Four-storey Building Research Articles

Active vibration control of frame structures with smart structures using piezoelectric actuators (Vibration control by control of bending moments of columns)

A smart structure was tested for active vibration control of frame structures in which the bending moment of the columns was controlled by stack-type piezoelectric actuators integrated into the columns. Excitation tests were carried out for a model of a four-storey building 3.7 m in height and 2000 kg in total weight in which thirty-two piezoelectric actuators were used for bending moment control. The actuators were installed in two ways: in one case eight actuators were attached to each column of the first storey, and in the other case four actuators were attached to each column of the first and second storeys. Two control strategies, a model-matching method and the control theory, were examined for the smart structure. The tests showed that the smart structure could effectively reduce the responses of the building model, and all combinations of actuator installation method and the control strategy yielded almost the same performance.

Smoke spread experiment in a multi-storey building and computer modelling

The CESARE-SMOKE model is a network model which can be used to estimate smoke spread in a multi-storey building when subjected to fire. The model calculates time-dependent temperature and species concentrations at locations remote from the room of fire origin. Spatial variation of physical parameters in a single enclosure with large aspect ratio can also be estimated. This paper describes a series of full-scale fire experiments that were designed to investigate the validity of the model. The experiments, involving steady state burning rates and a number of ventilation conditions, were conducted in a four-storey building. Temperature, pressure, flow velocity, smoke density and species concentrations were measured in various parts of the building. The chimney effect and its influence on temperature distribution in a stair shaft were observed. Comparisons are made between the experimental results and the model predictions. The experimental results are also compared with the predictions of the CFAST two-zone model. Suggestions are made for further improvements to the network model.

A Step Towards Evaluation of the Seismic Response Reduction Factor in Multistorey Reinforced Concrete Frames

A seismic nonlinear time-history analysis was made for four-, six-, and eight-storey reinforced concrete buildings. These buildings were made as three-dimensional space frame structures with shear walls in both orthogonal directions. They have five bays with 4.8 m spacing each in the horizontal direction, and three bays with 4.2 m spacing each in the transversal direction. The frames were designed according to the Jordanian Seismic Code of practice for Seismic Zones 4, 3, 2, and 1 as proposed for Jordan by several authors. Time-history analysis was made using the El Centro (N-S) earthquake record of May 1940 as an actual earthquake excitation. The response reduction factor (R) that primarily consists of two factors that are the ductility reduction (Rµ) and the overstrength (Ω), is obtained. It has been seen that the seismic zoning has a slight effect on the ductility reduction factor for different buildings, since it ranges from Zone 4 to Zone 1 as 2.37 to 2.52, 1.72 to 1.78, and 1.14 to 1.18 for four-, six-, and eight-storey buildings, respectively. Moreover, it is observed that, for different buildings and different seismic zones, the ductility reduction factor (Rµ) is slightly different from the system ductility factor (µ) especially for higher values of µ (i.e., Rµ ≅ µ). The response reduction factor, called overstrength (Ω), was evaluated. The overstrength factor was found to vary with seismic zones (Z) , number of stories, and design gravity loads. However, the dependency on seismic zones was the strongest. The average overstrength of these buildings in Zones 4 and 1 was 2.61 and 6.94, respectively. The overstrength increased as the number of storeys decreased: overstrength of a four-storey building was higher than an eight-storey building by 36% in Zone 4, and 39% in Zone 1. Furthermore, buildings of the three heights had an average overstrength 165.9% higher in Zone 1 than in Zone 4. These observations have a significant implications for the seismic design codes which currently do not take into account the variation of the response reduction factor, R (i.e., ductility reduction factor times overstrength).

International cooperation of Japanese pediatricians with Cairo University Pediatric Hospital.

In connection with 'Child Year' in 1980, an agreement on the construction and donation of a pediatric hospital was concluded between the Egyptian and Japanese Governments. Under this agreement, the Cairo University Pediatric Hospital (CUPH) was opened in March 1983, as a four-storey building with 240 beds, and including four operating rooms, an intensive care unit (ICU) and neonatal ICU. The technical cooperation and supply of medical equipment in all areas of CUPH is ongoing during this project. The subject matter of technical cooperation is as follows. (1) Dispatch of Japanese experts to Egypt for short and long terms. (2) Acceptance of Egyptian trainees to Japan. (3) Supply of medical equipment and materials. Through the first 5 years of this cooperation, the management of ICU, operating theaters, medical and surgical wards has improved markedly with great efforts from the Egyptian and Japanese staff. Based on this successful cooperation, the Pediatric Cardiovascular Center was established in 1988 with a two-storey extension in the hospital including two cardiac operation theaters, ICU and other special facilities. Now, CUPH has become the center of pediatric medical care in not only Egypt but also the surrounding Arabic countries, supported by the friendly and close relationship between Egypt and Japan.

