Prefabricated pipe pier

Abstract

The utility model relates to the field of constructional engineering, in particular to a prefabricated pipe pier which comprises a pier body, a reinforcement cage is arranged in the pier body, the reinforcement cage comprises prestressed reinforcements and spiral stirrups surrounding the prestressed reinforcements, and at least part of the spiral stirrups comprises a first spiral stirrup and a second spiral stirrup which are parallel to each other. The distance between the center of the section of the first spiral stirrup and the center of the section of the second spiral stirrup is d12, the distance between the spiral stirrups is d, and d12lt is obtained; and d. According to the prefabricated pipe pier, the stirrup matching rate is increased, and meanwhile the thickness of a steel bar protection layer of the pipe pier is not reduced; the diameter of the stirrup and the hoop matching rate can meet the requirements of existing specifications, and meanwhile, the requirements of a steel bar protection layer are met; and under the condition that the outer diameter and the wall thickness of the pipe pier are not changed, the bearing capacity is met, and the cost is saved.

Description

Technical Field

[0001] The utility model relates to the field of construction engineering, and particularly relates to a precast pipe pier. Background Art

[0002] The fully precast assembled pile-column integration technology has been successfully applied in new or renovated road projects in the fields of highway and municipal engineering. It is prefabricated in factories, with stable quality, time-saving construction period, land-saving, and good economy. The lower structure pier column adopts a centrifugal process for precast pipe piers, and the cage reinforcement is processed and formed by a roll welding process, with high production efficiency. However, for the existing pre-tensioned precast pipe piers used as bridge piers, the stirrup diameter and stirrup ratio do not meet the requirements of the existing specifications. If the stirrup diameter is increased, it is difficult to meet the requirements of the steel bar protection layer. To meet the bearing capacity requirements and the stirrup ratio requirements, the method of increasing the pipe pier diameter is adopted. Therefore, when the precast pipe pier is used as a bridge pier, what kind of structure can make the stirrup diameter and stirrup ratio meet the specification requirements, and at the same time meet the requirements of the steel bar protection layer, is an urgent problem to be solved. Content of the Utility Model

[0003] In view of the above problems, the utility model improves the structure of the stirrups, so that the stirrup diameter and stirrup ratio of the pipe pier meet the design and specification requirements, and has higher durability, high load-bearing capacity, and high ductility.

[0004] A precast pipe pier includes a pier body, and a steel reinforcement cage is arranged in the pier body. The steel reinforcement cage includes prestressed steel bars and spiral stirrups wound around the prestressed steel bars. At least part of the spiral stirrups are parallel first spiral stirrups and second spiral stirrups, and the center-to-center distance of the cross-sections of the first spiral stirrup and the second spiral stirrup is d 12 , the spiral stirrup spacing is d, and d 12 <d.

[0005] Preferably, the spiral stirrups are arranged along the entire length of the pier body.

[0006] Preferably, the diameters of the first spiral stirrup and the second spiral stirrup are D1 and D2 respectively; where d 12 =(D1 + D2) / 2 + X; where X represents the spacing floating range, and the value range of X is 0 - 20 mm.

[0007] Preferably, D1 = D2 or D1 < D2 or D1 > D2.

[0008] Preferably, the two end regions of the pipe pier are the first plastic hinge region and the second plastic hinge region respectively, and the middle is the ordinary region. The first spiral stirrup surrounds the prestressed steel bar throughout the length, and the second spiral stirrup is arranged in the first plastic hinge region and the second plastic hinge region; the diameter of the first spiral stirrup is D1, the diameter of the second spiral stirrup in the first plastic hinge region is D4, and the diameter of the second spiral stirrup in the second plastic hinge region is D5, where D1 = D4 or D1 < D4 or D1 > D4, D1 = D5 or D1 < D5 or D1 > D5, D4 = D5 or D4 < D5 or D4 > D5, and the distance between the centers of the cross-sections of the first spiral stirrup and the second spiral stirrup in the first plastic hinge region is d 14 ; and d 14 = (D1 + D4) / 2 + X1; the distance between the centers of the cross-sections of the first spiral stirrup and the second spiral stirrup in the second plastic hinge region is d 15 ; and d 15 = (D1 + D5) / 2 + X2; where X1 represents the first spacing floating range, X2 represents the second spacing floating range, and the value ranges of X1 and X2 are both 0 - 20 mm.

[0009] Preferably, non-prestressed steel bars are also arranged in the pier body, and the prestressed steel bars and the non-prestressed steel bars are arranged at intervals.

[0010] Preferably, the spacings of the spiral stirrups in the first plastic hinge region and the second plastic hinge region are d1 and d3 respectively, and the spacing of the spiral stirrups in the ordinary region is d2, where d1 < d2 and d3 < d2.

[0011] Preferably, both the first spiral stirrup and the second spiral stirrup are in contact with the prestressed steel bar.

