RU2466243C1 - Multispan two-storied transverse frame of building frame - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: frame comprises extreme and middle columns, rigidly resting against a foundation, slab crossbars, a cover truss and units of crossbars and truss connection with columns. The lower belt of the truss is connected with high-strength ropes with units of braces connection arranged in the middles of spans. In the span connection of the lower truss belt and ropes is made in two units. Each of units is arranged at the distance of 0.3-0.4 of the span length from the nearest column. Extreme and middle columns are equipped with support units of crossbars comprising safety devices that include struts, supports, sliders, suspensions and horizontal squabs. Devices of support units of crossbars at middle columns are additionally equipped with safety plates, springs, separating angle profiles, crossbar stiffening ribs and rotating supports.

EFFECT: reliability of a frame and prevention of building progressive collapse.

19 dwg

Description

The invention relates to the field of construction and can be used in metal frames of industrial and civil buildings, which, in accordance with the class of responsibility, have particularly important economic and social significance, as well as buildings with explosive technological processes.

The transverse frame of the building frame is known (RU 2319817, Е04С 3/38, С2), the structural scheme of which allows controlling the draft of its columns. Regulation of the stress state of the structure is carried out at relatively small values of sediment and roll. The disadvantage of this frame is the low degree of survivability in the event of large subsidence of the base soil, rolls, or the occurrence of beyond design basis impact associated with the instantaneous destruction of any support.

Also known is a multi-span transverse frame (RU 2010092, ЕВВ 1/24, ЕНН 5/00 С1), in which there are struts located in its plane and attached with their lower ends to the middle columns. The upper ends of these struts are attached to the crossbars. The spacers between the frames are attached at one end to the crossbars in the middle and extreme spans, and at the other end to the struts. The disadvantage of this frame is its high sensitivity to beyond design impacts, which may involve the destruction of individual beams or columns.

The objective of the invention is to ensure the survivability of the frame of the building frame in the event of an instant exclusion from the work of the supporting system of any rack or crossbar of any floor.

The technical result is a reliable structural design of the frame, which allows to prevent the progressive collapse of buildings in the event of beyond design basis impacts (local heating during a fire, failure in a karst funnel, large subsidence of the ground, man-made accident, terrorist attack, etc.).

The problem is solved in that a multi-span two-story transverse frame of the building frame is made, including the extreme and middle columns, rigidly resting on the foundation, the crossbars, the roof truss and the joints of the crossbars and the roof truss with columns, characterized in that the lower belt of the roof truss is connected with high-strength ropes located in the middle of the spans of the brace connection nodes, while in the span the connection of the lower belt of the coating farm and the ropes is performed in two nodes, each of which is located n at a distance of 0.3-0.4 of the span length from the nearest column, the extreme columns are connected to the foundation with high-strength guy wires, the extreme and middle columns are equipped with supporting nodes of the crossbars, containing safety devices, including struts, stops, sliders, suspensions and horizontal shorts, and the devices of the support nodes of the crossbars on the middle columns are additionally equipped with safety plates, springs, dividing angular profiles, stiffeners of the crossbars of the ceiling and rotating stops.

The calculations by the finite element method [1] in static and dynamic settings confirm the high degree of survivability of the frame in the case of instant removal from work of any rack or any crossbar.

The design is illustrated by diagrams. Figure 1 shows a diagram of the transverse frame, where 1 is the extreme columns, 2 are the middle columns, 3 are the crossbars, 4 is the truss, 5 are the safety plates, 6 are struts, 7 are high-strength guy wires, 8 are high-strength ropes; figure 2 - the connection node of the crossbars with the middle column (node A), which includes mechanisms and safety devices that prevent the progressive collapse of the frame during beyond design impact on this column, where 9 - spring, 10 - emphasis, 11 - suspensions, 12 - sliders, 13 - horizontal shortys, 14 - dividing angular profiles, 15 - stiffeners of crossbars, 16 - rotating stops pivotally connected to safety plates 5, 17 - support tables, 18 - square rods; figure 3 is a diagram of the operation of the node And with the destruction of the right bolt 3; figure 4 is a diagram of the node And when the destruction of the middle column 2 of the first floor or its subsidence; figure 5 - the connection node of the crossbars with the extreme column (node B), including a mechanism and safety devices that prevent the collapse of the structure of the overlap during the destruction of this crossbar; figure 6 is a side view of the node B; Fig.7 is a view of the node B during the destruction of the crossbar 3; on Fig - node In; figure 9 - node G; figure 10 - node D; figure 11 - node G; on Fig is a side view of the node; in Fig.13 is a diagram of the frame during the destruction of the extreme columns of the first floor; on Fig - when the destruction of the extreme columns of the second floor; on Fig - when the destruction of the middle column of the first floor; here the dashed line shows the struts that will be destroyed when the frame is deformed; in Fig.16 is a diagram of the frame during the destruction of the middle column of the second floor; on Fig - when the destruction of the element of the lower zone of the farm; in Fig.18 - with the destruction of the crossbar in the middle of the span; in Fig.19 - with the destruction of the crossbar in its support part.

