阅读说明：本技术 混凝土筒仓仓顶钢桁架加固的方法 (Method for reinforcing steel truss on top of concrete silo ) 是由 熊爱平 方国旺 韩啸 于 2021-05-14 设计创作，主要内容包括：本发明公开了一种混凝土筒仓仓顶钢桁架加固的方法,所述方法包括：1)在原有的库内钢桁架的顶部加设反梁,反梁即库顶加固钢板梁；2)将所述库顶加固钢板梁、库内钢桁架连接成一体结构；3)对所述库内钢桁架的变形和破坏点进行修复、加固。该方法具有加固效果好的优势。(The invention discloses a method for reinforcing a steel truss at the top of a concrete silo, which comprises the following steps: 1) the top of the original steel truss in the warehouse is additionally provided with a reverse beam, and the reverse beam is a steel plate beam reinforced on the top of the warehouse; 2) connecting the warehouse top reinforced steel plate beam and the warehouse inner steel truss into an integral structure; 3) and repairing and reinforcing the deformation and damage points of the steel truss in the warehouse. The method has the advantage of good reinforcing effect.)

1. A method for reinforcing a steel truss at the top of a concrete silo is characterized by comprising the following steps:

1) a reverse beam is additionally arranged at the top of the original steel truss (5) in the warehouse, and the reverse beam is a reinforced steel plate beam (1) on the top of the warehouse;

2) connecting the warehouse top reinforced steel plate beam (1) and the warehouse inner steel truss (5) into an integral structure;

3) and repairing and reinforcing the deformation and damage points of the steel truss (5) in the warehouse.

2. Method according to claim 1, characterized in that the stress σ to which the said roof reinforcement steel plate girder (1) is subjected satisfies the following condition: sigma is M.Y/I Z;

wherein M is a bending moment on the cross section; y is the distance from the stress point on the section to the neutral axis; IZ is the moment of inertia of the cross section to the neutral axis.

3. The method according to claim 1, characterized in that the stress to which the roof reinforcement steel plate girder (1) is subjected satisfies the following condition: sigma_max≤[σ]；σ_maxThe maximum stress to which the steel beam is subjected; [ sigma ]]The allowable stress of the steel beam material.

4. The method according to claim 1, characterized in that the shear stress τ to which the roof reinforcement steel plate girder (1) is subjected satisfies the following condition: τ ═ V · S/I · tw;

v is a shear force design value for calculating the action of the cross section along the plane of the web plate; s is the area moment of the hair cross section above the neutralization shaft centering on the neutralization shaft; i is the moment of inertia of the hair section; tw is the web width.

5. The method according to claim 1, characterized in that the shear stress τ to which the roof reinforcement steel plate girder (1) is subjected satisfies the following condition: tau is less than or equal to [ tau ]; [ tau ] is the designed shear strength of steel.

6. The method according to claim 1, characterized in that the warehouse top reinforced steel plate beam (1) and the warehouse inner steel truss (5) are connected through a plurality of steel truss reinforced hanging rods (2).

7. The method according to claim 1, wherein the material specification type and the number of the steel truss reinforcing hanger rods (2) are obtained by calculating the warehouse top reinforcing steel plate beam (1) and the warehouse inner steel truss (5), and the specific calculation formula is as follows:

acting force on the suspender: n is q.L/2 h;

the section stress of the suspender: sigma_max＝N/A≦[σ]；

Wherein: n is the acting force of the suspender, q is the design load of the original truss girder, L is the length of the suspender from the support, h is the height of the original steel truss, sigma_maxThe maximum stress on the suspension rod, A is the cross-sectional area of the suspension rod material, [ sigma ]]Allowable stress value of the suspender material;

and (3) calculating the section bearing capacity of the steel plate beam-steel truss combined beam after reinforcement:

a. and (4) checking and calculating the bending strength:

static load sigma₁＝(M_x+M'_x)/k·W^z _nx≤f；

Dynamic load sigma₂＝M_x/W_nx+M'_x/W^z _nx≤f；

Wherein σ₁Stress in cross section under static load, σ₂Is the stress in the section under the dynamic load; f is steelThe design value of the bending strength is 325.00N/mm²；M_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; w_nxThe net section resisting moment of the original component before reinforcement; w^z _nxThe net section resisting moment of the whole section after reinforcement; k is a reduction coefficient of reinforcement, and 0.9 is taken;

b. and (4) checking and calculating the shear strength:

static load τ₁＝(V+V')·S^z/k·I^z·t_w ^z≤f_v

Dynamic load τ₂＝V·S/I·t_w+V'·S^z/I·t_w ^z≤f_v

Wherein, tau₁Is shear stress in a stressed section under static load, tau₂The shear stress in the stressed section under dynamic load; v is the shear force of the original component for calculating the cross section effect before reinforcement; v' is an additional shearing force for calculating the cross section action of the reinforced member; s, S^zCalculating area moments of smaller cross sections outside the shear stress position to the neutral axis for the reinforced front and rear cross sections respectively; I. i is^zThe moment of inertia of the reinforced front and rear sections; t is t_wThe original thickness of the cross-section web plate before reinforcement is achieved; t is t_w ^zThe total thickness of the whole cross-section web after reinforcement is adopted; f. of_vThe shear strength of the steel is designed to be 170.00N/mm²K is a reduction coefficient of reinforcement, and 0.9 is taken;

c. checking and calculating the integral stability of the beam:

static load (M)_x+M'_x)/k·ψ_zb·W_zx≤f

Dynamic load M_x/ψ_zb·W_x+M'x/ψ_zb·W_zx≤f

Wherein, W_x、W_zxRespectively reinforcing the rough cross section resisting moment of the front component and the rear component; psi_zbCalculating the whole bending stability coefficient of the whole cross section after reinforcement according to the current specification; m_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; f is the design value of the bending strength of the steel,taking 325.00N/mm²。

Technical Field

The invention relates to a method for reinforcing a steel truss, in particular to a method for reinforcing a steel truss on the top of a concrete silo.

Background

The steel truss at the top of the silo is subjected to constant load and dynamic load for a long time in the using process, so that overload and fatigue damage are generated, and deformation and damage are generated, generally, the steel truss member nodes are subjected to fatigue deformation and desoldering under the action of long-term alternating load, the structural safety of the silo is influenced, and the normal use of production is influenced, so that the steel truss at the top of the silo needs to be reinforced.

The existing reinforcing method for the steel truss at the top of the concrete silo adopts a newly added reinforcing steel beam and a steel truss in the silo to be vertically arranged, a connection suspender is arranged at the intersection of a reinforcing steel plate beam and the steel truss, partial load is transmitted to the reinforcing steel plate beam through the suspender to reinforce the steel truss, the reinforcing arrangement mode is single in stress form, an original steel truss and the reinforcing steel plate beam cannot form a new combined beam system, and the working conditions and the performances of the steel truss and the reinforcing steel plate beam cannot be fully exerted.

Disclosure of Invention

The invention aims to provide a method for reinforcing a steel truss on the top of a concrete silo, which has the advantage of good reinforcing effect.

In order to achieve the above object, the present invention provides a method for reinforcing a steel truss at the top of a concrete silo, the method comprising:

1) the top of the original steel truss in the warehouse is additionally provided with a reverse beam, and the reverse beam is a steel plate beam reinforced on the top of the warehouse;

2) connecting the warehouse top reinforced steel plate beam and the warehouse inner steel truss into an integral structure;

3) and repairing and reinforcing the deformation and damage points of the steel truss in the warehouse.

Preferably, the stress σ borne by the storehouse top reinforced steel plate beam meets the following condition: sigma is M.Y/I Z;

wherein M is a bending moment on the cross section; y is the distance from the stress point on the section to the neutral axis; IZ is the moment of inertia of the cross section to the neutral axis.

Preferably, the stress borne by the storehouse top reinforced steel plate beam meets the following conditions: sigma_max≤[σ]；σ_maxThe maximum stress to which the steel beam is subjected; [ sigma ]]The allowable stress of the steel beam material.

Preferably, the shear stress τ borne by the roof reinforced steel plate girder satisfies the following condition: τ ═ V · S/I · tw;

v is a shear force design value for calculating the action of the cross section along the plane of the web plate; s is the area moment of the hair cross section above the neutralization shaft centering on the neutralization shaft; i is the moment of inertia of the hair section; tw is the web width.

Preferably, the shear stress τ borne by the roof reinforced steel plate girder satisfies the following condition: tau is less than or equal to [ tau ]; [ tau ] is the designed shear strength of steel.

Preferably, the warehouse top reinforcing steel plate beam and the warehouse inner steel truss are connected through a plurality of steel truss reinforcing hanging rods.

The material specification model and the suspender quantity of the steel truss reinforcing suspender (2) are obtained by calculating the warehouse top reinforcing steel plate beam (1) and the warehouse inner steel truss (5), and the specific calculation formula is as follows:

acting force on the suspender: n is q.L/2 h;

the section stress of the suspender: sigma_max＝N/A≦[σ]；

Wherein: n is the acting force of the suspender, q is the design load of the original truss girder, L is the length of the suspender from the support, h is the height of the original steel truss, sigma_maxThe maximum stress on the suspension rod, A is the cross-sectional area of the suspension rod material, [ sigma ]]Allowable stress value of the suspender material;

and (3) calculating the section bearing capacity of the steel plate beam-steel truss combined beam after reinforcement:

a. and (4) checking and calculating the bending strength:

static load sigma₁＝(M_x+M'_x)/k·W^z _nx≤f；

Dynamic load sigma₂＝M_x/W_nx+M'_x/W^z _nx≤f；

Wherein σ₁Stress in cross section under static load, σ₂Is the stress in the section under the dynamic load; f is the bending strength design value of the steel material, and 325.00N/mm is taken²；M_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; w_nxThe net section resisting moment of the original component before reinforcement; w^z _nxThe net section resisting moment of the whole section after reinforcement; k is a reduction coefficient of reinforcement, and 0.9 is taken;

b. and (4) checking and calculating the shear strength:

static load τ₁＝(V+V')·S^z/k·I^z·t_w ^z≤f_v

Dynamic load τ₂＝V·S/I·t_w+V'·S^z/I·t_w ^z≤f_v

Wherein, tau₁Is shear stress in a stressed section under static load, tau₂The shear stress in the stressed section under dynamic load; v is the shear force of the original component for calculating the cross section effect before reinforcement; v' is an additional shearing force for calculating the cross section action of the reinforced member; s, S^zCalculating area moments of smaller cross sections outside the shear stress position to the neutral axis for the reinforced front and rear cross sections respectively; I. i is^zThe moment of inertia of the reinforced front and rear sections; t is t_wThe original thickness of the cross-section web plate before reinforcement is achieved; t is t_w ^zThe total thickness of the whole cross-section web after reinforcement is adopted; f. of_vThe shear strength of the steel is designed to be 170.00N/mm²K is a reduction coefficient of reinforcement, and 0.9 is taken;

c. checking and calculating the integral stability of the beam:

static load (M)_x+M'_x)/k·ψ_zb·W_zx≤f

Dynamic load M_x/ψ_zb·W_x+M'x/ψ_zb·W_zx≤f

Wherein, W_x、W_zxRespectively reinforcing the rough cross section resisting moment of the front component and the rear component; psi_zbCalculating the whole bending stability coefficient of the whole cross section after reinforcement according to the current specification; m_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; f is the bending strength design value of the steel material, and 325.00N/mm is taken²。

In the technical scheme, the method is completed by the procedures of establishing a steel truss reinforcement model → selecting and calculating a reinforcement reversed beam → selecting a connecting point of a steel truss on the top of the bin and the reinforcement reversed beam → repairing deformation and damage points of the steel truss, and reinforcing → forming a combined beam by the repaired steel truss and a newly added reversed beam to jointly bear load, and the like, and has the following advantages:

1. through the reinforcement of the steel truss on the top of the silo, the structural safety of the silo and the normal operation of production can be realized, benefits are created for production enterprises, and losses are reduced.

2. The steel truss on the top of the silo is reinforced by the inverted beam, the silo is temporarily used only when the connecting rods are welded, the influence on production during the reinforcing process is extremely small, and the benefit is correspondingly increased.

3. The steel truss on the top of the silo is reinforced by the reversed beam, the structure of the silo top and the arrangement of a production process are not changed, and the construction and reinforcement cost can be obviously reduced.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a concrete silo constructed by the method for reinforcing the steel truss on the top of the concrete silo provided by the invention according to a preferred embodiment.

Description of the reference numerals

1. Steel plate beam 2 for reinforcing warehouse roof and steel truss reinforcing hanger rod

3. Steel beam pad 4 and concrete storehouse wall

5. Steel truss 6 and steel secondary beam in warehouse

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, unless otherwise specified, the directional words "upper, lower" and the like included in the terms merely represent the orientation of the terms in the conventional use state or are colloquially known by those skilled in the art, and should not be construed as limiting the terms.

The invention provides a method for reinforcing a steel truss at the top of a concrete silo, which comprises the following steps:

1) the top of an original steel truss 5 in the warehouse is additionally provided with a reverse beam, wherein the reverse beam is a reinforcing steel plate beam 1 on the top of the warehouse, specifically the reverse beam is parallel to the steel truss 5 in the warehouse, and the reverse beam is arranged right above the steel truss 5 in the warehouse;

2) the storehouse top reinforcing steel plate beam 1 and the storehouse inner steel truss 5 are connected into an integral structure, the storehouse top reinforcing steel plate beam 1 and the storehouse inner steel truss 5 are connected into a whole to form a new combined steel beam system, and meanwhile, the original stress system is kept to share the whole load of the storehouse top under the combined action;

3) and repairing and reinforcing the deformation and damage points of the steel truss 5 in the warehouse.

In the above method, in order to improve the stress capability of the whole combined steel beam system, preferably, the stress σ applied to the roof reinforcement steel plate beam 1 satisfies the following condition: sigma is M.Y/I Z; wherein M is a bending moment on the cross section; y is the distance from the stress point on the section to the neutral axis; IZ is the moment of inertia of the cross section to the neutral axis.

