Slurry system for construction of underwater pier pile foundation of extra-large bridge and preparation method of slurry system

Abstract

The invention discloses a slurry system for construction of an underwater pier pile foundation of an extra-large bridge and a preparation method of the slurry system. The slurry system comprises the following components in parts by weight: 12-20 parts of bentonite, 0.6-5 parts of sodium carbonate, 0.1-0.2 part of an anti-chlorinating agent, 0.1-0.2 part of carboxymethylcellulose and 70-90 parts of water. According to the slurry system disclosed by the invention, the flowability and the stability of the slurry are remarkably improved through scientific matching of the components, and the construction efficiency and the safety in the construction process of the underwater pier pile foundation of the extra-large bridge are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of underwater pier pile foundation construction, and in particular to a mud system for underwater pier pile foundation construction of a super-large bridge and a preparation method thereof. Background Art

[0002] During the construction of the super-large bridge, there are problems such as rapid water flow, complex water quality, and variable soil conditions. The local silt and fine sand layers above 20m below the groundwater level of the Yellow River are earthquake liquefaction layers. The silty clay and cementitious silty clay distributed in some sections are soft soils, which are scattered on the surface. The soft soil has high natural water content, large porosity, rheology, thixotropy, low strength and high compressibility.

[0003] Plain fill soil: tan, brownish yellow, brownish gray, yellowish gray, slightly dense, slightly wet to moist, mainly composed of silt, clay and sand, mainly distributed in the surface layer near villages and shrimp ponds, with a layer thickness of about 0.0 to 10.4m. Fill soil: tan, brownish yellow, variegated, dense, slightly wet to moist, mainly composed of silt and clay, mainly distributed in roads, dams and the foundation of the Yellow River bank, with a layer thickness of about 0.0 to 13.0m.

[0004] In the clay and sandy soil layers in the middle and lower parts of the bridge site, ginger stones are developed and locally enriched into layers; in some parts, the strata are cemented into layers by sand and gravel, and the rock cores are mostly columnar or short columnar; some drill holes reveal boulders and boulders.

[0005] The strata along the Yellow River Bridge belong to the North China strata, and the strata revealed within the exploration depth range are alluvial and diluvial layers of the Quaternary Holocene (Q4) and Upper Pleistocene (Q3). The surface layer along the line is the Quaternary Holocene alluvial layer (Q4lal) of silt, silty clay, clay and silty fine sand, which are interlayered or lens-shaped, with silty silty clay in some parts. The thickness of this layer is generally 15.0-42.0m, and calcareous nodules are occasionally seen; below it is the Quaternary Upper Pleistocene alluvial layer (Q3al) of clay, silty clay, silt, silty fine sand, containing irregular calcareous nodules and iron-manganese nodules. The local calcareous nodule layer is enriched with a thickness of up to 30-40cm, and the thickness of this layer is greater than 50m. The surface layer from Mo'nan Township, Xian County to Shangqiu is distributed with silt, silty clay, clay and fine sand layers of the Quaternary Holocene Recent Sedimentary Layer (Q42al), which are interlayered or lens-shaped, and are partially interbedded with silty silty clay. The thickness of this layer is generally 6 to 23.1m. The surface layer of the Quaternary Holocene Artificial Accumulation Layer (Q4ml) is scattered along the line, including fill soil, miscellaneous fill soil and plain fill soil.

[0006] Traditional mud has problems such as poor fluidity, insufficient stability and strong corrosion to construction equipment in the construction of super-large bridges, and cannot fully meet the requirements of super-large bridge pier foundation construction. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a mud system for the construction of pile foundations of underwater piers of super-large bridges and a preparation method thereof, which can effectively improve the construction efficiency and safety during the construction of pile foundations of underwater piers of super-large bridges.

[0008] The technical solution of the present invention is:

[0009] A mud system for the construction of underwater pier pile foundations of a super-large bridge comprises the following components by weight: 12-20 parts of bentonite, 0.6-5 parts of sodium carbonate, 0.1-0.2 parts of an anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 70-90 parts of water.

[0010] When the geological layer for the construction of the underwater pier pile foundation of the super-large bridge is a pure soil geological layer, the mud system includes the following components in parts by weight: 11-13 parts of bentonite, 0.5-0.7 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 85-90 parts of water.

[0011] When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a silty clay geological layer, the mud system includes the following components in parts by weight: 11-13 parts of bentonite, 1-1.5 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 85-90 parts of water.

[0012] When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a semi-sand and semi-soil geological layer, the mud system includes the following components in weight proportions: 15-20 parts of bentonite, 1.5-2 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 80-85 parts of water.

