Phenomenological models to predict rainfall-induced ground movements

Conference · Sun Dec 01 04:00:00 EST 1996

OSTI ID:400933

Grivas, D A; Schultz, B C ^[1]; O`Neil, G D; Simmonds, G R ^[2]

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1. Arista International Inc., Niskayuna, NY (United States)
2. Nova Gas Transmission Ltd., Calgary, Alberta (Canada)

Early effort on the development of models capable of predicting ground movement based on rainfall occurrences are presented. The study uses thirty years of rainfall records and an extensive database of slope movement measurements from instrumented sites. Results indicate that ground movements exhibit two components: a steady, small movement independent of rainfall; and an increased movement following heavy rainfall. Three factors are identified as impacting rainfall-induced ground movement, namely: (a) an impulse parameter that controls the rate of change of slope movement with changes in rainfall rates; (b) a rainfall threshold value that must be exceeded for incremental movement to occur; and (c) a time lag between the rainfall and movement events. Empirical models describe the observed phenomenon and provide quantitative estimates of the parameters needed to predict ground movements. Furthermore, a time series analysis is conducted to create a system that utilizes rainfall records (input) to predict ground movement (output). Cross-correlation analysis indicates that the effect of rainfall on movement peaks one month after the rainfall and diminishes after two months. A general expression for a time series model is derived and is quantified using data available at the Simonette river crossing. The usefulness of the model is demonstrated in an illustrative example that predicts statistical values of cumulative ground movement at the slope site over a ten year period. While the presented models are in the preliminary stage, early results indicate that potential ability to estimate slope movements for both initial designs and planned maintenance actions. Knowledge of expected movements, together with pipe-soil interaction models, provide a rational basis for implementing load and resistance factor design for pipelines as well as to pipeline integrity assessments.

• OSTI ID: 400933
• Report Number(s): CONF-9606279--; ISBN 0-7918-1494-7
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALBERTA
FORECASTING
GROUND MOTION
MATHEMATICAL MODELS
NATURAL GAS
PIPELINES
RAIN
SLOPE STABILITY
SOIL-STRUCTURE INTERACTIONS
TRANSPORT