TY - JOUR A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Taffe, A. A1 - Braml, T. ED - Sykora, M. ED - Lenner, R. ED - de Koker, N. T1 - On the Treatment of Measurement Uncertainty in Stochastic Modeling of Basic Variables N2 - The acquisition and appropriate processing of relevant information about the considered system remains a major challenge in assessment of existing structures. Both the values and the validity of computed results such as failure probabilities essentially depend on the quantity and quality of the incorporated knowledge. One source of information are onsite measurements of structural or material characteristics to be modeled as basic variables in reliability assessment. The explicit use of (quantitative) measurement results in assessment requires the quantification of the quality of the measured information, i.e., the uncertainty associated with the information acquisition and processing. This uncertainty can be referred to as measurement uncertainty. Another crucial aspect is to ensure the comparability of the measurement results.This contribution attempts to outline the necessity and the advantages of measurement uncertainty calculations in modeling of measurement data-based random variables to be included in reliability assessment. It is shown, how measured data representing time-invariant characteristics, in this case non-destructively measured inner geometrical dimensions, can be transferred into measurement results that are both comparable and quality-evaluated. The calculations are based on the rules provided in the guide to the expression of uncertainty in measurement (GUM). The GUM-framework is internationally accepted in metrology and can serve as starting point for the appropriate processing of measured data to be used in assessment. In conclusion, the effects of incorporating the non-destructively measured data into reliability analysis are presented using a prestressed concrete bridge as case-study. T2 - International Probabilistic Workshop 2022 (IPW2022) CY - Stellenbosch, South Africa DA - 09.09.2022 KW - Reliability KW - Assessment KW - Existing structures KW - Measurement uncertainty PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556580 DO - https://doi.org/10.14311/APP.2022.36.0109 SN - 2336-5382 VL - 36 SP - 109 EP - 118 PB - Czech Technical University CY - Prague AN - OPUS4-55658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan ED - Pellegrino, C. ED - Faleschini, F. ED - Zanini, M.A. ED - Matos, J.C. ED - Casas, J.R. ED - Strauss, A. T1 - From Uncertainty in Measurement to Certainty in Bridge Reassessment N2 - "The reassessment of bridges continues to take great importance both nationally and internationally. A major challenge is to find computation models reflecting the actual properties of the considered structures sufficiently accurate. Besides regular inspections, the conduction of advanced measurements is suitable to generate reliable information about a structure to be assessed. Prior to incorporating measurement results in reassessment, the relevance, the trueness, and the precision of the measured information needs to be stated. On the one hand, the use of information whose quality has not been assessed can lead to errors with serious consequences. On the other, the measurement of irrelevant information is inefficient. Although the use of measured data in assessment is currently mostly unregulated, their appreciation in reliability analyses is beneficial since the built environment can be assessed more realistically. Utilizing NDT in reassessment has the potential to extend remaining lifetimes of a structure, save resources, and improve infrastructural availabilities. The power of judgment regarding the decision on the reliability of an existing structure can be increased. In this contribution, an approach is outlined to process non-destructively gathered measurement data in a comparableway in order to include themeasured information in probabilistic reliability assessments of existing structures. An essential part is the calculation of measurement uncertainties. The effect of incorporating evaluated NDT-results is demonstrated by means of a prestressed concrete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results." KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2022 DO - https://doi.org/10.1007/978-3-030-91877-4_58 VL - 200 SP - 509 EP - 517 PB - Springer CY - Cham AN - OPUS4-54019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - Guideline on NDT-supported reliability assessment of existing structures N2 - The presentation summarizes the idea and the methodology of the ZfPStatik project and gives insight into three case studies, showing how non-destructive testing results can be utilized beneficially in the recalculation of existing prestressed concrete and reinforced concrete bridges. T2 - 2nd Conference of the European Association on Quality Control of Bridges and Structures – EUROSTRUCT2023 CY - Vienna, Austria DA - 26.09.2023 KW - Reliability KW - Assessment KW - Existing structures KW - Non-destructive testing PY - 2023 AN - OPUS4-58485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Küttenbaum, Stefan