Application And Research Of Reliability Theory In The Cement Concrete Pavement Engineering

Since the 20s of the 20th century, much research about the reliability theory in structure has been done in the world and it has gradually extended to every aspect in the analysis and design of structure. Our country included, the results of study have been already applied to many designing standards, which has promoted the development of theory of structure design. The paper statistically analyzes the main parameters influencing the reliability of highway engineering and puts forward a model of concrete pavement limit state as well as calculates and discusses the reliability of a road.The paper introduces the ways to measure the reliability, the derivation of reliability rate and reliability index. It systematically discusses the methods of reliability analysis using at home and abroad as well as the advantages and shortcomings of these methods. It analyzes not only the uncertain and ambiguity factors affecting the pavement of highway, but also a lot of situations not according to the facts. We get to know the reliability is important in analyzing the safety, enduring and economy of highway engineering. The paper demonstrates the requirement of reliability, concludes the factors which can affect the reliability of the highway, and analyzes the variability of main factors.Because of the existence of uncertain things, in fact, safe design of structure is a risk decision of suffering national economical controlling. It is required to keep balance between the expenses for building and for breaking transportation in future. Therefore it is necessary to pursue combining economy and safety in designing concrete pavement. The paper applies reliability theory to optimal design of total expense in concrete pavement, which makes the conception of optimal technology and reliability technology permeated into structure design and results in less expenses and more reliability.Eventually, based on Specifications of Cement Concrete Pavement Design for Highway (TJG D40-2002), the paper analyzes and calculates some projects, provides some functions in limit state of pavement affected by load, calculates the reliability index using advanced JC method and works out the corresponding procedures of calculation. It is verified that reliability method is reasonable and operational in pavement structure analysis.