RU2649207C1 - Protection system for construction structures from over-standard explosive, shock and seismic effects - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the field of construction and can be used for protection and guarantee the vitality of building structures with repeated over-standard dynamic impacts. System comprises a support, its lower part is fixed on a support surface and is made of separate support plates. Support plates are designed to install steel collapsible inserts with cross sections in the form of rings and are installed in depressions made on the supporting surface. Depth of the recesses is equal to the total thickness of the support plate and the folded wall insert. Each support plate width is not less than πR, where R is the outer radius of the folded insert, and the length corresponds to the length of the folded insert. Foldable inserts are uniformly installed on the supporting surface, and their length is determined by the given dependences taking into account the outer radius of the folded insert, the thickness of its wall, resistance of the material and the current load. Additionally flat jacks are installed on the supporting surface, connected to the pump station Number of jacks is chosen according to the weight of the construction structure and the lifting capacity of the jack. For the installation of the jacks in the supporting surface, grooves are made, the depth of them corresponds to the working output of the piston to a height not less than the outer diameter of the collapsible insert.

EFFECT: protection system has a minimum readiness for repeated over-standard explosive, shock and seismic impacts, it eliminates the mobility of the foldable inserts under the influence of loads and, thereby, ensures maximum preservation of the performance characteristics of the building structure.

5 cl, 5 dwg

Description

The invention relates to the field of construction and can be used to ensure the survivability of a building structure with repeated excessive explosive, shock and seismic impact, as well as in the design and construction of protective structures for civil defense.

Known frame structures for the invention patent RU 2085685, IPC E04H 009/00, E04H 009/02, E04B 001/24, E04B 001/18, E04B 001/92, E04C 003/38, published July 27, 1997, including foundations, racks and girders with gussets, hinges in the nodes of the racks with the foundations and girders, some of which are made in the form of plates and supporting fingers connecting them, and bolts, where all the hinges are made of plates and supporting fingers, and their plates are mounted on the foundations and ends of the racks and crossbars, and the racks and crossbars are made tubular, and the gussets are located at a distance from the connection nodes uprights and crossbars, wherein the frame is provided with energy-absorbing devices mounted luminaire between mullions and transoms and connected thereto by bolts. Also, each energy-absorbing device is made in the form of the lower and upper support tables of channels, the first of which is attached to the profile of the rack, and the second to the profile of the crossbar, a block of ductile material with vertical channels installed between the upper and lower support tables, and springs placed in the channels of the block and fixed with the upper end on the upper support table, and the lower end on the lower support table through the support discs, washers and nuts.

This invention allows to increase the efficiency of protection of buildings, structures from explosions by increasing the speed and reliability of operation using energy-absorbing structural elements

However, the invention does not take into account the degree of compliance of energy absorbing elements and the effect of these elements on building structures during and after emergency loading. This is important, as in some cases compliance may show a negative effect.

The closest analogue to the claimed invention, which is adopted as a prototype, is a device for ensuring the survivability of building structures with short-term dynamic effects according to the patent for the invention RU 2428549, IPC E04H 9/00, published on 09/10/2011. The device comprises a support of a lower metal element mounted on a supporting surface, and an upper metal element on which the building structure is directly supported, one of these elements being installed with the possibility of vertical movement, and a metal insert of circular cross section located between the lower and upper elements. The lower and upper support elements are made in the form of plates, and the metal insert is made in the form of a crushable insert and has a cross section in the form of a ring, and the length of the crushable insert is determined by the given dependence taking into account the outer radius of the insert, its wall thickness, material resistance, and current load. The technical result consists in increasing the survivability of a building structure with various types of short-term dynamic loads, ensuring the safety of the bearing capacity of the building structure, and reducing material consumption.

The positive aspect of this device is that the bulk of the kinetic energy of the shock is perceived and extinguished by intermediate elements (inserts), preserving the building structure from destruction and thereby ensuring its survivability. The dimensions of the inserts are used in accordance with the calculated load on the supporting surface. However, the positive effect has been experimentally proved only on the beam structures of the beam type and does not cover spatial structures such as shell or slab, supported along the contour, since the work of the structure is assumed in two directions, and for beams only in one.

In addition, the proposed protection system is aimed at ensuring the survivability of the building structure, only with a single exposure. The disadvantages of the device of the prototype should also include the mobility of the crushed inserts in the horizontal direction under the influence of dynamic loads.

The invention solves a technical problem, which consists in ensuring the survivability of a building structure with repeated excessive explosive, shock and seismic impact, as well as expanding the scope of the protection system.

The technical result consists in the maximum preservation of the operational characteristics of building structures during repeated exposure due to the use of the proposed protection system with a minimum readiness for repeated excessive explosive, impact and seismic effects and the exclusion of the mobility of creased inserts when exposed to loads.

The technical result and the solution of the technical problem are achieved as follows.

The system for protecting building structures from excessive explosive, shock and seismic effects, as well as the prototype device, includes a support with steel crushable inserts of an annular cross section, the lower part of which is fixed on the supporting surface, and steel crushable inserts are evenly mounted on the supporting surface. The length of each crease insert is made taking into account the outer radius of the crease insert, its wall thickness, material resistance and current load.

In contrast to the prototype, the lower part of the support in the inventive system consists of individual support plates, the number of which is equal to the number of crushed inserts. The width of each base plate is at least πR, where R is the outer radius of the crease insert, and the length corresponds to the length of the crease insert. To install these support plates on the support surface, recesses are made, the depth of which is equal to the sum of the thickness of the support plate and the wall thickness of the crushed insert. The difference from the prototype is also that on the supporting surface there are additionally installed flat jacks connected to the pumping station, their number n corresponds to the formula n = P / P _n , where P is the weight of the building structure, P _n is the lifting capacity of the jack. To install the jacks in the supporting surface, recesses are made. The depth of the recesses corresponds to the working output of the piston to a height of not less than the outer diameter of the crease insert.

In particular cases of execution, the supporting surface may be in the form of a round frame, a crossbar, a square or rectangular frame.

The length l of each crease insert is calculated by the formula

where P is the permissible design vertical load per supporting surface, including the dead weight of the structure;

R is the outer radius of the cross section of the crease insert;

σ is the steel resistance during bending of the crushable insert;

s is the wall thickness of the crushed insert.

и

каждой i и j сминаемых вставок, устанавливаемых на взаимно перпендикулярных сторонах рамы, соответствующих условно осям x и у, может быть рассчитана по формуламIn the case of a supporting surface in the form of a square or rectangular frame, the length

and

of each i and j creaseable inserts mounted on mutually perpendicular sides of the frame, corresponding to the axes x and y, can be calculated by the formulas

where Q _i is the concentrated force acting on the i crushed insert,

Q _j is the concentrated force acting on the j crushed insert,

R is the outer radius of the crease insert;

[σ] is the resistance of the material to be crushed insert;

s is the wall thickness of the crease insert,

moreover, the concentrated forces Q _i and Q _j acting on i and j crushable inserts are calculated by the formulas

where a is the length of one of the sides of the frame, located along the y axis;

b is the length of the adjacent side of the frame along the x axis;

x _i - for the first crease insert located on the side of the frame of length b - this is the origin, and for each subsequent set i-crease insert is the coordinate of the midpoint located between the geometric center of the ith crease insert and the geometric center of the previous crease insert ;

x _{i + 1} - the coordinate of the midpoint located between the geometric center of the i-th crushed insert and the geometric center of the subsequent

i + 1 creaseable insert;

for _j , for the first crease insert located on the side of the frame of length a, this is the origin, and for each subsequent jth crease insert, the coordinate of the midpoint located between the geometric center of the jth crease insert and the geometric center of the previous crease insert;

_{j + 1} is the coordinate of the midpoint located between the geometric center of the jth crushed insert and the geometric center of the subsequent j + 1 crushed insert;

q - uniformly distributed load according to the testimony of the force meter for a building structure supported on crush-resistant supports;

ν is the Poisson's ratio.

The calculation of the lengths of creaseable inserts for the supporting surface in the form of a square or rectangular frame in the latter case is most accurate to achieve the desired technical result.

The invention, characterized by the proposed combination of features, is not found among the known technical solutions, which confirms its novelty.

In the prior art, no devices have been found containing the distinguishing features of the invention, which make it possible to carry out comprehensive protection of building structures with repeated excessive explosive, shock and seismic effects.

Unlike the prototype, the crease insert is installed on a plate of a given size, placed in a recess of the supporting surface, which allows limiting horizontal displacement and, due to the specified height of the recess, to prevent contact between the supporting surface and the building structure, thereby preventing local destruction of the building structure. The width of the plate and, consequently, the recesses for it, which are at least half the circumference of the creaseable insert, do not prevent the crease from creasing completely under the action of loads. In the case of excess impact, namely, explosive, shock or seismic, part of the kinetic energy of the impact is absorbed by the crease insert, thereby being deformed, the remaining energy is absorbed by the building structure, while maintaining the bearing capacity and survivability of the structure.