A1 - Kainz, C. A1 - Braml, T. ED - Matos, J.C. T1 - Non-destructively Measurable Quantities Relevant to Reliability Assessment of Existing Concrete Bridges – Case Studies N2 - In reliability assessment of existing bridges, collected information about the structure can be utilized to modify partial safety factors and to refine characteristic values individually. In this way, uncertainties covered in initial calculation models and arising from assumptions can be reduced as well as biases identified and corrected. This allows for more realistic assessments and more appropriate decisions on actions to be taken. However, the on-site observation of information is generally associated with certain costs. For this reason, an efficient data-supported reassessment requires that only the individually relevant testing tasks are solved. Additional sensitivity analyses can further be used to specify the requirements on certain inspections, such as the testing result quality to be achieved, in order to avoid too imprecise or too expensive measurements on-site. In this contribution, the methodology for the demand-actuated definition of measurement objectives is demonstrated using the example of non-destructive concrete testing methods and findings from reassessments of two prestressed concrete bridges. Each case study includes the semi-probabilistic identification of structural weak points in ultimate and serviceability limit states, a comparison with respective probabilistic sensitivity analyses, and the subsequent derivation of parameters that are a) measurable and b) highly relevant in the individual reliability analyses. KW - Reliability KW - Assessment KW - Existing structures KW - Non-destructive testing PY - 2024 SN - 978-3-031-60270-2 DO - https://doi.org/10.1007/978-3-031-60271-9_18 VL - 494 SP - 209 EP - 219 PB - Springer CY - Cham AN - OPUS4-60613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Kainz, C. A1 - Braml, T. A1 - Keuser, M. A1 - Soukup, A. A1 - Küttenbaum, Stefan ED - Matos, J.C. T1 - Reassessment of Existing Concrete Bridges with Full Probabilistic Methods – Case Studies and Discussion of Relevant Input Parameters N2 - This article presents two case studies for a full-probabilistic assessment of existing concrete bridges combined with the use of the finite element method for the evaluation of the internal forces. Since the structures already exist, additional information about material parameters and loading conditions can be collected. With a sensitivity analysis, the contribution of each parameter to the total uncertainty is examined and the relevance of their actual value and variation is shown. The first case study is a single-span reinforced concrete frame bridge on the German highway A92 constructed in the year 1985. With a span of around 5 m, but a width of 27 m and a skewness of 70 gon, the bridge is modelled as a three-dimensional finite element model. The second case study is a two-span reinforced concrete frame bridge from 1986 with span lengths of about 7,50 m each. The superstructure is a 45 cm thick slab and the base plate has a thickness of 80 cm. The assessment is performed based on the semi-probabilistic safety concept according to the codes first and secondly with a full-probabilistic calculation. In this article the selection of parameters for the relevant input data are presented and discussed. The results of the sensitivity analysis are used for the setup of measurements to acquire important data for the modelling in the critical limit states. KW - Reliability KW - Assessment KW - Existing structures PY - 2024 SN - 978-3-031-60271-9 DO - https://doi.org/10.1007/978-3-031-60271-9_41 VL - 494 SP - 440 EP - 451 PB - Springer CY - Cham AN - OPUS4-60614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - On the Treatment of Measurement Uncertainty in Stochastic Modeling N2 - Measurement uncertainty calculations in stochastic moddeling of time-independent, NDT-based random variables to be used in refined assessment of existing structures T2 - International Probabilistic Workshop 2022 (IPW2022) CY - Stellenbosch, South Africa DA - 08.09.2022 KW - Reliability KW - Assessment KW - Existing structures KW - Measurement uncertainty PY - 2022 AN - OPUS4-55657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - From uncertainty in measurement to certainty in bridge assessment N2 - In this contribution, an approach is outlined to process non-destructively gath-ered measurement data in a comparable way in order to include the measured information in probabilistic reliability assessments of existing structures. An es-sential part is the calculation of measurement uncertainties. The effect of incor-porating evaluated NDT-results is demonstrated by means of a prestressed con-crete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results. T2 - 1st Conference of the European Association on Quality Control of Bridges and Structures – EUROSTRUCT2021 CY - Padova, Italy DA - 29.08.2021 KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2021 AN - OPUS4-53173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -