Construction calculation method of continuous concrete filled steel tube tied arch bridge

Abstract

The invention discloses a construction calculation method of a continuous concrete-filled steel tube tied arch bridge. The method comprises the following steps: a) determining a stress control point of a pier when concrete is poured into an arch rib steel tube according to the stress characteristics of the arch bridge; b) determining the influence line of the stress generated at the stress control point in the process of pouring concrete into the arch rib steel pipe; c) calculating the integral area of the stress influence line along the concrete pouring length in the arch rib steel pipe, and calculating the first stress generated by the poured concrete to the control point; d) calculating a second stress generated by the tie bar to the control point when the tie bar is tensioned; and e) determining the tension force and the tension mode of the tie bar and the concrete pouring mode of the arch rib steel pipe through the first stress and the second stress according to the stress balance condition at the control point. The method is simple in calculation, can quickly and simply determine the construction sequence, and improves the construction efficiency and safety.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a construction calculation method for a continuous steel tube concrete tied arch bridge. Background Art

[0002] After the arch ribs of the steel tube concrete arch bridge are installed, the empty steel tube truss arch is used as a template to pour the concrete in the steel tube. The concrete in the tube will generate horizontal thrust. When the general arch bridge is built in a mountainous area with good terrain, the arch seat and the mountain are usually used to offset the horizontal thrust of the arch foot. When the arch bridge is built on a plain, a tie arch bridge with piers is often used to offset the horizontal thrust of the arch foot by the tension of the tie rod. For a tie arch bridge, the pier bears the horizontal thrust and is the weak position of the structure. If the tension of the tie rod is unreasonable, the pier may bear too much horizontal thrust, causing excessive tensile stress at the bottom of the pier, which will affect the safety of the structure. During and after the pouring of the concrete in the tube, it should be ensured that the stress at the bottom of the pier does not exceed the allowable tensile stress. In view of construction deviation and safety considerations, the stress at the bottom of the pier should be guaranteed to be compressive stress. However, when the tie-arch bridge is a multi-span continuous arch bridge, in order to control the tensile stress at the bottom of the pier, it is necessary to use finite element method to repeatedly calculate the pouring sequence of concrete in the tube and the tensioning force of the tie rods. This is not only labor-intensive and inefficient, but also requires the tie rods to be tensioned multiple times, which increases the complexity of the construction. More importantly, it is difficult to achieve perfect results.

[0003] Therefore, for the construction of multi-span steel tube concrete tied arch bridges in plain areas, during the concrete pouring construction stage, it is necessary to find a safe, applicable, economical, fast and efficient method for pouring concrete in the tube and calculating the tie force, which can not only ensure the force safety of the structure, but also simplify the tie tensioning procedure and reduce the difficulty of construction. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a construction calculation method for a continuous steel tube concrete tie-bar arch bridge to solve the problem of the prior art using finite element to repeatedly calculate the pouring sequence of concrete in the tube and the tensioning force of the tie rods.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a construction calculation method for a continuous steel tube concrete tied arch bridge, the arch bridge includes a plurality of piers, and tie rods are arranged between the piers, and arch ribs made of steel tubes are arranged between adjacent piers, comprising the following steps:

[0006] a) Determine the control points when pouring concrete into the arch rib steel pipes of the piers according to the stress characteristics of the arch bridge;

[0007] b) determining the influence line of the stress generated at the control point during the process of pouring concrete into the arch rib steel pipe;

[0008] c) calculating the integral area of ​​the stress influence line along the concrete pouring length in the arch rib steel pipe, and calculating the first stress generated by the poured concrete at the control point;

[0009] d) Calculate the secondary stress generated by the tie rod at the control point when it is tensioned;

[0010] e) Determine the tensioning force and tensioning method of the tie rod and the concrete pouring method of the arch rib steel pipe according to the stress balance condition at the control point through the first stress and the second stress.

[0011] As an optimization, there are five piers, which are numbered as Pier 1, Pier 2...Pier 5 in sequence to form two side span arch ribs and two middle span arch ribs, wherein the arch diameter of the side span arch rib is smaller than the arch diameter of the middle span arch rib, and the control points are the center positions of Pier 1 and Pier 2 on opposite sides along the length of the arch bridge, and the control point on the side close to the middle span is Point 2, and the control point on the side far from the middle span is Point 4.

[0012] As an optimization, a finite element model of the arch bridge is established, the control points are determined, the influence lines of the stress generated at the control points by the process of pouring concrete into the arch rib steel pipe are calculated, and the integral area and the first stress are calculated based on the weight of the concrete line in the arch rib steel pipe.

[0013] As an optimization, the arch ribs include two parallel arch ribs, each arch rib includes four parallel steel pipes, and the steel pipes of the two arch ribs are symmetrically numbered as No. 1 steel pipe, No. 2 steel pipe, No. 3 steel pipe and No. 4 steel pipe; when all arch ribs are poured with concrete, the first stress at point 2 and point 4 of pier No. 1 and pier No. 2 is calculated by the following formula:

[0014]

[0015] In the formula, the general formula It represents the first stress at point j of pier i caused by pouring concrete in the arch rib steel pipe. It represents the stress caused by pouring concrete into a single steel pipe in the left and right arch ribs of the k-th span at point j of pier i, where i represents the pier number, j represents the control point position number, k represents the arch rib position number, q represents that the stress is caused by the concrete in the steel pipe, n represents the number of steel pipes in the arch rib, R represents the right arch rib, and L represents the left arch rib.

[0016] As an optimization, the tie rod includes a long tie rod and a short tie rod, which are numbered as tie rod No. 1 and tie rod No. 2. The two ends of the long tie rod are anchored on pier No. 1 and pier No. 5, and the two ends of the short tie rod are anchored on pier No. 2 and pier No. 4. When the tie rod is tensioned, the second stress generated at point No. 2 and point No. 4 of pier No. 1 and pier No. 2 is calculated by the following formula:

[0017]

[0018] In the formula, the general formula It represents the second stress generated at point j of pier i when tie rod l is tensioned. It represents the influence of the unit tension force of tie rod l on the stress at point j of pier i, where F(l) represents the tension force of tie rod l and l represents the tie rod number.

[0019] As an optimization, the equilibrium condition is to ensure that the stress at the control point is compressive stress when pouring concrete into the arch rib steel pipe and when tensioning the tie rod, that is,

[0020] When all the concrete is poured into the arch rib, the following conditions must be met:

[0021]

[0022] general formula It indicates the stress generated by the deadweight of the arch rib steel pipe before pouring concrete into the steel pipe;

[0023] When tensioning the tie rod, the following conditions must be met:

[0024]

[0025] The tensioning force range of the long tie rod is determined according to Formulas 9, 10, and 13, and the tensioning force range of the short tie rod is determined according to Formulas 11, 12, and 14. If there is no solution to the tensioning force range, the tensioning method adopts staged tensioning. The tensioning force range of staged tensioning is calculated by the stress after pouring concrete into a preset number of steel pipes of the arch rib until the tensioning force range has a solution, and the tensioning timing is selected after the concrete pouring in the preset number of steel pipes is completed.

[0026] As an optimization, the pouring method includes pouring the corresponding numbered steel pipes of the left and right arch ribs at the same time, first pouring the No. 1 steel pipe of the side span arch rib of one span, then pouring the No. 1 steel pipe of the other side span arch rib, then pouring the No. 1 steel pipe of the middle span arch rib of one span, then pouring the No. 1 steel pipe of the other middle span arch rib, and then cyclically pouring the No. 2 steel pipe, No. 3 steel pipe and No. 4 steel pipe in turn until the pouring of the entire arch rib steel pipe is completed.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) A method for calculating the tension force and timing of the tie rod is given, which avoids repeated calculations using finite element methods.

[0029] (2) Through calculation, the number of times the tie rods are tensioned can be reduced to ensure that no tensile stress occurs at the bottom of the pier, thus solving the problem of repeatedly tensioning the tie rods during the concrete pouring process.

