Island reef coral filler compaction pile and construction method thereof

Abstract

The application provides an island reef coral filler compaction pile and a construction method thereof. The construction method of the island reef coral filler compaction pile comprises the following steps: (1) using a weight to hammer the ground soil body to form a cylindrical hole; (2) first filling mixed sand and stone into the hole, the mixed sand and stone is composed of coral reef gravel and calcareous sand, then pouring a microbial curing liquid and a composite additive, the microbial curing liquid is composed of a composite bacterial liquid and seawater, the composite bacterial liquid is prepared from bacillus pasteurii, bacillus cereus and bacillus mucilaginosus, and the composite additive is composed of hydroxyl citronellal and eucalyptol; then using the weight to ram the filler; (3) repeating step (2) to ram and fill the pile hole to the ground to form the compaction pile. The construction method can significantly improve the quality of the compaction pile, significantly improve the single pile bearing capacity, and effectively reduce the relative usage amount of the microbial curing liquid.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of compaction piles, in particular to an island coral filler compaction pile and a construction method thereof. BACKGROUND

[0002] Coral gravel is light and porous, and has strong water absorption. It is a natural aggregate, and its main mineral components are aragonite and calcite, with a CaCO3 content of more than 96%, which belongs to high-quality gravel aggregate. Calcareous sand is mainly formed by the remains of marine organisms such as shells and algae through physical, chemical and biological processes, and its main component is carbonate sediment, with a CaCO3 content of more than 95%. The environment of islands and reefs is relatively complex, including long-term corrosion of seawater, complex geological structure characteristics, and various extreme environmental conditions. The untreated calcareous sand foundation may produce excessive settlement deformation, uneven settlement and sand liquefaction under complex geological environmental conditions, and cannot be directly used for engineering construction. The MICP (Microbial Induced Carbonate Precipitation) technology generally needs to consume more than one time of the volume of the corresponding raw material of microbial solidification liquid, and the quality of the compaction pile made by the traditional construction method needs to be improved. SUMMARY

[0003] Therefore, the present application provides an island coral filler compaction pile and a construction method thereof. The construction method of the present application can greatly reduce the relative use amount of microbial solidification liquid, significantly improve the single pile bearing capacity, and comprehensively improve the quality of the compaction pile.

[0004] The technical scheme of the present application is as follows:

[0005] A construction method of an island coral filler compaction pile, comprising the following steps:

[0006] (1) hammering the ground soil body with a heavy hammer to form a cylindrical hole;

[0007] (2) filling mixed sandstone into the hole, the mixed sandstone being composed of coral reef gravel and calcareous sand, then pouring microbial solidification liquid and composite additives, the microbial solidification liquid being composed of composite bacterial liquid and seawater, the composite bacterial liquid being prepared from Bacillus pasteurii, Bacillus cereus and Bacillus mucilaginosus, and the composite additives being composed of hydroxy citronellal and eucalyptol; and then tamping the filler with the heavy hammer;

[0008] (3) repeating step (2) to tamp and fill the pile hole to the ground to form a compaction pile.

[0009] Further, in step (1), the heavy hammer has a diameter of 200-600 mm, a length of 1-5 m, and a weight of 1.5-3.5 tons.

[0010] Further, in step (2), the viable bacterial concentration of the complex bacterial solution is (8-10) x 10 9 cfu / g.

[0011] Further, in step (2), the viable bacterial quantity ratio of Bacillus pasteurii, Bacillus cereus and Bacillus mucilaginosus in the complex bacterial solution is 0.5-1.5:2-4:5-7.

[0012] Further, in step (2), the mass ratio of the complex auxiliary agent prepared from the mixture of the medium-hydroxy citronellal and the eucalyptol is 0.7-0.8:0.2-0.3.

[0013] Further, in step (2), the mass ratio of the coral reef crushed stone and the calcareous sand in the mixed sandstone is 1:1.5-2.5.

[0014] Further, in step (2), the volume ratio of the mixed sandstone and the microbial solidification liquid is 1:0.4-0.6.

