processing requirements, and 3 detection of tunnels deeper than 90 m is difficult.

Subject Categories:

  • Geodesy
  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE