lower truss structures 32 a lower support component were installed the construction of the lower support structure was completed by joining said truss 32 to said liner anchor 32 with hanging bolts 41 the upper reinforcing assembly 43 was installed next in the meantime a ring support 36 was constructed on the top section 35a of the shielding wall 35 located in the center of the building next the ring support 36 was reinforced from the inside with reinforcements 36a as shown in fig2 followed by the erection of a series of support columns 37 on the circumferential top edges 20a of the wall 20 as shown in fig3 it is necessary to ensure that the heights of the ring support 36 and the support columns are larger than that of the top slab next upper truss structures 38 an upper support component were constructed horizontally and parallel to each other on top of the ring supports 36 and support columns 37 the supports on both sides of the upper truss structure 38 were provided as shown in fig3 by installing long span trusses 39 in parallel with each other utilizing the remaining columns 37 located on top surface of the wall 20 the long span truss 39 was supported at suitable distances with reinforcing bundles 33 placed on top of the support column 25 standing on the floor slab 24 the upper support assemblies were constructed by joining the upper truss 38 and 39 with lower truss structure 32 by attaching hanging bolts 40 to the flange sections of the said components 38 and 39 and to the.