[0030] (3) The steel pipes of the left and right arch ribs are poured with concrete at the same time, which replaces the problem of long pouring time of a single steel pipe in the existing method. In addition, pouring the left and right arch ribs at the same time can effectively solve the problem of inconsistent vertical deformation of the arch ribs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic structural diagram of an arch bridge in an embodiment;

[0032] Figure 2 A schematic diagram of the three-dimensional structure of an arch bridge in an embodiment;

[0033] Figure 3 A schematic diagram of the cross-sectional structure of an arch rib in an embodiment;

[0034] Figure 4 Schematic diagram of the concrete pouring sequence of the arch rib in the embodiment. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Example: See Figure 1-Figure 4 The object of the present invention is to provide a construction calculation method for a continuous steel tube concrete tied arch bridge, wherein the arch bridge comprises a plurality of piers, and tie rods are arranged between the piers, and arch ribs made of steel tubes are arranged between adjacent piers, comprising the following steps:

[0039] a) Determine the control points of the piers when pouring concrete in the arch rib steel pipes according to the stress characteristics of the arch bridge. In this embodiment, there are five piers, and the arch bridge is a symmetrical structure. Each pier includes two pier bodies. The pier described in this embodiment is one of the pier bodies, which does not affect the stress analysis. In this embodiment, the piers are numbered as Pier 1, Pier 2...Pier 5 in sequence to form two side span arch ribs and two middle span arch ribs, wherein the arch diameter of the side span arch rib is smaller than the arch diameter of the middle span arch rib. The control points are the center positions of Pier 1 and Pier 2 on the opposite sides along the length direction of the arch bridge, and the control point on the side close to the middle span is Point 2, and the control point on the side away from the middle span is Point 4.

[0040] b) determining the influence line of the stress generated at the control point by the process of pouring concrete into the arch rib steel pipe by establishing a finite element model of the arch bridge;

[0041] c) Calculate the integral area of ​​the stress influence line along the length of concrete poured in the arch rib steel pipe, and calculate the first stress generated by the poured concrete at the control point based on the weight of the concrete line in the arch rib steel pipe. The integral area is the integral of the influence line along the length of the steel pipe poured, which can be positive or negative. Positive values ​​represent tensile stress effects, and negative values ​​represent compressive stress effects. Specifically, the arch rib includes two parallel arch ribs, each arch rib includes four parallel steel pipes, and the steel pipes of the two arch ribs are symmetrically numbered as No. 1 steel pipe, No. 2 steel pipe, No. 3 steel pipe and No. 4 steel pipe; when all arch ribs are poured with concrete, the accumulated first stress at point 2 and point 4 of pier No. 1 and pier No. 2 is calculated by the following formula:

[0042]

[0043] In the formula, the general formula It represents the first stress at point j of pier o caused by pouring concrete in the arch rib steel pipe. It represents the stress caused by pouring concrete into a single steel pipe in the left and right arch ribs of the k-th span at point j of pier i, where i represents the pier number, j represents the control point position number, k represents the arch rib position number, q represents that the stress is caused by the concrete in the steel pipe, n represents the number of steel pipes in the arch rib, R represents the right arch rib, and L represents the left arch rib.

[0044] d) Calculate the secondary stress generated at the control point when the tie rod is tensioned.

[0045] Specifically, the tie rod includes a long tie rod and a short tie rod, which are numbered as tie rod No. 1 and tie rod No. 2. The two ends of the long tie rod are anchored on pier No. 1 and pier No. 5, and the two ends of the short tie rod are anchored on pier No. 2 and pier No. 4. When the tie rod is tensioned, the second stress generated at point No. 2 and point No. 4 of pier No. 1 and pier No. 2 is calculated by the following formula:

[0046]

[0047] In the formula, the general formula It represents the second stress generated at point j of pier i when tie rod l is tensioned. It indicates the influence of the unit tension force of tie rod l on the stress at point j of pier i. It can be positive or negative. Positive value indicates the influence of tensile stress, and negative value indicates the influence of compressive stress. Among them, F(l) indicates the tension force of tie rod l, and l indicates the tie rod number. When tensioning the tie rod, and is a negative value, and Is a positive value.

[0048] e) Determine the tensioning force and tensioning method of the tie rod and the concrete pouring method of the arch rib steel pipe according to the stress balance condition at the control point through the first stress and the second stress.

[0049] The equilibrium condition is to ensure that the stress at the control point is compressive stress when pouring concrete into the arch rib steel pipe and when tensioning the tie rod, that is,

[0050] When all the concrete is poured into the arch rib, the following conditions must be met:

[0051]

[0052] In the formula, the general formula It represents the stress generated by the deadweight of the arch rib steel pipe before pouring concrete into the steel pipe. It can be calculated by finite element method to ensure that the stress at the control position of the bottom of the pier is compressive stress. The value range of F(1) can be solved by formulas (9) and (10). The value range of F(2) can be solved by formulas (11) and (12).

[0053] First tension the tie rods, then pour concrete into the arch rib steel tubes. When tensioning the tie rods, ensure that the stress at the control position at the bottom of the pier is compressive stress, which must meet the following requirements:

[0054]

[0055] The value range of F(1) can be obtained from formulas (9) and (13), and the value range of F(2) can be obtained from formulas (10) and (14). If there is no solution, the concrete in the arch rib steel tube is poured in batches and the tie rods are tensioned in batches.

[0056] The tensioning force value range of the staged tensioning is calculated by the stress after pouring concrete into a preset number of steel pipes of the arch rib, until the tensioning force value range is solved, and the tensioning timing is selected after pouring the concrete into the preset number of steel pipes.

[0057] The pouring method includes pouring the corresponding numbered steel pipes of the left and right arch ribs at the same time, first pouring the No. 1 steel pipe of the side span arch rib of one span, then pouring the No. 1 steel pipe of the other side span arch rib, then pouring the No. 1 steel pipe of the middle span arch rib of one span, then pouring the No. 1 steel pipe of the other middle span arch rib, and then cyclically pouring the No. 2 steel pipe, the No. 3 steel pipe and the No. 4 steel pipe in turn until the pouring of the entire arch rib steel pipe is completed.

[0058] More specifically, further description and explanation are given below with reference to engineering examples.

[0059] The bridge is a bottom-supported steel tube concrete tied arch bridge. The main arch is composed of four connected arches with different spans, arranged as 190m+260m+260m+190m. All four arches are steel tube concrete truss arches, and the arch axis is in the form of a catenary, with an arch axis coefficient of 1.4. The calculated span of the arch rib with a span of 190m is 184m, and the calculated rise is 40.89m. The calculated span of the arch rib with a span of 260m is 254m, and the calculated rise is 56.44m. The arch rib steel is made of Q345, and the arch rib steel pipe is made of steel pipe with a diameter of 1000mm and a wall thickness of 22mm. C60 concrete is poured inside the steel pipe. The arch ribs are connected by cross braces, which increases the integrity of the arch ribs. The cross braces are trusses composed of steel pipes. Tie rods are divided into long tie rods and short tie rods. Tie rods are replaceable finished steel strand cables. The diameter of a single steel strand is 15.2 mm and the tensile strength is 1960 MPa. Short tie rods are anchored at piers 2 and 4. Long tie rods are anchored at piers 1 and 5. See the tie rod layout and anchorage position for details. Figure 1 .

[0060] Step 1: According to the established finite element model, since the structure is a symmetrical structure, point 2 and point 4 at the bottom of pier 1 and pier 2 are selected as control points, and their stress is used as the control target. Figure 2 .

