Open Access

Industrial facilities must be designed to withstand seismic actions as they exhibit an increased loss potential due to wide-ranging damage consequences and valuable process engineering equipment. Past earthquakes showed the social and political consequences of seismic damage to industrial facilities and sensitized the population and politicians worldwide for the possible hazard emanating from industrial facilities. Therefore, existing and planned industrial facilities are now usually equipped with monitoring systems and sensors to control the dynamic characteristics of the structural system and installations. The visualization and interpretation of sensor data is typically based on simple spreadsheets and non-standardized user-oriented solutions, which makes it difficult for building owners, facility managers and decisionmakers to evaluate and understand the data. The solution of this problem in the future are integrated BIM-Sensor approaches which allow the generation of BIM models incorporating all relevant information of monitoring systems. These approaches support the dynamic visualization of key structural performance parameters, the effective long-term management of sensor data based on BIM and provide a user-friendly interface to communicate with various stakeholders. A major benefit for the end user is the use of the BIM standard, which is the future standard anyway. The contribution presents the application of the integrated BIM-SHM approach for typical industrial facilities as part of an early warning and rapid response system for earthquake events currently developed in the research project “ROBUST” financially supported by the German Federal Ministry for Economic Affairs and Energy (BMWI).

Masonry infills are a common solution for inner and outer partitions in RC frame structures. However, uncontrolled and heavy damage to masonry infills in recent earthquake events often caused by the interaction of masonry infills with RC frames showed the high seismic vulnerability. Severe damage to masonry infills results in high economic losses and presents a threat to human safety. The bad seismic performance of masonry infills is a strong motivation for finding solutions that can prevent or reduce the damage to masonry infills. This paper presents the principles of an innovative system for decoupling of masonry infills from the surrounding frame. The decoupling is achieved by inserting recycled rubber strips between masonry infills and RC frame. The installed decoupling system postpones the activation of masonry infills under in-plane seismic loads and provides support under out-ofplane seismic loads. Experimental results on RC frames with rigidly connected infills and RC frames with decoupled infills are presented and compared for infills with and without openings. Results of the study show the highly improved seismic performance of masonry infills with the innovative decoupling system. Keywords: Infill collapse, In-plane, Out-of-plane, Decoupling system, Experimental tests

Reinforced concrete (RC) structures featuring masonry infill walls are widely prevalent globally, owing to various factors. Initially, they are straightforward and rapid to build, and secondly, masonry infills offer effective thermal insulation and fire resilience. Nevertheless, the seismic performance of this configuration is poor. The failure of RC frames with infills is a predominant occurrence in nearly all medium to strong earthquakes. The in-plane (IP) damage and out-of-plane (OOP) collapses of infills are frequently so profound that their restoration is deemed uneconomical. Consequently, repair expenses escalate, and the recovery process prolongs. Moreover, the collapse of infills in the OOP direction poses a threat to individuals near the structure and along evacuation paths. Throughout an earthquake, the RC frame distorts and interacts with rigid infill walls, altering the dynamic characteristics of the frame building and intensifying stresses in the frame components. Conventionally, the connection between the infill and frame is established using mortar, which is prone to damage even under minor drift levels, leading to a loss of contact between the infill and frame. This, in turn, results in a lackof boundary support for the infill in the OOP direction causing OOP infill collapse. Drawing on years of seismic experience and research findings, it is evident that a rigid connection between the infill and frame is insufficient. This paper introduces a decoupling system designed to separate/isolate the infill wall from the RC frame. The system utilizes recycled rubber strips positioned between the frame and infill. A comprehensive series of experiments was conducted to assess the efficacy of the decoupling system. Separate and combined tests for in-plane (IP) and out-of-plane (OOP) scenarios were executed, revealing that initial cracks in infills manifest after a 2% of drift. The study indicates that this innovative solution can prevent damage to masonry infills and rationalize seismic design.

