Patent RU-95108942-A (RU)
IPC: F03D11/00
Filed: 1995-05-31
Abstract: FIELD: civil engineering, applicable for fabrication of towers, mainly for wind-driven electric plants, as well as relaying towers, beacon towers, for installation of water reservoirs, supports of contact and cable systems. SUBSTANCE: the method consists in installation of curvilinear plate members with the convex surface inside with formation of an envelope having the shape of a rectilinear polygon in cross-section. Each pair of adjacent curvilinear members is connected inside the polygon by a longitudinal stiffening plate, triangles are formed from inside of the polygon at its angles, which at welding with the envelope at the triangle angles represent longitudinal box-section girders; transverse stiffening plates are installed from inside of the envelope, and the attachment frame is installed from outside of the envelope with a shift of the frame base from the end in the axial direction outside at a distance of 2-3 bo, where bo-thickness of the curvilinear plate member of the envelope, the transverse stiffening plate and frame are connected to the envelope; the frame is welded at least at two (upper and lower) levels, and the transverse stiffening plate is preliminarily shifted from the end deep into the envelope in the axial direction and fixed by welding in the gap between the upper and lower levels of the frame welding. The upper level of the frame welding with the envelope passes over the upper end of the frame, from outside of the envelope, and the lower level passes over the lower end of the envelope from inside of the frame. Fabrication of the structure is finished by joining of its sections with production of preliminarily calibrated stressed joints of the frames in the axial direction; the transverse stiffening plate is fixed to the envelope by intermittent welding, and preliminary shift of the transverse stiffening plate is accomplished in a gap confined within 0.3 to 0.8 of the frame height; the longitudinal stiffening plates are additionally welded to the transverse stiffening plates. The long-sized bearing structure uses curvilinear plate members interconnected into an envelope with formation of a rectilinear polygon in cross-section, it is furnished with longitudinal and transverse stiffening plates, attachment frames combined in a flange assembly, frame variable in section height with larger and smaller bases installed with the larger base on the side of the envelope end; the assembly inner surface has the shape and dimensions corresponding to the external shape and dimensions of the envelope, continuing the structure to the larger base of the frame joined to it with the similar part of the flange assembly of the adjacent section of the structure; width b of the larger base of the frame in the flange assembly is selected from relation: b=bo+(1.4...1.8)d+b=b+(1,4...1,8)d+Δ,, where bo - thickness of the curvilinear plate member, d - diameter of the attachment bolt, Δ - assembly gap between the attachment bolt head and frame vertical wall. The frame is made of a number of arc-shaping components, whose shape and dimensions correspond to the shape and dimensions of the envelope in the point of installation of the frame, it is stepped in height in the structure longitudinal section; the frame has a base and a wall ribbed on the side of the base, the wall thickness is not less than the envelope thickness, in plan it has trapezoidal cells that are open on the external side of the structure. At least one pin is installed in each are- shaped part of the frame, and the respective hole is made for it in the mating part of the frame of the adjacent section, at least one threaded attachment hole is provided in the frame of the upper section in the underlying sections of the structure. The structure may have windows on the curvilinear plates, they are made in the gap between the longitudinal stiffening plates of the adjacent ribs of the structure in hollow longitudinal girders of triangular section, formed by the adjacent curvilinear plates and longitudinal stiffening plate of the structure, it is furnished with hatches made in the transverse stiffening plates at least in two adjacent sections of the structure, as well as with additional transverse stiffening plates in the middle parts of the sections. EFFECT: enhanced reliability. 17 cl, 6 dwg