Column-beam cooperative construction method for deck type reinforced concrete arch bridge

Abstract

The invention discloses a cooperative construction method for a deck type reinforced concrete arch bridge column and a deck type reinforced concrete arch bridge beam. The method aims at the characteristics that the height of the spandrel column of the deck type arch bridge gradually increases from the midspan to the two banks, time difference exists in construction of high and low columns, and the construction progress of the low column and a corresponding cover beam is far faster than that of the high column. In the construction period of the on-arch stand columns, bridge floor beams are symmetrically erected from the midspan to the two banks through a cable hoisting system, the construction sequence of the stand columns and cover beams and the erection time of the bridge floor beams are reasonably adjusted, construction temporary balance weight loads are replaced by the dead weights of the bridge floor beams of permanent structures, and column-beam cooperative construction is achieved in a permanent and temporary combination mode; the problem that the structural strength of the concrete arch ring is insufficient due to uneven load distribution in the construction period of the on-arch stand column is solved.

Description

Technical Field

[0001] The present invention relates to the field of construction of arch bridge columns and beams, and more specifically to a method for collaborative construction of columns and beams of a deck-type reinforced concrete arch bridge. Background Art

[0002] During the construction of the superstructure of a deck-type reinforced concrete arch bridge, the arch columns are cast in segments. Since there is a large height difference in the arch columns from the mid-span to both banks, the columns are bound to have uneven pouring, which causes uneven internal force distribution of the concrete arch ring and insufficient structural strength, resulting in excessive tensile stress of the concrete near the arch feet. Currently, the solution is usually to arrange temporary construction counterweights at the mid-span position. The temporary construction counterweights need to continuously adjust the load size according to the construction progress of the columns. The process is complex and the construction is cumbersome. At the same time, the beam erection on the arch is also limited by the construction progress of the columns. The beam erection on the arch can only be carried out after the columns are constructed, which causes a lag in the construction period and increases the investment in construction costs. Summary of the Invention

[0003] Therefore, in order to solve the above deficiencies, the present invention provides a method for collaborative construction of columns and beams of a deck-type reinforced concrete arch bridge. The present invention is for the synchronous, symmetric and balanced pouring construction of the arch columns in segments. In view of the fact that the height of the arch columns of the deck-type arch bridge gradually increases from the mid-span to both banks, resulting in a time difference in the construction of high and low columns, and the construction progress of the low columns and the corresponding cap beams is much faster than that of the high columns. During the construction of the arch columns, the deck beams are symmetrically erected from the mid-span to both banks by a cable hoisting system. By reasonably adjusting the construction sequence of the columns, cap beams and the erection time of the deck beams, and using the self-weight of the permanent structure deck beam to replace the temporary construction counterweight load, the collaborative construction of columns and beams is realized by the combination of permanent and temporary structures, and the problem of insufficient structural strength of the concrete arch ring caused by uneven load distribution during the construction of the arch columns is solved.

[0004] The present invention is implemented as follows. A method for collaborative construction of columns and beams of a deck-type reinforced concrete arch bridge is constructed, and its characteristics are as follows: The specific construction process is as follows:

[0005] (1) The deck beams are prefabricated in the factory and transported to the site, and the deck beams are erected by a cable hoisting system.

[0006] (2) The concrete of the column segments is symmetrically and evenly poured at both banks in multiple working faces at the same time. The construction progress of the columns and the corresponding cap beams in the mid-span direction is much faster than that in the direction of both banks, resulting in uneven pouring segments of the columns. Based on formula (1), calculate whether the stress of the key section of the concrete arch ring caused by the current column pouring segment meets the requirements of formula (3). The key section is the section corresponding to the eighth point of the calculated span of the arch bridge. If the requirements are met, continue to pour the next column segment. Otherwise, the deck beams are sequentially erected from the mid-span to both banks by a cable hoisting system, and the stress of the key section of the concrete arch ring is calculated according to formula (2).

