CN111428296A - Pre-camber design method for continuous steel truss girder - Google Patents
Pre-camber design method for continuous steel truss girder Download PDFInfo
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Abstract
The invention discloses a method for designing the pre-camber of a continuous steel truss girder, which comprises the steps of obtaining the pre-camber of the steel truss girder with arching stress and the initial length of each rod piece; and acquiring the final stretching amount and the node position of each rod piece by a geometric method according to the pre-camber and the initial length of each rod piece. By using the method for designing the pre-camber of the continuous steel truss girder, the pre-camber of the steel truss girder with the arching stress and the initial length of each rod piece are firstly obtained, then the final length of each rod piece and the position of each node can be accurately obtained by using a geometric method according to the pre-camber and the initial length, and the pre-camber without the arching stress is finally obtained because the positions of each node and the lengths of each rod piece obtained by the geometric method are in a pure geometric relationship and do not naturally have the arching stress; design and construction lofting are carried out according to the result, arching stress can be basically eliminated, and further material and engineering investment are saved.
Description
Technical Field
The invention relates to the field of steel trussed beams, in particular to a method for designing the pre-camber of a continuous steel trussed beam.
Background
One important aspect in the design of a large-span railway steel truss girder bridge is to set the pre-camber, so that the line is smooth and passengers feel comfortable when a train passes through the bridge, and the running quality of the line is improved.
For the pre-camber of the steel truss girder, the setting of the pre-camber does not influence the bridge deck system, and the pre-camber is generally realized by adjusting the splicing seam value at the node of the upper chord (essentially, the length of the upper chord) of the upper chord. However, for the continuous steel truss, it is difficult to obtain a reasonable pre-camber value only by adjusting the length of the upper chord, so that not only the upper chord but also the lower chord, the web member, and the like need to be considered.
Various pre-camber design methods are commonly used at present, such as a geometric method, a displacement load arching method, a temperature rise and drop method and the like.
Displacement load arching, using the pre-arching value as the displacement load, is possible in principle, but may produce large arching stresses.
The method of raising and lowering the temperature has been more applied in the setting of the pre-camber of the steel truss bridge, such as in the simple beam, but for the hyperstatic structure such as the continuous steel truss, the method is easy to generate the arching stress, and the arching stress will cause the total stress level of the structure to increase, thereby causing the structure size to increase, and wasting the material and investment. Therefore, the pre-camber setting must consider the arching reaction force and the arching stress, so that the arching reaction force is as zero as possible, and the arching stress is as small as possible. When the pre-camber is set by adopting a temperature rise and drop method, the conventional algorithm is difficult to solve due to the fact that the number of rod pieces is large, and theoretical pre-camber (a negative value of constant load plus half live load deflection), arching counter-force and arching stress are also considered. For hyperstatic structures such as continuous steel trussed beams and the like, reasonable pre-camber can be obtained only by adopting a temperature rise and drop method, but the problem of arching stress is difficult to solve fundamentally.
The pre-camber arranged by the existing geometric method can only be used for a simpler truss structure, such as a simple supported beam, and cannot be applied to a complex continuous steel truss geometric method. The reason is that the pre-camber of the simply supported beam is generally realized by changing the length of the upper chord, while the length of the lower chord and the length of the web member are not changed; because the lengths of the lower chord member and the web members are known, the length of the upper chord member after the pre-camber is considered can be obtained according to geometric lofting; for the complicated continuous steel truss girder, the lengths of the upper chord member and the lower chord member and the web member need to be changed, so that the lengths of the lower chord member and the web member are unknown, and the length of the upper chord member cannot be obtained by adopting a geometric method.
In summary, in order to prevent arching stress from being generated after the structural design considers the pre-camber, it is necessary to research a new method for designing the pre-camber of the continuous steel truss girder.
Disclosure of Invention
The invention aims to: aiming at the problem that arch camber can be generated after the structural design of the continuous steel truss girder considers the arch camber in the prior art, the method for designing the arch camber of the continuous steel truss girder is provided, and not only can the arch camber without the arch camber be set, but also the geometric position relation after the arch camber is considered can be obtained.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for designing the pre-camber of a continuous steel truss girder,
acquiring the pre-camber of the steel truss girder with arching stress and the initial length of each rod piece;
and acquiring the final stretching amount and the node position of each rod piece by a geometric method according to the pre-camber and the initial length of each rod piece.
By adopting the method for designing the pre-camber of the continuous steel truss girder, the pre-camber of the steel truss girder with the arching stress and the initial length of each rod piece are firstly obtained, then the final length of each rod piece and the position of each node can be accurately obtained by using a geometric method according to the pre-camber and the initial length, and the pre-camber without the arching stress is finally obtained because the positions of each node and the lengths of each rod piece obtained by the geometric method are in a pure geometric relationship and do not naturally have the arching stress; design and construction lofting are carried out according to the result, arching stress can be basically eliminated, and further material and engineering investment are saved.
Preferably, the design method comprises:
the method comprises the following steps of (1) utilizing a geometric method to manufacture the steel truss girder, analyzing the freedom degree of each upper chord node of the steel truss girder, and respectively processing nodes with different freedom degrees without considering an upper chord during the analysis of the freedom degree;
the node with the degree of freedom of 0 is not processed;
removing redundant constraint (namely rod) of the node with the degree of freedom less than 0 to ensure that the degree of freedom is 0;
then, nodes with the degree of freedom of 0 are made;
reference point E of geometric method for selecting steel truss girderN；
Make a reaction withNAdjacent lower chord node E taking account of pre-camberN-1；
Make a reaction withNAdjacent pre-camber considered upper chord node AN-1；
Make a reaction withN-1Adjacent lower chord node E taking account of pre-camberN-2；
Make a reaction withN-1Adjacent pre-camber considered upper chord node AN-2；
The method is continuously adopted to obtain all the positions of the lower chord nodes with the pre-camber considered and the degree of freedom less than or equal to 0The position of a top chord node; it should be noted that the number of the above-mentioned nodes may vary according to the type of the steel truss girder truss, and the number is not necessarily continuous, nor is it necessarily consistent with the lower chord node ENThe number of the corresponding upper chord node is AN-1As long as the geometric positions of the nodes are adjacent, the node numbers are only used for convenience of explanation;
then according to the nodes obtained in the above steps, a chord-up node A with the degree of freedom > 0 is formedMThus, all node positions are obtained;
and finally, reducing the rod piece at the node with the degree of freedom less than 0.
Further preferably, a reference point E is madeNAdjacent lower chord node EN-1A1 is mixing EN-1To ENThe vertical distance of the node E is added with the pre-camber value to obtain a node EN-1The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-1ENThe length of the rod member being a radius, reference point ENMaking a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the lower chord node E after considering the pre-camberN-1。
Further preferably, with ENAs a center of circle, ENAN-1The length of the rod piece is a radius and is made into a circle; with EN-1As a center of circle, EN-1AN-1The length of the rod piece is a radius and is made into a circle; the two circles intersect at the upper chord node A after considering the pre-camberN-1。
Further preferably, E isN-2To ENThe vertical distance of the lower chord is added with the pre-camber value to obtain a lower chord node EN-2The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-2EN-1The length of the rod member being a radius, EN-1Making a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the lower chord node E after considering the pre-camberN-2。
Further preferably, with EN-1As a center of circle, EN-1AN-2The length of the rod piece is a radius and is made into a circle; with EN-2As a center of circle, EN-2AN-2The length of the rod piece is a radius and is made into a circle; the two circles intersect at the upper chord node A after considering the pre-camberN-2。
Further excellenceOptionally, connecting the upper chord node A with the obtained degree of freedom less than or equal to 0M-1And AM+1Taking the midpoint of the curve to obtain the upper chord node A with degree of freedom > 0 and taking account of pre-camberM。
Further preferably, the rods at the nodes with degrees of freedom < 0 are reduced, so that all rods are obtained.
Further preferably, when the continuous steel truss girder has an intermediate node, the design method includes:
reference point E of geometric method for selecting steel truss girderN；
Make a reference point ENAdjacent lower chord node E taking account of pre-camberN-1；
Make a reaction withNAdjacent pre-camber considered intermediate node BN；
Make a reaction withN-1Adjacent lower chord node E taking account of pre-camberN-2；
Make a reaction withN-1Adjacent pre-camber considered intermediate node BN-1；
Is made with BNAdjacent pre-camber considered upper chord node AN-1；
Continuously adopting the mode to obtain all the positions of the lower chord node, the middle node and the upper chord node with the degree of freedom less than or equal to 0 after the pre-camber is considered;
then according to the nodes obtained in the above steps, a chord-up node A with the degree of freedom > 0 is formedMThus, all node positions are obtained;
and finally, reducing the rod piece at the node with the degree of freedom less than 0.
Further preferably, a lower chord node at a fulcrum in the steel truss girder is selected as a reference point E of a geometric methodN。
Further preferably, a reference point E is madeNAdjacent lower chord node EN-1A1 is mixing EN-1To ENThe vertical distance of the node E is added with the pre-camber value to obtain a node EN-1The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-1ENThe length of the rod member being a radius, reference point ENMake a circle as the center of the circleThe intersection point of the circle and the horizontal straight line is the lower chord node E with the pre-camber taken into considerationN-1。
Further preferably, with ENAs a center of circle, ENBNThe length of the rod piece is a radius and is made into a circle; with EN-1As a center of circle, EN-1BNThe length of the rod piece is a radius and is made into a circle; two circles intersect at an intermediate node B taking account of pre-camberN。
Further preferably, E isN-2To ENThe vertical distance of the lower chord is added with the pre-camber value to obtain a lower chord node EN-2The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-2EN-1The length of the rod member being a radius, EN-1Making a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the lower chord node E after considering the pre-camberN-2。
Further preferably, with EN-1As a center of circle, EN-1BN-1The length of the rod piece is a radius and is made into a circle; with EN-2As a center of circle, EN-2BN-1The length of the rod piece is a radius and is made into a circle; two circles intersect at an intermediate node B taking account of pre-camberN-1。
Further preferably, with BNAs a center of a circle, BNAN-1The length of the rod piece is a radius and is made into a circle; with BN-1As a center of a circle, BN-1AN-1The length of the rod piece is a radius and is made into a circle; the two circles intersect at the upper chord node A after considering the pre-camberN-1。
Further preferably, the upper chord node A of which the degree of freedom ≦ 0 that has been obtained is connectedM-1And AM+1Taking the midpoint of the curve to obtain the upper chord node A with degree of freedom > 0 and taking account of pre-camberM。
Further preferably, the rods at the nodes with degrees of freedom < 0 are reduced, so that all rods are obtained.
Preferably, the pre-camber of the steel truss girder with arching stress is obtained by a temperature raising and lowering method based on an optimization theory.
Further preferably, the temperature raising and reducing method based on the optimization theory comprises the following steps:
obtaining a stress coefficient matrix of each rod piece of the steel truss girder, a displacement coefficient influence matrix of the nodes and a counter force coefficient influence matrix of the pivot according to the finite element model;
establishing an optimized mathematical model and an optimized equation according to a superposition principle;
and solving an optimal equation to obtain the initial stretching amount and the pre-camber of each rod piece, and further obtaining the initial length of each rod piece according to the initial stretching amount and the theoretical design length without considering the pre-camber, wherein the structure contains certain arching stress at the moment.
The pre-camber with the arching stress obtained by the temperature rising and reducing method based on the optimization theory is relatively uniform in full bridge and smaller in arching stress compared with a common method; and the difference of the initial stretching amount of each rod piece is not large, the condition that the stretching amount of a certain rod piece is large can not occur, and the length and the included angle of each rod piece can not be obviously changed compared with the theoretical design length and the included angle without considering the pre-camber.
In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:
1. by using the method for designing the pre-camber of the continuous steel truss girder, the pre-camber of the steel truss girder with the arching stress and the initial length of each rod piece are firstly obtained, then the final length of each rod piece and the position of each node can be accurately obtained by using a geometric method according to the pre-camber and the initial length, and the pre-camber without the arching stress is finally obtained because the positions of each node and the lengths of each rod piece obtained by the geometric method are in a pure geometric relationship and do not naturally have the arching stress; designing and construction lofting are carried out according to the result, arching stress can be basically eliminated, and further material and engineering investment are saved;
2. by applying the method for designing the pre-camber of the continuous steel truss girder, the pre-camber with the arching stress is obtained by the temperature rise and drop method based on the optimization theory, the generated arching stress is more uniform in a full bridge, and the arching stress is smaller compared with that of a common method; and the difference of the initial stretching amount of each rod piece is not large, the condition that the stretching amount of a certain rod piece is large can not occur, and the length and the included angle of each rod piece can not be obviously changed compared with the theoretical design length and the included angle without considering the pre-camber.
Drawings
FIG. 1 is a schematic view of the vertical arrangement of a continuous steel girder in the embodiment without considering the pre-camber;
FIG. 2 is a schematic view of step 5 in the example;
FIG. 3 is a schematic view of step 6 in the example;
FIG. 4 is a schematic view of step 7 in the example;
FIG. 5 is a schematic view of step 8 in the example;
FIG. 6 is a schematic view of step 9 in the example;
FIG. 7 is a schematic diagram of step 10 in the example;
fig. 8 is a schematic view of the vertical arrangement of the continuous steel girder in the embodiment in consideration of the pre-camber.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Examples
The method for designing the pre-camber of the continuous steel truss girder is applied to a railway super-large bridge, the bridge is a (140+224+140) m steel truss continuous girder, the height of a middle supporting point truss is 32m, the height of a side supporting point truss is 16m, the middle supporting point is gradually changed to an equal-height section by adopting a secondary parabola, the center distance of two main trusses is 14m, the length of a pitch is 14m, and N-shaped and K-shaped combined trusses are adopted.
As shown in FIG. 1, the figure only shows one half of the bridge structure, including the lower nodes E0-E18, the middle nodes B8-B12, and the upper nodes A1-A18, and the relative position relationship of the rods is shown in the figure.
The design method comprises the following steps:
firstly, acquiring the pre-camber of the steel truss girder with arching stress and the initial length of the steel truss girder and each rod piece by a temperature rise and drop method based on an optimization theory.
The method comprises the following steps of arranging m nodes, n rod pieces and k fulcrums; let the theoretical pre-camber at the ith point be si。
In this step, a unit temperature load (in this embodiment, a temperature load of 1 degree) is usually applied to a single member j of the steel truss to obtain a stress σ of the member iijDisplacement of node iijAnd reaction force r of fulcrum iijTraversing all the rods to obtain a stress coefficient matrix sigmaijThe displacement coefficient influence matrixij]And reaction coefficient influence matrix [ rij]。
And 2, establishing an optimized mathematical model and an optimized equation according to the superposition principle.
According to the principle of superposition, there are
WhereiniIs the displacement value of the ith node, σiIs the stress value of the ith rod member, riIs the reaction force of the ith fulcrum, TjTemperature load applied to jth bar.
Establishing an optimization equation by taking the weighted square sum of the pre-camber and the arching stress as an objective function and the support reaction force and the temperature load as constraint conditions
Wherein r isdi，ruiThe lower limit and the upper limit of the support reaction force of the ith point are respectively, the values need to be determined artificially, and theoretically, the smaller the value is, the better the value is; t isdi，Tuiα, respectively, the lower limit and the upper limit of the temperature load applied on the ith rod piece, the magnitude of the temperature load needs to be limited in order to prevent the expansion and contraction value of each rod piece from being too largePre-camber and camber stress.
And 3, solving an optimized equation, namely solving the equation (2), obtaining the temperature load of each rod piece, and obtaining the initial expansion amount of the rod piece according to the linear expansion coefficient formula of the rod piece.
In order to prevent the rod member from having too large expansion value, the maximum expansion value is set to be not more than 30mm, and the temperature load is set to be-150 < Ti< 150 (except E8E9, E9E10, E10E11 and E11E 12), the expansion and contraction of the E8E9, E9E10, E10E11 and E11E12 rods have great influence on arching stress through analysis, so that the temperature load of the four rods is-60 < TiLess than 60; in order to minimize the arching reaction force, let-1 < ri＜1。
Substituting the values into an optimized mathematical model, calculating and rounding the stretching amount to obtain the following results in table 1:
TABLE 1 temperature load of main truss member and length variation gauge of member
The pre-arching value and the arching stress value can be obtained by replacing the temperature T with the formula (1), and the pre-arching value is detailed in the following table 2:
TABLE 2 PRE-ARCH COMPARATIVE TABLE FOR CALCULATING PRE-ARCH
As can be seen from Table 2, the maximum error between the theoretical pre-camber and the calculated pre-camber is only 6 mm; in this case, the maximum arching stress of the structure was 51 MPa.
