A construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation

Abstract

The present invention belongs to the technical field of fly ash landfill, and particularly relates to a construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation. This method determines the landfill height and storage capacity of the area, and then successively performs the steps of the first implementation of the area, filling the landfill area to the first landfill height, the second implementation of the area, filling the landfill area to the second landfill height, repeating the second implementation of the area and landfill until the designed ground height and designed landfill height are reached, and then the construction of the area is completed. The present invention creatively proposes the construction of a fly ash landfill area at sea. By using waste soil as a reclamation material and solidified marine mud as an anti-seepage layer, the composite foundation treatment is adopted for the foundation of the area, and vertical marine mud solidification walls are set around the area, realizing the synchronous implementation of the construction and landfill of the area.

Description

Technical Field

[0001] The present invention relates to the technical field of fly ash landfill, and particularly relates to a construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation. Background Art

[0002] With the urban construction and economic development, the treatment of a large amount of domestic waste and construction waste faces huge challenges. The landfill method is the most common method for solid waste treatment at home and abroad. However, the continuous acceptance and disposal of solid waste landfills have made the storage capacity of more and more landfills close to saturation. The construction of new landfills has a particularly large demand for land, while the land around cities is in short supply. Therefore, the demand for the construction of marine landfills is increasing continuously.

[0003] Compared with landfills on land, marine solid waste landfills are affected by complex hydrodynamic environments, variable marine climates, deep marine sedimentary strata and other factors. If the solid waste or the generated leachate leaks, it will directly pollute the marine environment. Therefore, the prevention of pollutant diffusion treatment in marine landfills is relatively crucial. The foundation of marine solid waste landfills is often a thick layer of marine sedimentary silt, with large foundation deformation. The uneven settlement phenomenon at the base and slope of the traditional reservoir structure is serious, facing the problem of high foundation treatment difficulty. In addition, a large amount of reclamation materials are required for the construction of the reservoir area. The traditional sand and gravel materials are in short supply, not only facing the problems of high cost and serious environmental damage, but also having a long construction period and large investment for the construction of the reservoir area.

[0004] Wu Dongqing et al. (Research progress on the technology of recycling Singapore sludge and bottom ash from waste incineration for land reclamation [J]. Research of Environmental Sciences, 2018, 31(07): 1174-1181) studied the "new soil" technology of using the chemical-physical composite method (CPCM) to convert Singapore sludge and bottom ash from waste incineration into "sludge-bottom ash waste material matrix (MC-IBA Matrix)" for land reclamation. It was found that from both the environmental protection perspective and the engineering perspective, the "new soil" has feasibility and superiority as a reclamation material. This green technology can solve the dual problems of lack of landfill land and reclamation materials, but it does not propose a specific, safe and reliable construction method for marine landfill areas.

[0005] Based on the above problems, those skilled in the art urgently need to provide an environmentally friendly, economical, safe and reliable construction method for marine landfills to solve the problems such as high foundation treatment difficulty, shortage and high cost of reclamation materials, serious environmental damage and long construction period of the existing marine landfill area construction process. Summary of the Invention

[0006] The present application creatively proposes the construction of a marine fly ash landfill area, and provides a construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation, which has the advantages of high efficiency, environmental protection, economy, safety and reliability. The specific technical solutions are described as follows.

[0007] A construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation, comprising the following steps:

[0008] Step S1: Determine the landfill height and storage capacity of the landfill area;

[0009] Step S2: Conduct the first implementation of the landfill area;

[0010] Step S3: Fill the landfill area to the first landfill height;

[0011] Step S4: Conduct the second implementation of the landfill area;

[0012] Step S5: Fill the landfill area to the second landfill height;

[0013] Step S6: Repeat Step S4 and Step S5 until the designed ground height and designed landfill height are reached.

[0014] Further, the specific content of Step S1 is: According to the landfill standard of the fly ash landfill area, select a composite foundation treatment method, calculate the settlement of the composite foundation, and determine the landfill height and storage capacity of the landfill area.

