RIFT: Robust and interpolation-free technique for objective functions in geotechnical inverse analysis

This paper proposes a novel method of constructing objective functions, known as the robust and interpolation-free technique (RIFT), to be used in conjunction with inverse analysis. RIFT is free of interpolation and can avoid errors introduced by interpolation. Numerous validations performed using various functional forms, levels of data-density contrast, and data discrepancies demonstrate that RIFT is accurate and robust. The advantage of RIFT over the commonly used least-squares objective function is demonstrated. In addition, the applicability of RIFT as an objective function in inverse analysis is verified in two synthetic geotechnical engineering applications: laboratory tests and an excavation.