[0012] Preferably, both the first spiral stirrup and the second spiral stirrup are arranged outside the prestressed steel bar; or both are arranged inside the prestressed steel bar.

[0013] Preferably, the first spiral stirrup is arranged outside the prestressed steel bar, and the second spiral stirrup is arranged inside the prestressed steel bar, and the connecting line of the centers of the first spiral stirrup and the second spiral stirrup is perpendicular to the prestressed steel bar with which they are in contact.

[0014] Beneficial effects:

[0015] 1. For the precast pipe pier of the present utility model, while increasing the stirrup ratio, the thickness of the steel bar protection layer of the pipe pier is not reduced; it can make the stirrup diameter and stirrup ratio meet the requirements of the existing specifications while meeting the requirements of the steel bar protection layer; without changing the outer diameter and wall thickness of the pipe pier, the bearing capacity is satisfied and the cost is saved.

[0016] 2. The first spiral stirrup and the second spiral stirrup can be matched with stirrups of different models and specifications to meet different stirrup ratio requirements;

[0017] 3. Without affecting the forming of the pipe pier, the stirrup ratio is increased, which improves the lateral restraint of the stirrups on the pipe pile, thereby improving the vertical bearing capacity and seismic performance of the pipe pile; at the same time, it also effectively increases the ductility of high-performance concrete, improves crack resistance, and prevents brittle failure;

[0018] 4. For projects in cold regions, it can improve the anti-frost expansion capacity of the pipe pier and reduce the occurrence of vertical cracks in the pipe pier. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a reinforcement diagram of the pipe pier in the embodiment of the utility model;

[0020] Figure 2 In the embodiment of the utility model Figure 1 AA surface screenshot;

[0021] Figure 3 In the embodiment of the utility model Figure 1 Screenshot of BB surface;

[0022] Figure 4 A diagram of a spiral stirrup according to an embodiment of the present utility model;

[0023] Figure 5 This is a cross-sectional view of a spiral stirrup according to an embodiment of the present utility model;

[0024] Figure 6 A diagram of a spiral stirrup according to another embodiment of the present invention;

[0025] Figure numerals: 1-end plate, 21-prestressed steel bar, 22-non-prestressed steel bar, 3-spiral stirrup, 31-first spiral stirrup, 32-second spiral stirrup. DETAILED DESCRIPTION

[0026] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the embodiment described below is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] like Figures 1 to 5As shown in the figure, a precast pipe pier includes a pier body. The two ends of the pier body are end plates 1. A steel reinforcement cage is arranged inside the pier body. The steel reinforcement cage includes prestressed steel bars 21 and spiral stirrups 3 wound around the prestressed steel bars 21. At least part of the spiral stirrups 3 are parallel first spiral stirrups 31 and second spiral stirrups 32. The center-to-center spacing of the cross-sections of the first spiral stirrups 31 and the second spiral stirrups 32 is d 12 , the spacing of the spiral stirrups is d, and d 12 <d. Non-prestressed steel bars 22 are also arranged inside the pier body. The prestressed steel bars 21 and the non-prestressed steel bars 22 are arranged at intervals. The spiral stirrups 3 are arranged along the entire length of the pier body.

[0028] As Figure 4 shown in the figure, in this embodiment, all of the spiral stirrups 3 are parallel first spiral stirrups 31 and second spiral stirrups 32. The diameters of the first spiral stirrups 31 and the second spiral stirrups 32 are D1 and D2 respectively; among them, d 12 =(D1 + D2) / 2 + X; where X represents the range of spacing fluctuation. The value range of X is 0 - 20 mm, and D1 = D2 or D1 < D2 or D1 > D2 is satisfied.

[0029] Both the first spiral stirrup and the second spiral stirrup are in contact with the prestressed steel bar. In some embodiments, both the first spiral stirrup and the second spiral stirrup are arranged outside the prestressed steel bar; or both are arranged inside the prestressed steel bar. In other embodiments, the first spiral stirrup is arranged outside the prestressed steel bar, and the second spiral stirrup is arranged inside the prestressed steel bar. The connecting line of the centers of the first spiral stirrup and the second spiral stirrup is perpendicular to the prestressed steel bar with which they are in contact. The first spiral stirrup and the second spiral stirrup are respectively arranged on both sides of the prestressed steel bar, increasing the spiral stirrup spacing d, and the fluidity of the gravel in the concrete is better.