[0007] σ i = σ i,自重 + Δσ i,立柱 + Δσ i,盖梁 (1)

[0008] σ i = σ i,自重 + Δσ i,立柱 + Δσ i,盖梁 + Δσ i,桥面梁 (2)

[0009] σ i ≤ f t / 1.25 (3)

[0010] Where: σ i — The cumulative stress of the i-th key section of the arch ring at the current construction stage, σ i,自重 — The stress of the i-th key section of the arch ring generated only by the self-weight of the arch ring; Δσ i,立柱 — The stress increment of the i-th key section generated by the pouring of the column section; Δσ i,盖梁 — The stress increment of the i-th key section generated by the pouring of the capping beam; Δσ i,桥面梁 — The stress increment of the i-th key section generated by the deck girder; f t Is the design value of the axial tensile strength of the arch ring concrete, and the coefficient 1.25 is the stress reserve reserved to ensure the safety of the concrete arch ring.

[0011] (3) As shown in Figure 3 and Figure 4 , the stress of the key section of the concrete arch ring at the m + k + 1# section of the column pouring does not meet the requirements of formula (3). At this time, the w# deck girder at the mid-span is erected through the cable hoisting system to achieve mid-span counterweight.

[0012] Among them, m is the number of segments of the low column pouring at the mid-span position, k is the maximum number of segments for which the unbalanced pouring concrete stress of the remaining columns at the current stage meets the requirements, and w is the number of the deck girder at the mid-span position.

[0013] (4) As shown in Figure 5 and Figure 6 , after the mid-span deck girder is counterweighted, the columns continue to be poured with concrete up to the m + k + l# section. If the next section is continued to be poured, the stress of the key section of the arch ring during the pouring process does not meet the requirements of formula (3). At this time, the w - 1# and w + 1# deck girders are erected through the cable hoisting system for counterweight.

[0014] Among them, l is the maximum number of segments for which the unbalanced pouring concrete stress of the remaining columns at the current stage meets the requirements, and w - 1# and w + 1# are the numbers of the deck girders adjacent to the mid-span position.

[0015] (5) As shown inFigure 7 As shown, based on step (2), determine the number of unbalanced pouring segments of the subsequent columns and the timing of erection of the counterweight for the bridge deck beam, and successively complete the pouring of the subsequent columns and the erection of the bridge deck beam, and adopt the combination of permanent and temporary structures to realize the collaborative construction of columns and beams; where w-x# and w+x# are the numbers of the bridge deck beams in the crosswise direction of both banks.

[0016] The present invention provides a method for collaborative construction of columns and beams of a deck type reinforced concrete arch bridge; the present invention is for the sectional synchronous symmetric balanced pouring construction of the columns on the arch. Aiming at the characteristics that the height of the columns on the arch gradually increases from the mid-span to the crosswise direction of both banks, resulting in a time difference in the construction of high and low columns, and the construction progress of the low columns and the corresponding capping beams is much faster than that of the high columns, during the construction of the columns on the arch, the bridge deck beam is symmetrically erected from the mid-span to the crosswise direction of both banks by means of a cable hoisting system. By reasonably adjusting the construction sequence of the columns and capping beams and the erection timing of the bridge deck beam, using the self-weight of the permanent structure bridge deck beam to replace the temporary counterweight load during construction, the collaborative construction of columns and beams is realized by adopting the combination of permanent and temporary structures, and the problem of insufficient strength of the concrete arch ring structure caused by uneven load distribution during the construction of the columns on the arch is solved.

