CN111455810A

CN111455810A - Construction method for main body structure of steel box tied arch bridge

Info

Publication number: CN111455810A
Application number: CN202010395294.8A
Authority: CN
Inventors: 王在杭; 张存华; 王启明; 王云忠; 张文琮
Original assignee: Yunnan Investment Group Yunling Construction Co ltd
Current assignee: Yunnan Investment Group Yunling Construction Co ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2020-07-28

Abstract

The invention relates to the field of bridge construction, in particular to a construction process of a steel box tied arch bridge. The method is characterized in that under the condition that arch legs are not anchored, a statically indeterminate structure is converted into a statically indeterminate structure. The problems of foundation adaptability, full-bridge linearity, structural safety and the like in the construction of the main body structure of the steel box tied arch bridge can be effectively solved.

Description

Construction method for main body structure of steel box tied arch bridge

Technical Field

The invention relates to the field of bridge construction, in particular to a construction process of a steel box tied arch bridge.

Background

The steel box tied arch bridge has the advantages of large span, light structure, beautiful shape, material saving and the like, is widely applied to highway engineering projects, but has complex construction technology and great construction difficulty, often causes difficulty to construction, and needs to solve the problems of bridge spanning capability, foundation adaptability and the like. The steel box tied arch bridge is generally composed of arch ribs, a main beam, a suspender and the like. The arch rib adopts a steel box-shaped section, and the arch axis is a catenary; the main beam adopts a steel-concrete combined lattice beam system, wherein the main longitudinal beam is in a box-shaped section, the secondary longitudinal beam and the cross beam are in I-shaped sections, and a concrete bridge deck is arranged on the beam; the hanger rod adopts a parallel steel wire finished product bundle, and the tie rod adopts a full-anti-corrosion whole bundle replaceable and adjustable steel strand finished product bundle; the main bridge arch rib, the arch support and the lattice beam are all consolidated, the interior is a statically indeterminate structure system, and the exterior is an integral simply supported system. And a friction swinging type shock absorption and isolation support is arranged below the arch support. The main bridge arch abutment is a reinforced concrete member, and the arch abutment beam is a fully prestressed concrete member. The steel box tied arch bridge is suitable for mountainous and plain areas, has the advantages of large span, beautiful appearance, safe structure and the like, and is an ideal bridge form for crossing gullies, rivers, highways, railways and the like. Because the structural form of the steel box tied-arch bridge is complex and the technical difficulty is high, at present, no complete construction method for the mature steel box tied-arch bridge exists in China.

Disclosure of Invention

The invention aims to provide a construction method of a main body structure of a steel box tied-arch bridge, which can effectively solve the problems of foundation adaptability, full-bridge linearity, structural safety and the like in the construction of the main body structure of the steel box tied-arch bridge.

The invention discloses a construction method of a main body structure of a steel box tied arch bridge, which comprises the steps of adopting an inclined pulling buckling hanging method for construction, installing a lattice beam after the main body steel box arch is erected, tensioning a tied rod, installing a bridge deck, and finally tensioning the tied rod to form the bridge.

The construction method of the main body structure of the steel box tied arch bridge is characterized in that the method for converting the statically indeterminate structure into the statically indeterminate structure specifically comprises the following steps: the bridge main bridge is provided with 4 friction pendulum type shock absorption and isolation supports, the vertical bearing capacity of a single support is 70000kN, the shock absorption and isolation displacement is +/-400 mm, the curvature radius of the support is 6m, the friction coefficient is 0.03, the supports are divided into three types, namely a GD type, a DX type and an SX type, and the shock absorption and isolation initial force is 14000 kN in the fixed direction design; the temporary horizontal anti-push support arranged in the main bridge temporary anchoring system adopts a GPZ (II) 15SX support, a wedge-shaped steel cushion block is matched, the bearing capacity of the steel cushion block is not less than 1500t, and the support is detached after the bridge is formed; the temporary vertical support adopts a GPZ (II) 5SX support and is matched with the temporary support, the bearing capacity of the steel cushion block is not less than 500t, the support is tensioned by the first tie rod and the second tie rod, and the arch rib closure buckle cable is loosened and then detached.

The mounting bridge deck is characterized in that a plate-girder combination system is adopted for design, and in the mounting process, in order to ensure that the bridge deck is tightly combined with the steel lattice girder and maintain the hydrological environment under the condition of ensuring the common stress of concrete and steel, the bridge deck, the polyethylene foam plate and the steel lattice girder are sequentially mounted;

the method is characterized in that a customized polyethylene foam plate (with the section of 50mm × 8 mm) is used for single-sided glue to be attached to the bottom of a concrete bridge deck before bridge deck erection, and after the bridge deck is erected, reinforcing steel bars are installed and concrete is poured, so that concrete cement paste can be effectively prevented from entering gaps of steel beams and flowing into a reservoir.

The inclined pull buckling hanging method is characterized in that secondary tensioning is carried out on the basis of the inclined pull buckling hanging method, and the tensioning force is guaranteed.

Detailed Description

Embodiment 1, construction method of main body structure of steel box tied arch bridge of Jinji Dandan river bridge

The method comprises the steps of installing a lattice beam after the main steel box arch is erected, tensioning a tie bar, installing a bridge deck, and finally tensioning the tie bar to form a bridge. In the case of anchorless of the arch springing, the transition from the statically indeterminate structure to the statically indeterminate structure takes place.

