Moravčík Martin, Kraľovanec Jakub
Department of Structures and Bridges, Faculty of Civil Engineering, University of Zilina, Univerzitna 8215/1, 010 26 Zilina, Slovakia.
Materials (Basel). 2022 May 16;15(10):3548. doi: 10.3390/ma15103548.
Deterioration of materials and structures is an unavoidable fact, and prestressed concrete structures are not an exception. The evaluation of load-carrying capacity and remaining service life includes collecting various information. However, one type of information is essential and the most important, the state of prestressing, which inevitably decreases over time. Currently, many possible methods for the evaluation of prestressing are available. These techniques are part of the structural assessment and provide residual prestressing force value which is later used in the evaluation process. Therefore, it is suitable to provide the value of prestressing force based on certain probabilistic backgrounds. This study addresses the determination of residual prestressing force in pre-tensioned railway sleepers one year after their production, using the so-called Bayesian approach. This technique is focused on the validation of results obtained from the application of the non-destructive indirect saw-cut method. The Bayesian approach considers analytic calculation as the primary method of prestressing determination. In this paper, Monte Carlo simulation was used to determine the total variability that defines all Bayesian systems of probability functions. Specifically, a total of 1000 simulations was applied, and the current random vector of prestressing force derived from the analytical calculation has been assumed as a normally distributed function. Finally, obtained results for different depths of saw-cuts are compared. The results of the experimental and statistical determination of residual prestressing force provide its value with a 95% confidence level. This study suggests that the implementation of the probability approach can be an effective tool for determining prestress losses.
材料和结构的劣化是一个不可避免的事实，预应力混凝土结构也不例外。承载能力和剩余使用寿命的评估包括收集各种信息。然而，有一种信息是至关重要且最重要的，即预应力状态，它不可避免地会随着时间而降低。目前，有许多评估预应力的可行方法。这些技术是结构评估的一部分，并提供残余预应力值，该值随后用于评估过程。因此，基于一定的概率背景提供预应力值是合适的。本研究采用所谓的贝叶斯方法，解决了先张法铁路轨枕生产一年后的残余预应力确定问题。该技术专注于对无损间接锯切法应用所得结果的验证。贝叶斯方法将解析计算视为确定预应力的主要方法。在本文中，使用蒙特卡罗模拟来确定定义所有贝叶斯概率函数系统的总变异性。具体而言，总共进行了1000次模拟，并假设从解析计算得出的当前预应力随机向量为正态分布函数。最后，比较了不同锯切深度的所得结果。残余预应力的实验和统计测定结果在95%的置信水平下提供了其值。本研究表明，概率方法的实施可以成为确定预应力损失的有效工具。
