CN105507127A - Arch rib face internal multi-point restrained and distributed tied-arch bridge - Google Patents

Abstract

The invention discloses a multi-point restraint and distributed tied rod arch bridge in the arch rib plane. A plurality of longitudinal beams connected with the arch rib are arranged under the arch rib to form a distributed resistance to the constant and live load of the arch rib and balanced horizontal thrust. The tie rods; by setting vertical columns and diagonal rods on the longitudinal beams to connect with the bottom surface of the arch ribs, an elastic restraint support system is formed in the arch rib surface, thereby enhancing the overall rigidity and strength of the arch ribs. Compared with the span arch bridge, it has smaller mid-span arch rib bending moment and horizontal thrust of arch foot; has higher arch rib stability and stable bearing capacity, and smaller mid-span deformation, thus improving driving comfort ; And reduce the workload and cost of foundation construction.

Description

In-plane multi-point restraint and distributed tie-bar arch bridge

technical field

The invention belongs to a tie-bar arch bridge, in particular to a multi-point constrained and distributed tie-bar arch bridge in the arch rib plane.

Background technique

Tied arch bridge is a combination of two basic structural forms of arch and beam, which jointly bear the load, give full play to the structural performance and combined effect of beam bending and arch compression, and the horizontal thrust of the arch end is supported by tie rods, so that the arch end support No horizontal thrust is produced. At present, during the operation of arch bridges with concrete as the main material, under the action of temperature, vehicle load and other loads, transverse bridge cracks often appear in the mid-span of arch ribs, and a few have obvious downward deflection in the mid-span. Significantly decreased.

In the prior art, such as the Chinese patent CN1483895A, a tie-bar arch bridge integrated with urban roads is designed. The tie-bar arch bridge is provided with stiffened longitudinal beams and beams, and the stiffened longitudinal beams are applied longitudinal prestress to overcome the constant and live loads. The horizontal thrust of the arch rib, this method uses more materials, increases the cost of foundation construction, and is not easy to construct the old bridge; Chinese patent CN101638883A designs an arch bridge, and the arch bridge is provided with multiple load-transferring bridges between the bridge deck and the arch ring The components that transmit the load extend radially from the arch ring to the bridge deck to reduce the mid-span bending moment. This method increases the bending moment of the bridge deck and reduces the driving comfort.

Contents of the invention

In view of the above problems, the present invention provides an arch bridge with multi-point constraints in the plane of the arch rib and distributed tie rods. By adding longitudinal beams, columns and diagonal members under the arch ribs, the mid-span bending moment, deformation and arch foot of the arch bridge can be reduced. Horizontal thrust pushes the arch bridge to the maximum span, and is used to improve the stress and bearing capacity of the arch bridge, while reducing construction costs.

The present invention takes the following technical solutions to achieve the above object:

In the multi-point restraint and distributed tie-bar arch bridge in the arch rib plane, longitudinal beams (2), columns (3) and diagonal members (4) are set under the arch ribs (1), and the longitudinal beams (2), diagonal members ( 4) and columns (3) provide multi-point constraints on the arch rib (1), the longitudinal beam (2) is in the horizontal direction, and the two ends are connected with the arch rib (1) to form a distributed resistance against the constant and live load of the arch rib and balance The tie bar for horizontal thrust; the top of the column (3) is connected with the arch rib (1), and the bottom end is connected with the longitudinal beam (2); the diagonal rod (4) is arranged between the two columns, and the top of the diagonal rod (4) It is connected with the intersection of the longitudinal beam (2) and the column (3), and the bottom end is connected with the intersection of another column (3) and the arch rib (1), forming an elastic restraint support system in the surface of the arch rib.

A further technical solution of the present invention is: the ratio of the length of the longitudinal beam (2) to the span of the arch rib (1) is between 0.2 and 0.5.

A further technical solution of the present invention is: the ratio of the bending stiffness of the longitudinal beam (2) to the bending stiffness of the arch rib (1) is between 0.5 and 1.0.

A further technical solution of the present invention is: the ratio of the axial compressive stiffness of the column (3) to the axial compressive stiffness of the arch rib (1) is between 0.25 and 0.5.

A further technical proposal of the present invention is: the longitudinal beam (2) and the column (3) are all steel structures.