After excessive exposure, jacks connected to the pump station with manual or automatic control are put into operation as soon as possible. With the help of jacks, the structure is lifted to replace the creased inserts, as a result of which the building structure is mounted on the next supports, thereby the structure is ready for further excessive loads, which is a significant difference from the prototype, since the prototype does not provide for the construction lifting and replacement of creased inserts. The number of jacks depends on the mass of the building structure and the carrying capacity of the jacks themselves. The ability to replace crushed inserts in the shortest possible time increases the level of safety of structures and their survivability.

According to the prototype, crushable inserts are applicable only for reinforced concrete beam structures (crossbar), according to the invention, a number of building structures are covered, namely: a beam (crossbar), a shell of any configuration, plates with various bearing schemes, thereby expanding the scope.

The invention is illustrated by drawings, on the example of a building structure in the form of a plate supported on a rectangular frame (supporting surface).

In FIG. 1 is a general view of a building structure protection system.

In FIG. 2 - shows the placement of the crushed insert in the recess of the supporting surface.

In FIG. 3 - view A (Fig. 1) before the force action.

In FIG. 4 - view A (Fig. 1) after a force action.

In FIG. 5 - a fragment of the technological process of replacing crush inserts.

, и глубиной, определяемой по выражению: h=z+S, где h - глубина углубления, z - толщина нижних опорных пластин, S - толщина стенки сминаемой вставки (фиг. 2). На опорной поверхности 1 установлены в углублении 5 плоские домкраты 6, которые подключены к насосной станции с ручным или автоматическим управлением в режиме постоянной готовности к взрывному, ударному или сейсмическому воздействию. Минимальное число одинаковых плоских домкратов 6, необходимых для замены сминаемых вставок 3 после сейсмического, взрывного или ударного воздействия, определяется выражениемAccording to the invention, the protection system comprises supports from the lower plates 2 (Fig. 2), mounted on a supporting surface 1 on which the building structure (plate) is mounted 4. Between the plate 4 and the plate 2 are steel crush inserts 3 of circular annular cross-section. Along the perimeter of the supporting surface 1 for installing the lower supporting plates 2, grooves are made with linear dimensions: at least πR wide, where R is the outer radius of the crease insert 3, with a length equal to the length of the ith crease insert

, and the depth determined by the expression: h = z + S, where h is the depth of the recess, z is the thickness of the lower support plates, S is the wall thickness of the crushed insert (Fig. 2). On the supporting surface 1, flat jacks 6 are installed in the recess 5, which are connected to the pump station with manual or automatic control in constant readiness for explosive, impact or seismic effects. The minimum number of identical flat jacks 6 required to replace the creaseable inserts 3 after seismic, explosive or impact impact is determined by the expression

n = P / P _n ,

where P is the weight of the building structure,

P _n - load capacity of one jack,

n is the minimum number of flat jacks.

The jacks 6 are freely installed in the corresponding pre-prepared recesses 5 on the supporting surface 1 with the working output of the piston to a height of not less than 2R, where R is the outer radius of the crease insert. In the particular case considered in FIG. 1, the minimum number of jacks is n = 4 for a plate supported along the contour, which is at least one jack on each side. The number and parameters of creased inserts are the same in cross section and different in length for uniform deformation of inserts under uneven loads falling on the support points of the plate, which are calculated for a square base plate with supports located on the side of the plate equal to a, or for the base slabs of rectangular shape with supports located on the side of the slab length a and b.

The lengths of creased inserts are calculated based on the concentrated forces Q _i ; Q _j for each crushed insert.

with supports located on the side of the plate of length b

where q is a uniformly distributed load according to the readings of the force meter for a structure supported on rigid supports,

a is the short side of the plate,

b is the long side of the plate,

ν is the Poisson's ratio,

y is the coordinate of the point along the length of the side at which the support reaction is determined,

x is the coordinate of the point on the short side at which the support reaction is determined.

согласно формулеBased on the magnitude of the support load Q _i , choose the length of the crushed inserts

according to the formula

where: Q _i - support reaction attributable to the i-th crushed insert,

R is the outer radius of the crease insert,

σ is the resistance of the material of the crease insert (yield strength),

S is the wall thickness of the crushed insert.

Comprehensively preparing the supporting surface 1 to ensure the survivability of the structure, the plate 4 is installed on the crushable inserts 3, which makes it possible to restore the protection system after repeated explosive, shock and seismic effects.

