阅读说明：本技术 一种抗震性能梯度墩柱及其建造方法 (Anti-seismic performance gradient pier column and construction method thereof ) 是由 邓江东 刘爱荣 于 2019-09-25 设计创作，主要内容包括：本发明涉及混凝土墩柱技术领域,公开了一种抗震性能梯度墩柱及其建造方法。该抗震性能梯度墩柱包括混凝土墩柱、在墩柱内配置的钢筋和梯度配置的梯度筋组成。梯度筋为纤维筋或者形状记忆合金筋。通过梯度筋截面面积的连续或者梯级变化,在墩柱中形成抗震性能梯度。在建造中,根据墩柱的地震受力状态,确定墩柱性能梯度的大小和实现方式,使墩柱性能梯度区顶部截面达到极限曲率以前性能梯度区其它截面不大于其极限曲率。本发明可以实现在地震作用下墩柱性能梯度区同时达到塑性状态,采用本发明建造的墩柱塑性变形区大幅增大,从而变形性能和耗能能力等大幅提高,可以抵抗的地震峰值加速度大幅提高。(The invention relates to the technical field of concrete piers, and discloses an anti-seismic performance gradient pier and a construction method thereof. The anti-seismic performance gradient pier column comprises a concrete pier column, reinforcing steel bars arranged in the pier column and gradient reinforcing steel bars arranged in a gradient manner. The gradient ribs are fiber ribs or shape memory alloy ribs. And through the continuous or step change of the section area of the gradient rib, the anti-seismic performance gradient is formed in the pier column. During construction, according to the earthquake stress state of the pier column, the size and the implementation mode of the performance gradient of the pier column are determined, and other sections of the performance gradient area are not larger than the limit curvature before the top section of the performance gradient area of the pier column reaches the limit curvature. The invention can realize that the pier column performance gradient area simultaneously reaches the plastic state under the action of the earthquake, and the pier column plastic deformation area constructed by the invention is greatly increased, thereby greatly improving the deformation performance, the energy consumption capability and the like and greatly improving the peak acceleration of the earthquake which can be resisted.)

1. The utility model provides an anti-seismic performance gradient pier stud which characterized in that: the concrete pier comprises a concrete pier column, reinforcing steel bars arranged in the concrete pier column and gradient reinforcing steel bars arranged in the concrete pier column in a gradient mode.

2. The seismic performance gradient pier stud of claim 1, wherein: the concrete in the pier column is ordinary portland cement concrete or high-ductility concrete or high-performance concrete.

3. The seismic performance gradient pier stud of claim 1, wherein: the gradient ribs are fiber ribs or shape memory alloy ribs.

4. The seismic performance gradient pier stud of claim 1, wherein: the reinforcing steel bars are generally arranged in the full-length range of the pier stud, and the gradient ribs can be configured in the full-length range of the pier stud or in a partial range.

5. The seismic performance gradient pier stud of claim 1 or claim 4, wherein: the cross section area of the gradient rib can be continuously changed in the height direction of the pier column to form a gradient reinforcing rib; or gradient reinforcement is formed by multi-grade change in the height direction of the pier stud, and the area of the gradient reinforcement in each grade is unchanged.

6. A construction method of an earthquake-resistant performance gradient pier stud is characterized by comprising the following steps: the method comprises the following main steps:

s1, determining the stress state of the pier stud in the structure under the action of the earthquake;

s2, determining the size of the pier column performance gradient and the implementation mode of the gradient according to the earthquake stress state;

s3, designing according to the anti-seismic target and the performance gradient target, and determining the size, the material and the reinforcing bars of the pier column, including the height and the number of the gradient reinforcing bars in gradient configuration;

and S4, constructing the pier stud according to the design.

7. The method for constructing an earthquake-resistant performance gradient pier stud according to claim 6, wherein: in step S2, the size of the seismic performance gradient should ensure that when the top section of the performance gradient area reaches the limit curvature in the earthquake, the section curvature at other positions of the performance gradient area is not larger than the limit curvature.

Technical Field

The invention relates to the technical field of concrete piers, in particular to an anti-seismic performance gradient pier and a construction method thereof.

Background

Earthquake is a natural disaster with huge destructive power, and the strong earthquake frequently occurs in the global range, thus causing serious threat to the life and property safety of people. Concrete pier in the bridge structures and concrete column in the building structures are key components for bearing earthquake lateral load, easily occur earthquake damage and damage, cause personnel and property loss, and urgently need to improve the earthquake resistance performance level of pier column by a wide margin.

In order to resist the action of earthquake, the prior concrete pier columns (including piers, structural columns and the like) generally adopt a ductile earthquake-resistant design, and under the action of earthquake, the pier columns can generate obvious plastic deformation to resist the action of earthquake, and the energy input by the earthquake is dissipated so as to ensure that the pier columns cannot collapse and be damaged. However, in the prior art, the range of the plastic deformation area of the concrete pier column under the action of the earthquake is small, so that the ultimate deformation capacity of the pier column is limited, the damage is concentrated, the damage degree is severe, the earthquake-resistant grade is low, and the requirement of the people on the earthquake resistance of the structure at present is difficult to meet.

Disclosure of Invention

In order to solve the technical problems, the invention provides an earthquake-resistant performance gradient pier column and a construction method thereof, and aims to solve the technical problem that the concrete pier column in the prior art is low in earthquake-resistant grade.

The invention discloses a technical scheme of an earthquake-resistant performance gradient pier stud, which comprises the following steps:

the utility model provides an anti-seismic performance gradient pier stud includes the concrete pier stud and arranges the reinforcing bar in the concrete pier stud still includes the gradient configuration and is in the gradient muscle in the concrete pier stud.

As a further improvement to the technical scheme, the concrete in the pier column is ordinary portland cement concrete or high-ductility concrete or high-performance concrete.

As a further improvement to the technical scheme, the gradient ribs are fiber ribs or shape memory alloy ribs.

As a further improvement to the above solution, the reinforcing bars are generally arranged over the entire length of the pier. The gradient rib can be configured in the whole length range of the pier stud or in a partial range.

As a further improvement to the above technical solution, the cross-sectional area of the gradient rib may be continuously changed in the direction of the pier column height to form a gradient reinforcement; or gradient reinforcing bars are formed by multi-grade change in the height direction of the pier stud, and the area of the gradient reinforcing bars in each grade is unchanged.

The invention relates to a construction method of an earthquake-resistant performance gradient pier stud, which mainly comprises the following steps:

s1, determining the stress state of the pier stud in the structure under the action of the earthquake;

s2, determining the size of the pier column performance gradient and the implementation mode of the gradient according to the earthquake stress state;

s3, designing according to the anti-seismic target and the performance gradient target, and determining the size, the material and the reinforcing bars of the pier column, including the height and the number of the gradient reinforcing bars in gradient configuration;

and S4, constructing the pier stud according to the design.

As a further improvement to the above technical solution, in step S2, the size of the seismic performance gradient should ensure that when the top section of the performance gradient area reaches the limit curvature in the earthquake, the section curvature at other positions of the performance gradient area is not larger than the limit curvature.

Compared with the prior art, the seismic performance gradient pier column and the construction method thereof have the beneficial effects that:

the anti-seismic performance gradient pier column forms the anti-seismic performance gradient by arranging the stress ribs in the concrete pier column in a gradient manner, and the gradient change of the anti-seismic performance can ensure that the performance gradient area of the pier column can simultaneously reach a plastic state under the action of an earthquake. As the plastic deformation area of the pier column constructed by the method is greatly increased, the deformation performance, the energy consumption capability and the like are greatly improved, and the peak acceleration of the earthquake which can be resisted is greatly improved, the earthquake safety of the civil engineering structure is improved.

Through the design calculation of the earthquake resistance gradient area, the utilization degree of the mechanical property of each section material can be adjusted through the size of the gradient, and the earthquake damage degree of the pier stud is controlled through the configuration quantity of the gradient ribs and the height of the gradient area.

The deformation of the pier column is mainly concentrated in a small plastic hinge area, which is different from the prior art, the plastic deformation area of the pier column constructed by the invention is obviously increased, the performance of the material is fully utilized, and the consumption of the construction material is reduced.

Drawings

FIG. 1 is a continuous gradient concrete pier stud reinforcement diagram in the seismic performance gradient pier stud and the construction method thereof according to the embodiment of the invention;

FIG. 2 is a sectional view taken along line A-A of FIG. 1;

FIG. 3 is a sectional view taken along line B-B of FIG. 1;

FIG. 4 is a multi-grade gradient concrete pier stud reinforcement diagram in the seismic performance gradient pier stud and the construction method thereof according to the embodiment of the invention;

FIG. 5 is a sectional view taken along line C-C of FIG. 4;

FIG. 6 is a sectional view taken along line D-D of FIG. 4;

FIG. 7 is a graph of pier column section curvature versus bending moment;

fig. 8 is a plot of pier column cross-sectional curvature versus height;

FIG. 9 is a graph comparing a performance gradient pier column load displacement curve with a non-performance gradient pier column load-displacement experimental curve;

in the figure: 1-reinforcing steel bars; 2-gradient rib.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The concrete embodiment of the seismic performance gradient pier column comprises a concrete pier column and reinforcing steel bars 1 arranged in the concrete pier column, wherein two ends of the reinforcing steel bars extend to two ends of the concrete pier column. The earthquake-resistant performance gradient pier column further comprises gradient ribs 2 which are arranged in the concrete pier column in a gradient mode.

Wherein, the concrete pier is made of ordinary portland cement concrete, the steel bar 1 is ordinary steel bar, and the gradient bar 2 adopts glass fiber bar. In other embodiments, the fiberglass ribs may be replaced with shape memory alloy ribs.

If a continuously varying gradient is used, the reinforcement comprises a reinforcement bar 1 and a glass fibre reinforcement bar with a continuously varying cross-sectional area, as shown in fig. 1, 2 and 3. In this embodiment, a gradient of step change is adopted, and the reinforcing bars include reinforcing steel bars 1 and glass fiber reinforcing bars arranged in a step manner in cross-sectional area. The gradient rib is divided into two sections, specifically, the lower part of the pier column is provided with the glass fiber rib with the unchanged cross section area, and the upper part of the pier column is not provided with the glass fiber rib, so that the stress rib is arranged in a gradient manner in the length direction of the pier column.

The construction method of the seismic performance gradient pier column comprises the following main steps:

s1: firstly, the stress state of the pier stud in the structure under the action of earthquake is determined, and the determination method can be a reaction spectrum method, an earthquake response time-course analysis method and the like. The maximum earthquake bending moment at the bottom of the pier column is obtained, and the earthquake bending moment at the top of the pier column is zero.

S2, determining the performance gradient of the pier column to be two-grade gradient according to the earthquake stress state, wherein the gradient is that plastic hinges simultaneously appear at the bottom of the pier column and a position 70 cm away from the bottom surface of the pier column;

and S3, according to the requirements of an earthquake-resistant target and a performance gradient, determining the height of the pier column by 270 cm, the section size of 25 cm multiplied by 25 cm, the concrete strength grade of C45, the steel bar 1 of HRB425 grade, the glass fiber reinforcement strength of 500Mpa and the ultimate strain of 0.02 through design calculation. In this embodiment, two grades of gradients are adopted, and it is determined according to a bending moment-curvature (M- Φ) curve analysis of a section of a pier, the reinforcement is a reinforcement 1 located at 4 corners of the pier and 4 glass fiber reinforcements located in the middle of the section, the diameter of the glass fiber reinforcements is not changed, and the configuration height is 70 cm from the bottom of the pier, as shown in fig. 4, 5, and 6. The two grades are respectively one grade within a range of 70 cm from the bottom of the pier and one grade from 70 cm to the top of the pier, and the bearing capacity of the sections at the bottom of the pier and 70 cm from the bottom of the pier in the configuration corresponds to the earthquake stress state of the pier at the position obtained in the step S1, namely the two areas can simultaneously enter a plastic state.

In this embodiment, the glass fiber reinforcement has a great deformability and a constitutive relation of linear elasticity, and the cross-sectional bearing capacity of the glass fiber reinforcement after the reinforcement is yielded can be continuously increased, thereby facilitating the realization of the seismic performance gradient. For the comparison, another design 4 reinforcing bars and 4 glass fiber reinforcement mix the concrete pier stud of arrangement of reinforcement, the difference is that this pier stud glass fiber reinforcement is along the high full length configuration of pier stud, does not form the gradient, and other parameters are identical.

In order to control the damage degree of the section of each grade of gradient area, the arrangement number of the gradient ribs 2 can be increased or decreased. As shown in FIG. 7, when the number of the bottom gradient ribs 2 is increased, the curvature of the section of the gradient area is reduced under the same bending moment, and the maximum curvature of the section is from phi₂Reduced to phi₁The damage degree is reduced; the damage degree of the gradient area is increased after reducing the gradient reinforcement, and the section curvature in the figure is from phi₂Increase to phi₃。

S4: the concrete pier is manufactured according to the design, and the manufacturing and maintenance of the concrete pier are prior art and are not described in detail herein.

In order to test the seismic performance of the seismic performance gradient pier stud, the seismic test was performed in this example. The test result shows that the anti-seismic performance gradient concrete pier stud generates large plastic deformation in each grade region of the gradient, and the section curvature also generates two peak values at the pier bottom and the position 70 cm away from the pier bottom respectively, as shown in figure 8. The non-seismic performance gradient concrete pier stud only has a plastic deformation area at the bottom of the pier, and the section curvature is also only at a peak value at the bottom of the pier, as shown in fig. 8. Compared with a non-anti-seismic performance gradient concrete pier column, the limit lateral force of the anti-seismic performance gradient concrete pier column is basically unchanged, the limit displacement is greatly increased, and the anti-seismic performance is enhanced, as shown in fig. 9. Meanwhile, the glass fiber ribs in the concrete pier column with the gradient anti-seismic performance are less in consumption, and the material cost is low.

The invention provides an earthquake-resistant performance gradient pier stud and a construction method thereof, and compared with the prior art, the pier stud has the following advantages.

The construction method of the pier column with the seismic performance gradient forms the seismic performance gradient by configuring the gradient ribs 2 in the concrete pier column, and the gradient of the seismic performance can ensure that the pier column performance gradient area can simultaneously reach a plastic state under the action of an earthquake. The plastic deformation area of the pier column constructed by the method is greatly increased, so that the deformation performance, the energy consumption capability and the like are greatly improved, and the peak acceleration of the earthquake which can be resisted is greatly improved. The invention greatly improves the anti-seismic performance level of the concrete pier stud and ensures the seismic safety of the civil engineering structure.

In addition, the utilization degree of the mechanical property of the material of each section of the pier column can be adjusted through the size of the property gradient, so that the earthquake damage degree of the pier column can be controlled.

Unlike the prior art, the pier stud damage is mainly concentrated in a small plastic hinge area, the plastic deformation area of the pier stud constructed by the method is remarkably increased, the performance of the material is more fully utilized, and the consumption of the construction material is greatly reduced under the condition of reaching the same anti-seismic performance level.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.