Prestressed reinforced soil retaining wall and construction method thereof

Abstract

The present application relates to a kind of prestressed reinforced earth retaining wall and its construction method, prestressed reinforced earth retaining wall, including panel (1), reinforcement (2) and fill (3);The reinforcement (2) is transversely arranged in fill (3) and is connected panel (1), part or all reinforcement (2) other end is connected pile (4) or rock mass (5) and there is prestress;The pile (4) is longitudinally arranged in fill (3), and rock mass (5) is arranged behind fill (3).Compared with prior art, the rear part of the reinforcement is closely connected with the pile or rock mass, and a certain prestress is applied to the reinforcement through the fastening device, which greatly improves the tensile properties of the reinforcement.At this time, the panel, the reinforcement and the rear pile or rock mass will more tightly constrain the filler in the middle, so that the stability of the retaining wall is greatly improved and deformation is not easy to occur.

Description

Technical Field

[0001] This invention relates to the field of retaining wall technology, specifically to a prestressed reinforced soil retaining wall and its construction method. Background Technology

[0002] Reinforced soil retaining walls are composite structures mainly composed of three parts: panels, reinforcement, and backfill. Due to their advantages such as low cost, aesthetic appeal, and good seismic performance, reinforced soil retaining walls have been widely used in various engineering projects. Currently, design specifications for reinforced soil retaining walls only consider the contribution of the frictional force between the reinforcement and the soil to improving the stability of the retaining wall. This design does not fully utilize the tensile strength of the reinforcement. However, with the continuous development of reinforcement materials, the tensile strength of the reinforcement is now far greater than the frictional force between the reinforcement and the soil. Therefore, the existing design specifications for reinforced soil retaining walls are a waste of the reinforcement's strength. On the other hand, for projects such as high-speed railways that require strict deformation control, reinforced soil retaining walls currently struggle to meet their design requirements. Therefore, how to fully utilize the tensile strength of the reinforcement and more strictly control the deformation of reinforced soil retaining walls is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a prestressed reinforced soil retaining wall and its construction method, so as to give full play to the tensile strength of the reinforcement.

[0004] The objective of this invention can be achieved through the following technical solution: a prestressed reinforced soil retaining wall, comprising a panel, reinforcing bars, and backfill;

[0005] The reinforcement is horizontally arranged in the backfill and connected to the panel, and some or all of the reinforcement is connected to the pile or rock mass at the other end and is prestressed;

[0006] The piles are set longitudinally within the fill, and the rock mass is located behind the fill.

[0007] Preferably, the reinforcing bars are connected to the panel by a fastening device, and the reinforcing bars connecting the piles or rock mass are prestressed by the fastening device.

[0008] More preferably, the fastening device includes a threaded rod, a nut, a washer, a metal collar, a metal clamp, and an enlarged head;

[0009] The threaded rod passes through the panel, with a washer and nut connected to the threaded rod on the outer side of the panel, and an enlarged end on the inner side.

[0010] The metal collar is rotatably mounted on the threaded rod, and the outer side of the metal collar is mechanically connected to the reinforcing bar via metal clips.

[0011] More preferably, a smooth section is provided between the threaded section and the enlarged head of the threaded rod, the diameter of which is smaller than that of the threaded section and the enlarged head, and a metal collar is rotatably mounted on the smooth section.

[0012] More preferably, two quarter-circle shaped metal clips are welded to the outside of the metal collar, and the metal clips are mechanically connected to the reinforcing bar by screws.

[0013] Preferably, the metal clips are symmetrically arranged on the upper and lower sides of the metal collar.

[0014] More preferably, the prestress is 1 / 20 of the ultimate tensile strength of the reinforcing bar.

[0015] Preferably, one end of a portion of the reinforcing bar is connected to the panel, and the other end is connected to a pile via a crossbeam;

[0016] The reinforcing bars and the crossbeams are connected by a mechanical connection device.

[0017] Preferably, the pile is a precast concrete square pile.

[0018] Preferably, one end of all the reinforcing bars is connected to the panel, and the other end is connected to the rock mass via rock anchors.

[0019] Preferably, the panel is a reinforced concrete structure.

[0020] Preferably, the distance between the upper and lower layers of reinforcing bars is 400mm to 800mm.

[0021] Preferably, the mechanical connection device includes an L-shaped connecting piece, rivets, and bolts.

[0022] Preferably, the mechanical connection device is made of stainless steel.

[0023] Preferably, the fastening device is made of stainless steel.

[0024] Preferably, the reinforcing material is a galvanized metal strip, with the top and bottom surfaces being the surfaces with the largest area.

[0025] Preferably, the reinforcing material is a unidirectional geogrid made of high-strength fiberglass geosynthetic material.

[0026] A construction method for the above-mentioned prestressed reinforced soil retaining wall includes the following steps:

[0027] S1: Determine the height H of the retaining wall according to the project requirements;

[0028] S2: Drive piles at a distance of 0.7H from the rear of the panel, with the top of the pile 0.2H to 0.3H from the road surface and in direct contact with the top reinforcement. The pile spacing is set to 0.5 to 1H.

[0029] S3: Install crossbeams at the locations on the piles where reinforcement bars need to be connected;

[0030] S4: Install the bottom panel, fill in the soil and compact it until the first layer of reinforcement is in place, install the reinforcement, and place the reinforcement between the fastening device and the mechanical connection device. The length of the reinforcement is 0.7H.

[0031] S5: Install the second panel, repeat the steps of backfilling and connecting reinforcement until the top of the pile is reached. The reinforcement above the top of the pile should be 1.2H in length.

[0032] S6: After the reinforced soil retaining wall is built, tighten the nuts with a prestressed torque wrench to ensure that there is a certain amount of prestress in the reinforcement.

[0033] A construction method for the above-mentioned prestressed reinforced soil retaining wall includes the following steps:

[0034] a: Determine the height H of the retaining wall according to the project requirements;

[0035] b: Install the bottom panel, fill in the soil and compact it until the first layer of reinforcement is in place, install the reinforcement, and fix the ends of the reinforcement to the rock mass with rock anchors;

[0036] c: Install the second panel, repeat the steps of backfilling and connecting reinforcements until the retaining wall is completed;

[0037] d: After the reinforced soil retaining wall is built, tighten the nuts with a prestressed torque wrench to ensure that there is a certain amount of prestress in the reinforcement.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] 1. In traditional reinforced soil retaining walls, the rear of the reinforcement is basically unrestrained, and the stability of the retaining wall is maintained only by the friction between the reinforcement and the soil. This invention tightly connects the rear of the reinforcement to the pile or rock mass, and applies a certain amount of prestress to the reinforcement through a fastening device. This greatly enhances the tensile strength of the reinforcement. At this time, the panel, reinforcement, and the pile or rock mass at the rear will more tightly restrain the filling material in the middle, which greatly improves the stability of the retaining wall.

[0040] 2. The reinforced soil retaining wall of this invention contains piles inside, therefore its bearing capacity is much greater than that of traditional reinforced soil retaining walls;

[0041] 3. The present invention, through a fastening device, can perform long-term maintenance on reinforced soil retaining walls, ensuring that the prestress inside the reinforcement remains unchanged and guaranteeing the long-term stability of the structure.

[0042] 4. The panels of traditional reinforced soil retaining walls are generally not used as load-bearing components; their function is only to prevent the fill material from moving outward. The panels of this invention are made of reinforced concrete because they need to be subjected to the tensile force of the reinforcement to better restrain the soil inside. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the retaining wall structure in Embodiment 1 of the present invention;

[0044] Figure 2 This is a partial structural diagram of the retaining wall in Embodiment 1 of the present invention;

[0045] Figure 3 This is a schematic diagram of the fastening device according to Embodiment 1 of the present invention;

[0046] Figure 4 This is a schematic diagram of the mechanical connection device according to Embodiment 2 of the present invention;

[0047] Figure 5 This is a schematic diagram of the retaining wall structure in Embodiment 3 of the present invention;

[0048] In the diagram: 1-panel, 2-reinforcing material, 3-fill soil, 4-pile, 5-rock mass, 6-fastening device, 61-threaded rod, 62-nut, 63-washer, 64-metal collar, 65-metal clip, 66-enlarged head, 67-screw, 7-beam, 8-mechanical connection device, 81-L-shaped connecting piece, 82-rivet, 83-bolt, 9-rock mass anchor, 10-retained soil. Detailed Implementation

[0049] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0050] Example 1

[0051] A type of prestressed reinforced soil retaining wall, such as Figure 1 As shown, it includes panel 1, reinforcing bar 2, backfill 3, pile 4, fastening device 6, crossbeam 7, and mechanical connection device 8.

[0052] Among them, the reinforcing bar 2 is horizontally placed in the backfill 3 and connected to the panel 1 by the fastening device 6. The other end of part of the reinforcing bar 2 is connected to the pile 4 that is longitudinally placed in the backfill 3 by the mechanical connection device 8 and the crossbeam 7. The backfill 3 is the retaining body 10.

[0053] like Figures 2-3As shown, the fastening device 6 includes a threaded rod 61, a nut 62, a washer 63, a metal collar 64, metal clips 65, an enlarged head 66, and a screw 67. The threaded rod 61 passes through the panel 1. The outer end of the threaded rod on the panel 1 is connected to the washer 63 and the nut 62, while the inner end is the enlarged head 66. The purpose of the enlarged head 66 is to prevent the metal collar 64 from falling off. The metal collar 64 and the threaded rod can rotate. This design ensures that when prestress is applied by rotating the nut 62, the rotation of the threaded rod 61 will not affect the position of the reinforcing bar 2, thus ensuring that the reinforcing bar 2 remains flat within the soil. Two quarter-circle shaped metal clips 65 are welded to the outer side of the metal collar 64. The clips are mechanically connected to the reinforcing bar by the screw 67.

[0054] A construction method for the above-mentioned prestressed reinforced soil retaining wall includes the following steps:

[0055] (1) Determine the height H of the retaining wall according to the project requirements.

[0056] (2) Drive pile 4 at a distance of 0.7H from the rear of panel 1. Precast concrete square piles are preferred for this purpose. The length of the pile should not be less than 2.5H, and the top of the pile should be 0.2H to 0.3H from the road surface and in direct contact with the top reinforcement. The pile spacing (the distance between two adjacent piles) is set to 0.5 to 1H.

[0057] (3) Install a crossbeam 7 at the location where the reinforcing bar 2 needs to be connected on the pile 4. The crossbeam 7 is equipped with a mechanical connection device 8.

[0058] (4) Install the bottom panel 1, fill with soil and compact it up to the position of the first layer of reinforcement. Install reinforcement 2, that is, connect reinforcement 2 between the metal clamp 65 and the mechanical connection device 8. The reinforcement here is preferably made of high-strength and corrosion-resistant materials, such as galvanized metal strip reinforcement, high-strength fiberglass geogrid, etc. According to the requirements of the reinforced soil retaining wall design code, the length of the bottom reinforcement is 0.7H.

[0059] (5) Install the second panel 1, repeat the steps of filling soil and connecting reinforcement materials until the top of the pile. The reinforcement material above the top of the pile should be 1.2H in length, in order to reduce the uneven settlement of the reinforced soil retaining wall.

[0060] (6) After the reinforced soil retaining wall is erected, tighten the nut 62 with a prestressing torque wrench to ensure that there is a certain amount of prestress in the reinforcement 2. The preferred prestress here is 1 / 20 of the ultimate tensile strength of the reinforcement.

[0061] (7) The reinforced soil retaining wall should be maintained regularly during its later use and prestressed to compensate for the prestress lost due to the creep of the reinforcement.

[0062] Example 2

[0063] A prestressed reinforced soil retaining wall, the mechanical connection device 8 has the following structure: Figure 4 As shown, it includes an L-shaped connecting piece 81, a rivet 82, and a bolt 83. One side of the L-shaped connecting piece 81 is connected to the crossbeam 7 via the rivet 82, and the other side perpendicular to it is connected to the reinforcing bar 2 via the bolt 83. The reinforcing bar 2 is clamped and fixed between the upper and lower L-shaped connecting pieces 81. The rest is the same as in Embodiment 1.

[0064] Example 3

[0065] Considering that when constructing a retaining wall in front of a stable rock mass, such as in mountainous areas, the rock mass behind can serve as a good connecting material, and from a cost-saving perspective, the structure of the prestressed reinforced soil retaining wall in this embodiment is as follows: Figure 5 As shown, it includes panel 1, reinforcement 2, fill 3, stable rock mass 5, and rock mass anchor 9.

[0066] Among them, the reinforcing bar 2 is horizontally placed in the backfill 3 and connected to the panel 1 through the fastening device 6. The other end of all the reinforcing bars 2 is connected to the rock mass 5 behind the backfill 3 through the rock mass anchor nail 9.

[0067] A construction method for the above-mentioned prestressed reinforced soil retaining wall includes the following steps:

[0068] (1) Determine the height H of the retaining wall according to the project requirements.

[0069] (2) Install the bottom panel 1, fill it with soil and compact it until the first layer of reinforcement is in place. Install reinforcement 2, and fix the ends of reinforcement 2 to the rock mass 5 with rock anchor nails 9.

