An integrated model that is being developed under contract to the fhwa combines three different completed environmental effects models: the cms model, crrel model, and the tamu id model. It will be a comprehensive model that predicts the effects of air temperature, sunshine percentage, wind speed, rainfall, frost, and thawing actions on the performance of pavement. In the course of development, stochastic processes and random methods are employed to analyze past climatological data, and to estimate and predict the effects of the environment on the performance of pavement with specified confidence levels. This paper describes a computerized method that has been developed to generate simulated rainfall patterns for use in pavement analysis and design. The method is both practical and useful because it meets several important criteria. It uses data that are readily available; it predicts realistic rainfall patterns; it permits analysts to select how severe a condition they wish to represent; and it is simple to use. The paper presents the method used to simulate the rainfall patterns; shows how the united states is divided into nine climatic regions and which cities have been selected as representative of those regions; and gives four examples of both the required input data and the resulting simulated rainall patterns for a 95% confidence level. The model also includes the effect of freezing and thawingtemperatures on the amount of rainfall that is available to infiltrate the pavement, and this is illustrated in one of the examples. This paper appears in transportation research record no. 1252, Design, management, and operation of pavements.
Abstract