Pre-fabricated retaining wall backfill connection support fixing structure and construction method

Abstract

This invention belongs to the field of precast retaining wall construction technology, and discloses a precast retaining wall backfill soil connection support and fixing structure and construction method. The precast retaining wall backfill soil connection support and fixing structure includes a stepped support structure connected to the backwater side of the precast retaining wall. The stepped support structure consists of layers of cement-soil slabs, crushed stone reinforced slabs, and horizontal grouting pipes, with increasing widths from top to bottom. Crushed stone reinforced slabs are embedded within the cement-soil slabs, and horizontal grouting pipes are pre-embedded within the crushed stone reinforced slabs. Each layer of horizontal grouting pipes is connected to vertical grouting pipes through grouting connection pipes, forming a grouting pipe network. This invention utilizes a "clay layer + crushed stone layer + cement grout" to form a unified, load-bearing stepped support structure. The stepped support structure transfers the load, and the crushed stone channels allow the cement grout to evenly coat the clay, forming the cement-soil slab. This invention effectively improves the integrity, stress balance, and support strength of interconnected precast retaining walls, and is simple and efficient to construct.

Description

Technical Field

[0001] This invention belongs to the field of precast retaining wall construction technology, specifically relating to a precast retaining wall backfill soil connection support and fixing structure and construction method. Background Technology

[0002] The existing river channel support structure uses precast retaining walls and backfilled soil. Due to the uneven placement height of the precast retaining walls along the river or the inconsistent height of the backfilled soil, different precast retaining walls will be subjected to different loads, which will easily lead to misalignment and slippage between the precast retaining walls.

[0003] In order to enable the precast retaining walls to work together to resist the back soil, reduce the impact of groundwater on the precast retaining walls, and improve the integrity, stress balance and stability of the interconnected precast retaining walls, it is necessary to strengthen the back soil of the precast retaining walls so that the interconnected precast retaining walls form an integral structure and allow the backfilled back soil to act evenly on the precast retaining walls. Summary of the Invention

[0004] This invention aims to solve at least one technical problem existing in the background art, and provides a precast retaining wall backfill soil connection support and fixing structure and construction method. It utilizes "clay layer + crushed stone layer + cement grout" to form an integral stepped support structure, which is connected to and acts on the precast retaining wall. This allows for better load transfer between the precast retaining wall and the backfill soil that is subsequently backfilled on the stepped support structure, avoids misalignment and slippage between different precast retaining walls, and improves the integrity, stress balance and support strength of the interconnected precast retaining walls.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A precast retaining wall backfill soil connection and support structure includes a stepped support structure connected to the backwater side of the precast retaining wall. The stepped support structure is arranged in layers from top to bottom, with cement-soil slabs, crushed stone reinforced slabs and horizontal grouting pipes of increasing width.

[0007] The cement-soil slab contains a crushed stone reinforcing plate, and the horizontal grouting pipe is pre-embedded in the crushed stone reinforcing plate. The horizontal grouting pipes of each layer are connected to the vertical grouting pipes through grouting connection pipes to form a grouting pipe system.

[0008] Furthermore, the thickness of the stepped layers in the stepped support structure is either the same or increases from top to bottom.

[0009] Furthermore, the backfill soil above the stepped support structure is compacted, the upper surface of the backfill soil has a certain slope, and a surface treatment is performed on the upper surface of the backfill soil.

[0010] Furthermore, the slope of the upper surface of the backfill soil allows rainwater or accumulated water to flow back into the precast retaining wall;

[0011] The precast retaining wall has an opening at the top, which is filled with gravel, and a drainage channel at the bottom.

[0012] Furthermore, in the stepped support structure, the slope of the bottom layer of cement-soil slab is a sloping surface, while the slopes of the remaining upper layers of cement-soil slab are vertical slopes.

[0013] Furthermore, a geomembrane is installed at the joint between adjacent precast retaining walls.

[0014] Furthermore, the geomembrane is placed on the backwater side of the precast retaining wall connection joint.

[0015] Furthermore, the crushed stone reinforced plate is formed by grouting a crushed stone layer through the grouting pipe.

[0016] Furthermore, the cement-soil slab is formed by grouting a clay layer through the grouting pipe.

[0017] Meanwhile, the present invention also provides a construction method for a precast retaining wall backing soil connection and support structure, used to construct the precast retaining wall backing soil connection and support structure as described in any of the preceding claims, the method comprising the following steps:

[0018] Step S1: Place the precast retaining wall and reinforce the joints of the precast retaining wall with geomembrane.

[0019] Step S2: Backfill the clay layer and compact it manually. Backfill the clay layer with a crushed stone layer. Horizontal grouting pipes are pre-embedded in the crushed stone layer and then compacted manually. The horizontal grouting pipes are connected to the vertical grouting pipes through grouting connection pipes.

[0020] Step S3: Lay out clay layers, gravel layers and horizontal grouting pipes of different widths as required, backfill to the top of the precast retaining wall and grout, so that the grouting of the clay layer forms a cement-soil slab, the grouting of the gravel layer forms a gravel-reinforced slab, and the cement-soil slab and the gravel-reinforced slab form a stepped support structure and are connected to the precast retaining wall by pouring.

[0021] Step S4: Repeat steps S1-S3 to complete the construction of the back soil connection support and fixing structure for all precast retaining walls.

[0022] Furthermore, in step S3, the thickness of the stepped layers of the stepped support structure is set to be the same, or to increase from top to bottom.

[0023] Furthermore, it also includes the following steps:

[0024] Step S5: Backfill the back soil above the completed stepped support structure and compact it. Then, perform surface treatment on the upper surface of the backfilled back soil.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) The precast retaining wall back soil connection support and fixing structure provided by the present invention utilizes "clay layer + crushed stone layer + cement grout" to form an integral load-bearing stepped support structure, which is connected and acts on the precast retaining wall. The stepped support structure enables the precast retaining wall and the backfilled back soil on the stepped support structure to better transfer the load, avoid misalignment and slippage between different precast retaining walls, and improve the integrity, stress balance and support strength of the interconnected precast retaining walls.

[0027] (2) As the depth increases after backfilling the back soil, the active earth pressure generated by the back soil increases; while the precast retaining wall back soil connection support and fixing structure provided by the present invention, through the arrangement of a stepped support structure with increasing width from top to bottom, and the thickness of each stepped layer can also be set to increase from top to bottom, so that the passive earth pressure generated by the bottom stepped layer of the stepped support structure is also the greatest, thereby enabling the entire precast retaining wall to be subjected to balanced forces and consistent deformation displacements, thus improving the stability of the precast retaining wall;

[0028] (3) The prefabricated retaining wall back soil connection support and fixing structure provided by the present invention utilizes the channels of crushed stone to make the cement slurry evenly wrap the clay, and utilizes the clay bonding force to make the clay layer form a cement soil slab as a whole, avoiding soil loss and collapse due to precipitation and groundwater.

[0029] (4) When using steel formwork to cast and connect precast retaining walls, improper control of grouting pressure during grouting can cause lateral displacement of the steel formwork or precast retaining walls. This lateral displacement is difficult to detect with the naked eye and will seriously affect the overall consistency and overall stress balance of the interconnected precast retaining walls, thus affecting the support effect. However, the precast retaining wall back soil connection support and fixing structure provided by this invention uses a clay layer instead of steel formwork. During grouting, when the grouting pressure is too high, the clay layer will generally be displaced and pushed out by the grouting pressure before the precast retaining wall, which is easily observed with the naked eye. At this time, grouting can be stopped, the clay layer can be repaired, and the grouting pressure can be adjusted so that the clay is not pushed out and the grouting of the clay layer can be completed. In this way, the grouting pressure of the cement slurry can be controlled by the clay layer, so that the grouting pressure on one side of different precast retaining walls is basically the same, and the lateral displacement of the precast retaining walls during grouting can be ensured, thereby improving the overall consistency, overall stress balance, and overall stability of different precast retaining walls.

