防震災存活路網設計模型

Abstract

防災路網是防災城市的重要空間系統，因此防災路網之設計原理，乃是一重要議題。本研究針對震災特性，提出評量防災道路之空間防災性、路段關鍵性等方法，並應用存活路網理論來發展整體防災路網模型，設計目標為可靠、快捷、與全面。最短路徑森林路網、系統繞路路網、及互援路網，將此三種模型整合於存活路網模型。該模型具有諸多優勢；最短路徑森林確保責任分區內救援單位至災害需求地點的路徑最短；系統繞路則容忍區內路段遭受災害毀損而仍維持救援單位至區內所有需求場所的成本最小；互援路網構成區間橋接路徑以連結外部資源，提供區間救援單位相互備援的保障。最後本研究透過Java技術實作此存活路網模型，並提出棋盤式測試路網，以進行雙供給均勻需求分佈之情境模擬，結果發現，供給點彼此逐漸遠離時，平均旅行成本趨勢下降，繞路成本陡降漸緩，互援成本逐漸增加，而路網成本初期變幅明顯，而後漸減收斂。

Disaster-prevention network is a crucial system in a disaster prevention city. Therefore, how to establish design principles for the network becomes an important issue. In this paper, we proposed the method to assess the spatial performance and the importance against disasters in individual road sections. In the viewpoint of comprehensive network, we proposed the network design model with respect to the characteristics of earthquake disaster based on survival network theories. The design goals are to achieve features of rapidity, connectivity, and efficiency. Three network models: Shortest Path Forest Network (SPFN), Systematic Detour Network (SDN), and Mutual Assistance Network (MAN), are developed and integrated in the survivable network model. The proposed survivable network for earthquake disaster has significant advantages. The SPFN promises the shortest path within the responsible territories. The structure of SDN assures the network connectivity wherever any road link fails. The bridges of MAN let the supply units in different territories connect to each other hence insufficient self-capacity of one supply may be allowed. Finally the survivable network model was implemented with Java technology. And a case in a test network of grid pattern was given to show the features in the scenario of evenly scattered demand areas with two supply resources. It was found that where the two resources were increasingly separating from each other, the average travel cost steadily decreased; detour cost dropped dramatically and then declined slowly; mutual assistance cost gradually increased; network cost seriously varied in the initial stage, but converged to a gently decreasing trend afterwards.