Today, the planning and operation of new structures is fully integrated in the digital process chain and supported by Building Information Modelling (BIM), forming the basis of a digital twin. Beside the planning phase, where the digital twin is of great help for not only identifying collisions and having a central place with all structures, systems and components (SSC) and their attributes, the maintenance and Structural Health Monitoring (SHM) have been revolutionized with new generations of sensors and big data processing. Together with sensor data predictive maintenance programs can be developed and enhanced to early identify deviations from normal operation and avoid costly repairs due to damages. The sensor data can easily be integrated and displayed in an augmented or virtual reality environment to support the position identification inside the BIM model and train people. Structural health monitoring by itself is already established and a very useful tool to identify potential damages and visualize the collected data. Thanks to the common standards, the BIM technology is now also accepted and widely used. Nevertheless, the information inside a BIM model is conceived to be a static information and yet, there are no solutions to easily and permanently update the BIM model based on transient sensor data. Furthermore, the data collected by sensors to feed structural health monitoring usually require some post-processing and engineering interpretation to provide a meaningful picture of the SSCs and to draw conclusions by decision makers. Also there needs to be a consistent and structured data management to exploit the data and build a digital twin. The focus of the new approach is mainly on structures, as those are still not monitored on a regular basis and require a calibrated numerical model to reflect the real behavior. But it allows also the continues monitoring of arbitrary non-structural elements with importance for the building operation. All together it allows to study the dynamic performance by building simulation tools for a variety of different boundary conditions and over its lifetime (from design to dismantling). Thus, a novel approach to merge all three disciplines has been developed in order to combine the individual advantages and provide to the end user a highly modular, but still comprehensive dashboard for displaying the real-time behavior of the SSCs and also the quantification of damage indicators. Coupled in the future with artificial intelligence (AI) methods to derive even more robust indicators, taking into account all parameters and their associated uncertainties, opens a large variety of possibilities for utilities/owners and operators to improve reliability. The “intelligent” SHM integrates the dynamic sensor data into BIM models and displays with customizable dashboards the measurement data and evaluation results in a comprehensive manner to the end user. The system, initially designed to provide insights during and after an earthquake, is versatile and can integrate any sensor data, from e.g. temperature (slow incremental change) to accelerations (highly transient and high resolution). The development is based on open-source code and thus, easily adjustable to individual needs and tailor-made for each specific application and environment. The BIM model itself and the platform is located in the cloud or intranet and accessible through a web interface which makes it easily integrable in other environments. Only the sensors are local and transmit their data directly to a central system which can be connected via cables or wireless. The presented iSHM integrates BIM models together with dynamic data provided by sensors to visualize the structural performance of critical infrastructures based on a digital twin of the buildings. While for future structures the implementation is easy and efficient, as their digital twin will be created during the design and operation, for existing buildings it is more challenging to build an adequate twin, as the initial effort is high and sometimes information on the actual in-situ situation is missing. Nevertheless, comparing the benefits of an advanced, intelligent structural health monitoring and the ability to instantaneously derive performance indicators provides a competitive advantage and opens new possibilities. The developed system and its implementation are illustrated for a base-isolated 4-storey reinforced-concrete structure of the BioSense laboratory with highly sensitive equipment in Novi Sad, Serbia.

The seismic performance and safety of major European industrial facilities have a global interest for the whole of Europe and its citizens. However, the seismic design of these facilities is based on national, sometimes outdated seismic hazard analyses. The results of the commonly developed, fully harmonized newly released European Seismic Hazard Model ESHM20 provide a pertinent reference for seismic hazard at European scale and have been officially adopted as an “acceptable representation of the seismic hazard in Europe” in the ongoing revision of Eurocode 8. This study presents a large-scale investigation of the impact of the potential adoption of ESHM20 on the design of new industrial facilities as well as on the potential seismic risk of existing facilities at European level with respect to the current seismic codes. The horizontal elastic response spectra using ESHM20 in combination with the revised Eurocode 8 for selected industrial sites are compared with the respective response spectra of the national regulations for return periods of 475, 2500 and 5000 years. In addition, a single containment LNG tank is analysed for an industrial site in Germany using the design approach for liquid filled tanks according to the revised Eurocode 8. Furthermore, a deterministic and probabilistic seismic risk assessment of a vessel installed in a five-storey frame is performed for industrial sites in Greece and Germany. The examples show that a consistent procedure all over Europe would be desirable and a benefit for engineers in terms of comparability and achievement of the same safety targets. Based on the conducted illustrative studies, the consequences of a potential adoption of the revised Eurocode 8 and ESHM20 hazard maps are discussed and summarized with respect to the standard harmonisation process in Europe.