Field Experiments on the Castlegate Sandstone, Rangely Anticline, Colorado.
Abstract
Field experiments were performed in the Castlegate Sandstone (Rangely Anticline, Colorado) to measure the mechanical and transport properties of a rectangular block (2 m3) of rock containing a gouge-filled joint as a function of compressive stress to 30 bars. In preparation of the static loading tests, a thorough site investigation was conducted to determine the ambient stress and velocity field in the undisturbed rock mass. These studies revealed that the fractured, but otherwise homogeneous sandstone is pre-stressed to about 10 bars (1 MPa; 145 psi). Static loading tests performed on the isolated sandstone block indicate that either permanent compaction, or dilation and shear displacement of the calcite-filled joint begins at applied stress levels only slightly higher than the pre-stress. The results of these tests provide additional evidence that joint displacement can be triggered by distant high-yield sources of energy. The impact of this phenomenon on siting technology is emphasized. Attempts to measure fluid permeability with applied stress in these tight joints proved unsuccessful. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1977
- Accession Number
- ADA047731
Entities
People
- H. S. Swolfs