[0030] (5) The precast retaining wall back soil connection support and fixing structure provided by the present invention includes a vertical grouting pipe and a horizontal grouting pipe connected to the vertical grouting pipe with a width increasing from top to bottom. After grouting, the entire grouting pipe can act as a steel bar to play a connecting support role, thereby improving the integrity and stress strength of the overall load-bearing structure formed by the connection between the stepped support structure and the precast retaining wall.

[0031] (6) The construction method for the back soil connection support and fixing structure of the precast retaining wall provided by the present invention first reinforces the joints of different precast retaining walls with geomembrane, and then lays out clay layers, gravel layers and horizontal grouting pipes of different widths for each precast retaining wall, backfills to the top of the precast retaining wall and grouts, and so on, to complete the construction of the back soil connection support and fixing structure of all precast retaining walls. The whole construction process is simple and efficient, and the overall consistency and stability of the precast retaining wall are strong. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of the prefabricated retaining wall backfill soil connection support and fixing structure according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the grouting pipe according to an embodiment of the present invention;

[0034] Figure 3 This is a top view of the prefabricated retaining wall backfill soil connection support and fixing structure according to an embodiment of the present invention;

[0035] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0036] The markings in the diagram are as follows: 1-Precast retaining wall; 2-Grouting pipe, 201-Vertical grouting pipe, 202-Grouting connection pipe, 203-Horizontal grouting pipe, 2031-Grouting hole; 3-Cement-soil slab; 4-Gravel reinforced slab; 5-Geomembrane. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0039] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] Example 1

[0041] Combination Figure 1-4 As shown, this embodiment of the invention provides a precast retaining wall backfill soil connection and support structure, including a stepped support structure connected to the backwater side of the precast retaining wall 1. The stepped support structure is arranged in layers with increasing width from top to bottom: cement-soil slabs 3, crushed stone reinforced slabs 4, and horizontal grouting pipes 203. The crushed stone reinforced slabs 4 are installed inside the cement-soil slabs 3, and the horizontal grouting pipes 203 are pre-embedded inside the crushed stone reinforced slabs 4. Each layer of horizontal grouting pipes 203 is connected to vertical grouting pipes 201 through grouting connection pipes 202, forming grouting pipes 2. This structure is beneficial for the pre-embedding construction and grouting operation of grouting pipes 2. At the same time, the grouting pipes 2 act as steel bars inside the stepped support structure, playing a supporting and connecting role, which facilitates better load transfer to the backfill soil.

[0042] The horizontal grouting pipe 203 has grouting holes; the cement-soil slab 3 is formed by grouting a clay layer through the grouting pipe 2, and each clay layer has the same thickness, which is 200-300mm; the crushed stone reinforced slab 4 is formed by grouting a crushed stone layer through the grouting pipe 2.

[0043] The grouting pipe 2 is used for grouting, allowing cement grout to seep into the crushed stone layer and then through the pores of the crushed stone to the clay layer, uniformly coating the clay and forming cement slabs 3 and crushed stone reinforced slabs 4, which are also connected to the precast retaining wall 1 through cement grout. The "clay layer + crushed stone layer + cement grout" forms an integral, stepped support structure that acts on and connects to the precast retaining wall 1. The stepped support structure allows for better load transfer between the precast retaining wall 1 and the backfill soil that is subsequently backfilled onto the stepped support structure, preventing misalignment and slippage between different precast retaining walls and improving the integrity, stress balance, and support strength of the interconnected precast retaining walls.

[0044] The stepped support structure is backfilled with soil and compacted. As the depth increases after backfilling, the active earth pressure generated by the backfill soil increases. By arranging the stepped support structure with increasing width from top to bottom, the passive earth pressure generated by the lowest stepped layer of the stepped support structure is also the greatest, thereby making the entire precast retaining wall subjected to balanced forces and consistent deformation displacement, thus improving the stability of the precast retaining wall.

[0045] In some other embodiments, the thickness of the stepped layers of the stepped support structure also increases from top to bottom. The purpose of this arrangement is that, since the thickness of the stepped layers also increases from top to bottom, the width difference between two adjacent stepped layers or the height of the entire stepped support structure can be appropriately reduced, making it adaptable to construction sites of more different sizes and allowing for more flexible construction methods.