[0017] The beneficial effects of the present application are: (1) Based on the time difference in the construction of high and low columns, by reasonably adjusting the construction sequence of the columns and the erection timing of the bridge deck beam, the collaborative construction of columns and beams is realized, and the problem of insufficient strength of the concrete arch ring structure caused by uneven internal force distribution during the column construction is solved. (2) The method for collaborative construction of columns and beams effectively controls the tensile stress of the concrete arch ring during the construction of the superstructure on the arch, and avoids the additional increase in the designed cross-sectional size to meet the requirements of the concrete arch ring stress during construction. (3) The temporary counterweight load during the column construction is replaced by the permanent structure bridge deck beam, and the collaborative construction of columns and beams is realized by adopting the combination of permanent and temporary structures, which greatly speeds up the construction progress, has good economy, and the tensile stress of the concrete arch ring is effectively controlled through theoretical calculation. (4) It provides a new method for the construction of columns and the erection of bridge deck beams of a deck type reinforced concrete arch bridge. During the construction of columns and beams, the concrete arch ring is reasonably stressed, the structure is safe and reliable, and the cost is low, which can provide reference for subsequent similar projects. Description of the Drawings

[0018] Figure 1 Schematic diagram of the construction load action of the columns on the arch;

[0019] Figure 2 Optimization flow chart of synchronous construction of columns and beams;

[0020] Figure 3 Schematic diagram of unbalanced pouring caused by high and low columns;

[0021] Figure 4 Schematic diagram of the counterweight erection of the bridge deck beam at the mid-span;

[0022] Figure 5 Schematic diagram of unbalanced pouring of columns after counterweight of the bridge deck beam at the mid-span;

[0023] Figure 6 Schematic diagram of counterweight for synchronous erection of bridge deck girders in two adjacent spans near the mid-span;

[0024] Figure 7 Schematic diagram of the completion of the synchronous erection construction of columns and bridge deck girders. Detailed implementation manners

[0025] The following will combine with the attached Figures 1-7 The present invention will be described in detail below. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] The present invention provides a method for collaborative construction of columns and girders of a deck type reinforced concrete arch bridge here, and the following will describe it in detail;

[0027] The superstructure of the deck type reinforced concrete arch bridge includes the construction of columns, capping beams and bridge deck girders. Taking the sectional construction of columns as an example, the self-weight of the column casting section directly generates a vertical load on the concrete arch ring, thereby causing a change in the stress of the concrete arch ring. Based on this, a linear relationship between the change in the column load and the stress of the concrete arch ring is established by combining the influence matrix. As Figure 1 shown, when a unit vertical force P1 is applied to the 1# column alone and the vertical forces P i (i = 2…n) of the remaining columns are taken as zero, the stress increment of the key section of the concrete arch ring generated by the column section casting is σ j1 (j = 1…5), and the key section is the section corresponding to the eighth point of the calculated span of the arch bridge. Similarly, when a unit vertical force is applied to the i (i = 2…n)# column alone, the influence matrix C1 of the stress increment of the key section of the concrete arch ring generated by the column section casting is:

[0028]

[0029] Based on this, an influence matrix equation of the stress increment {Δσ 立柱} of the concrete arch ring generated by the column section casting and the change in the load of the superstructure column sectional construction {P} is constructed.

[0030] {Δσ 立柱} = [C1]·{P} (5)

[0031] Similarly, the capping beam is cast in one go, and the bridge deck girders are symmetrically erected from the mid-span to both banks for each span. Therefore, the stress increments {Δσ 盖梁}, {Δσ 桥面梁} and the influence matrix equation of the load change of each cross - beam and deck beam.

[0032] {Δσ 盖梁} = [C2]·{P 盖梁} (6)

[0033] {Δσ 桥面梁} = [C3]·{P 桥面梁} (7)

[0034] In the formula, [C2] is the influence matrix of the stress increment of the key section of the concrete arch ring caused by the unit load change during the casting of the cross - beam, [C3] is the influence matrix of the stress increment of the key section of the concrete arch ring caused by the unit load change during the erection of the deck beam, {P 盖梁} is the self - weight load vector of each cross - beam in the current stage, and {P 桥面梁} is the self - weight load vector of each cross - deck beam in the current stage.

[0035] Based on this, the stress equation of the key section of the concrete arch ring during the whole process of the construction of the super - structure on the arch is constructed.

