Test Embankment Dam of Fracture Grouting

Abstract

A fracture-grouting test section is a 7.1-m-high homogeneous dam of compacted silty clay on a foundation of the same material. Four test holes with different depths and lengths of casing are drilled at the dam crest along the dam axis. The grouting pressure variation curves are measured while the holes were grouted, and the shape and orientation of grout vein are recorded while the test section is excavated. The fracturing pressure is found to be directly related to the stress of the dam where fracturing started. The fracturing in an uncased hole starts near the middle height of the dam and expanded laterally and vertically. If long casing restricts fracturing within the lower part of the dam, the grout vein will have uniform thickness along the depth and be able to extend into foundation soil. All the grout veins are parallel to the dam axis and vertical.