Comparative study of the effects of three data‐interpretation methodologies on the performance of geotechnical back analysis

Abstract

Summary Back analysis can provide engineers with important information for better decision‐making. Over the years, research on back analysis has focused mainly on optimisation techniques, while comparative studies of data‐interpretation methodologies have seldom been reported. This paper examines the use of three data‐interpretation methodologies on the performance of geotechnical back analysis. In general, there are two types of approaches for interpreting model predictions using field measurements, deterministic versus population‐based, both of which are considered in this study. The methodologies that are compared are (a) error‐domain model falsification (EDMF), (b) Bayesian model updating and (c) residual minimisation. Back analyses of an excavation case history in Singapore using the three methodologies indicate that each has strengths and limitations. Residual minimisation, though easy to implement, shows limited capabilities of interpreting measurement data with large uncertainty errors. EDMF provides robustness against incomplete information of the correlation structure. This is achieved at the expense of precision, as EDMF yields wider confidence intervals of the identified parameter values and predicted quantities compared with Bayesian model updating. In this regard, a modified EDMF implementation is proposed, which can improve upon the limitations of the traditional EDMF method, thus enhancing the quality of the identification outcomes.

Methodology Maps for Model-Based Sensor-Data Interpretation to Support Civil-Infrastructure Management

“…This enhanced knowledge can be used to avoid unnecessary post-hazard closures of buildings while supporting a risk-based assessment to either close or retrofit essential buildings. Wang et al (2020Wang et al ( , 2019 studied the use of data-interpretation methodologies for reducing uncertainty related to excavations. Data from one stage of excavation is used to predict behavior at further stages of excavation leading to less conservative practices.…”

“…EDMF is suitable for all levels of systematic bias and uncertainty magnitudes, particularly cases involving high systematic bias (Reuland et al, 2017;Proverbio et al, 2018b;Pai et al, 2018Pai et al, , 2019Reuland et al, 2019a;Reuland et al, 2019b;Drira et al, 2019;Wang et al, 2020). Depending upon the computational constraints, EDMF can be implemented with either a grid sampling approach or an adaptive sampling (Raphael and Smith 2003;Proverbio et al, 2018b).…”

Systematic selection of field response measurements for excavation back analysis

“…The concept of correcting 2D model predictions to account for three-dimensional effects has been commonly adopted in the literature [9,17,22,29]. The strategy used in the current study has been successfully applied on a synthetic excavation example [49] and two full-scale multistage excavation case histories in Singapore [51,52]. Figure 6 shows the joint entropy of the eight inclinometers after each round of identification.…”

“…One of the alternative strategies for gaining knowledge of soil properties is through measurement of behaviour and back analysis. A back analysis, which is synonymous with system identification or model updating, is performed using measured field responses to obtain knowledge pertaining to material parameter values [8,14,15,16,41,45,51,52,57,58], from which engineers can make informed decisions and achieve better designs.…”

A nonlinear optimization method for calibration of large‐scale deep cement mixing in very soft clay deep excavation

“…In the geotechnical engineering field, many studies have made an effort to find soil parameters using the back-analyses method 6 ; Yapage, et al, 7 Li, et al, 8 Goh, et al, 9 Zhou, et al, 10 Ohtsu, et al, 11,12 Tang, et al, 13 Leon Bal and Meschke 14 used the finite-element program, for example, ABAQUS software and/or PLAXIS, for numerical modeling the soft soil improved by deep cement mixing (DCM) columns. 15 Waichita, et al 16,17 described the behavior of DCM columns-walled basement excavation and/or DCM columns under embankment load using PLAXIS 2D.…”