Construction method of ecological stepped retaining wall near waterwall

Abstract

The invention discloses a construction method of an ecological stepped retaining wall near a waterwall, which comprises the following steps of: measuring and setting out to determine the position of a reinforced concrete square pile, and mechanically sinking the pile; measuring and setting out to determine the position of a plain concrete cushion layer, erecting a template, and pouring the plain concrete cushion layer; lofting a reinforced concrete bottom plate profile on the plain concrete cushion layer, binding reinforcing steel bars, erecting a template, arranging a bottom plate settlement joint, and pouring concrete; the position of the non-woven geotechnical cloth is determined on the reinforced concrete bottom plate, and the non-woven geotechnical cloth is laid and fixed; the box type ecological block bodies are installed on the non-woven geotextile from bottom to top to form a step-shaped ecological retaining wall; backfilling the backwater side of the box-type ecological block body with a graded broken stone inverted filter layer in a layered manner, and wrapping and compacting the box-type ecological block body with non-woven geotextile; and backfilling the backwater side of the graded broken stone inverted filter layer with a water-permeable soil body in a layered manner and compacting the water-permeable soil body. According to the construction method provided by the invention, the structural strength and stability of the retaining wall can be improved, the drainage and reverse filtration requirements are met, soil particle loss and filter layer silting are prevented, and meanwhile, rapid ecological restoration can be realized.

Description

Technical Field

[0001] This invention relates to the field of embankment engineering, and in particular to a construction method for an ecological stepped retaining wall for a water-adjacent embankment. Background Technology

[0002] In recent years, with the acceleration of urbanization, the construction of retaining walls for water-side embankments has become particularly important in areas prone to flooding. If the embankment is constructed by filling in the water system, it will inevitably reduce the water area, increase the water flow velocity, accelerate the erosion and damage of the embankment, and damage the aquatic environment and ecology. At the same time, it will also increase the construction difficulty and cost of the embankment slope protection project.

[0003] Traditional retaining wall structures often prioritize structural stability while neglecting ecological functions, making it difficult to meet the environmentally friendly requirements of modern engineering projects. Furthermore, how to rationally design and construct retaining walls to ensure their long-term stability under complex river flow velocities and geological conditions is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a construction method for an ecological stepped retaining wall on a water-adjacent embankment, which improves the structural strength and stability of the retaining wall, meets drainage and filtration requirements, prevents soil particle loss and filter layer siltation, and enables rapid ecological restoration.

[0005] A construction method for an ecological stepped retaining wall for a waterfront embankment according to a first aspect of the present invention includes the following steps: Reinforced concrete square pile driving: The location of the reinforced concrete square piles is determined by surveying and setting out at the bottom of a pre-excavated foundation pit, and the piles are mechanically driven; Plain concrete cushion layer construction: The location of the plain concrete cushion layer is determined by surveying and setting out at the bottom of the foundation pit, formwork is erected, and the plain concrete cushion layer is poured; Reinforced concrete base slab construction: The outline of the reinforced concrete base slab is laid out on the plain concrete cushion layer, reinforcing bars are tied, formwork is erected, settlement joints are set, and concrete is poured; Non-woven geotextile laying: The location of the non-woven geotextile is determined on the reinforced concrete base slab, and it is laid according to design requirements. Fixed non-woven geotextile; Box-shaped ecological block installation: Install box-shaped ecological blocks from bottom to top on the non-woven geotextile, insert steel bars into the ecological blocks and fix them with grout to form a stepped ecological retaining wall; Set settlement joints of the ecological retaining wall are set and aligned with the settlement joints of the bottom slab to form a continuous joint; Construction of graded crushed stone filter layer: Backfill the graded crushed stone filter layer in layers on the backwater side of the box-shaped ecological block, wrap it with non-woven geotextile and compact it to form a slope sloping towards the backwater side; Layered backfilling of backfill soil: Backfill the permeable soil in layers on the backwater side of the graded crushed stone filter layer and compact it, with each layer compacted to a thickness not exceeding 20cm, and the slope of the permeable soil ecological retaining wall not exceeding the slope of the ecological retaining wall.

[0006] According to some embodiments of the present invention, step A further includes arranging a number of reinforced concrete square piles according to the design position and spacing, driving the reinforced concrete square piles according to the design elevation, removing the concrete within a 450mm length of the top of the reinforced concrete square piles, and connecting adjacent reinforced concrete square piles with guide beams.

[0007] According to some embodiments of the present invention, step A further includes the following reinforced concrete square pile driving process: foundation pit excavation, foundation leveling, surveying and setting out, pile driver positioning, reinforced concrete square pile hoisting, test pile, driving, hammer acceptance, pile head chiseling, pile position measurement and verification, pile foundation testing, formwork support, and guide beam construction.

[0008] According to some embodiments of the present invention, in step A, at least 50 mm of main reinforcement bars are exposed at the top of the reinforced concrete square pile and poured into the guide beam, or in step C, they are poured into the reinforced concrete base slab.

[0009] According to some embodiments of the present invention, step B further includes the following construction process for plain concrete cushion layer: cleaning the base, setting up formwork, pouring concrete, vibrating, leveling, and curing; the concrete pouring is carried out continuously without adding water; the formwork is set up and a C20 plain concrete cushion layer with a thickness of 150mm is poured; the vibration is mainly mechanical with manual intervention; and the curing is carried out by continuous wetting.

[0010] According to some embodiments of the present invention, step C further includes a stop block extending upward from the water-facing side of the reinforced concrete base slab, the stop block being used to abut against the ecological block located at the bottom.

[0011] According to some embodiments of the present invention, step C further includes a bottom plate settlement joint spacing of no more than 15m, a joint width of 20mm, and a polyethylene low-density foam board filling the joint.

[0012] According to some embodiments of the present invention, step E further includes inserting steel bars into the cavities inside the ecological block and pouring concrete or cement mortar into the cavities to fix the steel bars; a drainage pipe is installed at the bottom of the ecological retaining wall, and the drainage pipe is surrounded by gravel or sand.

[0013] According to some embodiments of the present invention, the graded crushed stone filter layer in step F also satisfies the following: a layered structure composed of crushed stone, pebbles or gravel; particles in each layer remain stationary under the action of seepage; finer particles in adjacent layers do not migrate to the pores of coarser layers; and extremely fine particles carried away by seepage do not form blockages in the filter layer.

[0014] A construction method for an ecological stepped retaining wall for a waterfront embankment according to an embodiment of the present invention has at least the following technical effects:

[0015] 1) This invention not only meets the needs of embankment protection, but is also more conducive to ecological protection than the traditional model. Since the box-shaped ecological blocks are prefabricated, the on-site pouring work is eliminated, which is more convenient and faster. At the same time, the use of surplus soil generated on the construction site for filling and the reserved space are conducive to vegetation growth, which can achieve multiple effects such as soil stabilization and slope protection, natural ecological environment protection, and river landscape creation.

[0016] 2) The construction of plain concrete cushion and reinforced concrete base slab strictly follows the specifications, and each step from rebar binding to concrete pouring and curing is controlled to ensure structural strength and durability; settlement joints are set to accommodate foundation deformation and reduce structural damage caused by uneven settlement.

[0017] 3) Sloping drainage pipes are installed at the bottom of the wall and the area around the pipes is properly treated. The graded crushed stone filter layer is backfilled in layers and wrapped with non-woven geotextile to meet the drainage and filtration requirements, prevent soil particle loss and filter layer siltation, and ensure the stability of the retaining wall structure.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a flowchart of the construction process of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention.