The main bridge is provided with 4 friction pendulum type shock absorption and isolation permanent supports, the vertical bearing capacity of a single support is 70000kN, the shock absorption and isolation displacement is +/-400 mm, the curvature radius of the support is 6m, the friction coefficient is 0.03, the supports are divided into three types, namely a GD type, a DX type and an SX type, and the shock absorption and isolation initial force is 14000 kN in the fixed direction design; in addition, 4 temporary horizontal anti-pushing supports and temporary vertical supports are respectively arranged, the maximum counter force of the temporary vertical supports is 21450kN, and the supports are detached after a bridge is formed. The construction process of the upper structure of the main bridge comprises the following steps:

(1) after the construction of the main pier is completed, an arch support and an arch support beam support are erected, a permanent support and a temporary support are installed, arch ribs, lattice girders, tie bar pipelines and tie bar anchorage devices are pre-buried, concrete for the arch support and the arch support beam is poured, and a beam prestress steel bundle is tensioned after the strength of the concrete reaches the design requirement.

(2) After the arch rib segments are sequentially hoisted and positioned by adopting the cable crane, the buckling cables and the temporary wind braces or the permanent wind braces are installed, and the closure segment arch rings are installed at the design temperature. After the arch rib is hoisted, the tie bar is tensioned to the designed cable force, and the arch rib buckle cable is gradually loosened from the arch crown to the arch springing.

(3) And (4) symmetrically installing lattice beams from two sides to the midspan in sequence by using the cable crane, and tensioning the tie bars to a designed cable force.

(4) Hoisting a first-stage bridge deck and pouring wet joints of the first-stage bridge deck, adjusting the line type of the main beam, sequentially consolidating all main beam sections from two sides of the span after the completion, installing tie rods according to design requirements, and respectively tensioning to design cable force; and (4) removing the arch rib buckle anchor cable and the wind-resistant steel cable.

(5) And hoisting the second-stage bridge deck slab, pouring wet joints of the second-stage bridge deck slab from the midspan to two sides, and finally pouring the cast-in-place slab between the lattice beam and the arch support beam. And (5) installing the tie bars according to the design and tensioning the tie bars to the design cable force.

(6) Installing a bridge deck auxiliary structure; and (5) dismantling the temporary support of the main pier.

The bridge deck slab adopts the slab-girder combination system to design, and in the installation, in order to make the bridge deck slab combine closely with steel lattice beam, guarantee under the common atress's of concrete and steel circumstances, keep the hydrology environment, adopt bridge deck slab + polyethylene cystosepiment + steel lattice beam to install in proper order.

The construction process of the reinforced concrete joint section comprises

1. Installing a positioning bracket, and positioning a steel structure section;

2. positioning and mounting the steel pull rod;

3. and (5) binding steel bars and installing templates.

The positioning support effectively controls the position movement of the steel box, effectively controls the installation direction of the steel pull rod, effectively controls the erection precision of the steel structure and facilitates site construction.

In order to prevent the damage and the damage of the support, secondary tensioning is carried out on the basis of a cable-stayed buckling method, and the tensioning cable force is ensured so as to avoid damaging the support and well ensure the safety of a full-bridge line type and a full-bridge structure.

Claims

1. A method for constructing the main body structure of steel box tied arch bridge includes such steps as installing lattice beam after the main steel box arch is erected, stretching tie rods, installing bridge deck, and stretching tie rods to form bridge.

2. The construction method of the main body structure of the steel box tied arch bridge according to claim 1, wherein the method for converting the statically indeterminate structure into the statically indeterminate structure comprises the following steps: the bridge main bridge is provided with 4 friction pendulum type shock absorption and isolation supports, the vertical bearing capacity of a single support is 70000kN, the shock absorption and isolation displacement is +/-400 mm, the curvature radius of the support is 6m, the friction coefficient is 0.03, the supports are divided into three types, namely a GD type, a DX type and an SX type, and the shock absorption and isolation initial force is 14000 kN in the fixed direction design; the temporary horizontal anti-push support arranged in the main bridge temporary anchoring system adopts a GPZ (II) 15SX support, a wedge-shaped steel cushion block is matched, the bearing capacity of the steel cushion block is not less than 1500t, and the support is detached after the bridge is formed; the temporary vertical support adopts a GPZ (II) 5SX support and is matched with the temporary support, the bearing capacity of the steel cushion block is not less than 500t, the support is tensioned by the first tie rod and the second tie rod, and the arch rib closure buckle cable is loosened and then detached.

3. The construction method of the main body structure of the steel box tied arch bridge according to claim 1, wherein the installation bridge deck is designed by a plate-girder combination system, and in the installation process, in order to make the bridge deck and the steel lattice girder tightly combined and ensure that the hydrological environment is maintained under the condition that the concrete and the steel are stressed together, the bridge deck, the polyethylene foam plate and the steel lattice girder are installed in sequence;

4. The construction method of the main body structure of the steel box tied arch bridge according to claim 1, wherein the oblique pulling and buckling method is a secondary pulling and buckling method based on a diagonal pulling and buckling method to ensure a pulling and tensioning force.