[0036] {σ} = {σ 自重} + {Δσ 立柱} + {Δσ 盖梁} (8)

[0037] {σ} = {σ 自重} + {Δσ 立柱} + {Δσ 盖梁} + {Δσ 桥面梁} (9)

[0038] In the formula, {σ} is the stress of the key section of the concrete arch ring in the current construction stage, and {σ 自重} is the stress of the key section of the concrete arch ring caused only by its self - weight.

[0039] In summary, the stress constraint equation of the key section of the concrete arch ring during the whole process of the construction of the super - structure on the arch is constructed.

[0040] {σ} ≤ {f t / 1.25} (10)

[0041] In the formula, {f t} is the design value of the axial tensile strength of the outer - wrapped concrete of the arch ring, and the coefficient 1.25 is the stress reserve reserved to ensure the safety of the concrete arch ring.

[0042] The above - mentioned optimization process of the synchronous construction of columns and beams based on the influence matrix and the superposition principle is as Figure 2 shown.

[0043] The specific construction process of this application is as follows:

[0044] (1) The bridge deck girders are prefabricated in the yard and transported to the site, where they are erected by the cable hoisting system.

[0045] (2) The concrete of the column segments is poured symmetrically and evenly at both banks with multiple working faces simultaneously. The construction progress of the columns and the corresponding capping beams in the mid-span direction is much faster than that in the direction of both banks, resulting in uneven pouring of the column segments. Based on formula (8), calculate whether the stress of the key section of the concrete arch ring caused by the currently poured column segment meets the requirements of formula (10). The key section is the section corresponding to the eighth point of the calculated span of the arch bridge. If the requirements are met, continue pouring the next column segment; otherwise, sequentially erect the bridge deck girders from the mid-span to both banks by the cable hoisting system and calculate the stress of the key section of the concrete arch ring according to formula (9).

[0046] (3) As Figure 3 and Figure 4 shown, the stress of the key section of the concrete arch ring when pouring the m + k + 1# column segment does not meet the requirements of formula (10). At this time, the w# bridge deck girder at the mid-span is erected by the cable hoisting system to achieve mid-span counterweight.

[0047] Where m is the number of segmented pouring sections of the low columns at the mid-span position, k is the maximum number of sections where the uneven pouring concrete stress of the remaining columns in the current stage meets the requirements, and w is the number of the bridge deck girder at the mid-span position.

[0048] (4) As Figure 5 and Figure 6 shown, after the mid-span bridge deck girder is counterweighted, the columns continue to be poured to the m + k + l# column segment of concrete. If pouring the next section continues, the stress of the key section of the arch ring during the pouring process does not meet the requirements of formula (9). At this time, the w - 1# and w + 1# bridge deck girders are erected by the cable hoisting system for counterweight.

[0049] Where l is the maximum number of sections where the uneven pouring concrete stress of the remaining columns in the current stage meets the requirements, and w - 1# and w + 1# are the numbers of the bridge deck girders adjacent to the mid-span position.

[0050] (5) As Figure 7 shown, based on step (2), determine the number of unbalanced pouring sections of the subsequent columns and the timing of erecting the bridge deck girders for counterweight, and sequentially complete the pouring of the subsequent columns and the erection of the bridge deck girders, and adopt the combination of permanent and temporary structures to achieve the coordinated construction of columns and girders; where w - x# and w + x# are the numbers of the bridge deck girders in the direction of both banks.

[0051] The beneficial effects of this application are as follows: (1) Based on the time difference in the construction of high and low columns, by reasonably adjusting the construction sequence of columns and the erection timing of the deck girder, the coordinated construction of columns and girders is achieved, solving the problem of insufficient strength of the concrete arch ring structure caused by uneven internal force distribution during column construction. (2) The coordinated construction method of columns and girders effectively controls the tensile stress of the concrete arch ring during the construction of the superstructure on the arch, avoiding the additional increase in the designed cross-sectional size to meet the requirements of the concrete arch ring stress during construction. (3) The temporary counterweight load during column construction is replaced by the permanent structure deck girder, and the coordinated construction of columns and girders is realized by combining permanent and temporary structures, greatly accelerating the construction progress, having better economy, and effectively controlling the tensile stress of the concrete arch ring through theoretical calculation. (4) It provides a new method for the construction of columns and the erection of deck girders of the through-type reinforced concrete arch bridge. During the construction of columns and girders, the concrete arch ring is reasonably stressed, the structure is safe and reliable, and the cost is low, which can provide reference for subsequent similar projects.

