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Risk-based approach in highway geometric design.

機譯：公路幾何設計中基于風險的方法。

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摘要

In current geometric design guides, the highway elements are designed using the deterministic approach. This approach considers below average driver characteristics and vehicle capabilities to produce designs that would satisfy the majority of road users. However, a design following this approach could be conservative and uneconomic since the probability of having simultaneous critical values for all design parameters could be very low. In addition, the current design methods rely on either horizontal or vertical projection of the road alignment, which may cause either underestimation or overestimation of the road supply.;In this research, a comprehensive approach for geometric design was developed based on reliability theory. The approach was applied to the sight distance design basis using the required sight distance (RqSD) as a demand and the distance actually available to drivers (AvSD) as a supply. Both simulation and analytical reliability techniques were used in the analysis. For RqSD calculations, a new approach was developed to account for the continuous change of longitudinal grade, expected loss of friction on horizontal curves, and it considers both deceleration rate and friction coefficient. As for AvSD calculations, both two and three dimensional values were calculated taking advantage of two existing programs based on the finite element technique.;Using Visual Basic.Net programming language, a computer program was developed; namely sight distance evaluation system (SDES). Using SDES, profiles can be generated for RqSD and/or AvSD at pre-determined intervals. At a given road section, RqSD and AvSD distributions can be evaluated to determine the probability of hazard (POH), which reflects the percentage of drivers who may suffer insufficient sight distance. POH profile was further evaluated in a real case study using data from Highway 61, Ontario. The POH values less than 0.05 % have mainly resulted along the entire route except for a few sections that had a maximum POH of 7.45 %. In addition, a reliability-based approach was developed to locate lateral obstructions along three-dimensional alignments using a certain POH. Two design aids were further developed for design and evaluation purposes on 400-m curves and 2H:1V side slope.
機譯：在當前的幾何設計指南中，使用確定性方法來設計高速公路元素。這種方法考慮了低于平均水平的駕駛員特征和車輛能力，以產生滿足大多數(shù)道路使用者的設計。但是，遵循此方法的設計可能是保守的，而且不經濟，因為所有設計參數(shù)同時具有臨界值的可能性可能非常低。另外，當前的設計方法依賴于道路路線的水平或垂直投影，這可能導致道路供應量的低估或高估。；在這項研究中，基于可靠性理論開發(fā)了一種綜合的幾何設計方法。該方法應用于視距設計基礎，使用所需的視距（RqSD）作為需求，而駕駛員實際可用的距離（AvSD）作為供應。分析中同時使用了仿真和分析可靠性技術。對于RqSD計算，開發(fā)了一種新方法來解決縱向坡度的連續(xù)變化，水平曲線上的預期摩擦損失，并同時考慮了減速率和摩擦系數(shù)。至于AvSD的計算，利用基于有限元技術的兩個現(xiàn)有程序來計算二維值和三維值。；使用Visual Basic.Net編程語言，開發(fā)了一個計算機程序；即視距評估系統(tǒng)（SDES）。使用SDES，可以以預定的時間間隔為RqSD和/或AvSD生成配置文件。在給定的路段，可以評估RqSD和AvSD分布以確定危險概率（POH），該概率反映了可能遭受視距不足的駕駛員的百分比。使用安大略省61號高速公路的數(shù)據(jù)在實際案例研究中進一步評估了POH分布圖。低于0.05％的POH值主要是沿著整個路線產生的，除了少數(shù)幾個部分的最大POH為7.45％之外。此外，還開發(fā)了一種基于可靠性的方法，以使用某個POH沿三維路線定位橫向障礙物。進一步開發(fā)了兩種設計輔助工具，用于設計和評估400 m曲線和2H：1V邊坡。

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  • 作者

    Sarhan, Mohamed.;

  • 作者單位

    Carleton University (Canada).;

  • 授予單位 Carleton University (Canada).;
  • 學科 Engineering Civil.;Transportation.
  • 學位 Ph.D.
  • 年度 2008
  • 頁碼 200 p.
  • 總頁數(shù) 200
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 建筑科學;綜合運輸;
  • 關鍵詞

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