[0013] When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a pure sandy geological layer, the mud system includes the following components in parts by weight: 15-20 parts of bentonite, 3-5 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 75-80 parts of water.

[0014] When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a rock geological layer, the mud system includes the following components in parts by weight: 20-25 parts of bentonite, 4-7 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 70-75 parts of water.

[0015] The sodium salt is sodium hydroxide.

[0016] A method for preparing a slurry system for construction of underwater pier pile foundations of a super-large bridge specifically comprises the following steps:

[0017] (1) Add clean water by weight into a stirrer, start the stirrer, keep the water flowing, then slowly add bentonite by weight and continue stirring until the bentonite is completely dissolved in the water to avoid agglomeration;

[0018] (2) While continuing to stir, gradually add sodium carbonate and carboxymethyl cellulose by weight to ensure that they are evenly dispersed and the mud is stable;

[0019] (3) While continuing to stir, add anti-chlorination agent by weight and stir again to make it evenly mixed;

[0020] (4) According to construction requirements, adjust the ratio of water to bentonite to achieve the mud entry index.

[0021] The mud inlet indexes are: mud specific gravity 1.1-1.3, viscosity 19-28 Pa·s, sand content not more than 4%, colloid rate not less than 95%, pH value greater than 6.5.

[0022] Advantages of the present invention:

[0023] The mud system for the construction of the underwater pier pile foundation of the super-large bridge prepared by the present invention has excellent fluidity and stability, shows good fluidity during the construction process, and ensures that the space required for the pier foundation is quickly filled; bentonite provides good adhesion and suspension; the addition of sodium carbonate can improve the stability and colloid rate of the mud and avoid the sedimentation of solid particles; carboxymethyl cellulose can increase the viscosity of the mud and improve the sand carrying capacity of the mud, thereby reducing the erosion and deposition of the well wall, and at the same time, cellulose can also absorb water molecules, reduce the loss of mud, maintain the stability of the mud, and further improve the rheological properties of the mud, so that the mud can better transport rock cuttings and waste residues underwater and reduce the resistance of the underground annulus; the use of anti-chlorination agents can effectively resist the corrosion of chloride ions in the Yellow River water to structural materials, effectively prolong the service life of the pile foundation structure, and reduce the maintenance cost. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0025] Example 1

[0026] When the geological layer for the construction of the pile foundation of the underwater pier of the super-large bridge is a pure soil geological layer, the mud system for the construction of the pile foundation of the underwater pier of the super-large bridge includes the following components in parts by weight: 12 parts of bentonite, 0.6 parts of sodium carbonate, 0.2 parts of anti-chlorination agent, 0.1 parts of carboxymethyl cellulose and 87.2 parts of water.

[0027] The preparation method of the mud system specifically comprises the following steps:

[0028] First, put clean water into the blender by weight, start the blender and keep the water flowing, then slowly add bentonite by weight and continue stirring to make the bentonite completely dissolved in the water to avoid agglomeration; then, while continuing to stir, gradually add sodium carbonate and carboxymethyl cellulose by weight to ensure that they are evenly dispersed. After the mud is stable, while continuing to stir, add anti-chlorination agent by weight and stir again to make it evenly mixed; finally, according to construction requirements, adjust the ratio of water to bentonite to achieve the mud entry index.

[0029] Example 2

[0030] When the geological layer for the construction of the pile foundation of the underwater pier of the super-large bridge is a silty clay geological layer, the mud system for the construction of the pile foundation of the underwater pier of the super-large bridge includes the following components in parts by weight: 12 parts of bentonite, 1 part of sodium carbonate, 0.2 parts of anti-chlorination agent, 0.1 parts of carboxymethyl cellulose and 86.7 parts of water.

[0031] The preparation method of the mud system is the same as that of Example 1.

[0032] Example 3

[0033] When the geological layer for the construction of the pile foundation of the underwater pier of the super-large bridge is a semi-sand and semi-soil geological layer, the mud system for the construction of the pile foundation of the underwater pier of the super-large bridge includes the following components in parts by weight: 15 parts of bentonite, 1.5 parts of sodium carbonate, 0.2 parts of anti-chlorination agent, 0.1 parts of carboxymethyl cellulose, 0.1 parts of sodium salt and 83.1 parts of water.

[0034] The preparation method of the mud system specifically comprises the following steps:

[0035] First, put clean water into the blender by weight, start the blender and keep the water flowing, then slowly add bentonite by weight and continue stirring to make the bentonite completely dissolved in the water to avoid agglomeration; then, while continuing to stir, gradually add sodium carbonate, carboxymethyl cellulose and sodium salt by weight to ensure that they are evenly dispersed. After the mud is stable, while continuing to stir, add anti-chlorination agent by weight and stir again to make it evenly mixed; finally, according to construction requirements, adjust the ratio of water to bentonite to achieve the mud entry index.

