Vibrational experiments at the HDR [Heissdampfreaktor] German/US cooperation

As part of an overall effort on the validation of seismic calculational methods, the US NRC/RES is collaborating with the Kernforschungszentrum Karlsruhe, FRG, in the vibrational/earthquake experiments conducted at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG. In the most recent experiments (SHAG), high level excitations were produced in the HDR by means of an eccentric-mass coastdown shaker capable of developing 1000 tons of force. The purpose of the experiments was to investigate full-scale structural response, soil-structure interaction, and piping and equipment response. Data obtained in the tests serve to evaluate analysis methods. In the SHAG experiments, loadings of the HDR soil-structure system approached incipient failure levels as evidenced by high peak accelerations and displacements, local damage, nonlinear behavior, soil subsidence, and wall strains which exceeded estimated limit values. Also, the performance of different pipe hanger configurations for the VKL piping system was compared in these tests under high excitation levels. The support configurations ranged from very rigid systems (strut/snubbers) to very flexible configurations (spring and constant force supports). Pretest and post-test analyses for the building/soil and piping response were performed and are being validated with the test data