[0070] (3) Install the second panel 1, and repeat the steps of filling soil and connecting reinforcement materials until the retaining wall is completed.

[0071] (4) After the reinforced soil retaining wall is erected, tighten the nut 62 with a prestressing torque wrench to ensure that there is a certain amount of prestress in the reinforcement 2. The preferred prestress here is 1 / 20 of the ultimate tensile strength of the reinforcement.

[0072] (5) The reinforced soil retaining wall should be maintained regularly during its later use and prestressed to compensate for the prestress lost due to the creep of the reinforcement.

[0073] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A prestressed reinforced soil retaining wall, characterized in that, Includes panel (1), reinforcement (2) and backfill (3); The reinforcement (2) is horizontally placed in the fill (3) and connected to the panel (1). Some of the reinforcement (2) is connected to the pile (4) at the other end, or all of the reinforcement (2) is connected to the rock mass (5) at the other end. The piles (4) are longitudinally set within the fill (3) or the rock mass (5) is set behind the fill (3); The reinforcement (2) is connected to the panel (1) by the fastening device (6), and the reinforcement (2) connecting the pile (4) or rock mass (5) is prestressed by the fastening device (6); The fastening device (6) includes a threaded rod (61), a nut (62), a washer (63), a metal collar (64), a metal clip (65), and an enlarged head (66). The threaded rod (61) passes through the panel (1). The threaded rod on the outside of the panel (1) is connected to a washer (63) and a nut (62), and the end on the inside is an enlarged head (66). The metal collar (64) is rotatably mounted on the threaded rod (61), and the outer side of the metal collar (64) is mechanically connected to the reinforcing bar (2) through a metal clip (65); The threaded rod (61) has a smooth rod section between the threaded section and the enlarged head (66). The diameter of the smooth rod section is smaller than that of the threaded section and the enlarged head (66). The metal collar (64) is rotatably mounted on the smooth rod section. Two quarter-circle shaped metal clips (65) are welded to the outside of the metal collar (64), and the metal clips (65) are mechanically connected to the reinforcing bar (2) by screws (67).

2. The prestressed reinforced soil retaining wall according to claim 1, characterized in that, The prestress is 1 / 20 of the ultimate tensile strength of the reinforcing bar (2).

3. The prestressed reinforced soil retaining wall according to claim 1, characterized in that, One end of the reinforcement (2) is connected to the panel (1), and the other end is connected to the pile (4) through the crossbeam (7); The reinforcing bar (2) and the crossbeam (7) are connected by a mechanical connection device (8).

4. The prestressed reinforced soil retaining wall according to claim 1, characterized in that, The pile (4) is a precast concrete square pile.

5. The prestressed reinforced soil retaining wall according to claim 1, characterized in that, All the aforementioned reinforcing bars (2) are connected to the panel (1) at one end and to the rock mass (5) at the other end through the rock mass anchor (9).

6. A construction method for a prestressed reinforced soil retaining wall as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Determine the height H of the retaining wall according to the project requirements; S2: Drive a pile (4) at a position 0.7H away from the rear of the panel (1), wherein the top of the pile should be 0.2H~0.3H away from the road surface and in direct contact with the top reinforcement (2), and the pile spacing is set to 0.5~1H; S3: Install a crossbeam (7) at the location where reinforcement needs to be connected on the pile (4); S4: Install the bottom panel (1), fill in the soil and compact it until the first layer of reinforcement is in place, install reinforcement (2), place reinforcement (2) between fastening device (6) and mechanical connection device (8), the length of reinforcement (2) is 0.7H; S5: Install the second panel (1), repeat the steps of backfilling and connecting reinforcement until the top of the pile. The reinforcement (2) above the top of the pile should be 1.2H in length. S6: After the reinforced soil retaining wall is built, tighten the nut (62) with a prestressed torque wrench so that there is a certain prestress in the reinforcement (2).

7. A construction method for a prestressed reinforced soil retaining wall as described in any one of claims 1 to 5, characterized in that, Includes the following steps: a: Determine the height H of the retaining wall according to the project requirements; b: Install the bottom panel (1), fill in the soil and compact it until the first layer of reinforcement is in place, install reinforcement (2), and fix the end of reinforcement (2) to the rock mass (5) with rock anchor nails (9); c: Install the second panel (1), repeat the steps of filling soil and connecting reinforcement materials until the retaining wall is completed; d: After the reinforced soil retaining wall is built, tighten the nuts (62) with a prestressed torque wrench so that there is a certain prestress in the reinforcement (2).

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