Seismic performance of reinforced concrete ductile moment-resisting frame buildings located in different seismic regions

Seismic areas in Canada are classified into three categories for three different combinations of acceleration and velocity seismic zones (Za < Zv, Za = Zv, and Za > Zv), and ground motions in different zonal combination areas are expected to have different frequency characteristics. The National Building Code of Canada specifies different levels of seismic design base shear for short-period buildings located in areas with different zonal combinations. The specification of seismic design base shear for long-period buildings is directly tied to zonal velocity, irrespective of seismic zonal combination. This paper evaluates the seismic performance of both high-rise long-period and low rise short-period reinforced concrete ductile moment-resisting frame buildings located in seismic regions having Za < Zv, Za = Zv, and Za > Zv. Two frame buildings have 10 and 18 storeys were used as structural models for high-rise buildings, while a set of four-storey buildings were used to represent low-rise buildings. All buildings were designed to the current Canadian seismic provisions and concrete material code. Three groups of earthquake records were selected as representative ground motions in the three zonal combination regions. The inelastic responses of the designed buildings to the three groups of ground motions were analyzed statistically. The results indicate that the distribution of inelastic deformations is significantly different for high-rise frame buildings situated in seismic regions with Za < Zv, Za = Zv, and Za > Zv. Inelastic deformation is concentrated in the lower storeys for high-rise buildings located in Za < Zv areas, whereas significant inelastic deformation can develop in the upper storeys for high-rise buildings situated in Za > Zv regions. The use of three different levels of seismic design base shear for short-period structures improves the consistency of ductility demands on low-rise buildings situated in the three different zonal combination regions. Despite the use of appropriate design base shears for different seismic regions, the ductility demands for these low-rise buildings are relatively high. To avoid excessive ductility demands, it is suggested that the seismic strengths for low-rise short-period buildings should not be significantly reduced from their elastic design base shears. Key words: earthquake, ground motion, seismic, design, reinforced concrete, frame buildings, beams, columns, ductility.

Optimum design of reinforced concrete shear walls

The recently published New Zealand Code of Practice for the Design of Concrete Structures (NZS 3101:1982) and the newly amended Code of Practice for General Structural Design and Design Loadings for Buildings (NZS 4203) permit a variety of possible design approaches for reinforced concrete shear wall structures. A series of wall designs for dimensionally similar four-storey and eight-storey buildings has been carried out and a comparison of construction cost estimates obtained together with an assessment of the relative design effort required for the different design options.

A method for the evaluation of the seismic capacity of existing reinforced concrete buildings in Japan

A three-level procedure for seismic capacity evaluation of existing reinforced concrete buildings, developed in Japan, is reviewed. The paper describes basic principles and their background which formed the basis of the evaluation method. The outline of the three-level procedure is given and the applications of the procedure to buildings which experienced several recent destructive earthquakes in Japan, are reviewed. A seismic protection index, to determine the appropriate level of seismic capacity, is proposed. A hypothetical four-storey frame building in New Zealand is evaluated by the three-level procedure. Subsequently comments are offered with respect to problems that may arise if the Japanese procedures were to be applied to buildings in New Zealand.

Cyclic load testing of two refined reinforced concrete beam-column joints

The paper describes the testing of two reinforced concrete beam-column joint units tested under incremented-static cyclic loading. The full size test units were based upon an interior beam-column joint of a four-storey framed building designed to the current NZ loading code and represent refinements on two previously tested conventional joints of similar dimensions. One unit differed from common practice by having a post-tensioned beam stressed to balance the floor dead load of the prototype structure whilst the second unit was detailed with haunched beams. Hinge formation occurred in the beams and stable hysteretic behaviour was obtained up to displacement ductilities of 10 for the prestressed unit and 6 for the haunched unit. The test results are analysed in terms of the draft NZ design code, DZ 3101, and the ACI Recommendations for beam-column joint design.

Dos obras de Craig Ellwood – (EE. UU.)

The Irvine complex is intended to serve a fast-growing community in California. It is situated in the proximity of the Orange Country Airport, and acts as an access nucleus to the industrial zone. It consists of four symmetrical blocks; the two single-storey buildings are banks; while the two four-storey buildings are for offices. The structure is of Corten steel, with curtain walls, and the interior makes use of all the comforts that modern techniques allow. Week-end house The single-family dwelling at San Luis Obispo is a weekend house of great simplicity in both structure and shape, suspended over a small valley. It was built by students of the Politecnic College of California as part of their practical work, and they took an active part in its construction.

Aberrant regeneration of the third cranial nerve

Aberrant regeneration of the third cranial nerve is most commonly due to its damage by trauma. A ten-month old child presented with the history of a fall from a four-storey building. She developed traumatic third nerve palsy and eventually the clinical features of aberrant regeneration of the third cranial nerve. The adduction of the eye improved over time. She was advised for patching for the strabismic amblyopia as well. Traumatic third nerve palsy may result in aberrant regeneration of the third cranial nerve. In younger patients, motility of the eye in different gazes may improve over time.