The principle of operation of the system for protecting building structures from excessive repeated explosive, shock and seismic effects is to repay the impact energy with crushable inserts and their subsequent rapid replacement after force exposure. In FIG. 2, the dotted line shows the crease insert 3 in the case of repayment of the impact energy.

Depending on the direction of the force, the movement pattern of the building structure will change. During a sudden excess loading, the main part of the kinetic energy of the shock is absorbed and extinguished by the crushable inserts 3, as a result, the building structure works in an elastic stage, which saves it from destruction and thereby ensures its survivability. Then, immediately using the jacks 6 installed on the supporting surface 1, the structure 4 is lifted to replace the creaseable inserts 3, for further operation with possible shock, explosive or seismic effects.

There are two possible options for the operation of the jacks 6, with manual or automated control, and in the latter case, the replacement speed of the crease inserts 3 is determined by the speed of the applied control system, which speeds up the readiness for a new power impact.

The work of the jacks 6 should be synchronous, to ensure the horizontal rise of the plate 4 (Fig. 1) and reduce local stresses in the plate 5.

The minimum number of jacks depends on the type of construction, for beams, girders n = 2, for plates, shells n = 4.

From the foregoing it follows that the proposed method allows for the survivability of the building structure with the possibility of subsequent repeated perception of explosive, shock or seismic effects.

Claims (28)

1. A system for protecting building structures from excessive explosive, shock and seismic effects, including a support with steel crushable inserts of an annular cross section, the lower part of which is fixed to the supporting surface, and steel crushable inserts are evenly mounted on the supporting surface and their length is made taking into account the outer radius crease insert, its wall thickness, material resistance and current load, characterized in that the lower part of the support consists of separate support plates, which the number of which is equal to the number of creaseable inserts, the width of each base plate is not less than πR, where R is the outer radius of the creaseable insert, and the length corresponds to the length of the creaseable insert; in this case, recesses are made to install the specified support plates on the support surface, the depth of which is equal to the total thickness of the support plates and walls of the crushable insert, in addition to this, flat jacks are additionally installed on the supporting surface, connected to the pump station, their number n corresponds to the formula n = P / P _n , where P is in with a building structure, P _n is the lifting capacity of the jack, and recesses for installing jacks are made in the bearing surface, the depth of which corresponds to the working output of the piston to a height not less than the outer diameter of the crease insert. 2. The system of protection of building structures according to claim 1, characterized in that the supporting surface is made in the form of a round frame. 3. The system of protection of building structures according to claim 1, characterized in that the supporting surface is made in the form of a crossbar. 4. The system of protection of building structures according to claim 1, characterized in that the length 1 of each crushable insert corresponds to the formula

where P is the permissible design vertical load per supporting surface, including the dead weight of the structure; R is the outer radius of the cross section of the crease insert; σ is the steel resistance during bending of the crushable insert; s is the wall thickness of the crushed insert. 5. The system of protection of building structures according to claim 1, characterized in that the supporting surface is made in the form of a square or rectangular frame, and the lengths l _i and l _{j of} each i and j creaseable inserts installed on mutually perpendicular sides of the frame, conventionally relative to the x axes and y are equal

, where Q _i is the concentrated force acting on the i crushed insert, Q _j is the concentrated force acting on the j crushed insert, R is the outer radius of the crease insert; [σ] is the resistance of the material to be crushed insert; s is the wall thickness of the crease insert, moreover, the concentrated forces Q _i and Q _j acting on i and j crushable inserts are calculated by the formulas

where a is the length of one of the sides of the frame, located along the y axis; b is the length of the adjacent side of the frame along the x axis; x _i - for the first crease insert located on the side of the frame of length b - this is the origin, and for each subsequent set i-crease insert is the coordinate of the midpoint located between the geometric center of the ith crease insert and the geometric center of the previous crease insert ; x _{i + 1} - the coordinate of the midpoint located between the geometric center of the i-th crushed insert and the geometric center of the subsequent i + 1 creaseable insert; y _j - for the first crease insert located on the side of the frame with length a - this is the origin, and for each subsequent jth crease insert - the coordinate of the midpoint located between the geometric center of the jth crease insert and the geometric center of the previous crease insert; y _{j + 1} is the coordinate of the midpoint located between the geometric center of the j-th crushed insert and the geometric center of the subsequent j + 1 crushed insert; q - uniformly distributed load according to the testimony of the force meter for a building structure supported on crush-resistant supports; ν is the Poisson's ratio.

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