[0030] As Figure 6 shown in the figure, in a possible embodiment, the two end regions of the pipe pier are a first plastic hinge region and a second plastic hinge region respectively, and the middle is a normal region. The first spiral stirrups 31 are wound around the prestressed steel bars 21 throughout the length. The second spiral stirrups 32 are arranged in the first plastic hinge region and the second plastic hinge region; the diameter of the first spiral stirrups 31 is D1, the diameter of the second spiral stirrups 32 in the first plastic hinge region is D4, and the diameter of the second spiral stirrups 32 in the second plastic hinge region is D5. Among them, D1 = D4 or D1 < D4 or D1 > D4, D1 = D5 or D1 < D5 or D1 > D5, D4 = D5 or D4 < D5 or D4 > D5. The center-to-center spacing of the cross-sections of the first spiral stirrups 31 and the second spiral stirrups 32 in the first plastic hinge region is d 14 ; and d 14 =(D1 + D4) / 2 + X1; the center-to-center spacing of the cross-sections of the first spiral stirrups 31 and the second spiral stirrups 32 in the second plastic hinge region is d 15; and d 15 =(D1+D5) / 2+X2; where X1 represents the first spacing floating range, X2 represents the second spacing floating range, and the value ranges of X1 and X2 are both 0-20mm. The spacings of the spiral stirrups 3 in the first plastic hinge zone and the first plastic hinge zone are d1 and d3 respectively, and the spacing of the spiral stirrups 3 in the ordinary zone is d2, where d1 <d2,d3<d2。

[0031] For example, the original pipe pier has an outer diameter of 800mm, a wall thickness of 130mm, a strength of C80, and stirrups of φ6mm cold-drawn steel bars, a stirrup spacing of 80mm, and a spacing of 50mm in the densified area. Using 2φ6mm cold-drawn steel bars as parallel stirrups, the shear bearing capacity of the pipe pier is increased by 25% and the ductility is increased by 12%.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A prefabricated pipe pier, comprising a pier body, wherein a steel cage is arranged inside the pier body, characterized in that: The steel cage comprises prestressed steel bars and spiral stirrups wrapped around the prestressed steel bars, wherein at least part of the spiral stirrups are parallel first spiral stirrups and second spiral stirrups, and the center distance between the cross-sections of the first spiral stirrups and the second spiral stirrups is d 12 , the spacing between spiral stirrups is d, and d 12 <d。 2. The prefabricated pipe pier according to claim 1, characterized in that: The spiral stirrups are arranged along the entire length of the pier shaft.

3. The prefabricated pipe pier according to claim 2, characterized in that: The diameters of the first spiral stirrup and the second spiral stirrup are D1 and D2 respectively; Among them, d 12 =(D1+D2) / 2+X; X represents the floating range of the spacing, and the value range of X is 0-20mm.

4. The prefabricated pipe pier according to claim 3, characterized in that: D1 = D2 or D1 < D2 or D1 > D2.

5. The prefabricated pipe pier according to claim 1, characterized in that: Both ends of the pipe pier are respectively the first plastic hinge region and the second plastic hinge region, and the middle is the ordinary region. The first spiral stirrup surrounds the prestressed steel bar throughout the length, and the second spiral stirrup is arranged in the first plastic hinge region and the second plastic hinge region; the diameter of the first spiral stirrup is D1, the diameter of the second spiral stirrup in the first plastic hinge region is D4, and the diameter of the second spiral stirrup in the second plastic hinge region is D5, where D1 = D4 or D1 < D4 or D1 > D4, D1 = D5 or D1 < D5 or D1 > D5, D4 = D5 or D4 < D5 or D4 > D5, and the distance between the centers of the cross-sections of the first spiral stirrup and the second spiral stirrup in the first plastic hinge region is d 14 ; and d 14 =(D1 + D4) / 2 + X1; the distance between the centers of the cross-sections of the first spiral stirrup and the second spiral stirrup in the second plastic hinge region is d 15 ; and d 15 =(D1 + D5) / 2 + X2; where X1 represents the first spacing floating range, X2 represents the second spacing floating range, and the value ranges of X1 and X2 are both 0 - 20 mm.

6. The prefabricated pipe pier according to claim 1, characterized in that: Non-prestressed steel bars are also provided in the pier shaft, and the prestressed steel bars and the non-prestressed steel bars are arranged at intervals.

7. The prefabricated pipe pier according to claim 5, characterized in that: The spacings of the spiral stirrups in the first plastic hinge region and the second plastic hinge region are d1 and d3 respectively, and the spacing of the spiral stirrups in the normal region is d2, where d1 < d2 and d3 < d2.

8. The prefabricated pipe pier according to claim 1, characterized in that: Both the first spiral stirrup and the second spiral stirrup are in contact with the prestressed steel bars.

9. The prefabricated pipe pier according to claim 1, characterized in that: Both the first spiral stirrup and the second spiral stirrup are arranged outside the prestressed steel bars; or both are arranged inside the prestressed steel bars.

10. The prefabricated pipe pier according to claim 1, characterized in that: The first spiral stirrup is arranged outside the prestressed steel bars, and the second spiral stirrup is arranged inside the prestressed steel bars, and the connecting line of the centers of the first spiral stirrup and the second spiral stirrup is perpendicular to the prestressed steel bar with which they are in contact.

Images