Engineering Commons^™

Residual Strength Of Franciscan-Derived Clay, Yingyi Xu

Master's Theses

In February of 2017 after a period of heavy rainfall, a slope destabilized behind Fremont Hall on the campus of Cal Poly San Luis Obispo. The geology of this slope stability failure is the Franciscan Complex. The Franciscan Complex, when weathered in place, results in clay soil that makes up the typical soil mantle on the hills throughout the region. Peak strength is the typical parameter tested to assess the strength of the soil. For the Franciscan-derived clay, the residual strength is the focus of this study to understand slope failure since the clay is the weakest portion of the …

Post-Liquefaction Residual Strength Assessment Of The Las Palmas, Chile Tailings Failure, Tristan Reyes Gebhart

Master's Theses

Assessment of post-liquefaction residual strength is needed for the development of empirically-based, predictive correlations for earthquake engineering design. Previous practice commonly assigned negligible strengths to liquefied materials for engineering analysis, producing overly-conservative designs. Increasingly available case history data, and improved analytical tools have allowed for more accurate and less overly-conservative estimation of soil residual strength, improving empirical predictive models. This study provides a new case history to the limited suite of (approximately 30) liquefaction failure case histories available for post-liquefaction in-situ strength predictive correlations.

This case history documents the Las Palmas gold mine tailings dam failure, resulting from seismic-induced liquefaction …