A construction method and backfill structure for backfilling and renovating a dry fountain pool

Abstract

This invention belongs to the field of building construction technology, and provides a construction method and backfill structure for the backfilling and renovation of a dry fountain pool. The construction method includes the following steps: S1, pouring a first layer of foamed concrete into the dry fountain pool, the first layer of foamed concrete being below the designed finished surface; S2, chiseling away the top of the existing piers; the remaining material from the chiseling process is left in the pool as part of the aggregate for the second layer of foamed concrete; S3, pouring a second layer of foamed concrete into the dry fountain pool up to the designed finished surface; S4, pouring a reinforced concrete layer on the basis of the second layer of foamed concrete to complete the backfilling of the dry fountain pool. The construction method of this invention has advantages such as high efficiency, material saving, and cost reduction.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology, specifically relating to a construction method and backfill structure for the renovation of dry fountains. Background Technology

[0002] With the advancement of urban landscape improvement projects, many existing dry fountains require backfilling and renovation due to functional adjustments. Dry fountains are typically shallow (0.5m~1.5m) with dense brick or concrete piers at the bottom to support the surface layer, and the bottom has a certain slope to ensure drainage. Common backfilling construction methods for dry fountains generally include the following: 1) The original piers and pool bottom paving were completely demolished and removed. Then, steel bars were re-tied at the bottom of the pool, ordinary concrete was poured to the design elevation, and finally the surface layer was laid. In other words, the entire dry fountain structure was demolished and a new concrete base was poured. However, this construction involves a large amount of demolition work, generates a lot of construction waste, and has a long construction period and high cost.

[0003] 2) Retain the existing piers and directly pour ordinary concrete or high-density lightweight concrete into the pool to enclose the piers and form an integral backfill layer. Although this construction method retains the original piers, it requires a large amount of ordinary concrete or high-density lightweight concrete, resulting in high material costs. Moreover, if ordinary concrete is used for filling, it may easily lead to excessive load, which may have an adverse effect on the foundation.

[0004] 3) Retain the original piers and fill the pool with low-strength foamed concrete. Although using low-density foamed concrete is lightweight and saves materials, its self-weight is insufficient. The buoyancy generated by the water accumulation during heavy rain may cause the backfill layer or surface layer to float, crack, and be damaged.

[0005] In other words, existing dry fountain backfilling and renovation methods all have various shortcomings, especially in their inability to balance construction efficiency and cost, buoyancy resistance, and material conservation. Therefore, it is necessary to propose a new construction method for dry fountain backfilling and renovation. Summary of the Invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a construction method for backfilling and renovating dry fountains, which has the advantages of high efficiency, material saving and cost reduction.

[0007] The technical solution adopted by this invention to solve its technical problem is: A method for backfilling and renovating a dry fountain includes the following steps: S1. Pour the first layer of foamed concrete into the dry fountain pool. The first layer of foamed concrete is located below the designed finished surface, which is lower than the original pier of the dry fountain pool. The first layer of foamed concrete covers part of the original pier. After the first layer of foamed concrete reaches the preset strength, proceed to the next step; S2. Remove the top of the original pier column; when removing it, use the surface of the first layer of foamed concrete as the elevation reference plane, and control the top surface of the original pier column after removal to correspond and be level with the designed surface, so as to achieve precise control of the removal elevation of the original pier column. The remaining material of the piers produced during the chiseling process is left in the pool and used as part of the aggregate for the second layer of foamed concrete. S3. Pour the second layer of foamed concrete into the dry fountain pool up to the designed finished surface; after the second layer of foamed concrete reaches the preset strength, proceed to the next step; S4. On the basis of the second layer of foamed concrete, the reinforced concrete layer is poured to complete the backfilling of the dry fountain.

[0008] A preferred embodiment of the present invention further includes a pre-construction treatment step: S00, On-site investigation and cleanup; Measure the actual dimensions of the dry fountain, the slope of the bottom, and the distribution of existing piers; clean up debris and sludge at the bottom of the fountain and keep the pouring surface clean.

[0009] Preferably, the pre-construction treatment steps further include: S0. Dry fountain pool compartmentalization design and isolation: The dry fountain pool is divided into several pouring zones, and extruded polystyrene boards are used to separate the pouring zones; at the same time, extruded polystyrene boards are laid around the dry fountain pool.

[0010] In a preferred embodiment of the present invention, in step S1, a low-pressure pump is used when pouring the first layer of foamed concrete, the height of the pouring outlet from the bottom of the pool is ≤1m, and the pouring is carried out in layers.

[0011] Preferably, in step S1, when pouring the first layer of foamed concrete, a test block for co-curing is left; the next step is carried out after the strength of the first layer of foamed concrete reaches 70% of the design strength.

[0012] In a preferred embodiment of the present invention, in step S4, a steel mesh is first tied to the second layer of foamed concrete, and PVC spacers are used to control the thickness; then a 100mm thick layer of concrete is poured to form a reinforced concrete layer.

[0013] The present invention also provides a backfill structure for dry fountains, which is implemented by the above-mentioned dry fountain backfilling and renovation construction method.

[0014] A backfill structure for a dry fountain includes an existing pier, a first layer of foamed concrete, a second layer of foamed concrete, and a reinforced concrete layer. The top of the existing pier is removed. The first layer of foamed concrete is lower than the existing pier after the removal is completed. The second layer of foamed concrete is poured on the first layer of foamed concrete and is level with the existing pier. The remaining material removed from the existing pier is used as aggregate when pouring the second layer of foamed concrete. The reinforced concrete layer is poured on the second layer of foamed concrete.

[0015] Preferably, the reinforced concrete layer includes a base layer and a surface layer, with the surface layer located above the base layer.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The construction method of this invention utilizes the self-weight of the existing piers as an anti-buoyancy counterweight, ensuring stable and reliable anti-buoyancy force unaffected by fluctuations in the density of foamed concrete, making it safer than relying solely on the material's own weight for anti-buoyancy. Simultaneously, its high strength forms an invisible skeleton, effectively enhancing the overall bearing capacity of the backfill layers (first and second layers of foamed concrete). Furthermore, by maintaining the original pier distribution, allowing them to directly bear the load of the upper reinforced concrete layer, the bearing capacity of the backfill structure is also guaranteed.

[0017] By preserving the original piers and removing their tops to the design elevation, their self-weight continues to play a role. Therefore, based on the total weight of the piers, the buoyancy resistance can be optimized from the conventional 10kN / m³ requirement to 7kN / m³, effectively saving on cement and other material costs. Furthermore, the original pier structure is fully utilized, and the pier debris from the removal process does not need to be transported off-site, reducing construction waste and making it environmentally friendly.

[0018] In terms of construction efficiency, since there is no need to completely demolish the original piers, earthwork excavation and transportation are reduced, and no additional anti-buoyancy measures are required, the construction period is effectively shortened.

[0019] The construction process offers at least the following advantages: Firstly, the initial pouring of the first layer of foamed concrete encapsulates and secures the lower part of the original pier, providing effective lateral restraint and preventing tilting or loosening during removal, thus ensuring the pier's stability. Using the surface of the first layer of foamed concrete as a reference level facilitates precise control of the pier removal elevation, avoiding elevation errors caused by the pool bottom slope. Excavated pier material is left directly within the pool without being removed or transported, serving as aggregate for the second layer of foamed concrete, saving materials. Finally, the removed pier remains intact, serving as counterweight and reinforcing reinforcement for subsequent backfill layers. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the cross-section of a dry fountain.

[0022] Figure 2 This is a top view of the dry fountain (division diagram; the extruded polystyrene boards around the dry fountain are not shown).

[0023] Figure 3 This is a cross-sectional schematic diagram of the first layer of foamed concrete poured during the backfilling and renovation construction of the dry fountain pool according to the present invention.

[0024] Figure 4 This is a schematic diagram of the cross-section of the original pier top that was removed during the backfilling and renovation construction of the dry fountain pool of the present invention (the dotted line represents the removed part).

