RESEARCH ON SHAKING TABLE TEST OF FRAME STRUCTURE CROSSING THE GROUND FISSURE WITH BRACES

To study the measures of disaster control for the structure crossing a ground fissure with steel braces, a 5 story RC frame crossing a ground fissure f₄ was taken as an example. A finite element analysis was carried out on structures without steel braces and those with different arrangements of steel braces. The weak part of the structure crossing a ground fissure was found and the scheme of arrangement for the test was determined. The shaking table test on a 1:15 scaled model structure crossing a ground fissure with braces was designed and tested. The aseismic behavior of the structure was analyzed in different cases. The dynamic characteristics, dynamic responses and failure mechanism of the structure under different excitations were obtained from the test. The research shows that the ground fissure site enhanced the dynamic response of the structure under an earthquake, and the impact from the hanging-wall was greater than that from the footwall. The steel braces used in this scheme provided lateral stiffness for the structure, and they reduced the dynamic response of the structure under the combined action of a ground fissure and an earthquake. The braces yielded before the structural members was destroyed, which dissipated earthquake input energy through their deformation and reduced structural damage. This indicated that the brace of a structure has a multiple aseismic fortification function so that the structure crossing the ground fissure was protected effectively. The research results provide a scientific basis for the disaster control of structures crossing ground fissures.