本研究主要是針對剛性鋪面於溫氏基礎（Dense liquid foundation）上傳統閉合解（AREA）回算方式對儀器要求（FWD）及假設無限版長理論推導過程兩項主要的條件限制作改善及回算適用範圍擴充，研究中利用ILLI-SLAB有限元素法程式、因次分析的原理來加以克服傳統限制，並以w/w/sub 0/的無因次因子作為回算方式的控制參數，再配合使用投影追逐迴歸法（PPR）建立一系列的撓度比預估模式，因此只需載重盤中央及其它任何徑向一點的表面撓度值，即可回算出路基反力模數及鋪面版彈性模數。依此研究流程，本研究亦配合IMSL之FORTRAN副程式庫與Visual Basic軟體程式之採用協助建立各相關分析之圖形界面，以建立一套非常容易使用之「TKUBAK」鋪面回算個人電腦程式，由此程式可直接輸入鋪面撓度值及鋪面資料並即時回算出鋪面彈性模數。在目前研究僅先就有限版長及路肩效應做鋪面彈性模數調整。經實例驗證及敏感度分析後發現，回算相對勁度半徑時，所需的撓度比預估模式精度須要很高，以確保回算彈性模數的精確性。 This study focused on the development of a backcalculation program forrigid pavements on the dense liquid foundation and strives to minimizethe major limitations and deficiencies of traditional backcalculationprocedures by modifying the most widely-used AREA deflection basinconcept. A modified closed-form deflection ratio (w/w/sub 0/)backcalculation procedure was introduced using the ILLI- SLAB finiteelement (F.E) program and the principles of dimensional analysis.Prediction models were developed using the projection pursuitregression technique for the modified deflection ratio. Subsequently,the proposed backcalculation procedure was implemented in auser-friendly backcalculation program (TKUBAK) to expand itsapplicability for any different NDT loading radius, sensor locations ,finite slab sizes, as well as locations of loading plate (interior,edge, and corner of the slab).
