RU2426840C1 - Frame of building with higher durability - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: building frame comprises double-storey double-span frames made of pillars rigidly fixed to a foundation and crossbars freely rested on them, a system of horizontal and vertical braces. Crossbars of every span in all transverse frames in areas of resting at the middle pillar have additional stiffening ribs, at the same time there are supports installed on crossbars hingedly joined with plates. In the level of each floor slabs the extreme pillars are joined with foundations by means of high-strength ropes, and in areas of connection of the extreme pillars of regular frames with crossbars there are plates added, which are hingedly joined with supports installed on box-like rods, which connect neighbouring frames and have additional stiffening ribs in areas of resting at pillars. The middle pillar of each end frame has an additional upper part with the height that does not exceed half of the floor height, and its head is connected with inclined ties with the extreme pillars.

EFFECT: improved bearing capacity of frame elements in order to prevent progressing collapse of buildings in case of exposure exceeding project parameters.

3 cl, 11 dwg

Description

The invention relates to the field of construction and can be used in the construction of low-rise buildings with a metal frame, which have a particularly important economic and social significance (objects of the first level of responsibility).

A building is known (RU 2133803, E04B 1/24, C1) with a reinforced frame structure in which the ceilings have transverse, longitudinal and diagonal crossbars. Longitudinal crossbars and columns form multi-span frames in a vertical plane. Diagonal crossbars connect adjacent transverse frames. At the same time, such a frame is not sufficiently protected from beyond design basis impacts.

A building is also known (RU 2146320, E04B 1/24, E04B 1/58, E04B 5/14, C1), including transverse frames consisting of columns rigidly connected to the foundation of the columns and rigidly connected to the columns of the crossbars, a system of horizontal and vertical stiffness bonds. The increased bearing capacity of the frame is ensured by the rigid structure of all nodes connecting the elements. However, the structural scheme of this frame does not provide an effective warning of progressive collapse in case of a sudden local destruction of any rack.

The objective of the invention is to ensure the survivability of the building in the event of local destruction of any of the columns due to beyond design impact.

The technical result is an increase in the bearing capacity of the frame elements in order to prevent the progressive avalanche-like collapse of buildings during beyond design impacts.

The problem is solved in that the frame of the building increased survivability, including two-story two-span frames, consisting of columns rigidly connected to the foundation of the columns and bolts freely supported on them, a system of horizontal and vertical stiffness bonds, characterized in that the crossbars of each of the spans of all transverse frames in places The supports on the middle column have additional stiffening ribs, while the crossbars are mounted pivotally connected to the plates, and at the level of the floors of each floor, the extreme columns are connected to the foundation tents with high-strength ropes, and at the junction points of the extreme columns of the row frames with the crossbars, plates are inserted that are pivotally connected to the stops mounted on the box-shaped rods connecting the adjacent frames and having additional stiffeners in the places of support on the columns, in addition, the middle column of each end frame has an additional upper part with a height of at least half the height of the floor, the head of which is connected by inclined puffs with the extreme columns.

A finite-element analysis of the frame in a dynamic setting [1] confirms the fulfillment of the building survivability conditions in the event of sudden decommissioning of any rack, which is possible with such beyond design impacts as subsidence of supports, karst or suffusion base failures, special temperature loads (arising, for example fire) or explosive loads.

The design is illustrated by diagrams. Figure 1 shows an ordinary transverse frame, where 1 - extreme columns, 2 - middle column, 3 - crossbars, 4 - high-strength ropes, 5 - plates, 6 - stops, 7 - hard disks of ceilings; figure 2 - end transverse frame, where 8 - inclined tightening, 9 - additional upper part of the column; figure 3 is a view of the frame in the longitudinal direction, where 10 are box-shaped rods, 11 are vertical stiffness bonds; figure 4 is a view in plan of the elements of the metal frame; figure 5 - diagram of the transverse frame of the frame with local destruction of the middle column of the first floor; figure 6 is a diagram of the transverse frame of the frame with local destruction of the middle column of the second floor; Fig.7 is a diagram of the frame with local destruction of the extreme columns of the first floor of the ordinary frame; on Fig is a diagram of the frame with local destruction of the extreme columns of the second floor of the ordinary frame; figure 9 is a fragment of the junction of the crossbars 3 with the plates 5, where 12 is the stiffener of the crossbar, 13 is an annular retainer, 14 is an angular profile with a cylinder; figure 10, 11 is a cross section of the fragment depicted in figure 9, where 15 is the guide.