[0022] Figure label:

[0023] 1. Reinforced concrete square piles, 2. Plain concrete cushion layer, 3. Reinforced concrete base slab, 4. Non-woven geotextile, 5. Ecological blocks, 6. Graded crushed stone filter layer, 7. Backfill soil behind the wall. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Reference Figures 1 to 2 This invention provides a construction method for an ecological stepped retaining wall for a water-adjacent road embankment, the specific steps of which are as follows:

[0028] A. Construction of reinforced concrete square piles

[0029] First, the foundation pit is excavated. The depth and dimensions of the pit are determined according to the design requirements. After excavation, the base is leveled to ensure that the flatness error is controlled within ±10mm. A total station is used for surveying and setting out, and the positions of the reinforced concrete square piles 1 are accurately determined and marked according to the design location and spacing.

[0030] After the pile driver is in place, check its verticality; the deviation should not exceed 0.5%. Use a crane to lift and lower the reinforced concrete square pile 1 slowly and vertically to the predetermined position. Conduct a test pile operation, selecting three reinforced concrete square piles 1 for trial driving to test the performance of the pile driving equipment and the influence of geological conditions on pile driving. Record and analyze the test pile data to determine the control parameters for formal driving.

[0031] During the formal pile driving process, a diesel pile driver was used, following the principle of "heavy hammer, low impact," to drive each square pile to the design elevation. After driving was completed, a hammer removal inspection was conducted. After the hammer was removed, the concrete within a 450mm length of the top of the reinforced concrete square pile 1 was chiseled away, exposing at least 50mm of the main reinforcement bars at the top of the reinforced concrete square pile 1. Adjacent reinforced concrete square piles 1 were connected by reinforced concrete guide beams, with the main reinforcement bars poured into the guide beams or subsequently poured into the reinforced concrete base slab 3. Finally, the pile positions were measured and verified, and the pile foundation was tested (using the low-strain method to test the integrity of the pile body). After passing the tests, subsequent construction proceeded.

[0032] B. Construction of plain concrete foundation layer

[0033] The bottom of the foundation pit was cleaned, removing debris, silt, and other contaminants to ensure the base was clean and free of standing water. Formwork was erected according to design requirements, and commercial concrete (C20 grade, 150mm thick) was poured. After the concrete was transported to the site, it was poured continuously without adding water, using a vibrator for mechanical compaction, supplemented by manual compaction, to ensure the concrete was dense and free of honeycomb or pitting on the surface.

[0034] After pouring, use a screed to level the surface, ensuring the flatness error of the plain concrete subbase 2 is controlled within ±5mm. Continuous moist curing is achieved by covering with plastic film and sprinkling water.

[0035] C. Construction of reinforced concrete base slab

[0036] On the plain concrete foundation layer 2, the outline of the reinforced concrete base slab 3 is laid out using a total station. Reinforcing bars are tied according to design requirements, and the spacing, diameter, and length of the reinforcing bars are calculated accurately. Reinforcing bar welding must be free of detachment, missed welds, and cracks. Reinforcing bar joints are welded, and the joints should preferably be located at the point of least stress in the component and staggered.

[0037] When setting up the base slab formwork, the formwork material should comply with relevant construction specifications, and its structure must have sufficient strength, rigidity, and stability, such as steel formwork, to ensure that the shape, dimensions, and relative positions of the poured concrete structure conform to the design specifications. The formwork surface should be smooth and flat, with tight joints and no grout leakage.

[0038] A stop block is installed on the water-facing side of the reinforced concrete base slab 3 to hold back the ecological block 5 located at the bottom.

[0039] Settlement joints are installed on the base plate. The spacing between settlement joints is no more than 15m, the joint width is 20mm, and they are aligned vertically. The joints are separated by 20mm thick polyethylene low-foaming boards, and the outer perimeter is sealed with single-component polyurethane sealant.

[0040] Ready-mixed concrete of grade C30 was used for pouring, and the reinforced concrete base slab was 500mm thick. Concrete pouring should be continuous; adding water en route or within the slab is strictly prohibited. The concrete should be leveled immediately after pouring. Vibration should primarily be used for compaction, with manual vibration used only in areas where it is difficult to use a vibrator, to ensure a smooth, honeycomb-free surface. The concrete should be continuously kept moist during curing.

[0041] D. Laying of non-woven geotextile

[0042] On the reinforced concrete base slab 3, determine the laying position of the non-woven geotextile 4 according to the design drawings. Unroll the non-woven geotextile 4 from the roller and lay it evenly on the marked area. Use special tools (such as U-shaped nails) to tightly bond the non-woven geotextile to the reinforced concrete base slab 3 to avoid gaps, and reinforce the edges to prevent the geotextile from shifting. Leave a certain length of non-woven geotextile 4 to wrap the graded crushed stone cushion layer.

[0043] E. Installation of box-type ecological blocks

[0044] The box-shaped ecological blocks 5 are installed one by one according to the designed pattern or method, with uniform gaps between the ecological blocks 5 to form a stepped ecological retaining wall. After the ecological blocks 5 are installed, steel bars can be inserted into the holes of the ecological blocks 5, and then concrete or cement mortar can be poured into the holes to fix the steel bars and make the connection between the ecological blocks 5 tighter. During the pouring process, ensure that the cement mortar is full and vibrated to compact it.

[0045] Settlement joints for the ecological retaining wall are installed according to design requirements, aligning with the settlement joints of the base slab to form a continuous joint. The joint is 20mm wide and filled with low-density polyethylene foam board. Drainage pipes with a certain slope are installed at the bottom of the ecological retaining wall, and the area around the drainage pipes is wrapped with gravel or sand to form a drainage channel, preventing soil from clogging the drainage pipes and ensuring that water behind the wall can be drained smoothly.

[0046] F. Construction of graded crushed stone filter layer

[0047] On the backwater side of the box-shaped ecological block 5, a graded crushed stone filter layer 6 is backfilled in layers. This layer consists of crushed stone, pebbles, or gravel. Clean, well-graded materials should be selected, and the backfilling should be done in layers, with each layer not being too thick to ensure compaction. After each layer of crushed stone is filled, compaction should be performed. Compaction can be done manually or mechanically to ensure the filter layer meets the following requirements: particles within each layer remain stationary under seepage; finer particles from adjacent layers do not migrate to the pores of coarser layers; and extremely fine particles carried away by seepage do not form blockages within the filter layer. During the crushed stone filling and compaction process, care should be taken to protect the geotextile to avoid damage.

[0048] G. Layered backfilling of the wall backfill soil

[0049] On the backwater side of the graded crushed stone filter layer 6, permeable soil is backfilled in layers and compacted, with each layer not exceeding 20cm in thickness to ensure the density and uniformity of the backfill. The slope of the backfill soil 7 behind the wall is consistent with or slightly smaller than the slope of the retaining wall to prevent landslides or collapses caused by excessive slope.

[0050] Strictly control the moisture content of the backfill soil and keep it within the allowable range of the soil. Maintain uniform humidity by adding water or draining water in a timely manner. To ensure that the quality of the backfill soil behind the wall meets the standards, a comprehensive quality test should be carried out, including multiple aspects such as soil compressibility, moisture content, cohesion and stability.

