Muneyoshi Numada

Seismic evaluation of earthquake resistance and retrofitting measures for two story masonry houses

This paper discusses on the shaking table test results of two 1:4 scale model of two-story masonry structure typically used in constructing low-rise residential buildings. This test is performed to provide a better understanding of the seismic behavior of the PP-band (polypropylene band) mesh retrofitted adobe masonry house. The test structure is subjected to a series of different levels of harmonic motion that applied along the longitudinal direction. The results of the shaking table tests on building models show that the PP-band retrofitting technique can enhance the safety of masonry buildings, even during severe ground motion.

Experimental investigation on the seismic performance of PP-band strengthening stone masonry houses

The collapse of stone masonry is one of the greatest causes of death in major earthquake events around the world. This paper investigates a recently developed retrofitting technology specifically aimed at preventing or prolonging the collapse of stone masonry buildings under strong earthquakes. This technology uses common polypropylene packaging straps to form a mesh, which is then used to prevent or prolong collapse. This paper examines the findings from static and dynamic testing of the proposed retrofit. It is shown that the proposed technique effectively prevents brittle masonry collapse and the loss of debris.

Shake Table Tests on FRP Retrofitted Masonry Building Models

AbstractThe current study is devised to evaluate the seismic performance of fiber-reinforced polymer (FRP) retrofitted buildings with openings at different FRP reinforcement levels. Required objectives are achieved by performing five shake table tests on 1/4-scale models of single-story boxlike masonry buildings. Out of five building models, one was an unreinforced masonry (URM) building model whereas the other four were retrofitted with different quantities and layouts of FRP reinforcement. FRP reinforcement is reduced by decreasing FRP strip widths and strip spacing and applying FRP strips on either the inside or outer faces of walls. Each building model was subjected to the same series of input ground motions with gradually increasing amplitudes. A series of diagonal compression tests was also conducted to decide the appropriate type of FRP and trial FRP reinforcement ratios for the masonry building models. Descriptions of the tested models are provided, including the structural response in terms of ba...

Applied Element Method Simulation of Fiber Reinforced Polymer and Polypropylene Composite Retrofitted Masonry Walls

In current research work, an attempt is made to simulate the behavior of a newly proposed composite material using 3-D Applied Element Method (AEM). Fiber Reinforced Polymer (FRP) being a strong material provides a significant increase in shear strength. Polypropylene band (PP-band) not only holds the masonry wall system into a single unit but also provides a fairly high deformation capacity at a very low cost of retrofitting. A composite of FRP and PP-band is proposed and applied on the surface of masonry wall. Verification of the proposed numerical model is achieved by conducting experiments on twelve masonry wallets. Out of twelve, six masonry wallets were tested in out of plane bending test and six were tested under in-plane forces in the form of diagonal compression test. Same wallet retrofitting scheme was selected for in-plane and out of plane experiments and all of them were analyzed using proposed 3-D AEM numerical simulation tool. Proposed numerical model has served satisfactory and has shown a fairly good agreement with experimental results which encourages the use of 3D-AEM to numerically simulate the behavior of non-retrofitted and retrofitted masonry wallets.

Development of IT Triage System （TRACY） to Share Regional Disaster Medical Information

We developed an IT (Information Technology) triage system for collecting disaster medical information in real time. FeliCa cards and card readers are used to obtain the number and condition of patients. The system is composed of two elements. First, the number of patients for each triage level and the accepted number of patients in each diagnosis and treatment department are obtained in real time, including response for changing triage level. Second, this information is shared in real time among hospitals, the administration, and residents who are searching for their family. A disaster drill utilizing this system was held at the University of Yamanashi Hospital with 450 participants. From the result of that, the present system could work for those two elements. TRACY was examined its availability and practicability in this drill.

Extracting Necessary Pparameters from Real Landslide Mass for Mitigating Landslide Disaster

This paper introduces ideas for extracting important parameters for landslide risk assessment from real landslide masses. The parameters included velocities estimated from mud spatters and therefore equivalent viscosities of fluidized soil masses. Mud spatters remaining on dwelling walls etc., which often show parabolic patterns, are used to estimate flow velocities. One example shows that the viscosity of a liquefied pyroclastic material is about two to three digits smaller than those obtained from torsional shear tests for sandy soil, indicating high potential for the fluidized volcanic products to travel fast a long distance even on this extremely gentle slope.