A series of 8 new complexes of titanium and zirconium with diamido ligands bearing an ethylene and propylene bridge between the two amido groups were synthesized and tested for ethylene polymerization. Titanium complexes bearing an ethylene bridge between the two amido groups showed higher activities than the derivatives with a propylene bridge. In the case of the zirconium complexes, the p...

Irregularities in bridge pier stiffness concentrate the ductility demand on short piers; while not operating on the longer and more flexible ones. The existence of non-uniform, ductility demand distribution in bridges significantly influences seismic response. As such, this paper proposes a new approach for balancing the ductility demand in irregular bridges by utilizing shape memory alloys (SM...

This study is devoted towards evaluating seismic performance of a three-span continuous highway bridge subjected to moderate to strong earthquake ground motions in its longitudinal direction. In this regard, nonlinear dynamic analysis of the bridge based on the direct time integration approach using the 4 order Runge-Kutta method is conducted. Two types of isolation bearings are used in the ana...

ABSTRCT: Elastic bearings have been used on simply supported bridges on high-speed railway in Taiwan to isolate train-induced vibration. However, their influence on dynamic behavior of the vehicle and bridge has not been fully investigated, and their vibration attenuation has not been quantificationally discussed. In this study, spring-damper elements with 12 degrees of freedom are established ...

Elastomeric bridge bearings have a history of use in the USA of close to 50 years. They are capable of carrying large vertical loads and allowing horizontal movement with low lateral force due to the extreme flexibility of the elastomeric material. They require little maintenance, have no moving parts, have good longevity and are very economical. The elastomer in bridge bearings is usually eith...

................................................................................................................................. iii ACKNOWLEDGMENTS .............................................................................................................v CONTENTS...................................................................................................................................

Continuous rigid frame bridge is a common type of bridge in California, where is a seismically active areas. Main structural features of the bridge, including asymmetry, hinge structure, concretion of girder and piers affect the seismic response of the bridge significantly. In order to evaluate the safety of the bridge under earthquake, the nonlinear models of girder, limiting steels in hinge, ...