Under the action of design loads, the diagrams of the transverse frame of the frame and side view are presented in figures 1-4.

With the local destruction of the middle column of any frame, a mechanism is formed consisting of plates 5 with stops 6 and crossbars 3, which moves vertically until the stops come into contact with the stiffeners of the crossbars 3. At the same time, a span bearing system is formed which works to bend with a thrust (see. 5, 6). In this case, horizontal thrust forces are perceived by extreme columns 1 and high-strength ropes 4.

When the extreme column 1 of the row frame is removed, a mechanism is formed consisting of plates 5 with stops 6 and box-shaped rods 10, which moves vertically until the stops come in contact with the stiffening ribs of the box-shaped rods (see Figs. 7, 8). In this case, in the direction of the step of the columns, a supporting system is formed, working on bending with a thrust. The horizontal efforts of the thrust are perceived by the extreme columns 1 of other frames included in the work by box-shaped rods 10, as well as by vertical stiffness bonds 11, and transferred to the foundation. When removing the extreme column of any floor of the end frame (see figure 2), the vertical loads will be redistributed through the inclined puffs 8 to adjacent columns.

A comparison of the structures of existing metal frames of buildings [2-3] and the proposed solution allows us to conclude that there is a significant reduction in the risk of progressive collapse of the bearing system, saving material resources and ensuring the safety of people in the face of beyond design basis impacts.

When removing one of the columns of the crossbar 3, moving along the guides 15, are in contact with the stops 6 (see Fig. 9). The articulation of the stops 6 with the plates 5 is achieved using angular profiles with cylinders 14. The fixing of the plates 5 is carried out by the guides 15 and the ring clamps 13 (see Fig. 10, 11).

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

Information sources

1. Agapov V.P. The finite element method in the statics, dynamics and stability of spatial thin-walled reinforced structures / M.: Ed. DIA, 2000 .-- 152 s.

2. Melnikov N.P. Metal structures of industrial buildings and structures. Designer's reference book / N.P. Melnikov, A.I. Bezhevets, Z.I. Braude and others - Vladimir, 1962 - 591 p.

3. Steel structures of buildings and structures. (Designer Handbook) / Under the general. ed. V.V. Kuznetsova (Central Research Institute Projectstalkonstruktsiya them.N.P. Melnikova) - M.: Publishing House ASV, 1998. - 512 p.

Claims (3)

1. The frame of the building survivability, including two-story two-span frames, consisting of columns rigidly connected to the base of the columns and bolts freely supported on them, a system of horizontal and vertical stiffness bonds, characterized in that the crossbars of each of the spans of all transverse frames in places of bearing on the middle column have additional stiffening ribs, while on the crossbars, stops are mounted pivotally connected to the plates, and at the level of the floors of each floor, the extreme columns are connected with the foundations with high-strength ropes , and at the joints of the extreme columns of the ordinary frames with the crossbars, plates are introduced that are pivotally connected to the stops mounted on the box-shaped rods connecting the adjacent frames and having additional stiffeners at the points of support on the columns, in addition, the middle column of each end frame has an additional upper a part with a height of at least half the height of the floor, the head of which is connected by inclined puffs to the extreme columns. 2. The frame according to claim 1, characterized in that the transverse frames include more than two spans. 3. The frame according to claim 1, characterized in that the transverse frames are single-story or have more than two floors.

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