Combined Observation by Means of Extensometer, Rotationmeters, and Tiltmeters

Summaryx, y, and z components of the relative displacement of the crustal movement, u, v, and w in the Osakayama Tunnel have been obtained by combinations of ∂v/∂x and ∂u/∂y observed by rotationmeters, ∂u/∂x, ∂v/∂y and ∂w/∂z by extensometers, and ∂w/∂x and ∂w/∂y by tiltmeters. Then, main strain and torational strains have been calculated. Another component of the rotationmeter to observe ∂w/∂x has been devised. Subtracting the value ∂w/∂x, observed by the rotationmeter, from the value, observed by the tiltmeter, the deflection of the vertical has been separated. Let u, v, and w be x, y, and z components of the displacement by the crustal movement, respectively. These components are written as follows: