Method suitable for in-situ solidification of seaside dredging white mud

Abstract

The invention provides a method suitable for in-situ solidification of seaside dredging white mud, and relates to the field of white mud solidification. According to the method suitable for in-situ curing of the seaside dredging white mud, a curing agent is a powdery curing agent, the specific gravity is 2950 kg / m < 3 >, and the curing agent is prepared from, by weight, 60-70 parts of steel slag, 10-15 parts of fly ash, 4-5 parts of cement, 2-3 parts of an exciting agent, 1-2 parts of polyamide resin, 3-5 parts of ardealite and 3-5 parts of sodium polyacrylate. The curing agent is subjected to a series of hydration and hydrolysis reactions with moisture, secondary minerals and other substances in the white mud to generate various hydration gelling products, and the gelling substances can bond and wrap fine particles in the white mud, so that the fine particles are pelletized, loose individuals are gelled into a whole with certain strength, and meanwhile, certain hydrophobicity is achieved.

Description

Technical Field

[0001] The invention relates to the field of white mud solidification, in particular to an in-situ solidification method suitable for seaside dredged white mud. Background Art

[0002] If the white mud content in the dredged soil at the seaside is extremely high, it is not easy to separate the white mud from it with the existing technology. In addition, the dredged white mud has high viscosity and weak to medium swelling properties. It expands, softens, and disintegrates significantly when absorbing water, and shrinks and cracks rapidly when losing water. The compacted foundation filled with this type of soil has poor water stability. When it encounters water or loses water, it has three major characteristics: expansion, contraction, and reversible deformation of expansion and contraction. Especially as the foundation of a heavy-bearing land yard at a dock, improper handling can easily lead to hazards such as uneven foundation settlement, excessive settlement, and lateral displacement, which can lead to instability and destruction of the buildings built on it, bringing about structural safety problems.

[0003] The plasticity index of white mud is 26.1, and it has strong hydrophilicity and is easy to disintegrate. After compaction, the white mud belongs to medium compressible clay with low strength. Therefore, dredged white mud is not easy to be directly used as yard filler for filling, and needs to be modified. However, the treatment effect of traditional sludge solidifier is not obvious, and it is still easy to decompose and dissolve in water after contacting water. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides a method for in-situ solidification of dredged white mud at the seaside, which solves the problem that the treatment effect of traditional sludge solidifying agents is not obvious and it is still easy to decompose and dissolve in water after contacting water.

[0005] (II) Technical solution To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for in-situ solidification of dredged white mud at the seaside, comprising a curing agent, a stirring system and a feeding system, wherein the curing agent is a powder curing agent with a specific gravity of 2950kg / m 3The curing agent is composed of the following raw materials in corresponding weight parts: 60-70 parts of steel slag, 10-15 parts of fly ash, 4-5 parts of cement, 2-3 parts of activator, 1-2 parts of polyamide resin, 3-5 parts of phosphogypsum, and 3-5 parts of sodium polyacrylate. The stirring system includes a strong stirring device, which includes two or more stirring heads that are symmetrically distributed at a certain angle on both sides of the connecting rod and are independently driven. The stirring head is driven by the hydraulic system of the excavator to ensure the uniformity of the stirring. The lateral speed of the stirring head is 50r / min~120r / min. The single stirring shape on the plane is rectangular rather than circular. The width of the stirring head is 1. The machine has a width of 3m to 1.8m and a height of 0.8m to 1.0m. The angle between the center of the mixing head is about 110 to 120 degrees (not a flat head), which can realize three-dimensional mixing of the curing agent and the soft soil. The feeding system includes automatic slurry feeding equipment, slurry pipes, and tanks. The maximum pressure of the slurry equipment is not less than 3MPa. The background feeding system can realize the simultaneous feeding of multiple curing agents. The automatic quantitative feeding system is installed in the background feeding system to control the curing agent discharge amount and discharge time, display and record the material consumption in the construction area in real time, ensure the curing agent consumption in each mixing interval and the entire block, and achieve automation and intelligence of curing agent spraying.

[0006] Preferably, the construction steps are as follows: a. The mixing equipment is directly inserted to mix the in-situ soil; b. The mixing equipment runs forward, gradually mixing and spraying the curing agent until it reaches the bottom of the curing design; c. The mixing equipment should run in reverse to slowly lift, stir and spray the curing agent. The stirring, lifting or lowering rate should be controlled at 0.1m / s~0.3m / s, and the curing agent slurry spraying rate should be controlled at 80kg / min~150kg / min. The specific rate should be adjusted according to the actual operation conditions on site to ensure uniform spraying and stirring during the construction process.

[0007] Working principle: The silt soil is solidified by in-situ vertical up and down mixing and solidification. To ensure the uniformity of mixing, vertical up and down mixing is performed multiple times within the solidification depth range. At the same time, the rate of descent and elevation is controlled. Too fast a speed will make it difficult for some silt soil to be mixed evenly with the solidifying agent, while too slow a speed will cause the solidifying agent to aggregate and cause the solidifying agent to agglomerate, affecting the uniformity of the solidified soil. According to the actual situation, the in-situ solidification equipment operator can increase the number of empty stirring to ensure uniform mixing. In addition, there is an overlap width of not less than 10cm between each solidification block to prevent leakage.

[0008] (III) Beneficial effects The present invention provides a method for in-situ solidification of dredged white mud at the seaside, which has the following beneficial effects: The method for in-situ solidification of dredged white mud at the seaside is developed based on the characteristics of the white mud. The solidifying agent undergoes a series of hydration and hydrolysis reactions with water and secondary minerals in the white mud to generate various hydrated gelling products. The gelling substances will cement and wrap the fine particles in the white mud to granulate them, and cement the loose individuals into a whole with a certain strength, while having a certain hydrophobicity. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a construction process flow chart of the present invention; Figure 2 It is a schematic diagram of the construction of the present invention; Figure 3 It is a schematic diagram of the connection between the stirring system and the feeding system of the present invention; Figure 4 It is a schematic diagram of the construction process of the present invention; Figure 5 It is a schematic diagram of the strong stirring equipment of the present invention. DETAILED DESCRIPTION

[0010] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0011] like Figure 1-5As shown, the embodiment of the present invention provides a method for in-situ solidification of dredged white mud at the seaside, including a curing agent, a stirring system and a feeding system. The curing agent is a powdered curing agent with a specific gravity of 2950kg / m3. The curing agent is composed of the following raw materials in corresponding parts by weight: 60-70 parts of steel slag, 10-15 parts of fly ash, 4-5 parts of cement, 2-3 parts of activator, 1-2 parts of polyamide resin, 3-5 parts of phosphogypsum, and 3-5 parts of sodium polyacrylate. The stirring system includes a strong stirring device, which includes 2 or more stirring heads that are symmetrically distributed on both sides of a connecting rod at a certain angle and are independently driven. The stirring head is driven by the hydraulic system of an excavator to ensure the uniformity of stirring. The lateral speed of the stirring head is 50r / min~1 The speed is 20r / min, and the single stirring shape is rectangular rather than circular on the plane. The width of the stirring head is 1.3m~1.8m, the height is 0.8m~1.0m, and the angle between the center of the stirring head is about 110~120 degrees (not flat head), which can realize three-dimensional mixing of curing agent and soft soil. The feeding system includes automatic slurry feeding equipment, slurry pipes, and tanks. The maximum pressure of the slurry equipment is not less than 3MPa. The background feeding system can realize the simultaneous feeding of multiple curing agents. The automatic quantitative feeding system is installed in the background feeding system to control the curing agent discharge amount and discharge time, display and record the material consumption in the construction area in real time, ensure the curing agent consumption in each mixing interval and the entire block, and achieve automation and intelligence of curing agent spraying.

[0012] The construction steps are as follows: a. The mixing equipment is directly inserted to mix the in-situ soil; b. The mixing equipment runs forward, gradually mixing and spraying the curing agent until it reaches the bottom of the curing design; c. The mixing equipment should run in reverse to slowly lift, stir and spray the curing agent. The stirring, lifting or lowering rate should be controlled at 0.1m / s~0.3m / s, and the curing agent slurry spraying rate should be controlled at 80kg / min~150kg / min. The specific rate should be adjusted according to the actual operation conditions on site to ensure uniform spraying and stirring during the construction process.

[0013] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for in-situ solidification of seaside dredged white mud, comprising a curing agent, a stirring system and a feeding system, characterized in that: The curing agent is a powder curing agent with a specific gravity of 2950kg / m 3 The curing agent is composed of the following raw materials in corresponding weight parts: 60-70 parts of steel slag, 10-15 parts of fly ash, 4-5 parts of cement, 2-3 parts of activator, 1-2 parts of polyamide resin, 3-5 parts of phosphogypsum, and 3-5 parts of sodium polyacrylate. The stirring system includes a strong stirring device, which includes two or more stirring heads that are symmetrically distributed at a certain angle on both sides of the connecting rod and are independently driven. The stirring head is driven by the hydraulic system of the excavator to ensure the uniformity of the stirring. The lateral speed of the stirring head is 50r / min~120r / min. The single stirring shape on the plane is rectangular rather than circular. The width of the stirring head is 1. The machine has a width of 3m to 1.8m and a height of 0.8m to 1.0m. The angle between the center of the mixing head is about 110 to 120 degrees (not a flat head), which can realize three-dimensional mixing of the curing agent and the soft soil. The feeding system includes automatic slurry feeding equipment, slurry pipes, and tanks. The maximum pressure of the slurry equipment is not less than 3MPa. The background feeding system can realize the simultaneous feeding of multiple curing agents. The automatic quantitative feeding system is installed in the background feeding system to control the curing agent discharge amount and discharge time, display and record the material consumption in the construction area in real time, ensure the curing agent consumption in each mixing interval and the entire block, and achieve automation and intelligence of curing agent spraying.

2. A method for in-situ solidification of seaside dredged white mud according to claim 1, characterized in that: The specific construction steps are as follows: a. The mixing equipment is directly inserted to mix the in-situ soil; b. The mixing equipment runs forward, gradually mixing and spraying the curing agent until it reaches the bottom of the curing design; c. The mixing equipment should run in reverse to slowly lift, stir and spray the curing agent. The stirring, lifting or lowering rate should be controlled at 0.1m / s~0.3m / s, and the curing agent slurry spraying rate should be controlled at 80kg / min~150kg / min. The specific rate should be adjusted according to the actual operation conditions on site to ensure uniform spraying and stirring during the construction process.

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