[0036] Example 4

[0037] When the geological layer for the construction of the pile foundation of the underwater pier of the super-large bridge is a pure sandy geological layer, the mud system used for the construction of the pile foundation of the underwater pier of the super-large bridge includes the following components in parts by weight: 18 parts of bentonite, 3 parts of sodium carbonate, 0.2 parts of anti-chlorination agent, 0.1 parts of carboxymethyl cellulose, 0.1 parts of sodium salt and 78.6 parts of water.

[0038] The preparation method of the mud system is the same as that of Example 3.

[0039] Example 5

[0040] When the geological layer for the construction of the pile foundation of the underwater pier of the super-large bridge is a rock geological layer, the mud system for the construction of the pile foundation of the underwater pier of the super-large bridge includes the following components in parts by weight: 20 parts of bentonite, 5 parts of sodium carbonate, 0.2 parts of anti-chlorination agent, 0.1 parts of carboxymethyl cellulose, 0.1 parts of sodium salt and 74.7 parts of water.

[0041] The preparation method of the mud system is the same as that of Example 3.

[0042] Mud detection and analysis:

[0043] The muds in Examples 1 to 5 were tested for mud indexes, and the test results are shown in Table 1 below.

[0044] Table 1

[0045]

[0046] The mud indicators in Table 1 all meet the mud entry indicators: mud specific gravity 1.1-1.3, viscosity 19-28 Pa·s, sand content not more than 4%, colloid rate not less than 95%, pH value greater than 6.5.

[0047] 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 slurry system for the construction of underwater pier pile foundations of a super-large bridge, characterized by: The invention comprises the following components by weight: 12-20 parts of bentonite, 0.6-5 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 70-90 parts of water.

2. The slurry system for construction of pile foundation of super-large bridge underwater pier according to claim 1, characterized in that: When the geological layer for the construction of the underwater pier pile foundation of the super-large bridge is a pure soil geological layer, the mud system includes the following components in parts by weight: 11-13 parts of bentonite, 0.5-0.7 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 85-90 parts of water.

3. The slurry system for construction of pile foundation of super-large bridge underwater pier according to claim 1, characterized in that: When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a silty clay geological layer, the mud system includes the following components in parts by weight: 11-13 parts of bentonite, 1-1.5 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose and 85-90 parts of water.

4. The slurry system for construction of pile foundation of super-large bridge underwater pier according to claim 1, characterized in that: When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a semi-sand and semi-soil geological layer, the mud system includes the following components in weight proportions: 15-20 parts of bentonite, 1.5-2 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 80-85 parts of water.

5. The slurry system for construction of pile foundation of super-large bridge underwater pier according to claim 1, characterized in that: When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a pure sandy geological layer, the mud system includes the following components in parts by weight: 15-20 parts of bentonite, 3-5 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 75-80 parts of water.

6. The slurry system for construction of pile foundation of super-large bridge underwater pier according to claim 1, characterized in that: When the geological layer for the construction of the underwater pier foundation of the super-large bridge is a rock geological layer, the mud system includes the following components in parts by weight: 20-25 parts of bentonite, 4-7 parts of sodium carbonate, 0.1-0.2 parts of anti-chlorination agent, 0.1-0.2 parts of carboxymethyl cellulose, 0.1-0.2 parts of sodium salt and 70-75 parts of water.

7. A slurry system for construction of pile foundation of a super-large bridge in water according to any one of claims 4 to 6, characterized in that: The sodium salt is sodium hydroxide.

8. The method for preparing a slurry system for construction of pile foundation of a super-large bridge in water according to claim 1, characterized in that: The specific steps include: (1) Add clean water by weight into a stirrer, start the stirrer, keep the water flowing, then slowly add bentonite by weight and continue stirring until the bentonite is completely dissolved in the water to avoid agglomeration; (2) While continuing to stir, gradually add sodium carbonate and carboxymethyl cellulose by weight to ensure that they are evenly dispersed and the mud is stable; (3) While continuing to stir, add anti-chlorination agent by weight and stir again to make it evenly mixed; (4) According to construction requirements, adjust the ratio of water to bentonite to achieve the mud entry index.

9. The preparation method according to claim 8, characterized in that: The mud inlet indexes are: mud specific gravity 1.1-1.3, viscosity 19-28 Pa·s, sand content not more than 4%, colloid rate not less than 95%, pH value greater than 6.5.

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