CN113047184A

CN113047184A - Construction method of connection structure of partially-filled concrete-filled steel tube pier and foundation with self-resetting function

Info

Publication number: CN113047184A
Application number: CN202110537893.3A
Authority: CN
Inventors: 马玥; 付明春; 刘颖; 于丰纶; 王占飞
Original assignee: Dalian Ocean University
Current assignee: Dalian Ocean University
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2021-06-29

Abstract

The invention relates to the field of bridge engineering, in particular to a construction method of a connecting structure of a partially-filled concrete-filled steel tube pier and a foundation with a self-resetting function. The technical scheme is as follows: the method comprises the following steps: the method comprises the following steps: pouring a concrete bearing platform; step two: installing a steel pipe and a perforated plate; step three: and tensioning the prestressed steel strands and the prestressed steel bars. The construction method of the connecting structure of the partially filled concrete-filled steel tube pier and the foundation with the self-resetting function, provided by the invention, has enough bearing capacity and self-resetting capability.

Description

Construction method of connection structure of partially-filled concrete-filled steel tube pier and foundation with self-resetting function

Technical Field

The invention relates to the field of bridge engineering, in particular to a construction method of a connecting structure of a partially-filled concrete-filled steel tube pier and a foundation with a self-resetting function.

Background

The traditional ductile bridge pier has high bearing capacity, good ductility and excellent seismic performance, but has poor restorability after earthquake.

The traditional self-resetting bridge pier is composed of a bearing component, a self-resetting component, an energy dissipation component and a joint, and is a novel anti-seismic bridge pier system appearing in recent years. The pier has the advantages of small permanent deformation after earthquake and good restorability, but the pier has small lateral stiffness and low bearing capacity and is not suitable for bridges in heavy-load traffic.

Two kinds of ductility pier and self-resetting pier in the traditional sense have common problems in use: the arrangement mode of the joint component.

(1) For a traditional ductile pier, a pier column is in rigid connection with a bearing platform, and seismic energy is dissipated through ductility of a plastic hinge area of the pier. However, the accumulated deformation of such a pier from elastic deformation to plastic deformation causes a large permanent residual deformation after the earthquake. Minor damage can be repaired, while bridges with severe damage need to be rebuilt, which is time and labor consuming and affects the normal traffic function of the bridge.

(2) For the traditional self-resetting bridge pier, the pier column and the bearing platform adopt hinged joints, the joints of the connecting mode are easy to be damaged by pressure, and the parallel and level butt joint contact joints are not beneficial to the transmission of shearing force and are easy to cause the shearing damage of prestressed reinforcements.

Disclosure of Invention

The invention provides a construction method of a connecting structure of a partially-filled concrete-filled steel tube pier and a foundation with a self-resetting function.

The technical scheme of the invention is as follows:

the construction method of the connecting structure of the partially filled concrete-filled steel tube pier and the foundation with the self-resetting function comprises the following steps:

the method comprises the following steps: cast concrete bearing platform

Embedding a supporting nut in the foundation and anchoring one end of the prestressed steel strand and one end of the prestressed reinforcement; installing a rectangular steel plate on a foundation, pouring a concrete bearing platform above the rectangular steel plate, wherein a preformed hole A is formed in the center of the concrete bearing platform, and a plurality of preformed holes B are formed in the periphery of the concrete bearing platform; penetrating out the prestressed steel strands from the preformed hole A, and penetrating out a plurality of prestressed steel bars from the preformed hole B;

step two: mounting steel pipe and perforated plate

Installing a perforated plate at the top of the concrete bearing platform, installing a steel pipe at the upper part of the perforated plate, and welding the perforated plate and the steel pipe into a whole by using a stiffening rib; pouring filling concrete into the steel pipe, arranging a reserved hole C in the center of the filling concrete, enabling the reserved hole C to be concentric with the reserved hole A, and enabling the prestressed steel strand to penetrate out of the reserved hole C;

step three: stretching prestressed strand and prestressed reinforcement

Tensioning the prestressed steel strand by using a post-tensioning method, and anchoring the upper end of the prestressed steel strand by using a backing plate and a supporting nut; and tensioning the prestressed reinforcement by using a post-tensioning method, and anchoring the upper end of the prestressed reinforcement on the perforated plate by using a supporting nut.

Further, in the construction method of the connection structure of the partially filled concrete-filled steel tube pier and the foundation with the self-resetting function, the cross section of the steel tube is square, rectangular, circular or oval.

Further, according to the construction method of the connection structure of the partially-filled concrete-filled steel tube pier and the foundation with the self-resetting function, the spiral ribs are arranged around the upper end of the prestressed steel strand, and the spiral ribs are arranged in the filled concrete.

The invention has the beneficial effects that:

1. when the connecting structure is used in earthquake, certain bending deformation and then swinging occur, the steel pipe generates a good energy dissipation effect, earthquake damage can be controlled within a certain range to avoid damage of the main body structure, and the connecting structure has good earthquake resistance.

2. After the earthquake, the steel pipe and the filled concrete can be pulled back to the original shape by the prestressed steel strands and the prestressed steel bars, so that the residual deformation is reduced, and the pier is restored to the original position.

3. The invention has simple construction, safe and reliable quality and convenient popularization.

Drawings

FIG. 1 is a schematic view of a connection structure of a partially-filled concrete-filled steel tube rectangular pier and a foundation with a self-resetting function in example 1;

FIG. 2 is a schematic perspective view of a connection structure of a partially-filled concrete-filled steel tube rectangular pier and a foundation with a self-resetting function in example 1;

FIG. 3 is a schematic view of a deformation state of a connection structure of a partially-filled concrete-filled steel tube rectangular pier and a foundation with a self-resetting function;

fig. 4 is a schematic perspective view of a connection structure between a partially-filled concrete-filled steel tube rectangular pier and a foundation having a self-resetting function in example 2.

Detailed Description

Example 1

As shown in fig. 1 and 2, the construction method of the connection structure of the partially filled concrete-filled steel tube pier and the foundation having the self-restoration function includes the following steps:

the method comprises the following steps: cast concrete bearing platform 9

Embedding a support nut 11 in the foundation and anchoring one ends of the prestressed steel strands 6 and the prestressed steel bars 8; installing a rectangular steel plate 14 on a foundation, pouring a concrete bearing platform 9 above the rectangular steel plate 14, arranging a preformed hole A in the center of the concrete bearing platform 9, and arranging a plurality of preformed holes B10 around the concrete bearing platform 9; the prestressed steel strands 6 penetrate out of the preformed holes A, and the plurality of prestressed steel bars 8 penetrate out of the preformed holes B10;

step two: mounting the steel pipe 1 and the perforated plate 12

Installing a perforated plate 12 at the top of a concrete bearing platform 9, installing a steel pipe 1 on the upper part of the perforated plate 12, wherein the section of the steel pipe 1 is rectangular, and welding the perforated plate 12 and the steel pipe 1 into a whole by using a stiffening rib 5; pouring filling concrete 2 into the steel pipe 1, wherein a preformed hole C7 is formed in the center of the filling concrete 2, the preformed hole C7 is concentric with the preformed hole A, and the prestressed steel strand 6 penetrates out of the preformed hole C7; spiral reinforcements 4 are arranged around the upper ends of the prestressed steel strands 6, and the spiral reinforcements 4 are arranged in the filling concrete 2;

step three: stretching prestressed steel strand 6 and prestressed reinforcement 8

Tensioning the prestressed steel strand 6 by using a post-tensioning method, and anchoring the upper end of the prestressed steel strand by using a backing plate 3 and a supporting nut 11; the prestressed reinforcement 8 is tensioned by a post-tensioning method, and the upper end is anchored on a perforated plate 12 by a supporting nut 11.

As shown in fig. 3, in the figure: p_PInternal force of prestressed steel strand, L_PEffective length of prestressed reinforcement, delta total: total horizontal displacement, θ: opening angle of pier, d is pier column section diameter, h_c: height of pier column, G_c: dead weight of pier, G_sup: superstructure load, F_EDiTension generated by the ith prestressed reinforcement, e: rotation point, h: distance from the upper structure load point of action to the top of the concrete cap, A_PArea of the cross section of the prestressed steel strand, d_EDi: distance from ith prestressed reinforcement to point e, c: distance from the point of rotation to the edge of the pier.

During earthquake, under the action of horizontal earthquake force, the pier is firstly subjected to bending deformation to consume energy, then a clearance angle theta is formed between the pier and the concrete bearing platform 9, the pier starts to rotate, the clearance angle theta is continuously increased along with the continuous increase of horizontal load, and the tension F of the prestressed reinforcement 8 is_EDiAnd 6 tension P of prestressed steel strand_PQuickly increased and 6 tension P of prestressed steel strand_PThe yield bearing capacity is not reached in the whole stress process of the pier. The total horizontal displacement delta total comprises horizontal displacement generated by bending deformation of the bridge pier and horizontal displacement generated by rotation of the bridge pier. And after the earthquake load is unloaded, the pier is restored to the original position by utilizing the tensile force of the prestressed reinforcement 8 and the prestressed steel strand 6.

Example 2

As shown in fig. 4, the difference from example 1 is that the cross-sectional shape of the steel pipe 1 is circular.

Claims

1. the construction method of the connection structure of the partially filled concrete-filled steel tubular pier and the foundation with self-reset function, is characterized in that, comprises the steps:

Step 1: Pour the concrete cap

Pre-embed the support nut in the foundation and anchor one end of the prestressed steel strand and the prestressed steel bar; install a rectangular steel plate on the foundation, pour a concrete cap on the rectangular steel plate, set a reserved hole A in the center of the concrete cap, A plurality of reserved holes B are arranged around the bearing platform; the prestressed steel strands are pierced from the reserved holes A, and a plurality of prestressed steel bars are pierced from the reserved holes B;

Step 2: Install steel pipes and perforated plates

Install a perforated plate on the top of the concrete bearing platform, install a steel pipe on the upper part of the perforated plate, and use a stiffener to weld the perforated plate and the steel pipe into a whole; pour concrete into the steel pipe, and set a reserved hole in the center of the filled concrete C, the reserved hole C is concentric with the reserved hole A, and the prestressed steel strand is passed through the reserved hole C;

Step 3: Tension of prestressed steel strands and prestressed steel bars

The prestressed steel strand is stretched by post-tensioning method, and the upper end is anchored with a backing plate and a back-up nut;

2 . The construction method for the connection structure of the partially filled CFST bridge pier and the foundation with self-reset function according to claim 1 , wherein the cross-sectional shape of the steel pipe is square, rectangle, circle or ellipse. 3 .

3. The construction method of the connection structure of the partially filled concrete-filled steel tubular pier and the foundation with self-resetting function according to claim 1, characterized in that, spiral bars are arranged around the upper end of the prestressed steel strand, and the spiral bars are arranged in the filling in concrete.