And secondly, acquiring the final expansion amount and the node position of each rod piece by a geometric method according to the pre-camber and the initial length of each rod piece.
Step 4, removing the upper chord and analyzing the freedom degree of the upper chord node, wherein the analysis shows that the freedom degree of A10 is equal to 1, the freedom degrees of A7 and A13 are equal to-1, and the freedom degrees of the other upper chord nodes are equal to 0; selecting a lower chord node at a fulcrum in the steel truss as a datum point E of a geometric methodNThe coordinate value is set to (0, 0).
Specifically, as shown in fig. 1 and 2, E10 is used as a reference (0, 0).
Step 5, making reference point ENAdjacent lower chord node EN-1A1 is mixing EN-1To ENThe vertical distance of the node E is added with the pre-camber value to obtain a node EN-1The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-1ENThe length of the rod member being a radius, reference point ENMaking a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the node E after considering the pre-camberN-1。
Specifically, as shown in fig. 2, when pre-camber is applied based on E10 (0, 0), the elevation y of E9 with respect to E10 is (4888.9-10.7) is 4878.2, and the length 14839.1 of E9E10 is used as a radius to make a circle. And taking the intersection point of the circle and the elevation y value of E9 as the E9 point.
Step 6, with ENAs a center of circle, ENBNThe length of the rod piece is a radius and is made into a circle; with EN-1As a center of circle, EN-1BNThe length of the rod piece is a radius and is made into a circle; two circles intersect at an intermediate node B taking account of pre-camberN。
Specifically, as shown in fig. 3, the length 16000 of E10B10 is a radius circle, the length 17873.4 of E9B10 is a radius circle, and the intersection point of the two circles is B10.
Step 7, adding EN-2To ENThe vertical distance of the lower chord is added with the pre-camber value to obtain a lower chord node EN-2The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-2EN-1The length of the rod member being a radius, EN-1Making a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the node E after considering the pre-camberN-2。
Specifically, as shown in fig. 4, E8 is rounded off at the elevation y-8886.1 (8888.9-2.8) relative to E10, with the radius being the length 14570.2 of E9E 8; and taking the intersection point of the circle and the elevation y value of E8 as the E8 point.
Step 8, with EN-1As a center of circle, EN-1BN-1The length of the rod piece is a radius and is made into a circle; with EN-2As a center of circle, EN-2BN-1The length of the rod piece is a radius and is made into a circle; two circles intersect at an intermediate node B taking account of pre-camberN-1。
Specifically, as shown in fig. 5, a circle is drawn by taking the length 11111.1 of E9B9 as a radius, a circle is drawn by taking the length 15702.5 of E8B9 as a radius, and the intersection point of the two circles is B9.
Step 9, as shown in fig. 6, the above method is continuously adopted to obtain the positions of all the lower chord nodes, the middle nodes and the upper chord nodes except a10 (the degree of freedom of the a10 node is 1) after the pre-camber is considered;
step 11, as shown in fig. 8, connect A7B8, connect a13B12, complete all the rods.
The positions of the nodes and the lengths of the rod pieces obtained by the geometric method are in a pure geometric relationship, and arch camber stress does not exist naturally.
Specifically, the length, the node coordinates, and the included angle of each member are shown in fig. 8, and it can be known from a comparison of fig. 1 and 8 that, when the pre-camber without arching stress is taken into consideration, the lengths of the upper and lower chords are changed, the length of the web member is basically unchanged, and the included angle between the chords and the web member is changed.
The final amount of each rod was as follows in table 3:
TABLE 3 comparison table of initial and final expansion of rod
As can be seen from Table 3, the maximum difference between the initial expansion amount and the final expansion amount is 2.3mm at the position A12A13, the rest is basically about 1mm, and the smaller difference indicates that the temperature raising and lowering method based on the optimization theory can obtain better pre-camber and initial expansion amount; these differences are due to arching stresses. The design length of each rod piece, the position of each node and the included angle of each rod piece can be accurately obtained by adopting the final expansion amount and the pre-camber value, then design and construction lofting are carried out according to the result, the arching stress can be basically eliminated, and further the material and the engineering investment are saved.
In the embodiment, the pre-camber with arching stress and the initial length of each rod piece are obtained by adopting a temperature raising and lowering method based on an optimization theory, and the final rod piece length is obtained by adopting a geometric method for correction, so that the pre-camber without arching stress is realized, and the method is a scientific and reliable pre-camber design method.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A method for designing the pre-camber of continuous steel truss girder is characterized in that,
acquiring the pre-camber of the steel truss girder with arching stress and the initial length of each rod piece;
and acquiring the final stretching amount and the node position of each rod piece by a geometric method according to the pre-camber and the initial length of each rod piece.
2. The design method according to claim 1,
the method comprises the steps of (1) utilizing a geometric method to manufacture the steel truss girder, analyzing the degree of freedom of each node of the steel truss girder, and respectively processing nodes with different degrees of freedom without considering an upper chord during degree of freedom analysis;
the node with the degree of freedom of 0 is not processed;
removing redundant constraint of the node to enable the degree of freedom of the node to be 0 at first when the degree of freedom of the node is less than 0;
then, nodes with the degree of freedom of 0 are made;
reference point E of geometric method for selecting steel truss girderN；
Make a reaction withNAdjacent lower chord node E taking account of pre-camberN-1；
Make a reaction withNAdjacent pre-camber considered upper chord node AN-1；
Make a reaction withN-1Adjacent lower chord node E taking account of pre-camberN-2；
Make a reaction withN-1Adjacent pre-camber considered upper chord node AN-2；
Continuously adopting the mode to obtain all the positions of the lower chord nodes with the pre-camber considered and the positions of the upper chord nodes with the degree of freedom less than or equal to 0;
then according to the nodes obtained in the above mode, an upper chord node A with the degree of freedom being more than 0 is formedMThus, all node positions are obtained;
and finally, reducing the rod piece at the node with the degree of freedom less than 0.
3. The design method according to claim 2, wherein the lower chord node at the fulcrum in the steel truss is selected as a reference point E of the geometric methodN。
4. The design method of claim 2, wherein reference point E is madeNAdjacent lower chord node EN-1A1 is mixing EN-1To ENThe vertical distance of the node E is added with the pre-camber value to obtain a node EN-1The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-1ENThe length of the rod member being a radius, reference point ENMaking a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the lower chord node E after considering the pre-camberN-1。
5. The design method of claim 4, wherein E isNAs a center of circle, ENAN-1The length of the rod piece is a radius and is made into a circle; with EN-1As a center of circle, EN-1AN-1The rod member has a length ofMaking a circle with the radius; the two circles intersect at the upper chord node A after considering the pre-camberN-1。
6. The design method according to claim 5, wherein E isN-2To ENThe vertical distance of the lower chord is added with the pre-camber value to obtain a lower chord node EN-2The vertical coordinate of (2) is used for making a horizontal straight line through the point; with EN-2EN-1The length of the rod member being a radius, EN-1Making a circle as the center of the circle, wherein the intersection point of the circle and the horizontal straight line is the lower chord node E after considering the pre-camberN-2。
7. The design method of claim 6, wherein E isN-1As a center of circle, EN-1AN-2The length of the rod piece is a radius and is made into a circle; with EN-2As a center of circle, EN-2AN-2The length of the rod piece is a radius and is made into a circle; the two circles intersect at the upper chord node A after considering the pre-camberN-2。
8. The design method according to claim 7, wherein the upper chord node A having obtained the degree of freedom ≦ 0 is connectedM-1And AM+1Taking the midpoint of the curve to obtain the upper chord node A with degree of freedom > 0 and taking account of pre-camberM。
9. The design method according to claim 8, wherein the bars at the nodes having the degree of freedom < 0 are restored to obtain all the bars.
