本研究致力於建立一套現地B-WIN系統，以期可由橋梁結構的監測資料，來建立橋梁之荷載譜，協助橋梁工程師對於橋梁結構作有效的維護管理，確保用路人的行車舒適與安全。通過橋梁受移動荷載作用下所量測得到之多點應變歷時資料來識別出通過車輛之總重及軸重，這種方法稱之為橋梁動態載重識別 (Bridge Weigh-In-Motion)。本法結構動力方程式做為基本，進行橋梁動態載重識別，首先將所擬分析之橋梁結構有限元素化，推導出應變、外力荷載與自由度之間的關係，並利用對位移以形態函數分解的方式，以減少反算程式在反覆運算求解的所耗費的時間。藉由引入線性離散時間系統(Linear Discrete-Time System) 中的狀態空間系統(State-Space System)和在線性代數中求解近似值的Tikhono正規化法，利用動態規劃(Dynamic Programming)演算法進行反算,求解出橋梁上的移動載重。此外，使用商用軟體ANSYS分析橋梁模型結構受多軸移動載重之行為，將所算得之應變值代入反算程序中，驗證此多軸動態反算理論識別多軸移動載重之可行性與準確度。通過對橋梁結構模型的移動荷載作用之實驗，討論真實情況下出現的各種因素對於各軸識別準確性的影響，作為後續現地應用之參考。;The goal of this research is to develop a bridge weigh- in- motion (BWIM) system to back calculate the axel and total load applied on the bridge by the measured strain data. A loading spectrum of the monitored bridge can be used for the effective maintenance and management work of the bridge. This multi-axel loading identification theory is based on the dynamic equations of bridge structures. The relations among the nodal freedoms, strains and external loads are derived from the theory of finite element method. The displacement field of the bridge structure is constructed by the shape functions of elements. Using the state space system, Tikhonov regularization method and the dynamic programming algorithm to reverse calculate the moving load on the bridge. Numerical simulation of the bridge structure is analyzed by the ANSYS code to obtain the strain data corresponding to the given moving load. Then, these strain data are applied into the backward analysis algorithm of the load identification to verify the feasibility and accuracy of this algorithm. This multi-axel loading identification algorithm was further evaluated through laboratory tests. Factors affect the accuracy of load identification are discussed as the reference for the future research and application.
