Eight years have been passed after the collapse of Sampoong Department Store. Although more than five hundred people were killed at once due to the collapse, many irrational system and specifications which blew that disaster still alive. In this paper, some irtational system and specifications were reviewed. Better rational system and specification were suggested at various levels of design, construction and maintenance of buildings.
It was general that WSD, USD, LSD etc. used in old do not consider area situation of each country and environment differences. But if concept of PBD which is supplement shortcoming of old design method and optimized design is introduced construction could be designed economical and plan systematically. It is purposed that this paper informs explanation and present condition for material and construction part of Asia Concrete Model Code. Also PBD design details which is suitable in comprehensive substance will be presented later.
This paper studied the efficiency of retrofitting of reinforced concrete structure which was not designed to endure an earthquake. The earthquake in Kobe, Japan showed that there was a great possibility of having an earthquake even in big city and the damages were concentrated on mid or low story buildings which were not considered to be protected from an earthquake. This experiment used reinforced concrete structure which restrained side-by-side displacement-to test durability against an earthquake. This study deals with the structural performance of reinforced concrete frame structures strengthened with steel materials.
The structure which was designed until then had no resistance to earthquake, since enforcement ordinance for seismic design was established in 1988. Most of mid or low story building have no resistance to earthquake, though it is the structure which was designed since then. Prior to this experiment, the experiment, which was repair and retrofit method for seismic performance progress of the reinforcement structure which was not designed to be protected from an earthquake, had been performed and obtained good results. The aim of study is that repair the structure and evaluate seismic performance of the repaired structure in the case of the structure damaged by earthquake.
This paper presents the experimental results of a Soil-Cement Composite Earth Retaining Wall comprised of reinforced concrete underground wall, H-shaped steel beams in earth retaining wall and fiber reinforced soil cement wall. Sixteen specimens are tested to evaluate the bending capacity of the wall. Main variables in the test are strength of concrete, arrangement of shear connector, soil-cement, and fiber reinforcement. Test results are as follows. (1) Composite member under positive moment showed 18% increase of the maximum strength. (2) After soil cement was reinforced with fiber by adding 1% of soil cement weight, compared to cases not reinforced with fiber, strength of under compression increased 7%, moreover, 30% of strength enhancement was shown under tension case also. (3) When the composite member resists positive bending moment (i.e., H-shaped steel beam is in compression), the strength is increased by 18%. Moreover, 7% additional strength enhancement appears after the soil cement is reinforced by fiber. As a results, fiber reinforced soil cement has strength enhancement effect up to 25%.
Recently the construction of residential building faces many difficulties due to the shortage of building materials and works. Simplifying the stage of processing and assembling reinforcing rods and increasing the efficiency of them in reinforced concrete construction can be used to settle the difficulties. In the respect, structural wire-fabric is utilized. The purpose of this study, instead of deformed steel bars, to examine the utilization of slab joint, which is accompanied with a large deformation in the structure subjected to seismic loads, to suggest reinforcing method which is efficient, easily constructible and structurally safe. The results are as follows ; 1. The ductility capacity of continuous slab joints reinforced by welded wire fabric is less than that with deformed bar. But continuous slab joint is reinforced by deformed bar for the longitudinal reinforcement, it is increase strength and ductility capacity. 2. It is recommended that simple cut jointing of welded wire fabric should be avoided in wall-wall joints.
Recently, there has been a tendency to use composite deck plates in high-rise building and apartment construction due to its cost efficiency and less installation time. The purpose of current study is to clarify structural performance of deck plate and further safety through carefully designed experimental program. In order to clarify bending capacity and joint continuity, specimens were divided for positive and negative moment and testing parameters are thickness of deck plate, slab thickness, and various reinforcements The results of experimental test are following; (1) When the thickness of deck plate is 1.0mm, the strength increased by 1.3~10.1%, and 2.0~3.5% comparing the case of 0.8mm deck plate thickness. The thickness of deck plate did not play significant role in terms of strength of the slab in both positive and negative moment tests. (2) The yield strength of slab in positive moment test, having 200mm slab thickness and D13 reinforcement steel, was increased by 28.4~34.8% comparing 160mm slab thickness and D10 reinforcement steel case. And 22.4~25.1% of yield strength was increased after install bottom reinforcement steel. (3) In negative moment test results showed that the increase of yield strength when the bottom reinforcement installed was 2.0~2.3% in 200mm slab thickness and 2.0~3.0% in 160mm slab thickness. In positive moment test, the increase of yield strength was 22.8~26.7% in 200mm slab thickness due to bottom reinforcement, and 11.4~20.5% in 160mm slab thickness. The reason being bottom reinforcement in negative moment contributes less amount of yield strength compare to positive moment location is that the bottom reinforcement resists compression force where the deck plate has enough strength already.
The purpose of this study is to propose the general method for evaluating the equivalent damping ratios of a structure with supplemental response control dampers. We define Lyapunov function of which derivative can be expressed in autoregressive form and evaluate the equivalent damping ratios by using Lyapunov function and its derivative. This Lyapunov function may be called as generalized structural energy. In this study, it is assumed that the response of a structure is stationary random process and control dampers do not affect the modal shapes of a structure, and the structure has proportional damping. Proposed method can be used to get the equivalent damping ratios of a structure with non-linear control dampers such as friction dampers as well as linear control dampers. To show the effectiveness of the proposed method, we evaluate the equivalent damping ratios of a structure with viscous dampers, AMDs, and friction dampers. The equivalent damping ratios from proposed method are compared to those from eigenvalue analysis for linear control dampers, and those from time history analysis for non-linear control dampers, respectively.
The purpose of this paper is to present a design method for friction damper (FD) for inelastic response control of short-period structure. A critical design parameter of FD is maximum friction force (MFF) and previous study evaluated MFF using equivalent damping ratio which is based on the maximum displacement. This procedure, however, gives the overestimated MFF for short-period structure. In this study, MFF of FD is evaluated based on RMS displacement response which is obtained by using given maximum response and peak factor. Numerical analysis shows that proposed method provide a reasonable MFF of FD for short-period structure.
In this study, the control perfomances of Tuned Mass Damper (TMD) and Tuned Liquid Column Damper (TLCD) are evaluated and compared for seismically excited structures. Results show that TLCD is more effective than TMD for interstory drift control while TLCD is as effective as TMD for acceleration control. In special, it is shown that interstory drifts are maximally controlled in lower floors and accelerations are reduced most in upper floors. This indicates that TLCD is an effective controller for earthquake-induced structures in terms of structural safety as well as serviceability.