[0061] Step 2: Calculate the stress influence line of concrete pouring in the pipe on the control point of the bridge pier

[0062] Step 3: Calculate the area corresponding to the stress influence line

[0063] The stress integral area of ​​the left and right arch rib steel tube concrete poured at point 2 at the bottom of pier 1 for the first and second spans is:

[0064]

[0065] The stress integral area of ​​the left and right side arch rib steel tube concrete poured at point 4 at the bottom of pier 1 in the first and second spans is:

[0066]

[0067] The stress integral area of ​​the left and right side arch rib steel tube concrete poured at point 2 at the bottom of pier 2 for the first and second spans is:

[0068]

[0069] The stress integral area of ​​the left and right side arch rib steel tube concrete poured at point 4 at the bottom of pier 2 in the first and second spans is:

[0070]

[0071] Step 4: The weight of the concrete line in the tube is q = 17.59 kN / m. According to formulas (1) to (4), the stress caused by concrete pouring at the stress control point at the bottom of the pier can be calculated.

[0072] The stress at point 2 of Pier 1 is: the concrete in the single steel pipes on the left and right sides of the first span is The single pipes on the left and right sides of the second span are poured

[0073] The stress at point 4 of Pier 1 is: the concrete in the single steel pipes on the left and right sides of the first span is The single pipes on the left and right sides of the second span are poured

[0074] The stress at point 2 of pier 2 is: the concrete in the single steel pipes on the left and right sides of the first span is The single pipes on the left and right sides of the second span are poured

[0075] The stress at point 4 of Pier 2 is: the concrete in the single steel pipes on the left and right sides of the first span is The single pipes on the left and right sides of the second span are poured

[0076] After the concrete pouring of the four steel tubes on the left and right arch ribs was completed, the accumulated stress at the bottom of Pier 1 and Pier 2 was:

[0077]

[0078] Step 5: Based on the finite element model, obtain the influence of tie rod tension on the stress control points at the bottom of Pier 1 and Pier 2 before concrete pouring. The long tie rods are anchored at Pier 1 and Pier 5. The influence of each 100kN tension on the stress at the bottom of Pier 1 is: The short tie rods are anchored at Pier 2 and Pier 4. The stress effect of each 100kN tension on the bottom of Pier 2 is: According to formulas (5) to (6), the stress caused by the tension force of the tie rod is:

[0079] Step 6: After the steel pipe arch construction is completed,

[0080] In order to ensure the safety of the bridge piers, after the arch rib steel tube concrete is fully poured, the stress at the bottom of the bridge pier is all compressive stress, that is, [σ] < 0. The feasible domain of the tie tension force of the long tie rod F(1) and the short tie rod F(2) can be obtained using formulas (9) to (12).

[0081] F(1)≥2488.1kN, F(1)≤3926.9kN. F(2)≥1001.5kN, F(2)≤4437.5kN.

[0082] The tension limits of long tie rods and short single-beams are 4625 kN and 3650 kN, respectively. Therefore, after the concrete in the arch rib steel tube is fully poured, no tensile stress appears at the bottom of the pier. The tie force of the long tie rod is in the range of [2488.1, 3926.9], and the tie force of the short tie rod is in the range of [1001.5, 3650]. The lower limit is taken, that is, F(1) = 2488.1 kN, F(2) = 1001.5 kN.

[0083] Step 8: First tension the tie rods, then pour concrete into the arch rib steel tube. To ensure that the bottom of the pier is under pressure when the tie rods are tensioned before pouring concrete, the feasible domain of the tie rod tensioning force of the long tie rod F(1) and the short tie rod F(2) can be obtained by using formulas (9) and (13), as well as formulas (10) and (14).

[0084] F(1)≥2488.1kN, F(1)≤1800.5kN. F(2)≥1001.5kN, F(2)≤2636.5kN.

[0085] The value of the short tie rod is 1001.5 kN. There is no solution for the long tie rod F(1). Therefore, the long tie rod is tensioned in batches during the concrete pouring process. Repeat step 4 to step 8. In order to minimize the tension of the long tie rod, when half of the arch rib concrete is poured, two steel pipes are poured on the left and right arch ribs of each span.

[0086] Feasible region of tie tension force for the long tie F(1).

[0087] F(1)≥1514.1kN, F(1)≤1800.5kN.

[0088] The first long tie rod tensioning force is 1514.1 kN. The second tensioning value is 2488.1-1514.1=974 kN.

[0089] At this time, we get the long tie rod tensioned twice, the first long tie rod tensioning force is 1514.1kN. The second tensioning value is 2488.1-1514.1=974kN. The short tie rod is tensioned once, and the tensioning force is 1001.5.

[0090] Infusion method: Figure 4 As shown,

[0091] Combined with the influence of Step 4 in-tube concrete pouring on Pier 1 and Pier 2, and the structural characteristics of the bridge, the first and fourth spans have small spans, while the second and third spans have large spans, and the pouring sequence of the bridge is given.

[0092] Stage 1 is the arching of steel tube arch ribs. Stage 2 is the first tensioning of long tie rods, with a tension force of 1514.1kN. Stage 3 is the tensioning of short tie rods, with a tension force of 1001.5kN.

[0093] Stage 4 is symmetrical pouring of No. 1 steel pipe in the first span. Stage 5 is symmetrical pouring of No. 1 steel pipe in the fourth span. Stage 6 is symmetrical pouring of No. 1 steel pipe in the second span. Stage 7 is symmetrical pouring of No. 1 steel pipe in the third span. Stage 8 is symmetrical pouring of No. 2 steel pipe in the first span. Stage 9 is symmetrical pouring of No. 2 steel pipe in the fourth span. Stage 10 is symmetrical pouring of No. 2 steel pipe in the second span. Stage 11 is symmetrical pouring of No. 2 steel pipe in the third span.

[0094] Stage 12 is the second tensioning of the tie rod with a tension force of 974kN.

[0095] Stage 13 is symmetrical pouring of No. 3 steel pipe in the first span. Stage 14 is symmetrical pouring of No. 3 steel pipe in the fourth span. Stage 15 is symmetrical pouring of No. 3 steel pipe in the second span. Stage 16 is symmetrical pouring of No. 3 steel pipe in the third span. Stage 17 is symmetrical pouring of No. 4 steel pipe in the first span. Stage 18 is symmetrical pouring of No. 4 steel pipe in the fourth span. Stage 19 is symmetrical pouring of No. 4 steel pipe in the second span. Stage 20 is symmetrical pouring of No. 4 steel pipe in the third span.

[0096] In summary, the present invention

[0097] (1) A method for calculating the tension force and timing of the tie rod is given, which avoids repeated calculations using finite element methods.

[0098] (2) Through calculation, the number of times the tie rods are tensioned can be reduced to ensure that no tensile stress occurs at the bottom of the pier, thus solving the problem of repeatedly tensioning the tie rods during the concrete pouring process.

[0099] (3) The steel pipes of the left and right arch ribs are poured with concrete at the same time, which replaces the problem of long pouring time of a single steel pipe in the existing method. In addition, pouring the left and right arch ribs at the same time can effectively solve the problem of inconsistent vertical deformation of the arch ribs.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A construction calculation method for a continuous steel tube concrete tied arch bridge, the arch bridge comprising a plurality of piers, with tie rods arranged between the piers, and arch ribs made of steel tubes arranged between adjacent piers, characterized in that: The following steps are included: a) Determine the control points when pouring concrete into the arch rib steel pipes of the piers according to the stress characteristics of the arch bridge; b) determining the influence line of the stress generated at the control point during the process of pouring concrete into the arch rib steel pipe; c) calculating the integral area of ​​the stress influence line along the concrete pouring length in the arch rib steel pipe, and calculating the first stress generated by the poured concrete at the control point; d) Calculate the secondary stress generated by the tie rod at the control point when it is tensioned; e) Determine the tensioning force and tensioning method of the tie rod and the concrete pouring method of the arch rib steel pipe according to the stress balance condition at the control point through the first stress and the second stress.

