摘要: | 在公路工程之興建與管理生命週期中,橋梁為扮演跨越河川、山谷等障礙物之重要公路設施,台灣因多山谷、且河川短且急促,且地狹人稠,公路系統中橋梁之數量不少。橋梁初始之規劃內容,實足影響後續之設計方針、施工方法與維護策略。早期因受限於設計與施工技術的不足,而造成目前橋梁維護工作的大量負荷。傳統以人力進行橋梁之規劃,必須考量空間、法規、需求、施工技術、地質等各項因素,每產生一個可行方案,往往耗費大量人力與時間,使得規劃者無法產生更多的替代方案,以選擇較佳且合適之規劃方案。 橋梁之規劃必須考量用路人因素、橋址地形、地物、環境因素、經濟性、整體配置、橋下淨空、結構型式與尺寸等,且必須根據不同的設計條件,不時地修正。橋梁規劃亦須考量橋梁主體與環境空間使用之間的衝突與平衡性,而橋梁規劃之結果亦將影響後續設計之內容、施工方法與未來維護之策略。因此,橋梁規劃工作之流程,除為不斷修正程序外,可視為規劃工作之生命週期循環。 本研究主要目的為提出一套適用於橋梁初步規劃階段之橋梁自動規劃系統(Automatic Bridge Planning System, 簡稱ABPS),ABPS整合物件導向與地理資訊技術記錄工址空間資訊,包括地形、地物、地質與水文等,並且以複合知識庫儲存公路路線設計規範及訪談自專家之橋梁規劃經驗。規劃者於地理資訊圖層中標定橋梁起迄點,並輸入規劃之需求條件後,ABPS將進行知識庫推理與空間分析,輸出符合工址條件與設計規範之最低成本較佳方案,輸出結果包括公路路線設計、橋廊分析、橋帶分析、跨距配置、落墩分析、構件型式尺寸、成本工期估算、橋梁橫斷面尺寸繪製等,可作為橋梁細部設計之基本準則。 Several factors influence a bridge's geometrical alignment and the length of its spans, thereby affecting the construction method and cost. In the preliminary design phase, the alignment and spans are typically designed according to the design engineer's experience. However, the resulting design, while feasible, may not be the most economical, due to the many possible combinations and permutations of span lengths. This research presents an integrated, automatic bridge planning system (ABPS) in which relevant site data, such as hydrological and geological conditions, and existing obstacles, are computerized in an object-oriented environment. Code requirements for bridge design, common bridge construction methods, and knowledge elicited from experts, are represented in various knowledge bases. The system input is a set of start/end positions of the bridge, marked by the designer on a geographical map on the computer screen. The system outputs a set of most feasible solutions that not only meet the site conditions and code requirements, but also involve minimal construction costs. The output includes geometrical alignment, span lengths, structural units, and major beam sizes, which altogether serve as basic criteria for the detailed design of a bridge. |