Water saturation effect on the compressive strength of rocks

• Main Author: Muhammad Saufi Ahari.
• Other Authors: School of Civil and Environmental Engineering
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Civil engineering::Geotechnical
• Online Access: http://hdl.handle.net/10356/53879
• Institution: Nanyang Technological University

In the design and construction which involves pile foundation, the compressive strength of rocks is an important parameter to consider. As high rise buildings are often built with deep foundation piles that will penetrate through rocks subjected to various degree of water saturation, this study aims to determine the effect of water saturation on the compressive strength of rocks. Hydrocal gypsum cement specimens were prepared by molding it and the specimens were then kept in oven and air dry to obtain dry and semi-dry specimens. The specimens were soaked in water to achieve different water saturation contents. Unconfined Compression Tests were conducted on the specimens to determine their compressive strengths. Water saturation percentage ranging from 0% to 14% were tested for both oven and air dried. The test results showed that the compressive strength for air dried specimens have higher strength than oven dried specimens. Analysis of the recorded high-speed footage showed that the vertical crack can be seen for dry specimens and slow progressive side cracks for wet specimens, hence validating the test results. This study proved the weakening effect of water on the compressive strength of rocks and hence recommends that the saturated compressive strength should be used for a more conservative design of foundation supporting high rise structure.