NL2030527B1

NL2030527B1 - All-in-one anti-floating device with open prestressed high-strength concrete pipe pile and anti-floating anchor rod

Info

Publication number: NL2030527B1
Application number: NL2030527A
Authority: NL
Inventors: Sun Gan; Bai Xiaoyu; Zhang Jingke; Wang Yonghong; Wang Fengjiao; Yan Nan; Zhang Mingyi; Wang Xueling; Jing Desheng; Xu Shaoshuai
Original assignee: Univ Qingdao Technology
Priority date: 2022-01-13
Filing date: 2022-01-13
Publication date: 2022-11-30
Also published as: NL2030527A

Abstract

The present invention belongs to the technical ﬁeld of ground foundation engineering, and relates to an all-in-one anti-ﬂoating device with an open prestressed high-strength concrete pipe pile and an anti-ﬂoating anchor rod. The device is simple in structure, quick, easy and convenient to mount, high in operability, energy-saving, and environmentally friendly, has outstanding economical and social beneﬁts, reduces the construction procedures of separately manufacturing the anti-ﬂoating anchor rod, shortens the construction period, and reduces the cost.

Description

ALL-IN-ONE ANTI-FLOATING DEVICE WITH OPEN PRESTRESSED HIGH-STRENGTH CONCRETE PIPE PILE AND ANTI-FLOATING ANCHOR ROD TECHNICAL FIELD

[01] The present invention belongs to the technical field of ground foundation engineering, and relates to an all-in-one anti-floating device with a composite-material anti-floating anchor rod and a prestressed high-strength concrete pipe pile, in particular to an all-in-one anti-floating device with an open prestressed high-strength concrete pipe pile and an anti-floating anchor rod.

BACKGROUND ART

[02] At present, an anti-floating anchor rod is basically mainly made of steel bars. The anti-floating anchor rod is placed in a relatively poor environment. It is located under water or in a dry-wet cycling area all the year round. Chloride ions in groundwater cause the reinforced anchor rod to be chemically corroded. Especially in the construction of urban railway systems, a stray current generated makes the reinforced anchor rod electrochemically corroded at the same time, which greatly reduces the service life of the anti-floating anchor rod. Therefore, the anti-corrosion problem of an anchor rod structure is more prominent. However, the current anti-corrosion problem has not been fundamentally broken.

SUMMARY

[03] The present invention aims to overcome the shortcomings in the existing art, and provides an all-in-one anti-floating device with an open prestressed high-strength concrete pipe pile and an anti-floating anchor rod, which achieves the objective that the prestressed high-strength concrete pipe pile can resist both a vertical pressure and the buoyancy force of groundwater.

[04] In order to achieve the above objective, a main body structure of the all-in-one anti-floating device with the open prestressed high-strength concrete pipe pile and the anti-floating anchor rod includes a Glass Fiber Reinforced Polymer (GFRP) anti-floating anchor rod body locator, a fixed support, an alignment bracket, a GFRP anti-floating anchor rod body, an open prestressed high-strength concrete pipe pile, an expand tip, an inverted L-shaped steel bar, a round steel plate, a cushion layer, and a foundation slab; one end of the GFRP anti-floating anchor rod body locator is bound to the GFRP anti-floating anchor rod body, and the other end of the GFRP anti-floating anchor rod body locator is bound to a reserved hole of a ringlike steel plate in the fixed support.

The fixed support is mounted on a flat ground; the alignment bracket is mounted on the GFRP anti-floating anchor rod body and is connected with the open prestressed high-strength concrete pipe pile; the GFRP anti-floating anchor rod body is a full-thread GFRP solid anchor rod, an anchorage length and a diameter of which are determined according to an anchorage force; and a material of the expand tip is a GFRP material.

A round hole is reserved in the center; a thread is formed on an inner wall of the aperture; the size of the aperture is determined according to the diameter of the GFRP anti-floating anchor rod body; a diameter of an outer contour of the expand tip 1s 5 times that of the reserved round hole; the expand tip is mounted on an outer surface of a top end of the GFRP anti-floating anchor rod body in a thread coupling manner and is poured in the foundation slab; a mixed solution containing epoxy resin and an EP type curing agent in a mass ratio of 2: 1 is injected to the thread coupling part of the expand tip and the GFRP anti-floating anchor rod body; the inverted L-shaped steel bar is made of a plain round steel bar having a diameter of 8 mm, and has a length determined according to the anchorage length; the round steel plate has a thickness of 4 mm and a diameter less than an inner diameter of the prestressed high-strength concrete pipe pile; and the round steel plate is just placed inside the open prestressed high-strength concrete pipe pile.

The inverted L-shaped steel bar is welded with the round steel plate and is uniformly distributed at an edge of the round steel plate at an included angle of 120 degrees; the cushion layer is prepared from C15 fine stone plain concrete; the cushion layer is paved on the ground and has a top surface that is trowelled, so that the surface of the cushion layer is flat, which facilitates binding the steel bar onto it. The foundation slab is made of reinforced concrete and is arranged on the cushion layer, and a length of the GFRP anti-floating anchor rod body anchored in the foundation slab is determined by the anchorage force.

[05] Compared with the existing art, the present invention has the advantages that the open prestressed high-strength concrete pipe pile can bear a pressure and resist the buoyancy force of the groundwater, which integrates pressure resistance with floating resistance, thereby reducing the construction procedures of separately manufacturing the anti-floating anchor rod; no large-size equipment such as a jumbolter are required on the site, so the construction period can be shortened; and furthermore, the open prestressed high-strength concrete pipe pile is a prefabricated pile (a fabricated foundation) that is convenient to construct and can bear both the pressure and a tensile force caused by floating resistance, thus optimizing the mechanical characteristic of the pile and improving the mechanical property of the pile body. On the basis of this, the dimension (including a pile diameter and a pile length) of the original open prestressed high-strength concrete pipe pile can be further optimized, so as to achieve the objectives of saving materials, reducing energy consumption, and reducing the construction cost. The present invention is simple in structure, quick, easy and convenient to mount, high in operability, energy-saving, and environmentally friendly, has outstanding economical and social benefits, reduces the construction procedures of separately manufacturing the anti-floating anchor rod, shortens the construction period, reduces the cost, and can obtain higher and more reliable pulling resistance.

BRIEF DESCRIPTION OF THE DRAWINGS

[06] FIG. 1 is a schematic diagram of a main body structure of an all-in-one anti-floating device with an open prestressed high-strength concrete pipe pile and an anti-floating anchor rod of the present invention.

[07] FIG. 2 is a schematic diagram of an alignment bracket of the present invention.

[08] FIG. 3 is a diagram of relative positions of a trapezoid steel sheet, a seamless steel tube with inner wire, and a stiffening rib steel sheet.

[09] FIG. 4 is an A-A sectional diagram of FIG. 3 of the present invention.

[10] FIG. $ is a schematic structural diagram of an expand tip of the present invention.

[11] FIG. 61s a top view of the expand tip of the present invention.

[12] FIG. 7 is a top view of a fixed support of the present invention.

[13] FIG. 8 is B-B sectional diagram of the fixed support of FIG. 7 of the present invention.

[14] FIG. 9 is a diagram of relative positions of an inverted L-shaped steel bar 7 IO and a round steel plate 8 of the present invention.

[15] FIG. 10 is a C-C sectional view of FIG. 9.

[16] FIG. 11 1s a schematic structural diagram of the inverted L-shaped steel bar 7 of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[17] Embodiments

[18] In this embodiment, a main body structure of an all-in-one anti-floating device with an open prestressed high-strength concrete pipe pile and an anti-floating anchor rod includes a Glass Fiber Reinforced Polymer (GFRP) anti-floating anchor rod body locator 1, a fixed support 2, an alignment bracket 3, a GFRP anti-floating anchor rod body 4, an open prestressed high-strength concrete pipe pile 5, a expand tip 6, an inverted L-shaped steel bar 7, a round steel plate 8, a cushion layer 9, and a foundation slab 10; one end of the GFRP anti-floating anchor rod body locator 1 is bound to the GFRP anti-floating anchor rod body 4, and the other end of the GFRP anti-floating anchor rod body locator is bound to a reserved hole of a ringlike steel plate 2-2 in the fixed support 2, so as to prevent the aligned GFRP anti-floating anchor rod body 4 from sliding down and ensure that an anchorage length meets a design requirement. The fixed support 2 1s mounted on a flat ground to ensure its stability; the alignment bracket 3 is mounted on the GFRP anti-floating anchor rod body 4 and is connected with the open prestressed high-strength concrete pipe pile 5 to ensure that the GFRP anti-floating anchor rod body 4 is located on a center line of the aperture of the open prestressed high-strength concrete pipe pile 5; the GFRP anti-floating anchor rod body

4 is a full-thread GFRP solid anchor rod, an anchorage length and a diameter of which

5 are determined according to an anchorage force; and a material of the expand tip 6 is a GFRP material (that is the same as the material of the GFRP anti-floating anchor rod body 4) A round hole is reserved in the center; a thread 1s formed on an inner wall of the aperture; the size of the aperture is determined according to the diameter of the GFRP anti-floating anchor rod body 4; a diameter of an outer contour of the expand tip

61s 5 times that of the reserved round hole; the expand tip 6 is mounted on an outer surface of a top end of the GFRP anti-floating anchor rod body 4 in a thread coupling manner and is poured in the foundation slab 10; and a mixed solution containing epoxy resin and an EP type curing agent in a mass ratio of 2: 1 is injected to the thread coupling part of the expand tip 6 and the GFRP anti-floating anchor rod body 4, so as to, on the one hand, enlarge a stressed area of an anchorage end, diffuse the stress and increase the anchorage force, and on the other hand, achieve a water stop purpose.

The inverted L-shaped steel bar 7 is made of a plain round steel bar having a diameter of 8 mm, and has a length determined according to the anchorage length; the round steel plate 8 has a thickness of 4 mm and a diameter slightly less than an inner diameter of the prestressed high-strength concrete pipe pile 5; and the round steel plate 8 is just placed inside the open prestressed high-strength concrete pipe pile 5. The inverted L-shaped steel bar 7 is welded with the round steel plate 8 and is uniformly distributed at an edge of the round steel plate 8 at an included angle of 120 degrees, so as to avoid anchorage mortar from being injected within an entire pile length range of the open prestressed high-strength concrete pipe pile 5. The anchorage mortar is only injected within an anchorage depth range determined by the anchorage force, so as to achieve the objectives of saving materials and reducing the construction cost.

The cushion layer 9 is prepared from C15 fine stone plain concrete; the cushion layer 9 is paved on the ground and has a top surface that is trowelled, so that the surface of the cushion layer 1s flat, which facilitates tying the steel bar onto it and also plays a role of protecting the foundation slab 10. The foundation slab 10 is made of reinforced concrete. It is constructed according to a construction drawing and the requirements of the Code for Basic Design of Building Foundation (GB50007—2011) and is arranged on the cushion layer 9. A length of the GFRP anti-floating anchor rod body 4 anchored in the foundation slab 10 is determined by the anchorage force.

[19] In this embodiment, the alignment bracket 3 consists of bolts 3-1, nuts 3-2, steel lobes 3-3, first steel sheets 3-4, steel sleeves 3-5, second steel sheets 3-6, trapezoid steel sheets 3-7, wire rods 3-8, seamless steel tubes 3-9 with inner wires, and stiffening rib steel sheets 3-10. The steel lobes 3-3 are formed by uniformly partitioning the seamless steel tube according to 90 degrees, and have a diameter that is determined according to the diameter of the GFRP anti-floating anchor rod body 4. Two ends of the steel lobes 3-3 are welded with the first steel sheets 3-4, and holes are reserved in centroid positions of the first steel sheets 3-4; sizes of the holes can allow the bolts 3-1 to pass; the adjacent steel lobes 3-3 are coupled and connected together through the bolts 3-1 and the nuts 3-2; and the bounding stress of the steel lobes 3-3 and the GFRP anti-floating anchor rod body 4 is increased by tightening the bolts 3-1 and the nuts 3-2. An axisymmetric line of each steel lobe 3-3 is welded with the steel sleeve 3-5 along an outer surface of the steel lobe 3-3; the steel sleeve 3-5 is made of a seamless steel tube and has a thickness of 2 mm, a diameter of 2.5 cm, and a length that is determined according to the inner diameter of the open prestressed high-strength concrete pipe pile 5, and it is ensured that a length of the wire rod 3-8 in the steel sleeve 3-5 is twice its length outside the steel sleeve 3-5, thus determining the length of the wire rod 3-8; the wire rod 3-8 is a solid iron rod having a diameter of 2 cm, and a surface of the wire rod is provided with a thread; and the second steel sheet 3-6 has an edge length of 5 cm and a thickness of 2 mm. One end of the wire rod 3-8 is mounted in the steel sleeve 3-5, and the other end is welded to the centroid of the second steel sheet 3-6, so as to enlarge the stressed area of an inner wall of the open prestressed high-strength concrete pipe pile 5 and improve the overall stability; the diameter of the seamless steel tube 3-9 with an inner wire is determined according to the diameter of the wire rod 3-8; and the seamless steel tube 3-9 with an inner wire is connected with the wire rod 3-8 in a thread coupling manner and has a length of 3 cm. The trapezoid steel sheet 3-7 has a height of 5 cm and a thickness of 2 mm; the trapezoid steel sheet 3-7 is welded to an outer wall of the seamless steel tube 3-9 with an inner wire; the stiffening rib steel sheet 3-10 is welded between the seamless steel tube 3-9 with an inner wire and the trapezoid steel sheet 3-7; the stiffening rib steel sheet 3-10 is triangular, with a thickness of 2 mm, and an edge length of each of the two right-angle sides is 3 cm to improve the intensity and the stability of the trapezoid steel sheet 3-7 and the seamless steel tube 3-9 with an inner wire. During mounting of the alignment bracket 3, the seamless steel tube 3-9 with an inner wire on the wire rod 3-8 is adjusted to enable the GFRP anti-floating anchor rod body 4 to be located on a center line of the aperture of the open prestressed high-strength concrete pipe pile 5, and the seamless steel tube 3-9 with an inner wire is adjusted to enable the second steel sheet 3-6 to be clung to the inner wall of the open prestressed high-strength concrete pipe pile 5.

[20] In this embodiment, a specific process of realizing all-in-one floating resistance by the open prestressed high-strength concrete pipe pile and the anti-floating anchor rod is as follows:

[21] (1) the open prestressed high-strength concrete pipe pile 5 is piled or statically pressed at first; the inner wall of the open prestressed high-strength concrete pipe pile 5 is cleaned to be smooth; the ground around the pile is leveled;

[22] (2) three inverted L-shaped steel bars 7 are uniformly welded to the edge of the round steel plate 8 at an included angle of 120 degrees and are mounted on the top surface of the open prestressed high-strength concrete pipe pile 5, ensuring that a distance from a bottom end of the GFRP anti-floating anchor rod body 4 to an upper surface of the round steel plate 8 is not shorter than 50 cm;

[23] (3) the seamless steel tube 2-1 and the ringlike steel plate 2-2 are welded together to form the fixed support 2, and holes are symmetrically reserved in the ringlike steel plate 2-2 as long as the sizes of the holes can allow iron wires to pass; the fixed support 2 is then mounted, and it is ensured that the lower end of the fixed support 2 extends into the soil by 5 cm to stabilize it;

[24] (4) holes are reserved in the centroids of the first steel sheets 3-4 as long as the sizes of the holes allow the bolts 3-1 to pass; the first steel sheets 3-4 are welded to the two ends of the steel lobes 3-3; each steel sleeve 3-5 is welded on an arc bisector of each steel lobe 3-3 and faces the outside; four steel lobes 3-3 are coupled and connected together through the bolts and the nuts;

[25] (5) the wire rods 3-8 are closely welded to the centroids of the second steel sheets 3-6, ensuring that the wire rods 3-8 are perpendicular to upper surfaces of the second steel sheets 3-6;

[26] (6) the trapezoid steel sheets 3-7 are closely connected to outer walls of the seamless steel tubes 3-9 with inner wires in a welded manner, ensuring that upper surfaces of the trapezoid steel sheets 3-7 are perpendicular to the seamless steel tubes 3-9 with inner wires, and the stiffening rib steel sheets 3-10 are welded between the seamless steel tubes 3-9 with inner wires and the trapezoid steel sheets 3-7;

[27] (7) the steel lobes 3-3 are fixed on the GFRP anti-floating anchor rod body 4; the bounding stress of the steel lobes 3-3 and the GFRP anti-floating anchor rod body 4 is increased by tightening the bolts 3-1 and the nuts 3-2; two sets of steel lobes are mounted according to the anchorage length; a distance between the two sets of steel lobes is determined according to the anchorage length of the GFRP anti-floating anchor rod body 4; two iron wires are bound to the GFRP anti-floating anchor rod body 4 between the two sets of steel lobes and are ensured to be tightened without sliding;

[28] (8) the seamless steel tubes 3-9 with inner wires and the wire rods 3-8 are connected together in the thread coupling manner, and the seamless steel tubes 3-9 with inner wires are adjusted according to the inner diameter of the open prestressed high-strength concrete pipe pile 5, ensuring that a ratio of the lengths of the wire rods 3-8 at the upper ends and the lower ends of the seamless steel tubes 3-9 with inner wires is 2: 1:

[29] (9) the wire rods 3-8 are plugged into the steel sleeves 3-5; the GFRP anti-floating anchor rod body is located on the central axis of the inner diameter of the open prestressed high-strength concrete pipe pile 5 by means of adjusting the seamless steel tubes 3-9 with inner wires on the wire rods 3-8, and the second steel sheets 3-6 are ensured to be clung to the inner wall of the open prestressed high-strength concrete pipe pile 5; finally, the length of the GFRP anti-floating anchor rod body in the open prestressed high-strength concrete pipe pile 5 is an anchorage length design value, and a thickness of a protective layer between the lower end of the GFRP anti-floating anchor rod body 4 and the round steel plate 8 is ensured to be not less than 20 cm;

[30] (10) the two iron wires on the GFRP anti-floating anchor rod body 4 are fixed on the two reserved holes of the fixed support, and each iron wire is ensured to be tightened and tensioned to avoid the GFRP anti-floating anchor rod body 4 from sliding down;

[31] (11) the upper end of the GFRP anti-floating anchor rod body 4 is sealed with a plastic film (to prevent sputtering of mortar during pouring of the mortar); mortar is poured and is made to be flush with the top surface of the open prestressed high-strength concrete pipe pile 5; and

[32] (12) after maintenance for 24 hours, an iron wire cutter is used to perform cutting along the concrete top surface, and the plastic film at the top of the GFRP anti-floating anchor rod body 4 is removed; the expand tip 6 is mounted and is tightened to the GFRP anti-floating anchor rod body 4, ensuring that the GFRP anti-floating anchor rod body 4 is flush with the upper surface of the expand tip; and after the mounting is completed, the cushion layer 9 and the foundation slab 10 are constructed according to the construction drawing and the requirements of the relevant specifications.

Claims

-10-

Conclusions l.

All-in-one anti-float device with an open pipe stack of high strength prestressed concrete and an anti-float anchor bar, characterized in that a main body structure is a Glass Fiber Reinforced Polymer (GFRP) anti-float anchor bar finder, a fixed support, an alignment support, a GFRP anti-floating anchor bar body, an open pipe stack with high strength prestressed concrete, an extension top, an inverted L-shaped steel bar, a round steel plate, a buffer layer and a foundation plate; wherein one end of the GFRP anti-float anchor rod locator is bonded to the GFRP anti-float anchor rod body and the other end of the GFRP anti-float anchor rod locator is bonded to a served cavity of a ring-like steel plate in the fixed support; wherein the fixed support is mounted on a flat ground; wherein the alignment bracket is mounted on the GFRP anti-float anchor bar body and connected to the open high strength prestressed concrete pipe stack, the GFRP anti-float anchor bar body being a full thread GFRP solid anchor bar, where an anchor length and diameter are determined according to an anchor force, wherein a material of the extension tip is a GFRP material; wherein a round cavity is provided in the center; wherein a thread is formed on an inner wall of the opening, the size of the opening being determined according to the diameter of the GFRP anti-float anchor rod body; wherein a diameter of an outer contour of the extension tip is 5 times that of the provided cavity; wherein the extension tip is mounted on an outer surface of an upper end of the GFRP anti-float anchor rod body in a wire-engaging manner and molded into the foundation plate; wherein a mixed solution containing epoxy resin and an EP type curing agent in the mass ratio of 2:1 is inserted into the thread coupling portion of the extension tip and the GFRP anti-float anchor rod body; wherein the inverted L-shaped steel bar is made of a flat round steel bar with a diameter of 8 mm and has a length determined according to the anchor length; wherein the round steel plate has a thickness of 4 mm and a diameter less than an inner diameter of the high strength prestressed concrete pipe stack; wherein the round steel plate is located within the open high strength prestressed concrete pipe stack; wherein the inverted L-shaped steel bar is welded to the round steel plate and evenly spaced on an edge of the round steel plate on a

S11 - 120 degree abutting angle; wherein the buffer layer is made of C15 stone of simple concrete; wherein the buffer layer exists on the ground and has an upper surface that is troweled so that the surface of the buffer layer is flat, which facilitates the bonding of the steel rod to the buffer layer, the foundation plate being made of reinforced concrete and arranged by the buffer layer and wherein a length of the GFRP anti-buoyancy anchor rod body in the foundation plate is determined by the anchor force.