[0046] Meanwhile, in this embodiment of the invention, the clay layer is grouted through the grouting pipe 2 to form a cement-soil slab 3, so that the "clay layer + crushed stone layer + cement grout" form an integral, stress-bearing stepped support structure. In addition, another function of the clay layer is:

[0047] When steel formwork is directly used to cast and connect precast retaining walls, improper control of grouting pressure during the grouting process can lead to lateral displacement of the steel formwork or precast retaining walls. This lateral displacement is difficult to detect with the naked eye and will seriously affect the overall consistency and stress balance of the interconnected precast retaining walls, thus affecting the support effect. However, the precast retaining wall backfill soil connection and support structure provided by this invention uses a clay layer instead of steel formwork. During the grouting process, when the grouting pressure is too high, the clay layer will generally be displaced and pushed out by the grouting pressure before the precast retaining wall, which is easily observed with the naked eye. At this time, grouting can be stopped, the clay layer can be repaired, and the grouting pressure can be adjusted to prevent the clay from being pushed out while still completing the grouting of the clay layer. In this way, the grouting pressure of the cement slurry can be controlled by the clay layer, so that the grouting pressure on one side of different precast retaining walls is basically the same, and it can ensure that the precast retaining walls do not undergo lateral displacement during the grouting process, thereby improving the overall consistency, stress balance, and overall stability of different precast retaining walls.

[0048] In addition, the precast retaining wall 1 has an opening at its upper end, which is filled with gravel and has a drainage channel at the bottom for drainage. The upper surface of the backfill soil has a certain slope and is treated with a surface layer to allow rainwater or accumulated water to flow back into the precast retaining wall 1 and then be discharged through the drainage channel at the bottom of the opening. The surface layer treatment can be laying a layer of concrete, masonry, or planting vegetation, etc.

[0049] Furthermore, in the stepped support structure, the bottom layer of cement-soil slab 3 has a sloping surface, while the slopes of the remaining upper layers of cement-soil slab 3 are vertical. The purpose of this design is:

[0050] (1) The vertical slope of the upper layer can better play the role of the clay layer as a template to control the grouting pressure. When the clay layer is pushed out by the grouting pressure, the grouting pressure is adjusted in time so that the grouting pressure does not push out the clay and can complete the grouting of the clay layer. This ensures that the precast retaining wall does not undergo lateral displacement during the grouting process, and improves the overall consistency, overall stress balance, and overall stability of different precast retaining walls.

[0051] (2) When the backfill soil is backfilled and compacted above the stepped support structure, the vertical slope and the horizontal plane of the adjacent steps form a right angle structure, which can better contact and support the backfill soil and evenly transfer the load to the entire stepped support structure.

[0052] (3) The bottom slope is a sloping surface, which can better balance the large active earth pressure generated at the bottom of the backfill soil and ensure the stability of the entire stepped support structure.

[0053] Meanwhile, the precast retaining wall back soil connection support and fixing structure provided in this embodiment of the invention utilizes the channels of crushed stone to allow cement slurry to uniformly coat the clay, and utilizes the bonding force of the clay to form a cement-soil slab as a whole, which can avoid soil loss and collapse caused by precipitation and groundwater.

[0054] In addition, such as Figure 3-4 As shown, a geomembrane 5 is provided at the joint between adjacent precast retaining walls 1 to reinforce the joint of the precast retaining walls and reduce water accumulation at the joint of the precast retaining walls due to precipitation or other reasons; the geomembrane 5 is specifically provided on the back side of the joint of the precast retaining walls.

[0055] Example 2

[0056] This invention provides a construction method for a precast retaining wall backing soil connection and support structure, used to construct the precast retaining wall backing soil connection and support structure in Embodiment 1.

[0057] The construction method includes the following steps:

[0058] Step S1: Place the precast retaining wall and reinforce the joints of the precast retaining wall with geomembrane.

[0059] Step S2: Backfill the clay layer and compact it manually. Each clay layer is 200-300mm thick. Backfill the clay layer with a crushed stone layer. Horizontal grouting pipes 203 are pre-embedded in the crushed stone layer. Then, compact it manually. The horizontal grouting pipes 203 are connected to the vertical grouting pipes 201 through grouting connection pipes 202.

