本研究是針對剛性鋪面於彈性固體基礎上傳統回算方式對儀器的限制及理論推導過程的無限版長假設條件，利用ILLI-SLAB有限元素法程式及因次分析的原理來加以克服。文中並以無因次撓度比（w/w/sub 0/）作為回算方式的控制參數，再配合使用投影追逐迴歸法建立中央、邊緣及角隅載重的撓度比預估模式，因此只需載重盤中央及其它任何一點的撓度值，即可回算出二層鋪面版之彈性模數。日前僅先就有限版長做調整，並依此模式建立「TKUBAK」回算程式，直接輸入鋪面撓度值後可回算出鋪面彈性模數。經驗證後發現，「TKUBAK」回算程式所回算出的答案與理論值相當接近，當使用傳統回算程式回算時，回算出的答案值須作調整以提高準確度，減少誤差量。 This study focused on the development of a backcalculation program forrigid pavements on the elastic solid foundation and strives tominimize the major limitations and deficiencies of traditionalbackcalculation procedures by modifying the most widely-used AREAdeflection basin concept. A modified closed-form deflection ratio(w/w/sub 0/) backcalculation procedure was introduced using theILLI-SLAB finite element (F.E) program and the principles ofdimensional analysis. Prediction models were developed using theprojection pursuit regression technique for the modified deflectionratio . Subsequently, the proposed backcalculation procedure wasimplemented in a user-friendly backcalculation program (TKUBAK) toexpand its applicability for any different NDT loading radius, sensorlocations, finite slab sizes, as well as locations of loading plate(interior, edge, and corner of the slab).
