Statistical Parameters of In-A-Lane Multiple Truck Presence and a New Procedure to Analyze the Lifetime of Bridges

摘要

Design and evaluation of highway bridges requires the assessment of live loads, which can involve a considerable degree of uncertainties. These uncertainties typically refer to the number of vehicles, weight of vehicles, headway distance, type of vehicles, axle spacing, axle load, speed of vehicles and other factors. Therefore, in order to perform a reliability analysis, it is necessary to consider live load as a random variable. Multiple truck presence (MTP) and headway distance also are two random variables that should be deliberated for the assessment of live load. The basic goal of this study is to update the statistical parameters of in-a-lane MTP, using the recent available weigh-in-motion (WIM) data, and then delineate the relationship between the bridge lengths and the influence of MTP events. However, since MTP is a time-dependent variable, the statistical parameters of MTP influences should be determined for the considered lifetime of the bridge. Therefore, the main contribution of this study is to propose a new methodology to calculate the statistical parameters of MTP for different time periods. The dataset for this study includes WIM data from 19 stations throughout the United States, which were collected by the Federal Highway Administration over 5 years, with timestamp accuracy of one-hundredth of a second.