The beneficial effects of the present invention are:

Through repeated experiments, an arch bridge with multi-point constraints in the arch rib plane and distributed tie rods was designed. Longitudinal beams, columns and diagonal bars were added under the arch ribs to provide multi-point constraints and improve the force transmission path of the arch bridge. The load in the middle part of the arch span is delivered to the longitudinal beam, and the load is jointly carried by the longitudinal beam and the arch rib, which increases the bearing capacity and stiffness of the arch bridge, reduces the mid-span bending moment of the arch rib and the horizontal thrust of the arch foot, and increases the arch bridge. The stability of the rib; the control bending moment in the span of the arch rib is reduced, that is, under the same section and span, it can carry a larger load; the maximum deflection of the span of the arch rib under the load is reduced, and the Driving comfort; the horizontal thrust and bending moment of the arch bridge feet are reduced, and the amount of foundation engineering is reduced; under the same arch rib cross-section, the span of the arch bridge is increased; the stability and bearing capacity of the arch are improved; The span arch bridge, multi-point restraint in the arch rib plane and distributed tie-bar arch bridge have better economic benefits.

Description of drawings

Fig. 1 is the structural diagram of the multi-point restraint and distributed tie rod top-supported arch bridge in the multi-longitudinal arch rib plane of the present invention;

Fig. 2 is the structural diagram of the multi-point restraint and distributed tie rod under-supported arch bridge in the multi-longitudinal arch rib plane of the present invention;

Fig. 3 is the structural diagram of the multi-point restraint and distributed tie-rod top-supporting arch bridge in the single longitudinal beam arch rib plane of the present invention;

Fig. 4 is a structural diagram of the arch bridge with multi-point restraint in the arch rib plane and distributed tie rods in the present invention.

In the figure: 1, arch rib; 2, longitudinal beam; 3, column; 4, diagonal rod.

detailed description

The present invention will be described below in conjunction with accompanying drawings 1-4 and embodiments 1-3.

Example 1:

The arch bridge in Example 1 is an overhead arch bridge with a span of 100.00m, a reinforced concrete box-shaped arch rib, a net rise height of 11.10m, and a rise-span ratio of 1/9. The foundation, the abutment on both sides is the embedded abutment of mortar rubble, the enlarged foundation of open cut, and the longitudinal beam (2), the column (3) and the diagonal rod (4) are added under the arch rib (1), and the arch rib (1 ) bending stiffness and compressive stiffness are 7.23×1011kN·m2 and 1.24×108kN·m respectively; horizontal steel truss longitudinal beams (2) with lengths of 20m, 35m and 50m are erected respectively, and their bending stiffness and compressive stiffness are both They are 3.62×1011kN m2 and 1.24×108kN m2 respectively, and the longitudinal beam (2) and the arch rib are fixed; five vertical steel bars with a compressive stiffness of 3.10×107kN m are installed under the arch rib (1). The truss column (3), the top of the column (3) is hinged to the arch rib (1), and the bottom end is fixed to the 50m longitudinal beam (2). ) column body is fixedly connected with the other two longitudinal beams; a diagonal rod (4) is set between two adjacent columns, the top of the diagonal rod (4) is hinged with the intersection of the arch rib (1) and the column, and the bottom end It is fixedly connected to the intersection of another column and the 50m longitudinal beam (2), and the adjacent diagonal bars are connected to each other. The engineering cost of the multi-point restraint and distributed tie-bar arch bridge in the arch rib plane is about 73% of the construction cost of the existing arch bridge project with the same span, that is, the construction cost of the existing arch bridge project with a span of 100m is the same. The multi-point restraint and distributed tie-bar arch bridge can increase the span to 120m, increase the bearing capacity and stiffness of the arch bridge, reduce the mid-span bending moment of the arch rib, and the horizontal thrust of the arch foot, and increase the stability of the arch rib .

Example 2:

The arch bridge in Example 2 is an under-supported arch bridge with a span of 100.00m reinforced concrete box-shaped arch ribs, a net rise height of 11.10m, and a rise-span ratio of 1/9. A longitudinal beam (2) is added below the arch rib (1) , columns (3) and diagonal rods (4), arch ribs (1) have bending stiffness and compressive stiffness of 7.23×1011kN m2 and 1.24×108kN m2 respectively; Steel truss longitudinal beam (2), its flexural rigidity and compressive rigidity are 5.10×1011kN m2, 1.24×108kN m2 respectively, longitudinal beam (2) and arch rib are all fixed; arch rib (1) below Set up 6 vertical steel truss columns (3) with a compressive stiffness of 4.95×107kN·m, the top of the columns (3) is hinged to the arch rib (1), and the bottom is fixed to the 50m longitudinal beam (2). The joints are respectively 15m, 19m, 23m, 27m, 31m and 35m, and the column body (3) is fixedly connected with the other two longitudinal beams; a diagonal web bar (4) is set between two adjacent columns, and the diagonal web The top of the bar (4) is hinged to the intersection of the arch rib (1) and the column, the bottom end is fixed to the intersection of another column and the 50m longitudinal beam (2), and the adjacent diagonal bars are connected to each other. The engineering cost of the multi-point restraint and distributed tie-bar arch bridge in the arch rib plane is about 75% of the construction cost of the existing arch bridge project with the same span, that is, the construction cost of the existing arch bridge project with a span of 100m is the same. The multi-point restraint and distributed tie-bar arch bridge can increase the span to 118m, increase the bearing capacity and stiffness of the arch bridge, reduce the mid-span bending moment of the arch rib, and the horizontal thrust of the arch foot, and increase the stability of the arch rib .

Example 3:

The arch bridge in Example 3 is an overhead arch bridge with a span of 100.00m, a reinforced concrete box-shaped arch rib, a net rise height of 11.10m, and a rise-span ratio of 1/9. The foundation, the abutment on both sides is the embedded abutment of mortar rubble, the enlarged foundation of open cut, and the longitudinal beam (2), the column (3) and the diagonal rod (4) are added under the arch rib (1), and the arch rib (1 ) The bending stiffness and compressive stiffness are 7.23×1011kN m2 and 1.24×108kN m respectively; the erection length is 45m, and the bending stiffness and compressive stiffness are 7.23×1011kN m2 and 1.24×108kN m2 respectively The truss is used as the longitudinal beam (2), and the longitudinal beam (2) is fixedly connected to the arch rib; four vertical steel truss columns (3) with a compressive stiffness of 6.20×107kN·m are arranged under the arch rib (1), The top of the column (3) is hinged to the arch rib (1), and the bottom end is fixed to the longitudinal beam (2). The fixed points are respectively 18m, 23m, 27m and 32m, and a diagonal web is set between two adjacent columns. Rod (4), the top of the diagonal rod (4) is hinged with the intersection point of the arch rib (1) and the column, and the bottom end is fixedly connected with the intersection point of another column and the 50m longitudinal beam (2), and the adjacent diagonal rods are connected to each other connect. The engineering cost of the multi-point restraint and distributed tie-bar arch bridge in the arch rib plane is about 80% of the construction cost of the existing arch bridge project with the same span, that is, the construction cost of the existing arch bridge project with a span of 100m is the same. The multi-point restraint and distributed tie-bar arch bridge can increase the span to 115m, increase the bearing capacity and stiffness of the arch bridge, reduce the mid-span bending moment of the arch rib, and the horizontal thrust of the arch foot, and increase the stability of the arch rib .

Embodiment 1-3 is compared with the stressed parameters of the prior art as follows:

Claims (5)

1. multi-point constraint and distributed bowstring arch bridge in arch rib face, it is characterized in that: in arch rib (1) below, longeron (2), column (3) and diagonal web member (4) are set, described longeron (2) is horizontal direction, and two ends are connected with arch rib (1); Column (3) top is connected with arch rib (1), and bottom is connected with longeron (2); Diagonal web member (4) is arranged between two columns, and diagonal web member (4) top is connected with the intersection point of arch rib (1) and column, and bottom is connected with the intersection point of another column and longeron (2).

2. multi-point constraint and distributed bowstring arch bridge in arch rib face according to claim 1, is characterized in that, described longeron (2) length and arch rib (1) across footpath ratio between 0.2 ~ 0.5.

3. multi-point constraint and distributed bowstring arch bridge in arch rib face according to claim 1, is characterized in that, the bending rigidity of described longeron (2) and arch rib (1) bending rigidity ratio are between 0.5 ~ 1.0.

4. multi-point constraint and distributed bowstring arch bridge in the arch rib face according to any one in claim 1-3, it is characterized in that, the axial compression resistance rigidity of described column (3) and arch rib (1) axial compression resistance stiffness ratio are between 0.25 ~ 0.5.

5. multi-point constraint and distributed bowstring arch bridge in arch rib face according to claim 1, is characterized in that, described longeron (2) and column (3) are steel work.