Applications - Example 3
The MUST-SIM facility provides many essential features that aid in significantly advancing the state-of-the-art in integrated seismic testing and analysis. The examples of application of the MUST-SIM Facility may be formulated from different angles. Three such examples are considered here: research needs in seismic risk mitigation, end-user industrial needs, and integration with existing NEES facilities.
Application 3: Testing and Analysis of Full-Scale Bridges with their Foundations
Three bridge piers in the laboratory, deck and foundation from analysis (note that boxes are placed on top to utilize their own weight in the axial load on piers, which is further adjusted during the test from the vertical DOF).
The behavior of bridges during earthquakes is vital to the network performance and may have a most significant effect on societal systems (e.g. effect of the collapse of I-880 and a span of the Oakland Bay Bridge in the 1989 Loma Prieta earthquake; damage to the Santa Monica freeway during the Northridge earthquake of 1994, EERI 1995). Further investigations are needed to quantify the effect of incoherent ground motion on short and medium span bridges in particular. In this application example, the three piers of a bridge are tested in the laboratory while the deck and the foundation system are modeled using finite elements. If only two piers are tested, the third box may be utilized to test the foundation system (even with one box, if path-dependence of the foundation-soil system is ignored, the sub-structuring technique can deliver soil response information for both piers, even when the actions from them onto the soil are different). The results from such tests not only give verifiable seismic performance data, but can also be used to derive damage-functionality relationships currently lacking. Recent experience in Gujarat, India, has indicated that seriously damaged bridges may still be functional. Such information would be of great significance in a network performance context.
The above-described applications serve to demonstrate how the test-analysis results from this new facility will aid in (i) providing the basis for measures to mitigate the effect of earthquakes on existing infrastructure and (ii) furnish data upon which enhanced design procedures may be derived for future construction. In both cases, the most realistic boundary and loading conditions are applied. By providing extensive and realistic information on the deformation capacity of existing infrastructure components and systems, including soil response, as well as investigating new design concepts, this facility contributes to the mitigation of earthquake effects on the existing built environment. It also provides an opportunity to design new systems with enhanced seismic resistance. Its integration potential with existing NEES facilities is high because of its modularity and its complementary characteristics.