On 3-5 story steel structure building, conventional structural system has several problems, such as (1)security of quality of structure, (2)lavor-saving and reduction of types of skilled worker at the construction. In this paper, as the means of solving those problems, pre-engineered building system in which the building design, in-plant manufacturing and field construction are collectively systemized, is presented. The outline of developed structural system, computer aided design and manufacturing system and estimation of the results of erection are described.
The Center for Advanced Technology for Large Structural Systems at Lehigh University in U.S.A. has developed a new and innovative series of beam-to-column connections that can be adapted to automated erection processes. The connections developed and tested include a simple shear connection, an all steel moment connection and a semi-rigid composite connection. All of these connection schemes incorporate the use of a self-aligning, self-guiding connector called the ATLSS Connector. The connector was recently used and proven successful in a field demonstration. ATLSS together with the National Instituteof Standards and Technology has been developing a multi-degree of freedom crane to allow these connection systems to be constructed by a hilly automated process.
Structural behaviors of connections, which were reinforced by vertical steel plate crossing ribs and the corner weld of columns were partial penetration weld, composed of concrete filled square tubular steel column and steel H-beam have been studied by cruciform tensile test and beam-and-column subassemblages subjected to earthquake type loading. Stable and ductile hysteresis loops have been obtained in the subassemblage test results. The estimated yield and ultimate strengths of the connections by yield line theory show approximate agreement with test results. And yield shear capacity of the joint panel is fairly predicted by considering simple stress transfer mechanism.
A redecking method for damaged reinforced concrete slab is proposed. The prefabricated steel deck of battledeck floor type, which consists of a deck plate, longitudinal ribs and small transverse ribs, is used and some cross beams are added to the existing bridge to support the deck. Static loading tests of large scale models were carried out and the structural details were developed. Fatigue tests of the models were also conducted to check the durability. Applying this method, a bridge was widened and reinforced. Two loading tests of the bridge were executed, i.e. during the construction and after the completion. This paper presents the outline of these tests and the reconstruction work.
New concept of connection between steel beams and cold-formed square tube column is proposed. To investigate beam-to-column connections reinforced by increasing thickness of column, beam-to-column sub-assemblage tests were carried out under cyclic loadings.Test results show that the connection can absorb sufficient seismic energy and that the yield strengths predicted by yield line theory agree well with experimentals. Parametric study using FE method has been carried out. The result shows that the width of beam flange and thickness of reinforced part of column have great influence on yield strength and that reinforcing length can be decided by yield line theory. In addition, empirical formulae to estimate rotational rigidity of connection was obtained.
Based upon "Factory Innovation Program FA2l", some robots assembly lines for bridge fabrication had been completed in NKK Tsu Works. In the box girder pannel line, the I-girder line and the transverse rib line, 26 welding robots which adopted the high speed rotating arc 'gelding process have been displaying the special capability and effect. In order to save the teaching operation for robots, we have developed the teachingless robot data system using the own CAD/CAM system "NEW BRISTLAN."
This Report describes of welding robot that was developed for column to column joining on construction site. As a consequence of difficult conditions of welding i n hazardous surroundings the shortage and the ageing of welders can be predicted. This problem will become more serious in several years. The authors developed the robot that aimed at solution of this problem and improving the quality and efficiency of welding.
With the recent increase in needs for taller and more diverse buildings, sophistication of buildings techniques has been sought enthusiastically. Specifically, mechanization and automation have been implemented with a view to improving productivity and safety. Thus not only the hardware technology for simple introduction of machinery but the software technology for controlling such machinery have been demanded. The wire lift-up method, using wire to lift a construction, was developed and performed. Because it's regular arrangement of work is very different from some general methods, we need away that we can understand a condition and accuracy of work during construction. Then we developed the realtime data monitoring system for wire lift-up method and put it into the construction. This paper shows the outline of the wire lift-up method and the realtime data monitoring system.
This paper presents the tests on a newly developed bolting joint, which is a kind of fastening system using high strength friction type bolts and is able to fasten on one-side of spacing joints . Considering the results of tests and simplicity of fastening procedure, it was concluded that newly fastening system was capable for the application to structural steel work.And this fastening system was used for strengthening of a existing steel arch bridge, it was clarified that this fastening system was good use for the joints on closed sectional members, such as arch and truss chords.
Some Automatic Ultrasonic Testing Systems (AUT) which consist of anautomatic scanning system, an ultrasonic testing system with several proves and a computer have been developed recently. In order to adopt these AUT systems for the non-destructiveexamination of weld bridge members as the substitute for Xray testing, the performance of AUT systems has been examined Test pieces which include various weld defects were made and tested by using five AUT system beside Xray and manual ultrasonic test Advantages and disadvantages of AUT system, characteristics of ultrasonics tests are discussed from the view paint of fatigue and fracture control of bridge members.
The galvanized high strength steel wire with a tensile strength of 180 kgf/mm2 has been developed. This wire is characterized by that it contains 1%Si. The ductility, delayed fracture characteristic and corrosion resistance of this wire are equal to those of the conventional wires, while the fatigue strength, creep strength and low temperature toughness of this wire are higher than those of the conventional wires. This wire also provides excellent cable characteristics, such as resistance to lateral pressure and bending stress and socket fitting.
In order to evaluate the applicability of wide flats and steel plates produced by electric furnaces to steel structures of buildings, experiments on subassemblages of the members with the beam-to-column welded connections are carried out. 27 specimens are prepared and examined under cyclic loading until the ultimate state. 15 specimens fractured at the T-butt joint between the flange of column and the lower flange of the beam where the type for the site welding is adopted as the detail of the groove and scallop. The phenomena of the fractures are categorized to 6 types depending on the ratio of the yield loads among the column, the beam and the beam-to-column connection, material toughness and quality of welding including tack weldings.
The features of the fractures at the beam-to-column welded connections with wide flats or steel plates produced by electric furnaces are tried to be related to the material properties. As the material tests, tension tests for the thickness direction of the plates, V-notch Charpy tests for the base metals and HAZ, hardness tests on the welded zones, furthermore measurements of non-metallic inclusions, grain size, contents of N, 0 etc. are executed. The phenomena of the fractures and ductility capacities of the connections corresponds to these factors of the material properties