2. The construction calculation method of a continuous steel tube concrete tied arch bridge according to claim 1 is characterized in that: There are five piers, which are numbered as Pier 1, Pier 2, ... Pier 5, to form two side span arch ribs and two middle span arch ribs, wherein the arch diameter of the side span arch rib is smaller than the arch diameter of the middle span arch rib, and the control points are the center positions of Pier 1 and Pier 2 on opposite sides along the length direction of the arch bridge, and the control point on the side close to the middle span is Point 2, and the control point on the side far from the middle span is Point 4.

3. The construction calculation method of a continuous steel tube concrete tied arch bridge according to claim 2 is characterized by: By establishing a finite element model of the arch bridge, the control points are determined and the influence lines of the stress generated at the control points during the process of pouring concrete into the arch rib steel pipe are calculated, and the integral area and the first stress are calculated according to the weight of the concrete line in the arch rib steel pipe.

4. The construction calculation method of a continuous steel tube concrete tied arch bridge according to claim 2 is characterized in that: The arch ribs include two parallel arch ribs, each of which includes four parallel steel pipes, and the steel pipes of the two arch ribs are symmetrically numbered as No. 1 steel pipe, No. 2 steel pipe, No. 3 steel pipe and No. 4 steel pipe; when all arch ribs are poured with concrete, the first stress at point 2 and point 4 of pier No. 1 and pier No. 2 is calculated by the following formula: In the formula, the general formula It represents the first stress at point j of pier i caused by pouring concrete in the arch rib steel pipe. It represents the stress caused by pouring concrete into a single steel pipe in the left and right arch ribs of the k-th span at point j of pier i, where i represents the pier number, j represents the control point position number, k represents the arch rib position number, q represents that the stress is caused by the concrete in the steel pipe, n represents the number of steel pipes in the arch rib, R represents the right arch rib, and L represents the left arch rib.

5. The construction calculation method of a continuous steel tube concrete tied arch bridge according to claim 4 is characterized in that: The tie rods include a long tie rod and a short tie rod, which are numbered as tie rod No. 1 and tie rod No.

2. The two ends of the long tie rod are anchored on pier No. 1 and pier No. 5, and the two ends of the short tie rod are anchored on pier No. 2 and pier No.

4. When the tie rods are tensioned, the second stress generated at point No. 2 and point No. 4 of pier No. 1 and pier No. 2 is calculated by the following formula: In the formula, the general formula It represents the second stress generated at point j of pier i when tie rod l is tensioned. It represents the influence of the unit tension force of tie rod l on the stress at point j of pier i, where F(l) represents the tension force of tie rod l and l represents the tie rod number.

6. The construction calculation method of a continuous steel tube concrete tied arch bridge according to claim 4 is characterized in that: The equilibrium condition is to ensure that the stress at the control point is compressive stress when pouring concrete into the arch rib steel pipe and when tensioning the tie rod, that is, When all the concrete is poured into the arch rib, the following conditions must be met: In the formula, the general formula It indicates the stress generated by the deadweight of the arch rib steel pipe before pouring concrete into the steel pipe; When tensioning the tie rod, the following conditions must be met: The tensioning force value range of the long tie rod is determined according to Formulas 9, 10, and 13, and the tensioning force value range of the short tie rod is determined according to Formulas 11, 12, and 14. If there is no solution to the tensioning force value range, the tensioning method adopts staged tensioning. The tensioning force value range of staged tensioning is calculated by the stress after pouring concrete into a preset number of steel pipes of the arch rib until the tensioning force value range has a solution, and the tensioning timing is selected after the concrete pouring in the preset number of steel pipes is completed.

7. The construction calculation method for a continuous steel tube concrete tied arch bridge according to claim 4 is characterized in that: The pouring method includes pouring the corresponding numbered steel pipes of the left and right arch ribs at the same time, and first pouring the No. 1 steel pipe of the side span arch rib of one span, and then pouring the No. 1 steel pipe of the other side span arch rib, and then pouring the No. 1 steel pipe of the middle span arch rib of one span, and then pouring the No. 1 steel pipe of the other middle span arch rib, and then cyclically pouring the No. 2 steel pipe, the No. 3 steel pipe and the No. 4 steel pipe in turn until the pouring of the entire arch rib steel pipe is completed.

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