Hokuriku Shinkansen's Takasaki-Nagano section is 117 kilometer long and it will bring a new service between Tokyo and Nagano in one and half hour. This article, I introduces three characteristic concrete bridges in this section. On constructing Kirizumigawa bridge, a prestressed concrete strutted beam bridge, two technical methods were adopted to control the effect against the environment : the lowering erection method for the slant piers and the cantilever erection method for the main girder. Daini Chikumagawa bridge, the first cable-stayed prestressed concrete bridge in Shinkansen, set up the record of the longest span of the concrete railway bridges (133.9 meters). Yashiro Minami and Yashiro Kita bridges (main span : 105 and 90 meters each) are extradosed prestressed concrete bridges and this structural type can decrease the beam height of middle-sized concrete railway bridges.

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High-fluidity concrete was applied for concrete filled steel tubular columns in the construction of the North Tower of the Nakono-sakaue 2-chome urban redevelopment project. The concrete works were conducted under the newly established guideline for high-fluidity concrete by Housing & Urban Development Corporation. In the construction, high-strength light-weight concrete with the design strength of 30 MPa was pumped up to the 30 th floor level. Pressure of concrete pump and properties of concrete before and after pumping were measured when concrete was pumped to 10th, 21st and 30th floor.

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The New PLS (Pre-Lining Support) Method was used to widen the Hodogaya Tunnel on the New Yokohama Highway to three lanes along the section of about 200 meters. The greater part of the soil was consolidated silt, on the top of which lay layers of loam and embankments. The overburden was from to 17 meters in thickness. The New PLS Method is a Pre?Lining Support Method, in which the perimeters of the tunnel face is excavated with chain cutter, and immediately reinforced with concrete in the form of ribs to build an arched shell. In this paper, it is describes that New PLS Method, quick hardened concrete using this method and site work.

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Based on the actual results of HiRC technology, our super high-rise RC structure technology, we have developed a new technology capable of constructing reinforced concrete structures up to 50 stories by making use of high strength structural materials together with the rationalization of both design and construction method. This new technology has been fully realized in the construction of The Scene Johoku, a super high-rise RC structure of 45 stories with the height of 160m thanks to the high strength concrete with the designed compressive strength of 60 MPa using belite portland cement and the high strength reinforcing steel bar with the yield point of 700 MPa. Here in this paper, the execution of the high strength concrete together with the outline of the construction work will be reported.c

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