Suggestion of ultimate strength formulas of partial frame pile cap composed of exterior column, foundation beam and pile

Currently, there is no research and few valid experiments of pile caps. And shear failure mechanism of a pile, exterior column and foundation beam and pile caps in RC structure is not resolved yet under bi-lateral loading. Therefore, a performance evaluation method based on mechanical behaviour for pile caps has not been established. First, the fracture type was specified from the experimental results. Secondary, the ultimate strength formula of the pile cap was proposed based on the previous experimental results. It is a theoretical formula based on the truss-arch theory. It was confirmed that this formula can accurately evaluate the ultimate strength of the pile cap

The 2-components of the 31-stem homotopy groups of the 9 and 10-spheres

Group structures of the 2-primary components of the 31-stem homotopy groups of spheres were studied by Oda in 1979. There are,however, two incompletely determined ｇroups. In this paper,our investigation with Toda's composition method gives structures of them.ArticleJournal of the Faculty of Science Shinshu University 46: 1-19(2015)departmental bulletin pape

Impact of the Reinforcement Detailing on Seismic Performance of Isolated Non-structural Walls

Following the observation of severe damage to structurally isolated non-structural reinforced concrete walls after major earthquakes, researchers began to reassess the effectiveness and connection detail of non-structural walls to moment-resisting frames. A method to control damages to the non-structural wall, is to cast exterior non-structural concrete wall elements to be monolithic with frame elements, without anchoring the wall longitudinal bar. The non-anchorage of the wall longitudinal bar significantly increases the drift capacity of the wall and decreases damage. Using an experimental approach, this study assesses the influence of reinforcement detailing and quantity of the transverse reinforcements on the strength and drift capacity of the non-structural hanging wall. This study further evaluates the workability mechanism of the transverse reinforcements and reinforcement detailing with concrete. The non-anchorage of hanging walls, having boundary confinements, was found to exhibit a higher drift and strength capacity than similar walls with the anchored detailing without boundary confinements. The strength capacity of the anchored detailing hanging walls with minimum amounts of reinforcements was higher than that of the non-anchored specimen. The boundary confinements were found to be more influential on the capability of the hanging wall when placed along with non-anchored detailing reinforcement

The Structural Performance of Reinforced Concrete Members with Monolithic Non-Structural Walls under Static and Dynamic Loads

The required base shear and drift limit for post-disaster management buildings have increased in the Japanese Building Code following major seismic events. One method to satisfy these requirements for reinforced concrete frame buildings is to cast exterior non-structural concrete wall elements to be monolithic with frame elements, but without anchoring the longitudinal wall reinforcing. This provides additional stiffness and strength while limiting significant damage in the non-structural wall. In this study, the structural performances of such elements were evaluated using static and dynamic experimental tests. The result indicates that non-structural walls that were neither isolated by seismic slits nor anchored to the adjacent walls with longitudinal reinforcements experienced less damage and higher deformability compared with walls having seismic slits. The confinement reinforcing impact was not observed on the strength and drift capacity of the beam member, owing to the large number of transverse reinforcements. However, the confinements limited the damage and nearly prevented concrete crushing. The maximum horizontal load of the specimen could be predicted using cross-sectional analysis, and the authors propose a simple equation to predict it with sufficient accuracy