No abstract

Three-dimensional shaking table tests on a ten-story reinforced concrete building were conducted with sliding bases and with fixed bases at E-Defense in 2015. This paper reports on the test results in case of sliding bases. The purpose of the project is to develop a new foundation system that would ensure continued use of the building even subjected to an extreme earthquake motion. Cast-iron plates were placed at the bottom of the foundation bases and on concrete bases, which allows base sliding. The base sliding dislocation was 84mm to 189mm, while uplifting of 5mm to 40mm was observed at the corner.

In modern society, architectural and civil engineering structures such as reinforced concrete buildings require high seismic performance to minimize the ‘megarisk’ exposed from urban earthquake hazards. In the reinforced concrete structures, the bond resistance between rebar and concrete is one important parameter for discussing its performance and it has been typically evaluated by measuring the strain distribution along the embedded rebar. Here, we present in-situ strain and stress measurements for the rebar in reinforced concrete using time-of-flight neutron diffraction as a novel alternative technique to typical strain gauges. It was demonstrated in this study that the three-dimensional deformation behavior of the embedded rebar in normal-strength concrete, cured in air, can be accurately measured under pull-out loading using time-of-flight neutron diffraction. Wider applications of neutron diffraction in the structural engineering field are expected for advanced understanding of actual phenomena on reinforced concrete structures.

No abstract

In order to use a damaged building continuously after earthquake, owners and/or stakeholders need to understand residual seismic capacity of the building. In Japan, a method to evaluate residual seismic capacity for damaged buildings had been developed. In order to evaluate residual seismic capacity of damaged building, the damage level of structural elements should be evaluated properly. This paper presents the results of damage analysis based on experimental data obtained from a full-scale static loading test [1] on a five-story reinforced concrete building tested at Building Research Institute. The damage rating for the specimens evaluated by the residual seismic capacity concept [3] was ”Moderate” or ”Heavy” at 0.5% and 1% building drift angle despite the structure maintaining horizontal load carrying capacity. This implies that the applied method gives a conservative result for ductile buildings, such as relatively new moment resisting frames designed after 1981. In order to apply the method used in this paper to new buildings, the damage evaluation method for structural elements should be advanced more in the future.