The frame consists of end columns 1 and middle columns 2 rigidly mounted on the foundation (see FIG. 1). In the level of the floor and the floor of the building, the extreme columns 1 are connected to the foundation with high-strength guy wires 7. The crossbars 3 are freely mounted on the supporting tables 17 connected to the extreme and middle columns (see FIGS. 2 and 5). Farm 4 freely rests on the extreme (see Fig. 9) and medium (see Fig. 8) columns. In each span, the lower girdle of the truss is connected in two nodes G (see Fig. 1, 11) with high-strength ropes 8 with a node D (see Fig. 10). Each of the nodes W is located at a distance of 0.3-0.4 of the span from the nearest column.

The connection points of the crossbars with the extreme and middle columns have safety devices, including stops 10, struts 6, sliders 12, connected by suspensions 11 with horizontal shorts 13, and square rods 18 welded to the lower girders of the crossbars 3, and the middle columns additionally have dividing angles profiles 14 (see figure 2), safety plates 5, springs 9, stiffeners of crossbars 15 and rotating stops 16, pivotally connected to safety plates 5.

When the extreme column 1 of the first or second floor is destroyed (see Fig. 1), the vertical loads transferred to this column are perceived by farm 4 (see Figs. 13, 14).

Upon the destruction of any of the middle columns 2 of the first floor (see Fig. 1), a kinematic chain is formed consisting of safety plates 5, springs 9, crossbars 3 connected to the column, and struts 6. The movement of the chain lasts until the springs 9 and fully compress jamming of the ribs 15 of the crossbars of the rotary stops 16 (see figure 4). If the displacements of the chain turn out to be large, then the span of the truss 4 and the struts 6 will collapse, and a constructive system is formed that works with the spacer. The horizontal forces of the thrust are perceived by adjacent beams and transmitted through high-strength guy wires 7, connecting the foundations with columns at the level of overlap, to the foundation (see Fig. 14, 17). When the middle column of the second floor is destroyed (see Fig. 16), the vertical load transferred earlier to the column is redistributed through the truss to neighboring columns.

When one of the crossbars is destroyed, the disconnected parts of the crossbar under the action of loads turn on the support table 17 (see Fig. 3 and Fig. 7), while the horizontal shorties 13 release the suspensions 11 connected with the sliders 12. The sliders 12 move by gravity before contact with the stops 10, at the same time, the struts 6 connected to the sliders and crossbars are included in the operation, which are 6 struts that absorb the loads transferred to the crossbars. To eliminate the destruction of the attachment of the struts to the crossbars, square rods are introduced 18. On the middle columns 2 are installed corner distribution profiles 14, which serve as guides for the sliders 12.

When the element of the lower belt of the truss coating is destroyed, collapse of the coating is prevented by high-strength ropes 8 that transfer the load from the coating to the corresponding node D of the farm.

Analysis of the typical structures of metal frames of buildings [2] and the proposed solution allows us to conclude that the proposed design has increased survivability. This significantly reduces the risk of progressive collapse of the bearing system in the event of beyond design basis impacts.

The developed frame is made of steel and alloys used in construction, and mounted by known techniques.

BIBLIOGRAPHIC LIST

1. Sekulovich M.I. Finite Element Method [Text] / M.I.Sekulovich. - M .: Stroyizdat, 1993 .-- 664 p.

2. Melnikov N.P. Metal structures of industrial buildings and structures. Designer Handbook [Text] / N.P. Melnikov, A.I. Bezhevets, Z.I. Braude and others - Vladimir, 1962. - 591 p.

Claims (1)

The multi-span two-story transverse frame of the building frame, including the extreme and middle columns, rigidly resting on the foundation, the crossbars, the roof truss and the joints of the crossbars and the roof trusses with columns, characterized in that the lower belt of the roof truss is connected to the brace junction nodes located in the middle of the spans high-strength ropes, while in the span, the connection of the lower girdle of the coating truss and the ropes is performed in two nodes, each of which is located at a distance of 0.3-0.4 of the span length from the nearest The extreme columns are connected to the foundation by high-strength guy wires, the extreme and middle columns are equipped with support nodes of the floor beams, containing safety devices, including struts, stops, sliders, suspensions and horizontal shorts, and the devices of the support nodes of the floor beams on the middle columns are additionally equipped with safety plates, springs, dividing angular profiles, stiffeners of crossbars of the ceiling and rotating stops.

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