In the above method, in order to improve the stress capability of the whole combined steel beam system, preferably, the stress applied to the roof reinforced steel plate beam 1 satisfies the following conditions: sigma_max≤[σ]；σ_maxThe maximum stress to which the steel beam is subjected; [ sigma ]]The allowable stress of the steel beam material.

In the above method, in order to improve the stress capacity of the whole combined steel beam system, preferably, the shear stress τ applied to the roof reinforced steel plate beam 1 satisfies the following condition: τ ═ V · S/I · tw; v is a shear force design value for calculating the action of the cross section along the plane of the web plate; s is the area moment of the hair cross section above the neutralization shaft centering on the neutralization shaft; i is the moment of inertia of the hair section; tw is the web width.

In the above method, in order to improve the stress capacity of the whole combined steel beam system, preferably, the shear stress τ applied to the roof reinforced steel plate beam 1 satisfies the following condition: tau is less than or equal to [ tau ]; [ tau ] is the designed shear strength of steel.

In the above method, the connection manner between the roof reinforced steel plate beam 1 and the steel truss 5 in the warehouse can be selected in a wide range, but in order to further improve the connection effect, it is preferable that the roof reinforced steel plate beam 1 and the steel truss 5 in the warehouse are connected by a plurality of steel truss reinforced suspenders 2.

In the above embodiment, the material and number of the steel truss reinforcing hanger rods 2 can be selected in a wide range, but in order to improve the stress capability of the whole combined steel beam system, preferably, the material specification model and the number of the steel truss reinforcing hanger rods 2 are obtained by calculating the top reinforcing steel plate beam 1 and the steel truss 5 in the warehouse, and the number of the hanger rods is selected according to the structural characteristics of the steel truss, and 5 are selected in this example.

The specific calculation formula is as follows:

acting force on the suspender: n is q.L/2 h

The section stress of the suspender: sigma_max＝N/A≦[σ]

The material specification model and the suspender quantity of the steel truss reinforcing suspender (2) are obtained by calculating the warehouse top reinforcing steel plate beam (1) and the warehouse inner steel truss (5), and the specific calculation formula is as follows:

acting force on the suspender: n is q.L/2 h;

the section stress of the suspender: sigma_max＝N/A≦[σ]；

Wherein: n is the acting force of the suspender, q is the design load of the original truss girder, L is the length of the suspender from the support, h is the height of the original steel truss, sigma_maxThe maximum stress on the suspension rod, A is the cross-sectional area of the suspension rod material, [ sigma ]]Allowable stress value of the suspender material;

and (3) calculating the section bearing capacity of the steel plate beam-steel truss combined beam after reinforcement:

a. and (4) checking and calculating the bending strength:

static load sigma₁＝(M_x+M'_x)/k·W^z _nx≤f；

Dynamic load sigma₂＝M_x/W_nx+M'_x/W^z _nx≤f；

Wherein σ₁Stress in cross section under static load, σ₂Is the stress in the section under the dynamic load; f is the bending strength design value of the steel material, and 325.00N/mm is taken²；M_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; w_nxThe net section resisting moment of the original component before reinforcement; w^z _nxFor strengthening the whole net cross sectionMoment resistance; k is a reduction coefficient of reinforcement, and 0.9 is taken;

b. and (4) checking and calculating the shear strength:

static load τ₁＝(V+V')·S^z/k·I^z·t_w ^z≤f_v

Dynamic load τ₂＝V·S/I·t_w+V'·S^z/I·t_w ^z≤f_v

Wherein, tau₁Is shear stress in a stressed section under static load, tau₂The shear stress in the stressed section under dynamic load; v is the shear force of the original component for calculating the cross section effect before reinforcement; v' is an additional shearing force for calculating the cross section action of the reinforced member; s, S^zCalculating area moments of smaller cross sections outside the shear stress position to the neutral axis for the reinforced front and rear cross sections respectively; I. i is^zThe moment of inertia of the reinforced front and rear sections; t is t_wThe original thickness of the cross-section web plate before reinforcement is achieved; t is t_w ^zThe total thickness of the whole cross-section web after reinforcement is adopted; f. of_vThe shear strength of the steel is designed to be 170.00N/mm²K is a reduction coefficient of reinforcement, and 0.9 is taken;

c. checking and calculating the integral stability of the beam:

static load (M)_x+M'_x)/k·ψ_zb·W_zx≤f

Dynamic load M_x/ψ_zb·W_x+M'x/ψ_zb·W_zx≤f

Wherein, W_x、W_zxRespectively reinforcing the rough cross section resisting moment of the front component and the rear component; psi_zbCalculating the whole bending stability coefficient of the whole cross section after reinforcement according to the current specification; m_xCalculating the bending moment at the section of the original component before reinforcement; m'_xCalculating an additional bending moment at the cross section for the reinforced rear member; f is the bending strength design value of the steel material, and 325.00N/mm is taken²。

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.