[0015] Further, Step S2 includes:

[0016] Step S21: Conduct the first backfilling of soil above water. After forming a dike around the landfill area, construct a vertical anti-seepage wall;

[0017] Step S22: Lay a geogrid mat and a drainage cushion layer, bury the groundwater drainage facilities, and then construct the composite foundation pile foundation;

[0018] Step S23: Lay a geotextile, and then construct an anti-seepage layer above the geotextile. At the same time, construct the first height section of the sea mud solidification wall around the landfill area;

[0019] Step S24: Lay a geomembrane and a geotextile in the landfill area, and construct a leachate diversion layer and leachate drainage facilities.

[0020] Further, the specific content of Step S4 is: Backfill the soil around the landfill area, and construct the second height section of the sea mud solidification wall and the geomembrane on the wall around the landfill area.

[0021] Further, the anti-seepage layer in Step S23 is composed of solidified sea mud, which can achieve rapid construction.

[0022] Further, the leachate drainage facilities in Step S24 include leachate drainage pipes.

[0023] Further, the geotextile in Step S23 is laid above the drainage cushion layer.

[0024] Further, the geomembrane in the reservoir area in step S24 is laid above the anti-seepage layer.

[0025] Further, the drainage cushion layer in step S22 also serves as a groundwater drainage layer, and the drainage pump is automatically started and stopped by a liquid level gauge to control the height of the groundwater level.

[0026] Further, the materials used in the backfill construction in step S21 and step S4 are all waste soil, and a backfill layer is finally formed after the backfill construction.

[0027] Further, the landfill materials in step S3 and step S5 are all solidified fly ash packages.

[0028] Compared with the prior art, the advantages and effects of the present application are as follows:

[0029] 1. The present invention uses waste soil as the reclamation material, uses solidified sea mud as the anti-seepage layer, adopts a composite foundation treatment for the reservoir area foundation, and sets up a vertical sea mud solidification wall around the reservoir area, realizing the synchronous implementation of the reservoir area construction and landfill; the present application innovatively proposes a green backfill treatment technology using waste soil and solidified sea mud as the reservoir area construction materials, realizing resource utilization, local material utilization, low-carbon environmental protection; breaking through the drawbacks of uneven settlement at the traditional reservoir area slope boundary.

[0030] 2. The present invention innovatively proposes a treatment technology for the vertical boundary of the reservoir area, using a variable cross-section sea mud solidification wall as the retaining structure to achieve the goal of rapid landfill in sub-construction.

[0031] 3. The present invention innovatively proposes a composite foundation treatment method, which does not require prior foundation treatment. The drainage cushion layer also serves as a groundwater drainage layer, and the drainage pump is automatically started and stopped by a liquid level gauge to control the height of the groundwater level.

[0032] 4. The present invention innovatively proposes a treatment technology using solidified sea mud as the anti-seepage layer of the reservoir area, replacing the use of clay to achieve the goal of rapid construction.

[0033] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, so as to be implemented in accordance with the content of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following takes the preferred embodiments of the present application and combines with the drawings to describe in detail as follows.

[0034] Those skilled in the art will understand the above and other purposes, advantages and features of the present application more clearly according to the following detailed description of the specific embodiments of the present application in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts do not necessarily need to be drawn according to the actual scale.

[0036] Wherein:

[0037] Figure 1 is a flowchart of a construction method for a fly ash landfill area with a large deformed ultra-soft marine foundation provided by the present application;

[0038] Figure 2 is a plan view of a fly ash landfill area with a large deformed ultra-soft marine foundation provided by the present application;

[0039] Figure 3 is a cross-sectional view of a fly ash landfill area with a large deformed ultra-soft marine foundation provided by the present application;

[0040] Wherein: 1 - Composite foundation pile foundation; 2 - Marine mud solidification wall; 3 - Groundwater pumping and drainage facility; 4 - Drainage cushion layer; 5 - Impervious layer; 6 - Geomembrane in the storage area; 7 - Filling layer; 8 - Leachate diversion layer; 9 - Leachate drain pipe; 10 - Vertical impervious wall. Detailed implementation manners

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. In the following description, specific details such as specific configurations and components are provided only to help comprehensively understand the embodiments of the present application. Therefore, those skilled in the art should clearly understand that various changes and modifications can be made to the embodiments described here without departing from the scope and spirit of the present application. In addition, descriptions of known functions and structures are omitted in the embodiments for clarity and conciseness.

[0042] It should be understood that the "one embodiment" or "the present embodiment" mentioned throughout the specification means that the specific features, structures, or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "one embodiment" or "the present embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner.

[0043] In addition, the present application may repeat reference numerals and / or letters in different instances. Such repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0044] The term "and / or" in this document is merely a description of the relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, B exists alone, and both A and B exist simultaneously. The term " / and" in this document describes another relationship between associated objects, indicating that two relationships may exist. For example, A / and B may represent: A exists alone, and both A and B exist. Additionally, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0045] The term "at least one" in this document is merely a description of the relationship between associated objects, indicating that three relationships may exist. For example, at least one of A and B may represent: A exists alone, both A and B exist simultaneously, and B exists alone.

[0046] It should also be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion.

[0047] Embodiment 1

[0048] This embodiment introduces a method for constructing a fly ash landfill area on a large-deformation ultra-soft marine foundation. The landfill area is established above the seabed hard soil layer. For the construction method, please refer to the appendix Figure 1 , including the following steps:

[0049] Step S1: Determine the landfill height and storage capacity of the landfill area;

[0050] Step S2: First implementation of the landfill area;

[0051] Step S3: Landfill the landfill area to the first landfill height;

[0052] Step S4: Second implementation of the landfill area;

[0053] Step S5: Landfill the landfill area to the second landfill height;

[0054] Step S6: Repeat Step S4 and Step S5 until the designed ground height and designed landfill height are achieved, thus realizing the goal of rapid landfill through staged construction.

[0055] Preferably, the step S1 is specifically as follows: According to the landfill standard of the fly ash landfill area, select the composite foundation treatment method, calculate the settlement of the composite foundation, and determine the landfill height and storage capacity of the area.

[0056] Preferably, the step S4 is specifically as follows: Backfill the soil around the area, and construct the second height section of the marine mud solidification wall 2 and the geomembrane on the wall surface around the area.

[0057] Preferably, the material used in the backfill soil construction in the step S4 is waste soil, and a fill layer 7 is finally formed after the backfill soil construction.

[0058] Preferably, the landfilled materials in the step S3 and the step S5 are both solidified fly ash packages.

[0059] For the plan view of a fly ash landfill area with a large deformation ultra-soft soil foundation on the sea constructed in this embodiment, please refer to the appendix Figure 2 For the sectional view, please refer to the appendix Figure 3 .

[0060] The technical effect achieved by this embodiment is: This embodiment innovatively proposes a treatment technology for the vertical boundary of the area, and uses a variable-section marine mud solidification wall as the retaining structure to achieve the goal of rapid landfill in multiple phases of construction.

[0061] Embodiment 2

[0062] Based on the above Embodiment 1, this embodiment introduces the specific method for the first implementation of a fly ash landfill area with a large deformation ultra-soft soil foundation on the sea, including the following steps:

[0063] Step S21: For the first time, backfill the soil on the water. After forming a dam around the area, construct the vertical impervious wall 10;

[0064] Step S22: Lay the geonet mat and the drainage cushion layer 4, bury the groundwater drainage facility 3, and then construct the composite foundation pile 1;

[0065] Step S23: Lay the geotextile, and then construct the impervious layer 5 above the geotextile. At the same time, construct the first height section of the marine mud solidification wall 2 around the area;

[0066] Step S24: Lay the geomembrane 6 and the geotextile in the area, and construct the leachate diversion layer 8 and the leachate drainage facility.

[0067] Preferably, the impervious layer 5 in the step S23 is composed of solidified marine mud, and the material used in the backfill soil construction in the step S21 is waste soil; through the green backfill treatment technology, the disadvantages of uneven settlement of the traditional slope boundary of the area are overcome.

[0068] Preferably, the leachate drainage facility in the step S24 includes the leachate drain pipe 9.

[0069] Preferably, in the step S22, the geonet mat is laid on the top of the vertical impervious wall 10, the drainage cushion layer 4 is laid above the geonet mat, and the composite foundation piles 1 are driven equidistantly between the vertical impervious walls 10.