[0052] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A construction method for collaborative construction of columns and beams of a through-type reinforced concrete arch bridge, characterized in that, After the construction of the concrete arch ring is completed, the construction process of the columns, capping beams and deck girders is as follows: (1) Prefabricate the deck girders in the prefabrication yard in advance; (2) Pour the concrete of the column segments symmetrically and evenly at both banks with multiple working faces simultaneously; (3) Pour the concrete of the capping beams; (4) Erector the deck girders.

2. The collaborative construction method of columns and beams of a deck-type reinforced concrete arch bridge according to claim 1, wherein The stresses generated in the key sections of the arch ring by the pouring of the column segment concrete, the capping beam concrete and the erection of the deck girders are calculated according to Formulas (1) and (2): σ i = σ i,自重 + Δσ i,立柱 + Δσ i,盖梁 (1) σ i = σ i,自重 + Δσ i,立柱 + Δσ i,盖梁 + Δσ i,桥面梁 (2) σ i ≤f t / 1.25 (3) Where: σ i — The cumulative stress of the i-th key section of the arch ring in the current construction stage, σ i,自重 — The stress of the i-th key section of the arch ring generated only by the self-weight of the arch ring; Δσ i,立柱 — The stress increment of the i-th key section generated by the casting of the column segment; Δσ i,盖梁 — The stress increment of the i-th key section generated by the casting of the capping beam; Δσ i,桥面梁 — The stress increment of the i-th key section generated by the deck girder; f t is the design value of the axial tensile strength of the arch ring concrete, and the coefficient 1.25 is the stress reserve reserved to ensure the safety of the concrete arch ring.

3. The collaborative construction method of columns and beams of a deck-type reinforced concrete arch bridge according to claim 1, characterized in that, The columns at the mid-span of the arch ring are short in height, while the columns at the arch feet are tall in height, resulting in unequal numbers of column pouring segments, and making the construction progress of the mid-span columns and the corresponding capping beams much faster than that of the arch feet.

4. The method for collaborative construction of columns and beams of an upper-supported reinforced concrete arch bridge according to claim 1, characterized in that When the stresses in the key sections of the arch ring generated by the pouring of the column segment concrete and the capping beam concrete satisfy Formula (3), continue to pour the concrete of the subsequent column segments and capping beams; when the stresses do not satisfy Formula (3), the deck girders shall be erected symmetrically from the mid-span to both banks, and the stresses in the key sections of the arch ring shall be calculated according to Formula (2), and it shall be judged whether the requirements of Formula (3) are satisfied. If the requirements are satisfied, continue to pour the concrete of the column segments and capping beams. If the requirements of Formula (3) are not satisfied, continue to erect the deck girders until the requirements of Formula (3) are satisfied.

5. The method for collaborative construction of columns and beams of a through-type reinforced concrete arch bridge according to claim 2, characterized in that, The key section of the arch ring mentioned above is the arch ring section corresponding to dividing the calculated span L of the arch bridge into eight equal parts. According to the symmetry of the arch bridge, the key sections of the half-span arch bridge are the arch feet, L / 8, L / 4, 3L / 8, L / 2 (arch crown).

6. The method for collaborative construction of columns and beams of a deck type reinforced concrete arch bridge according to claim 1, characterized in that The construction of the columns on the arch is carried out in sequence, and the coordinated construction of the columns and beams of the superstructure reinforced concrete arch ring is realized through the combination of permanent and temporary structures, ensuring that the stresses in the key sections of the arch ring always meet the requirements of Formula (3) during the entire construction process of the columns, capping beams and deck girders.

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