[0051] After construction is completed, herbaceous plants or low shrubs suitable for local growth can be planted in the cavities and stepped platforms inside ecological block 5. Ecological greening can be carried out by artificially sowing grass seeds or transplanting seedlings, so as to realize the ecological protection function of the ecological stepped retaining wall of the water embankment.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A construction method for an ecological stepped retaining wall on a water-adjacent embankment, characterized in that, Includes the following steps: A. Construction of reinforced concrete square piles: At the bottom of the pre-excavated foundation pit, the location of the reinforced concrete square piles (1) is determined by measurement and layout, and the piles are driven mechanically; B. Plain concrete cushion layer construction: The location of the plain concrete cushion layer (2) is determined by surveying and setting out at the bottom of the foundation pit, the formwork is erected, and the plain concrete cushion layer (2) is poured. C. Construction of reinforced concrete base slab: Lay out the outline of reinforced concrete base slab (3) on plain concrete cushion layer (2), tie the reinforcing bars, set up formwork, set settlement joints for base slab, and pour reinforced concrete base slab (3). D. Laying of non-woven geotextile: Determine the position of non-woven geotextile (4) on the reinforced concrete base plate (3), and lay and fix the non-woven geotextile (4) according to the design requirements. E. Installation of box-shaped ecological blocks: Install box-shaped ecological blocks (5) on the non-woven geotextile (4) from bottom to top. Insert steel bars into the ecological blocks (5) and fix them with grout to form a stepped ecological retaining wall. Set settlement joints of the ecological retaining wall are set and aligned with the settlement joints of the bottom plate to form a through joint. F. Construction of graded crushed stone filter layer: Graded crushed stone filter layer (6) is backfilled in layers on the back side of the box-shaped ecological block (5), wrapped with non-woven geotextile (4) and compacted to form a slope sloping towards the back side; G. Layered backfilling of backfill soil behind the wall: Permeable soil is backfilled and compacted in layers on the back side of the graded crushed stone filter layer (6). The compaction thickness of each layer shall not exceed 20cm, and the slope of the permeable soil ecological retaining wall shall not be greater than the slope of the ecological retaining wall.

2. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: In step A, several reinforced concrete square piles (1) are arranged according to the design position and spacing, the reinforced concrete square piles (1) are driven according to the design elevation, the concrete within a 450mm long range of the top of the reinforced concrete square piles (1) is removed, and the adjacent reinforced concrete square piles (1) are connected by guide beams.

3. The construction method for an ecological stepped retaining wall for a waterfront embankment according to claim 2, characterized in that: In step A, the construction process of the reinforced concrete square pile (1) includes excavation of the foundation pit, leveling of the foundation, measurement and layout, positioning of the pile driver, hoisting and placing of the reinforced concrete square pile (1), test pile, driving, acceptance of hammering, chiseling of pile head, measurement and verification of pile position, pile foundation testing, formwork, and construction of guide beam.

4. The construction method for an ecological stepped retaining wall for a waterfront embankment according to claim 2, characterized in that: In step A, the main reinforcement bars of the reinforced concrete square pile (1) with a length of at least 50 mm are exposed at the top and poured into the guide beam, or in step C, they are poured into the reinforced concrete base plate (3).

5. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: In step B, the construction process of the plain concrete cushion layer (2) includes cleaning the base, setting up formwork, pouring concrete, vibrating, leveling, and curing. The concrete pouring is carried out continuously without adding water. The plain concrete cushion layer (2) with a thickness of 150mm and C20 is poured using formwork. The vibration is mainly done by machinery and supplemented by manual labor. The curing is carried out by continuous wetting.

6. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: In step C, a stop block is provided on the water-facing side of the reinforced concrete base slab (3), and the stop block is used to hold the ecological block (5) located at the bottom.

7. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: In step C, the spacing of the settlement joints in the base plate is no more than 15m, the joint width is 20mm, and the joints are filled with polyethylene low-density foam board.

8. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: In step E, the reinforcing steel is inserted into the cavity inside the ecological block (5), and concrete or cement mortar is poured into the cavity to fix the reinforcing steel; a drainage pipe is set at the bottom of the ecological retaining wall, and the drainage pipe is surrounded by gravel or sand.

9. The construction method of an ecological stepped retaining wall for a waterfront embankment according to claim 1, characterized in that: The graded crushed stone filter layer (6) described in step F satisfies: (a) A layered structure consisting of crushed stone, pebbles or gravel; (b) The particles within each layer remain stationary under the action of seepage; (c) Finer particles in adjacent layers do not migrate to the pores of coarser layers; (d) The extremely fine particles carried away by seepage do not form silt in the filter layer.

10. The construction method according to any one of claims 1-9, characterized in that: After the construction is completed, plants are planted in the ecological block (5) to achieve ecological greening.

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