CN102635063A - Post-tensioned prestressing steel pipe high-strength concrete superposition bridge pier and construction method thereof - Google Patents

Abstract

A post-tensioned prestressed steel pipe high-strength concrete composite bridge pier and its construction method, including steel pipes, a plurality of unbonded prestressed tendons are arranged in the steel pipes, and in-pipe concrete is poured between the inner wall of the steel pipes and the unbonded prestressed tendons, Steel pipes, unbonded prestressed tendons and concrete inside the pipe form a core column, and concrete outside the core column is poured outside the core column to form a laminated pier, and a number of prefabricated steel pipes with vertical prestressed tendons are installed and arranged inside the traditional reinforced concrete pier. Concrete core column. After the installation and construction of the internal prestressed steel tube high-strength concrete core column is completed, the external reinforced concrete skeleton of the pier is bound and the external concrete is poured to form a vertical prestressed steel tube high-strength concrete composite bridge pier that is poured at different times. Among them, the internal prestressed core column is made by the post-tensioning method. The invention effectively improves the anti-seismic safety and effectiveness of the existing pier structure, and has the characteristics of high bearing capacity, good anti-seismic performance, convenient construction and self-resetting.

Description

Post-tensioned prestressed steel tube high-strength concrete composite bridge pier and its construction method

technical field

The invention belongs to the technical field of bridge engineering, and relates to a post-tensioned prestressed steel pipe high-strength concrete composite bridge pier and a construction method thereof.

Background technique

As a key component of bridge structure, the seismic design of bridge piers has always been an important research topic in the field of bridges. my country's current railway bridges and highway bridges mainly use reinforced concrete piers. It should be noted that while reinforced concrete piers have the advantages of high structural rigidity, good fatigue performance, good moldability and reasonable cost, they also generally have weak stirrup restraint, low ductility, low shear strength and poor seismic performance. Due to the low shear resistance, compressive bearing capacity and deformation capacity of bridge piers, shear failure, combined compression-bending-shear-torsion failure and overturning collapse are prone to occur. In recent years, many earthquakes at home and abroad have reinforced Concrete bridge piers were severely damaged and difficult to repair. Earthquake damage occurred, which caused great difficulties for disaster relief and post-disaster repair and reconstruction during the earthquake. Therefore, while striving to improve and improve the seismic performance of traditional reinforced concrete piers, the innovation and development of new and efficient steel-concrete composite piers and the development of seismic design methods for composite piers have gradually become the focus of attention and research hotspots in the current bridge engineering field.

Under the background of extensive research and application of concrete-filled steel pipe columns and concrete-filled steel pipe composite columns in building construction, concrete-filled steel pipe concrete-filled bridge piers and concrete-filled steel-filled steel-filled column piers (abbreviated as concrete-filled steel pipe composite bridge piers) have also been popularized and applied in bridge projects at home and abroad. . Since the steel pipes are built into the reinforced concrete piers, the composite steel pipe concrete piers not only have the advantages of the steel pipe confined concrete in the steel pipe concrete piers, but also solve the problems of steel pipe corrosion and local buckling under compression. Existing research results show that concrete filled steel pipe composite piers (columns) have high strength, high ductility, good energy consumption, and good seismic performance. In order to effectively reduce the residual deformation of the bridge structure after the earthquake and facilitate the repair and reinforcement of the bridge after the earthquake, scholars at home and abroad have recently proposed the design principle of "vertical prestressed pier" (or self-resetting function), that is, by arranging vertical prestressed pier inside the reinforced concrete pier. Stressed tendons, so that the residual deformation of the bridge pier after the earthquake due to the tension of the vertical prestressed tendons can be effectively reduced. Existing research results show that vertical prestressing can not only effectively reduce the residual deformation of bridge piers and realize the self-resetting function after earthquakes, but also make good contributions to improving the lateral displacement stiffness, impact resistance, overturning resistance and progressive collapse resistance of bridge piers.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the object of the present invention is to provide a post-tensioned prestressed steel tube high-strength concrete composite bridge pier and its construction method, which effectively improves the seismic safety and effectiveness of the existing bridge pier structure, and has a bearing capacity High, good seismic performance, convenient construction and self-resetting characteristics provide advanced technology for bridge construction.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A post-tensioned prestressed steel pipe high-strength concrete composite bridge pier, comprising a steel pipe 2, a plurality of unbonded prestressed tendons 3 arranged in the steel pipe 2, and in-pipe concrete poured between the inner wall of the steel pipe 2 and the unbonded prestressed tendons 3 1. The steel pipe 2, the unbonded prestressed tendon 3 and the concrete inside the pipe form a core column 5, and the outside concrete 4 is poured outside the core column 5 to form a laminated pier.

The cross-section of the superimposed pier is circular or square.

The pre-unbonded prestressed tendons 3 are covered with hoses or wrapped with unbonded materials.

There are multiple core columns 5, and concrete 4 outside the pipe is poured between adjacent core columns 5 to form a multi-core column superimposed pier.

The concrete 1 inside the pipe is high-strength concrete, and the concrete 4 outside the pipe is ordinary concrete or high-strength concrete.

The present invention also provides a construction method for the prestressed steel pipe high-strength concrete composite bridge pier: arranging a plurality of unbonded prestressed tendons 3 inside the steel pipe 2 along its length direction, then pouring the concrete 1 inside the steel pipe 2 and compacting and vibrating After the concrete 1 in the pipe reaches a certain strength, the core column 5 of the prestressed steel tube high-strength concrete is formed, the core column 5 is connected with the foundation embedded anchor bolt and the base plate of the core column foot, installed and fixed to the predetermined position of the pier, and the core column Binding of external steel bars and pouring of external concrete to form a pre-tensioned prestressed steel tube high-strength concrete composite pier, and finally stretching and anchoring unbonded prestressed tendons in the core column to form a post-tensioned high-strength steel tube high-strength concrete composite pier piers.

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

(1) High bearing capacity: Since the core column of the laminated pier is made of high-strength concrete and is located inside the pier, the high-strength concrete in the core column is constrained by the steel pipe and the concrete outside the core column, and the strength of the high-strength concrete can be improved and fully exerted. The cross-sectional shear bearing capacity, vertical compressive bearing capacity and combined compression-bending-shear-torsion load-bearing capacity can all be significantly improved, which can effectively improve the bearing capacity of bridge pier for small bias failure, shear failure and end compression-bending-shear composite failure. Under the same design load, the section size of the bridge pier can be effectively reduced, so as to achieve the effects of saving materials, increasing the appearance and increasing the crossing space under the bridge.

(2) Good seismic ductility: Since the high-strength concrete in the core column of the composite pier is well restrained, the deformation capacity of the high-strength concrete is greatly improved. The axial pressure is small (that is, the ratio of the external reinforced concrete to bear the axial pressure is small), and the steel pipe is not easy to be damaged by local buckling instability due to the constraints of the inner and outer concrete. Therefore, the composite pier has good ductility and energy dissipation performance . The good elastic-plastic deformation capacity, ductility performance and energy dissipation capacity of prestressed steel tube high-strength concrete composite piers can effectively prevent and avoid serious damage and collapse of bridge piers under large earthquakes, and can effectively improve the seismic performance and safety of concrete bridge piers .

(3) Large elastic stiffness: setting prestressed core columns in the superimposed piers can effectively increase the elastic lateral displacement stiffness of the pier, thereby effectively reducing bridge vibration and elastic deformation of the pier when trains and heavy vehicles are running and under small earthquakes, which can improve Vehicle driving safety and comfort.

(4) Good self-resetting property: setting the prestressed core column in the superimposed pier is equivalent to forming a vertical prestressed pier. Afterwards, it has a good self-centering function, so that the bridge pier basically returns to the original position of the pier after a small or medium earthquake, and it will not be irreparable or even collapsed due to large residual deformation under strong earthquakes.

(5) Good robustness: In recent years, vehicles and ships often hit bridge piers, causing serious damage or even collapse of bridge piers (Guangzhou Jiujiang Bridge). The double function of high-strength concrete core column and external reinforced concrete can effectively improve the robustness of the pier, enhance the anti-seismic, anti-collision, anti-shock, anti-overturning and anti-successive collapse capabilities of the pier, and improve the safety performance of the pier.

(6) Good durability: Compared with the traditional concrete-filled steel pipe piers with exposed steel pipes, since the steel pipes in the high-strength concrete piers with prestressed steel pipes are located in the center of the concrete piers, there is no need to consider the anti-corrosion problem of the steel pipes in the composite columns, and the durability of the piers is effectively improved and more applicable For pier structures with higher environmental categories.

(7) Good pouring quality: Since the prestressed steel tube high-strength concrete core column can be prefabricated in the factory, the quality of high-strength concrete pouring in the steel tube high-strength concrete core column can be well guaranteed, which can avoid the difficulty of pouring high-strength concrete in the core column caused by on-site pouring Compactness and difficulty in on-site maintenance.

(8) Good economy: The high-strength concrete in the composite bridge pier is well constrained by the steel pipe and the external concrete, which can give full play to the performance advantages of ultra-high-strength concrete and use a large amount of ultra-high-strength concrete. The cross-sectional size of the pier and the amount of concrete can be greatly reduced. economic benefits. The existing experience shows that compared with ordinary reinforced concrete structures, the cost of ordinary steel pipe concrete structures with the same performance is basically the same as that of reinforced concrete structures. Prestressed steel pipe high-strength concrete composite piers have obvious economic advantages compared with traditional steel pipe concrete piers because of the use of thin-walled steel pipes, the amount of steel used is very small, and the cost of anticorrosion and maintenance of steel pipes can be avoided.

Generally speaking, the prestressed steel tube high-strength concrete composite bridge pier is a new type of bridge pier with good mechanical performance, seismic performance and durability, convenient construction, reasonable cost and easy quality control, which conforms to the current "solid" structure of civil engineering structures in my country. , safe and durable” development direction, has a good prospect for application and promotion.

Description of drawings

Fig. 1 is a schematic structural diagram of Embodiment 1 of the present invention.

FIG. 2 is a top view of FIG. 1 .

Fig. 3 is a construction process diagram of the present invention.

Fig. 4 is a schematic structural diagram of Embodiment 2 of the present invention.

FIG. 5 is a top view of FIG. 4 .

Fig. 6 is a schematic structural diagram of Embodiment 3 of the present invention.

FIG. 7 is a top view of FIG. 6 .

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Example 1: High-strength concrete composite bridge pier with single core column prestressed steel tube with circular cross section

Referring to Figures 1 and 2, a post-tensioned prestressed steel pipe high-strength concrete composite bridge pier includes a steel pipe 2, six pre-unbonded prestressed tendons 3 are arranged in the steel pipe 2, and the inner wall of the steel pipe 2 is connected to the pre-unbonded prestressed steel pipe 2. In-pipe concrete 1 is poured between the tendons 3, steel pipe 2, pre-unbonded prestressed tendons 3 and in-pipe concrete 1 form a core column 5, and external concrete 4 is poured outside the core column 5 to form a laminated pier, and the laminated pier The cross section is circular.

The construction steps of the laminated pier are shown in Figure 3, as follows:

Step 1, determine the diameter and wall thickness of the steel pipe 2, the diameter, quantity and arrangement position of the unbonded prestressed tendons 3, and the strength and mix ratio of the concrete 1 inside the pipe and the concrete 4 outside the pipe according to the design requirements;

Step 2, fixing the steel pipe 2, and arranging unbonded prestressed tendons 3 inside the steel pipe 2 according to design requirements;

Step 3: Concrete 1 in the pipe is poured by pumping method, and the concrete 1 in the pipe is compacted and vibrated. After the concrete 1 in the pipe is cured to a certain strength, a prestressed steel pipe high-strength concrete core column 5 is formed, and the concrete 1 in the pipe is high-strength concrete;

Step 4, transport the core column 5 to the construction site, connect it with the foundation embedded anchor bolt and the base plate of the core column column, install and fix it to the predetermined position of the pier;

Step 5, binding the outer steel bars of the core column, erecting the steel bar skeleton 6, and carrying out the external concrete pouring construction to form and form the pretensioned prestressed steel pipe high-strength concrete composite bridge pier;

Step 6, stretching and anchoring the unbonded prestressed tendons 3 in the core column to form a post-tensioned prestressed steel pipe high-strength concrete composite bridge pier.

A high-strength concrete composite bridge pier with prestressed steel tubes with a circular cross-section is prepared, as shown in Figures 1 and 2. The cross-section of the steel tubes 2 is circular, and the number of unbonded prestressed tendons 3 is six.

Example 2: High-strength concrete composite bridge pier with square cross-section single core column prestressed steel pipe

Referring to Fig. 4 and Fig. 5, a post-tensioned prestressed steel pipe high-strength concrete composite bridge pier includes a steel pipe 2, six pre-unbonded prestressed tendons 3 are arranged in the steel pipe 2, and the inner wall of the steel pipe 2 is connected with the pre-unbonded prestressed In-pipe concrete 1 is poured between the tendons 3, steel pipe 2, pre-unbonded prestressed tendons 3 and in-pipe concrete 1 form a core column 5, and external concrete 4 is poured outside the core column 5 to form a laminated pier, and the laminated pier The cross section is circular.

The construction steps of the laminated pier are shown in Fig. 3, which is consistent with the method in Embodiment 1.

The prepared high-strength concrete composite bridge pier with single core column prestressed steel pipe with rectangular cross-section is shown in Fig. 4 and Fig. 5. The cross-section of the steel pipe 2 is rectangular, and the number of unbonded prestressed tendons 3 is six.

Example 3: High-strength concrete composite bridge pier with multi-core columns and prestressed steel pipes with elliptical cross-section

Referring to Fig. 6 and Fig. 7, there are three core columns 5, and concrete 4 inside the tube is poured outside the core columns 5 and between adjacent core columns 5 to form a multi-core column laminated pier, and the cross section of the laminated pier is elliptical.

The construction steps are as follows:

Step 1, determine the diameter, wall thickness and quantity of the steel pipe 2 according to the design requirements, the diameter, quantity and arrangement position of the unbonded prestressed tendons 3, and the strength and mix ratio of the concrete 1 inside the pipe and the concrete 4 outside the pipe;

Step 2, fixing the steel pipe 2, and arranging unbonded prestressed tendons 3 inside the steel pipe 2 according to design requirements;

Step 3: Concrete 1 in the pipe is poured by pumping method, and the concrete 1 in the pipe is compacted and vibrated. After the concrete 1 in the pipe is cured to a certain strength, a prestressed steel pipe high-strength concrete core column 5 is formed, and the concrete 1 in the pipe is high-strength concrete;

Step 4, transport multiple core columns 5 to the construction site, connect them with the foundation embedded anchor bolts and the base plates of the core columns, and install and fix them to the predetermined positions of the pier;

Step 5: Bundle the steel bars outside the core column and erect the steel bar skeleton 6. The steel bar frame 6 is erected on the outside of the arranged core columns 5, and the external concrete pouring construction is carried out to form a pre-tensioned prestressed steel pipe high-strength concrete composite pier;

Step 6, stretching and anchoring the unbonded prestressed tendons 3 in the core column to form a post-tensioned prestressed steel pipe high-strength concrete composite bridge pier.

The present invention can also include multiple embodiments such as double-core columns, three-core columns and four-core columns prestressed steel pipe high-strength concrete composite bridge piers. In each embodiment, the concrete 1 in the pipe is high-strength concrete, and the concrete 4 outside the pipe can be ordinary concrete or high-strength concrete. Concrete isolation.

Claims (8)

1. superimposed bridge pier of post-stressed high strength concrete filled steel tube; Comprise steel pipe (2); It is characterized in that, be furnished with many unbonded prestressing tendons (3) in the steel pipe (2), pouring has pipe inner concrete (1) between steel pipe (2) inwall and the unbonded prestressing tendon (3); Steel pipe (2), unbonded prestressing tendon (3) and pipe inner concrete (1) form a stem stem (5), and concrete (4) forms superimposed bridge pier outside pipe has been built in stem stem (5) outside.

2. the superimposed bridge pier of post-stressed high strength concrete filled steel tube according to claim 1 is characterized in that, said unbonded prestressing tendon (3) is with flexible pipe or parcel non-cohesive material.

3. the superimposed bridge pier of post-stressed high strength concrete filled steel tube according to claim 1 is characterized in that, said superimposed bridge pier cross section is square, circle or rectangle.

4. the superimposed bridge pier of post-stressed high strength concrete filled steel tube according to claim 1 is characterized in that, said stem stem (5) has the outer concrete (4) of equal gate spool between a plurality of, adjacent stem stem (5), forms the superimposed bridge pier of multicore post.

5. the superimposed bridge pier of post-stressed high strength concrete filled steel tube according to claim 1 is characterized in that said pipe inner concrete (1) is a high-strength concrete, and managing outer concrete (4) is ordinary concrete or high-strength concrete.

6. the job practices of the superimposed bridge pier of the said pre-stressed steel pipe high-strength concrete of claim 1; It is characterized in that, in steel pipe (2), arrange many unbonded prestressing tendons (3), then pouring pipe inner concrete (1) and closely knit vibrating in steel pipe (2) along its length direction; After inner concrete to be managed (1) reaches certain intensity; Promptly form the stem stem (5) of pre-stressed steel pipe high-strength concrete, stem stem (5) is connected with stem stem suspension column base plate through plinth cast-in fixing bolt very, install and fix to the bridge pier precalculated position; Carry out outer reinforcing bar binding of stem stem and outside concrete pouring construction; Form the superimposed bridge pier of Pretensioned prestressing steel pipe high-strength concrete, carry out stretch-draw, the anchoring of unbonded prestressing tendon in the stem stem at last, form the superimposed bridge pier of post-stressed high strength concrete filled steel tube.

7. the job practices of the superimposed bridge pier of pre-stressed steel pipe high-strength concrete according to claim 6 is characterized in that, said stem stem (5) has the outer concrete of equal gate spool between a plurality of, adjacent stem stem (5), forms the superimposed bridge pier of multicore post.

8. the job practices of the superimposed bridge pier of pre-stressed steel pipe high-strength concrete according to claim 6 is characterized in that said pipe inner concrete (1) is a high-strength concrete, and managing outer concrete (4) is ordinary concrete or high-strength concrete.

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