Alternative Title

Paper No. 6.05

Location

St. Louis, Missouri

Date

11 Mar 1998, 4:30 pm - 6:30 pm

Abstract

Discharges up to 60,000 cfs that lasted 21 days caused extensive erosion of the unlined spillway chute excavated in alternating layers of limestone and shale. An empirical model allowed to evaluate the extent of erosion anticipated for future events. Parametric calculations showed that relatively low discharges a long period of time are critical for the induced damage. It was determined that the spillway can safely pass the design discharge if weathering of rock exposed by erosion is prevented. Accordingly, the interim repair was designed to protect the rock units, especially the critical limestone layers, from weathering. Although it is expected much of the repair to be eroded during future spillway flows, it will ensure the spillway can safely pass the next discharge event.

Department(s)

Civil, Architectural and Environmental Engineering

Meeting Name

4th Conference of the International Conference on Case Histories in Geotechnical Engineering

Publisher

University of Missouri--Rolla

Document Version

Final Version

Rights

© 1998 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Erosion and Repair of Unlined Spillway Chute Excavated in Rock

St. Louis, Missouri

Discharges up to 60,000 cfs that lasted 21 days caused extensive erosion of the unlined spillway chute excavated in alternating layers of limestone and shale. An empirical model allowed to evaluate the extent of erosion anticipated for future events. Parametric calculations showed that relatively low discharges a long period of time are critical for the induced damage. It was determined that the spillway can safely pass the design discharge if weathering of rock exposed by erosion is prevented. Accordingly, the interim repair was designed to protect the rock units, especially the critical limestone layers, from weathering. Although it is expected much of the repair to be eroded during future spillway flows, it will ensure the spillway can safely pass the next discharge event.