STABILITY EVALUATION OF THE MEDINA DAM

摘要

The Lake Medina Dam is located on the Medina River in Medina County, Texas, approximately 20 miles west, northwest of San Antonio. The dam was constructed between 1911 and 1913. The project is owned and operated by the Bexar-Medina-Atascosa Counties Water Control & Improvement District No. 1 (BMA) and is a registered national historic landmark. Lake Medina Dam is a concrete gravity dam. In July 2002, the historic flood of record occurred at the project and reservoir level behind Lake Medina Dam reached its highest recorded level - the crest of the dam. During the flooding event, the Texas Natural Resource Conservation Commission (TNRCC) State Dam Safety Office performed on site inspection of the dam to evaluate the safety of the structure. Lack of engineering data resulted in the state dam safety office classifying the dam as conditionally unsafe. After the historic 2002 flood, a comprehensive structural stability analysis was performed by URS to evaluate the safety of the dam. This paper discusses the methods of analysis used to evaluate the dam and estimate the safety of the project. Specifically included in this paper is the comparison between two-dimensional and three-dimensional analyses, and the evalaution of stability against the current safety guidelines.