[0070] Preferably, the geotextile in the step S23 is laid above the drainage cushion layer 4.

[0071] Preferably, the geomembrane 6 in the reservoir area in the step S24 is laid above the impervious layer 5, a geotextile is laid above the geomembrane 6 in the reservoir area, the leachate diversion layer 8 is constructed above the geotextile, and a layer of geonet mat is laid above the leachate diversion layer 8.

[0072] Preferably, the drainage cushion layer 4 also serves as a groundwater drainage layer, and the pumping and drainage pump is automatically started and stopped by a liquid level gauge to control the height of the groundwater level.

[0073] The technical effects achieved by this embodiment are as follows: This embodiment uses the muck as the reclamation material, uses the solidified sea mud as the impervious layer, adopts the composite foundation treatment for the reservoir area foundation, and sets up the vertical sea mud solidification wall around the reservoir area, realizing the synchronous implementation of the reservoir area construction and landfill; innovatively proposes the green backfilling treatment technology of using muck and solidified sea mud as the reservoir area construction materials, realizing resource utilization, using local materials, and being low-carbon and environmentally friendly; breaking through the drawbacks of uneven settlement at the traditional reservoir area slope boundary; innovatively proposes the composite foundation treatment method, where the foundation does not need to be pre-treated, the drainage cushion layer also serves as the groundwater drainage layer, and the pumping and drainage pump is automatically started and stopped by a liquid level gauge to control the height of the groundwater level; innovatively proposes the treatment technology of using solidified sea mud as the reservoir area impervious layer, replacing the use of clay, and achieving the goal of rapid construction.

[0074] The above are only the preferred embodiments of the present invention, and they do not limit the protection scope of the present invention. For those skilled in the art, the present invention can have various changes and modifications. All changes, modifications, substitutions, integrations, and parameter changes made to these embodiments by conventional substitutions or capable of achieving the same functions without departing from the principles and spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation, characterized in that It includes the following steps: Step S1: Determine the landfill height and storage capacity of the reservoir area; Step S2: Implement the reservoir area for the first time; Step S3: Landfill to the first landfill height; Step S4: Implement the reservoir area for the second time; specifically: backfill the soil around the reservoir area, and construct the second height section of the marine mud solidification wall (2) and the geomembrane on the wall surface around the reservoir area; Step S5: Landfill to the second landfill height; Step S6: Repeat Step S4 and Step S5 until the designed ground height and designed landfill height are reached; The said Step S2 includes: Step S21: Backfill the soil on the water surface for the first time. After forming a dam around the reservoir area, construct a vertical impervious wall (10); Step S22: Lay a geonet mat on the top of the vertical impervious wall (10), lay a drainage cushion layer (4) above the geonet mat, bury a groundwater drainage facility (3), and then drive composite foundation piles (1) at equal intervals between the vertical impervious walls (10); Step S23: Lay a geotextile above the drainage cushion layer (4), and then construct an impervious layer (5) above the geotextile. At the same time, construct the first height section of the marine mud solidification wall (2) around the reservoir area; Step S24: Lay a geomembrane (6) and a geotextile in the reservoir area above the impervious layer (5), construct a leachate diversion layer (8) above the geotextile, lay a layer of geonet mat above the leachate diversion layer (8), and then construct a leachate drainage facility; The said impervious layer (5) is composed of solidified marine mud; The materials used for the backfill construction in Step S21 and Step S4 are all waste soil; The said drainage cushion layer (4) also serves as a groundwater drainage layer, and the drainage pump is automatically started and stopped by a liquid level gauge to control the groundwater level height.

2. The construction method of a fly ash landfill area on a large-deformation ultra-soft marine foundation according to claim 1, characterized in that, The leachate drainage facility in Step S24 includes a leachate drainage pipe (9).

3. A method for constructing a fly ash landfill area on a large-deformation ultra-soft marine foundation according to claim 1, characterized in that, The backfill construction in Step S21 and Step S4 finally forms a fill layer (7).

4. A construction method for a fly ash landfill area on a large-deformation ultra-soft marine foundation according to claim 1, characterized in that, The landfill materials in Step S3 and Step S5 are both solidified fly ash packages.

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