Natural Hazards Engineering Research Infrastructure at Lehigh: Large-Scale Real-time Multi-Directional Hybrid Simulation Experimental Facility

The Natural Hazards Engineering Research Infrastructure (NHERI) Experimental Facility at Lehigh University, a National Science Foundation sponsored facility, will provide means to conduct research to mitigate the impact of natural hazards that includes earthquakes on structures. This facility provides experimental resources for accurate, large-scale, multi-directional simulations that enable the effects of natural hazard events on civil infrastructure systems with potential soil-foundation effects to be investigated. The facility’s experimental resources, including a strong floor, multi-directional reaction wall, static and dynamic actuators, and testing algorithms supports large-scale, multi-direction, real-time hybrid simulations that combine physical experiments with computer-based simulations for evaluating performance of large-scale components and systems. The types of laboratory simulations and tests enabled by the facility include: (1) hybrid simulation (HS), which combines large-scale physical models with computer-based numerical simulation models, (2) geographically distributed hybrid simulation (DHS), which is a HS with physical models and/or numerical simulation models located at different sites; (3) real-time hybrid earthquake simulation (RTHS), which is a HS conducted at the actual time scale of the physical models; (4) geographically distributed real-time hybrid earthquake simulation, which combines DHS and RTHS; (5) dynamic testing (DT), which loads large-scale physical models at real-time scales through predefined load histories; and (6) quasi-static testing (QS), which loads large-scale physical models at slow rates through predefined load histories. The facility resources enable multiple, large-scale simulations and tests to be conducted simultaneously, enabling numerous users to work concurrently without significant interruption. The large-scale hybrid simulations are a unique resource for system-level response data, since they enable the definition of the "system" to be expanded well beyond the size of typical laboratory physical models. At the same time, due to its large size, the facility accommodates large-scale physical models, which reduces scaling effects associated with typical, small physical models. A broad array of instrumentation, large-scale data acquisition systems, and advanced sensors provides the system-level data needed for advancing computational modeling and simulation. The new discoveries and knowledge from these simulations will enable researchers to develop and validate new hazard mitigation solutions, and innovative hazard-resistant structural concepts.