For TOKYO WAN AQUA-LINE (Traps -Tokyo Bay Highway) the slurry shield method was employed. Because of the long length of tunnel the shield machines from both side were joined under the ground. In this process, the ground freezing method was used as an assistant method and slurry around shield machine was frozen at -30°C. Though machines were also cooled, it was difficult to employ pre- and/or post-heat for prevention from cold cracking. In this study, the welding procedure for water proof and reinforcement welding without pre- and/or post-heat to obtain enough joint strength was examined by experiments. The propriety of welding design was also confirmed in mock-up test. The actual underground connection was finished and TOKYO WAN AQUA-LINE is now under service.
In this paper, response of the three-dimensional multi-span rigid frame bridges against for the Hyogo-ken Nanbu earthquakes, a TYPE ll seismic acceleration, will be described. The bridges including seven steel piers were fully modeled by finite element model so that the interaction of the movement of each piers and elastic plastic response are able to take into account. The result shows that the relative displacement of the border of two sections is small enough compare to “Se”, overlapped length of a girder at a support and suspended joint. It was confirmed that the bridges will not be catastrophically damaged against for the TYPE ll seismic.
At WF beam to RHS column connections diaphragms are commonly used. In this paper statical characteristics of a new type connecting method without diaphragms were experimentally investigated. In this method the side of flanges of the beam ends were welded to vertical stiffners, and the ends of the stiffners were welded to the corners of RHS columns. It is generally recomended to avoid welding at the corners of cold formed RHS member. In this experimented study the influence of welding at those parts upon the statical characteristics of the welded connection is investigated. By means of two types monotonic tension tests and cyclic loading test it becomes clear that the welding at the corners of columns has no bad influence upon the statical characteristics of welded connections.
The Hyogo-ken Nanbu Earthquake, occurred on January 17, 1995, caused serious damage to the bridge structures. Loosening was observed in a few hanger cables of two Nielsen-Lohse bridges after the earthquake. In this paper, the causes of loosening and slackness of hanger cables during this inland earthquake are investigated through the response spectrum analysis, static elasto plastic finite displacement analysis by using the incremental seismic load and dynamic response analysis by using the actually recorded earthquake wave, of one of the two Nielsen-Lohse bridges.
ABSTRACT This paper is a study of earthquake-resistant ability of 75 existing low and middle rise steel buildings. Outline of the investigated structures was reported in part.1. The main items of the investigation about earthquake-resistant ability are the story drift angle at the base shear coefficient"Co"=0.2, story stiffness ratio and horizontal load-carrying capacity. The story drift angle of almost all those buildings are smaller than 1/200. The story stiffness ratio of all buildings are larger than 0.6. The horizontal load-carrying capacity Qu/Qun are larger than 1.0 in 80% buildings. Consequently, almost surveyed buildings earthquake-resistant ability satisfied the demand of the conditions of route-3 defined at the Building Standard Low.
This research aims at clarifying the mechanical-property distribution in cold roll-formed steel square tubes. It is found that both corners and flat portion are significantly hardened and consequently that increases in strength, and decrease both in elongation and impact energy. However, these deficiencies are recovered by temperature annealing and normalizing. In test scope, mechanical-properties make recovery with temperature annealing. However, steel's softening was ahead of recovery on the heat treatment of normalizing.
Full-scale fracture tests were carried out to investigate the influence of the types of scallops and toughness on fracture behavior of built-up H-shaped beams. Test results show that (1) although the different modes of fracture were observed between specimens which had scallops with boxing welding and without one, there was no remark able difference on the deformation capacity between them; (2) the difference of the defor mation capacity between specimens using high toughness hot-rolled plates and specimens using low toughness one appeared clearly.
Dynamic response analyses using 4-degree-of-freedom vehicle model were performed to investigate the effects of the long wavelength components on the traffic vibrations of highway bridges. The numerical results demonstrated that vibration caused by heavy running vehicles would be very dependent on the longitudinal profile of the long wavelength component which varied according to the vehicle speed.
The structural performance of H-beam-and-RHS-column space subassemblages subjected to the cyclic reversal loading under high compressive force on the column are presented. The column thickness at beam-to-column connection area is increased by the induction heating process. The structural performance and failure mode of the specimens were investigated by the cyclic reversal loading test . The finite element and in-plane numerical analyses are carried out to estimate the elastic-plastic behavior of the specimens. The local strength of beam-to-column connection subjected to bi-axial bending moment is evaluated by the yield line theory.