Existing non-destructive test for evaluation of concrete compressive strength may show deviation in results analysis due to deterioration of precision by strength calibration and dry or humid condition by age, so there needs be testing method to determine long term structural internal force by collecting specimen with no damage of structure and measuring compressive strength through destruction test. This research applied to mock-up member the compressive strength evaluation method using joint separation mold that can plan and produce specimen cured in the same composition environment as concrete structure by attaching arbitrary(joint separation) to the form before concrete piling, and as a result, the management specimen was contrary to the hydration temperature of the member or was affected by external atmospheric temperature, however the joint separation specimen connected to structure and managed in the same environment showed a temperature curve similar to the member and decrease in temperature difference. Additionally, from initial age, with the compressive strength of joint separation specimen most similar to core strength，stable compressive strength can be evaluated up to design criteria strength 100MPa, so the method is proposed as an evaluation technique that can confirm highly reliable concrete quality.
Recently expanding market for largely scale construction projects, cost management of construction project have been increasingly recognized as an important factor responsible for the project success. But public organizations have been continuously operating the same methods as before in cost estimating, so it raise an issue of reliability for estimated cost. Therefore, this study present a highly reliable model that makes preliminary estimates based quantity data in early design stage. it enables engineers to efficiently manage total cost of project as well as partial cost estimating. This study develop a model of database that is created with historical data conducted by government offices. The model proposed can estirnate a cost for RC Structure in schematic design stage, and it is applied to CBR+GA logics to explore best similar cases. In case of estimating methods used to previous research, it is based on actual cost data. Due to the cost estimating compensated by inflation rate vary in market economic conditions, it will follow as an inevitable consequence of reliability problem. It needs to find better way to ensure accuracy through quantity database. Also, This study has been conducted in attempts to verify the reliability of preliminary estirnation. It is checked for the feasibility of presented model with P-National Tax Service Project aside from the database.
In this study, a shear wall-slab damper system for seismic retrofitting of existing low-rise school buildings was proposed. The proposed system is to control the earthquake-induced vibration of the existing building structures using the energy dissipation effect of hysteretic damper inserted between the extended shear wall and existing moment frame. The numerical analyses were performed to investigate the vibration control efficiency of the shear wall-slab damper system and to identify the range of optimal yielding strength of the slab damper. In addition, variation of shear force of the extended shear wall with regard to the yield strength of the dampers in a range from 10 to 100 percent of the maximum base shear force of the retrofitted structure was investigated. The numerical analyses results showed that the maximum displacement of the structures with the slab damper whose yield strength is equal to 20 percent of the maximum base shear. On top of that, the slab damper system reduced the shear force of the shear wall by about 50 percent in comparison with the existing frame-shear wall system with rigid diaphragm slabs.
Most of the school buildings were built before the seismic code was established. To consider the sunlight and ventilation to the partition walls are built about 1m height beside columns at typical school buildings. For the reason, columns which is consisted school building occur brittle failure shape by the reduced effective depth. In this study, experimental test for retrofitting effect by Aramid Fiber Reinforced Polymers(AFRP) strips on masonry infilled reinforced concrete(RC) frames is performed. The test results were to ensured enough time to evacuate due to the enhancement of ductility and strength of school buildings to withstand earthquakes using AFRP strips .
In this study, compare the results that used period of an object building and a structural analysis program in order to to analyze the effect that a slab element to oppose a vertical load opposes to lateral loading of a structure. Compared with to analyze the results to the Diaphragm which is existing analysis and a way do modeling to an plate element to slab element of RC wall type structures to give a change of rigidity with 100%, 50%, 30%
High-rise apartments of shear wall system are governed by flexural behavior like a cantilever beam. Installation of the damper-brace system in a structure governed by flexural behavior is not suitable. Because of relatively high lateral stiffness of the shear wall, a load is not concentrate on the brace and the brace cannot perform a role as a damping device. In this paper, a friction damper applying flexibility of shear wall is proposed in order to reduce the deformation of a structure. To evaluate performance of the proposed friction damper, nonlinear time history analysis is executed by SeismoStruct analysis program and MVLEM(Multi Vertical Linear Element Model) be used for simulating flexural behavior of the shear wall. It is found that control performance of the proposed friction damper is superior to one of a coupled wall with rigid beam. In conclusion, this study verified that the optimal control performance of the proposed friction damper is equal to 45% of the maximum shear force inducing in middle-floor beam with rigid beam.
In this study, nonlinear dynamic characteristics of a tuned liquid column damper (TLCD) varying with the amplitude of excitation input are evaluated through shaking table tests and numerical model of a TLCD. The tuned mass damper (TMD) analogy of a TLCD is used to simplify the formulation, in which involves equivalent viscous damping of the inherent nonlinear damping term of a TLCD. The equivalent TMD model of a TLCD shows that the dynamic behavior of a TLCD is affected by the natural frequency, the damping ratio and the ratio of total liquid mass to the mass in horizontal column of a TLCD. Shaking table test is performed to obtain experimental transfer functions that describe the dynamic behavior of a TLCD specimen subjected to a harmonic loading with various excitation amplitudes. Transfer functions for various excitation amplitudes are measured from shaking table acceleration to both the liquid displacement within a TLCD container and the control force produced by a TLCD specimen. Also, the dissipation energy due to the inherent damping of a TLCD is measured from the shaking table test varying with excitation amplitude. The variation of design parameters of a TLCD according to the excitation amplitude is investigated by comparing the transfer functions obtained from the shaking table test to those derived from the TMD analogy of a TLCD. These results showed that both the natural frequency and the mass ratio of a TLCD are independent on the variation of excitation amplitude, while the damping ratio of a TLCD increases with larger excitation amplitude.