[0025] Figure 5 This is a cross-sectional schematic diagram of the second layer of foamed concrete poured during the backfilling and renovation construction of the dry fountain pool according to the present invention.

[0026] Figure 6 This is a schematic cross-sectional view of the reinforced concrete layer poured during the backfilling and renovation construction of the dry fountain pool according to the present invention.

[0027] in: 1-Base slab, 2-Existing pier column, 3-Extruded polystyrene board, 4-First layer of foamed concrete, 5-Design finished surface, 6-Surplus material, 7-Second layer of foamed concrete, 8-Reinforced concrete layer, 801-Base layer, 802-Surface layer. Detailed Implementation

[0028] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of the present invention; the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] Example 1 See Figures 1-6 This embodiment discloses a construction method for backfilling and renovating a dry fountain, which can take into account the advantages of anti-buoyancy requirements and material saving. The method includes the following steps: S00. On-site inspection and cleanup. Measure the actual dimensions of the dry fountain, the slope of the bottom, and the distribution of the existing piers; clean up debris and sludge from the bottom of the fountain and keep the pouring surface clean.

[0031] S0. Dry fountain pool compartmentalization design and isolation. The dry fountain pool is divided into several pouring zones, which are separated by extruded polystyrene boards 3; at the same time, extruded polystyrene boards 3 are laid around the dry fountain pool.

[0032] For example, the dry fountain pool can be divided into four pouring zones (A, B, C, and D) from south to north (each zone is approximately 35m long). The zones are separated by 40mm thick extruded polystyrene (XPS) boards, which serve as both construction joints and expansion joints to release stress. 40mm XPS boards are also laid around the perimeter of the dry fountain pool to prevent pouring from affecting surrounding facilities. This compartmentalized design allows for continuous operation in four zones, facilitating subsequent material recycling and optimizing the construction schedule.

[0033] S1. According to the divided zones, pour the first layer of foamed concrete 4 in each zone of the dry fountain pool. Use a low-pressure pump for pouring, with the pouring outlet ≤1m from the bottom of the pool, and pour in layers (each layer ≤200mm). At the same time, leave test blocks for curing. After the strength of the first layer of foamed concrete 4 reaches 70% of the design strength, proceed to the next step.

[0034] The first layer of foamed concrete 4 is located below the designed finished surface 5, which is lower than the original pier 2 of the dry fountain pool; the first layer of foamed concrete 4 partially encloses the original pier 2. For example, the first layer of foamed concrete 4 can be poured up to 250mm below the designed finished surface 5.

[0035] S2. The top of the original pier 2 is removed. A small excavator (such as SY60-9) can be used to remove the top of the original pier 2. An 18mm template is laid along the machine's travel path to protect the paving stones and the first layer of foamed concrete 4 that has already been poured. Since the first layer of foamed concrete 4 has already wrapped and fixed the lower part of the original pier 2, it forms an effective lateral constraint, which can effectively prevent the original pier 2 from tilting or loosening during the removal process, ensuring the stability of the pier.

[0036] During the removal process, the surface of the first layer of foamed concrete 4 is used as the elevation reference plane to ensure that the top surface of the original pier 2 after removal is level with the designed finished surface 5, thus achieving precise control of the removal elevation of the original pier 2. For example, the elevation of the top surface of the original pier 2 after removal can be taken as 250mm above the surface of the first layer of foamed concrete 4. Compared with the traditional method of laying out lines and removing concrete at the bottom of the original pool, the construction method of "pouring first and then removing" provides more precise elevation control, significantly reduces errors, and ensures the consistency of the thickness of the reinforced concrete layer 8.

[0037] The remaining material 6 from the piers produced during the chiseling process is left in the pool and used as part of the aggregate for the second layer of foamed concrete 7.

[0038] S3. Pour the second layer of foamed concrete 7 into the dry fountain pool up to the designed finished surface 5. During pouring, ensure that the remaining material 6 of the pier column is evenly distributed and forms a whole with the foamed concrete. After the second layer of foamed concrete 7 reaches the preset strength, proceed to the next step; During the above steps S1-S3, the original stress layout of the pier 2 was maintained, and the high strength of the original pier 2 was used to form an invisible skeleton, which effectively improved the overall bearing capacity of the backfill layer.

[0039] S4. Construct the reinforced concrete layer 8 on the basis of the second layer of foamed concrete 7. First, tie the steel mesh on the second layer of foamed concrete 7 and use PVC spacers to control the thickness. Then, pour 100mm thick concrete to form the reinforced concrete layer 8.

[0040] Curing should be carried out promptly after pouring. After the cement has fully set, joints should be cut to complete the backfilling of the dry spray pool. The joint cutting dimensions can be referenced as follows: joint width 10mm, depth 15mm, spacing ≤6m.

[0041] The reinforced concrete layer 8 includes the base layer 801 and the surface layer 802. For specific construction requirements, please refer to the landscape design requirements.

[0042] The backfilling and renovation method for the dry fountain in this embodiment has good anti-buoyancy capability: Since the retained piers have a large self-weight (the density of brick or concrete is about 18~22kN / m³), and they are densely distributed on the bottom of the pool (1m×1m spacing), their total mass is sufficient to resist the buoyancy generated by the water accumulation in the pool during rainstorms. There is no need to rely on the self-weight of foamed concrete for anti-buoyancy, so it is permissible to optimize the density of foamed concrete from 10kN / m³ to 7kN / m³.

[0043] It also possesses excellent load-bearing capacity: Since the original stress layout of pier 2 remains unchanged during construction, the pier is retained in its original location and directly bears the load of the upper reinforced concrete layer 8, preserving the original structural stress path. The compressive strength of the pier is far higher than that of foamed concrete, forming an "invisible skeleton" in the backfill layer, effectively dispersing the upper load, improving overall stiffness and load-bearing capacity, and preventing local settlement or cracking. Compared with the traditional practice of "demolishing the pier and recasting" (changing the stress path and losing the contribution of the original structure), this invention preserves the original structural stress system, achieving collaborative load-bearing between the pier and foamed concrete. Moreover, this invention preserves the original structural stress system, transforming the original pier 2 from an "encased object" into a "reinforced skeleton," fully utilizing its structural potential, which is fundamentally different from the traditional "demolishing and rebuilding" in terms of stress system.

[0044] Significant results were also achieved in saving material costs: by utilizing the counterweight of the pier columns, the density of the foamed concrete could be optimized from 10kN / m³ to 7kN / m³, saving approximately 30% of cement per cubic meter. Based on the 2338m³ of this project, this translates to a saving of hundreds of tons of cement, significantly reducing material costs. Furthermore, the existing structure was fully utilized, reducing construction waste; leftover materials from the pier columns were reused on-site, further conserving resources; and the reduced density of the foamed concrete decreased cement usage, lowering carbon emissions and making it environmentally friendly.

[0045] In terms of construction efficiency: the construction is simplified and the construction period is shortened. There is no need to demolish the original pier 2, which reduces earthwork excavation and transportation. No additional anti-buoyancy measures are required. The compartmentalized and continuous operation improves construction efficiency, and the total construction period is shortened by about 20% to 30% compared with the traditional solution.

[0046] Example 2 See Figures 3-6 This embodiment discloses a backfill structure for a dry fountain, implemented using the aforementioned dry fountain backfilling and renovation construction method. The dry fountain backfill structure includes an original pier 2, a first layer of foamed concrete 4, a second layer of foamed concrete 7, and a reinforced concrete layer 8. A bottom slab 1 is provided on the bottom surface of the dry fountain. The top of the original pier 2 is removed. The first layer of foamed concrete 4 is lower than the original pier 2 after the removal work is completed. The second layer of foamed concrete 7 is poured on top of the first layer of foamed concrete 4 and is level with the original pier 2. The remaining material 6 removed from the original pier 2 serves as aggregate when pouring the second layer of foamed concrete 7. The reinforced concrete layer 8 is poured on top of the second layer of foamed concrete 7.

[0047] In this embodiment, the first layer of foamed concrete 4 and the second layer of foamed concrete 7 form a foamed concrete backfill layer, which is poured between the bottom of the pool and the pier. The density is 7kN / m³ and the compressive strength is ≥1Mpa.

[0048] The reinforced concrete layer 8 includes a base layer 801 and a surface layer 802, with the surface layer 802 located above the base layer 801. The thickness of the reinforced concrete layer 8 can be designed to be 100mm, reinforced, and poured on top of the foamed concrete layer, serving as the final load-bearing surface layer 802.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A construction method for backfilling and renovating a dry fountain, characterized in that, Includes the following steps: S1. Pour the first layer of foamed concrete into the dry fountain pool. The first layer of foamed concrete is located below the designed finished surface, which is lower than the original pier of the dry fountain pool. The first layer of foamed concrete covers part of the original pier. After the first layer of foamed concrete reaches the preset strength, proceed to the next step; S2. Remove the top of the original pier column; when removing it, use the surface of the first layer of foamed concrete as the elevation reference plane, and control the top surface of the original pier column after removal to correspond and be level with the designed surface, so as to achieve precise control of the removal elevation of the original pier column. The remaining material of the piers produced during the chiseling process is left in the pool and used as part of the aggregate for the second layer of foamed concrete. S3. Pour the second layer of foamed concrete into the dry fountain pool up to the designed finished surface; after the second layer of foamed concrete reaches the preset strength, proceed to the next step; S4. On the basis of the second layer of foamed concrete, the reinforced concrete layer is poured to complete the backfilling of the dry fountain.

2. The construction method for backfilling and renovating a dry fountain according to claim 1, characterized in that, It also includes pre-construction treatment steps: S00, On-site investigation and cleanup; Measure the actual dimensions of the dry fountain, the slope of the bottom, and the distribution of existing piers; clean up debris and sludge at the bottom of the fountain and keep the pouring surface clean.

3. The construction method for backfilling and renovating dry fountains according to claim 2, characterized in that, The pre-construction treatment steps also include: S0. Dry fountain pool compartmentalization design and isolation: The dry fountain pool is divided into several pouring zones, and extruded polystyrene boards are used to separate the pouring zones; at the same time, extruded polystyrene boards are laid around the dry fountain pool.

4. The construction method for backfilling and renovating a dry fountain according to claim 1, characterized in that, In step S1, a low-pressure pump is used to pour the first layer of foamed concrete, the pouring outlet is ≤1m above the bottom of the pool, and the concrete is poured in layers.

5. The construction method for backfilling and renovating dry fountains according to claim 1 or 4, characterized in that, In step S1, when pouring the first layer of foamed concrete, test blocks are left for curing; after the strength of the first layer of foamed concrete reaches 70% of the design strength, the next step is carried out.

6. The construction method for backfilling and renovating a dry fountain according to claim 1, characterized in that, In step S4, a steel mesh is first tied to the second layer of foamed concrete, and PVC spacers are used to control the thickness; then a 100mm thick layer of concrete is poured to form a reinforced concrete layer.

7. A dry fountain backfill structure formed by the dry fountain backfilling and renovation construction method according to any one of claims 1-6, characterized in that, The structure includes an existing pier, a first layer of foamed concrete, a second layer of foamed concrete, and a reinforced concrete layer. The top of the existing pier is removed. The first layer of foamed concrete is lower than the existing pier after the removal is completed. The second layer of foamed concrete is poured on top of the first layer of foamed concrete and is level with the existing pier. The remaining material removed from the existing pier is used as aggregate when pouring the second layer of foamed concrete. The reinforced concrete layer is poured on top of the second layer of foamed concrete.

8. The backfill structure for the dry fountain pool according to claim 7, characterized in that, The reinforced concrete layer includes a base layer and a surface layer, with the surface layer located above the base layer.

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