10. The design method according to any one of claims 1 to 9, wherein the pre-camber of the steel girder having arching stress is obtained by a temperature raising and lowering method based on an optimization theory.
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| CN202010189079.2A CN111428296B (en) | 2020-03-17 | 2020-03-17 | Pre-camber design method for continuous steel truss girder |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113722794A (en) * | 2021-08-16 | 2021-11-30 | 中交第二航务工程局有限公司 | Finite element simulation method for orthotropic steel bridge deck slab-truss combined structure |
| CN114741925A (en) * | 2022-04-15 | 2022-07-12 | 中铁大桥勘测设计院集团有限公司 | Method, device and equipment for calculating rod piece expansion and contraction amount and readable storage medium |
| CN116226972A (en) * | 2023-01-04 | 2023-06-06 | 中铁大桥勘测设计院集团有限公司 | Continuous steel truss girder pre-camber setting method and continuous steel truss girder |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050038636A1 (en) * | 2000-03-03 | 2005-02-17 | Beck Technology, Ltd. | Computer-implemented building design and modeling and project cost estimation and scheduling system |
| CN101054794A (en) * | 2006-11-13 | 2007-10-17 | 柯猎奇 | Long-lasting protective layer for bridge construction original shape |
| CN107025347A (en) * | 2017-04-10 | 2017-08-08 | 中铁二院工程集团有限责任公司 | A kind of multiple line railway bridge rail linear control method |
| CN109583119A (en) * | 2018-12-11 | 2019-04-05 | 佛山科学技术学院 | A kind of setting method for large span through truss girder bridge factory camber |
-
2020
- 2020-03-17 CN CN202010189079.2A patent/CN111428296B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050038636A1 (en) * | 2000-03-03 | 2005-02-17 | Beck Technology, Ltd. | Computer-implemented building design and modeling and project cost estimation and scheduling system |
| CN101054794A (en) * | 2006-11-13 | 2007-10-17 | 柯猎奇 | Long-lasting protective layer for bridge construction original shape |
| CN107025347A (en) * | 2017-04-10 | 2017-08-08 | 中铁二院工程集团有限责任公司 | A kind of multiple line railway bridge rail linear control method |
| CN109583119A (en) * | 2018-12-11 | 2019-04-05 | 佛山科学技术学院 | A kind of setting method for large span through truss girder bridge factory camber |
Non-Patent Citations (4)
| Title |
|---|
| 但启联: "基于无应力状态控制法的钢桁梁桥起拱研究", 《哈尔滨工程大学学报》 * |
| 刘学信等: "铁路预应力钢桁梁设计理论与应用", 《西南交通大学学报(自然科学版)》 * |
| 向律楷等: "钢桁梁预拱度设置方法研究", 《四川建筑》 * |
| 陈建峰等: "南广铁路桂平郁江特大桥主桥钢梁预拱度设置", 《铁道建筑》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113722794A (en) * | 2021-08-16 | 2021-11-30 | 中交第二航务工程局有限公司 | Finite element simulation method for orthotropic steel bridge deck slab-truss combined structure |
| CN113722794B (en) * | 2021-08-16 | 2023-09-19 | 中交第二航务工程局有限公司 | Finite element simulation method for orthotropic steel bridge deck truss combined structure |
| CN114741925A (en) * | 2022-04-15 | 2022-07-12 | 中铁大桥勘测设计院集团有限公司 | Method, device and equipment for calculating rod piece expansion and contraction amount and readable storage medium |
| CN114741925B (en) * | 2022-04-15 | 2023-12-29 | 中铁大桥勘测设计院集团有限公司 | Method, device and equipment for calculating rod expansion and contraction amount and readable storage medium |
| CN116226972A (en) * | 2023-01-04 | 2023-06-06 | 中铁大桥勘测设计院集团有限公司 | Continuous steel truss girder pre-camber setting method and continuous steel truss girder |
| CN116226972B (en) * | 2023-01-04 | 2024-04-19 | 中铁大桥勘测设计院集团有限公司 | Continuous steel truss girder pre-camber setting method and continuous steel truss girder |
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