[0060] Step S3: Lay out clay layers, gravel layers and horizontal grouting pipes 203 of different widths as required, backfill to the top of the precast retaining wall 1 and grout, so that the grouting of the clay layer forms a cement-soil slab 3, the grouting of the gravel layer forms a gravel reinforced slab 4, the cement-soil slab 3 and the gravel reinforced slab 4 form a stepped support structure and are connected to the precast retaining wall by pouring.

[0061] In step S3, the thickness of the stepped layers of the stepped support structure can be set to be the same or to increase from top to bottom. The specific thickness can be flexibly set according to the construction scenario.

[0062] Step S4: Repeat steps S1-S3 to complete the construction of the back soil connection support and fixing structure for all precast retaining walls 1;

[0063] Step S5: Backfill the back soil above the completed stepped support structure and compact it. Perform surface treatment on the upper surface of the backfilled back soil to reduce rainwater or water infiltration.

[0064] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method of a precast retaining wall backfill soil connecting support fixing structure, characterized by, The precast retaining wall back soil connection support and fixing structure includes a stepped support structure connected to the back water side of the precast retaining wall. The stepped support structure is arranged in layers from top to bottom, with the width of cement-soil slabs, crushed stone reinforced slabs and horizontal grouting pipes increasing progressively. The cement-soil slab contains a crushed stone reinforcing plate, and the horizontal grouting pipe is pre-embedded in the crushed stone reinforcing plate; the horizontal grouting pipe of each layer is connected to the vertical grouting pipe through a grouting connection pipe to form a grouting pipe together. Includes the following steps: Step S1: Place the precast retaining wall and reinforce the joints of the precast retaining wall with geomembrane. Step S2: Backfill the clay layer and compact it manually. Backfill the clay layer with a crushed stone layer. Horizontal grouting pipes are pre-embedded in the crushed stone layer and then compacted manually. The horizontal grouting pipes are connected to the vertical grouting pipes through grouting connection pipes. Step S3: Lay out clay layers, gravel layers and horizontal grouting pipes of different widths as required, backfill to the top of the precast retaining wall and grout, so that the grouting of the clay layer forms a cement-soil slab, the grouting of the gravel layer forms a gravel-reinforced slab, and the cement-soil slab and the gravel-reinforced slab form a stepped support structure and are connected to the precast retaining wall by pouring. Step S4: Repeat steps S1-S3 to complete the construction of the back soil connection support and fixing structure for all precast retaining walls.

2. The construction method of the precast retaining wall backfill soil connection support fixed structure body according to claim 1, characterized in that, The stepped support structure has the same thickness for each step or increases in thickness from top to bottom.

3. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, The stepped support structure is backfilled with soil and compacted. The upper surface of the backfilled soil has a certain slope and is treated with a surface layer.

4. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 3, characterized in that, The slope of the upper surface of the backfill soil allows rainwater or accumulated water to flow back into the precast retaining wall. The precast retaining wall has an opening at the top, which is filled with gravel, and a drainage channel at the bottom.

5. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, In the stepped support structure, the slope of the bottom layer of cement-soil slab is a sloping surface, while the slopes of the remaining upper layers of cement-soil slab are vertical slopes.

6. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, A geomembrane is installed at the joint between adjacent precast retaining walls.

7. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 6, characterized in that, The geomembrane is placed on the backwater side of the precast retaining wall connection joint.

8. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, The crushed stone reinforced plate is formed by grouting a crushed stone layer through the grouting pipe.

9. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, The cement-soil slab is formed by grouting a clay layer through the grouting pipe.

10. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, In step S3, the thickness of the stepped layers of the stepped support structure is set to be the same, or to increase from top to bottom.

11. The construction method for the precast retaining wall backfill soil connection support and fixing structure according to claim 1, characterized in that, It also includes the following steps: Step S5: Backfill the back soil above the completed stepped support structure and compact it, and perform surface treatment on the upper surface of the backfilled back soil.

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