[0015] Further, in step (2), the volume ratio of the mixed sandstone and the complex auxiliary agent is 1:0.1-0.2.

[0016] Further, in step (2), the volume ratio of the microbial solidification liquid and the seawater is 1:2.5-3.5.

[0017] An island reef coral filler compaction pile is prepared by the method of any one of the present application.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] (1) The construction method of the present application not only greatly reduces the relative use amount of the microbial solidification liquid, but also significantly improves the single pile bearing capacity and the compaction pile quality.

[0020] (2) The compaction pile prepared by the present application uses coral reef crushed stone as coarse aggregate and calcareous sand as fine aggregate, and adopts the complex bacterial solution of Bacillus pasteurii, Bacillus cereus and Bacillus mucilaginosus to better promote the crystallization and precipitation of calcium carbonate, effectively improve the cementation effect, improve the strength of the compaction pile, and greatly reduce the use amount of the microbial solidification liquid by adding the complex auxiliary agent prepared from the mixture of the medium-hydroxy citronellal and the eucalyptol, so that the compaction pile quality and the single pile bearing capacity are significantly improved, and the durability in the marine environment is improved.

[0021] (3) Under the impact of the tamping hammer, the coarse aggregate of coral gravel and the fine aggregate of calcareous sand are fully compacted. At the same time, the microbial solidification liquid and composite additives are also fully mixed with the aggregate. The composite bacteria continuously cement the coral aggregate and the surrounding calcareous sand strata during the metabolism process, so that the strength of the single pile can be greatly improved in the later stage. The high temperature generated by the hammer is conducive to the growth of microorganisms, which helps to avoid uneven settlement.

[0022] (4) The compaction piles produced by this invention have a high single pile bearing capacity and have very high application value; the construction method is simple and easy to implement, with a high construction quality assurance rate; the construction efficiency is high, the construction period is short, and the speed is fast.

[0023] (5) No mud is generated during the construction process. Coral reef gravel and calcareous sand are used as raw materials, which turns waste into treasure, is environmentally friendly, and saves project costs. Detailed Implementation

[0024] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0025] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0026] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0027] The hammer used in this embodiment of the invention has a diameter of 400mm, a length of 3m, and a weight of 2.5 tons.

[0028] Example 1

[0029] A construction method for coral filler compaction piles for islands and reefs includes the following steps:

[0030] (1) Clean and level the site; lay out and verify the construction lines; check and debug the construction equipment; position the pile driver so that the center of the hammer is aligned with the center of the pile position; hammer to form a hole, lift the hammer and let it fall freely to impact the foundation soil to form a hole to the design depth (15m); use the hammer to hammer the foundation soil to form a cylindrical hole.

[0031] (2) First fill the hole with 0.2m 3 The mixture consists of coral reef gravel and calcareous sand in a mass ratio of 1:2.0, then a microbial solidification solution and a composite additive are added, with a volume ratio of 1:0.5:0.15. The microbial solidification solution consists of a composite bacterial solution and seawater in a volume ratio of 1:3.0, with a viable bacteria concentration of 10. 10cfu / g, the complex bacteria liquid is prepared from Bacillus pasteurii, Bacillus cereus and Bacillus mycoides, the ratio of the number of live bacteria of the three is 1:3:6; the complex additive is composed of hydroxy citronellal and eucalyptol with a mass ratio of 0.75:0.25; and the fillers are rammed by the weight again.

[0032] (3) Repeat step (2) to ram the pile hole to the ground to form the compaction pile.

[0033] Example 2

[0034] A construction method of an island reef coral filler compaction pile, comprising the following steps:

[0035] (1) clean and level the site; perform construction line laying and line checking; check and debug the construction equipment; position the pile machine so that the center of the weight is aligned with the center of the pile site; hammer to form a hole, lift the weight, and let it fall freely to impact the ground soil to form a hole to the designed depth (15 m); form a cylindrical hole by hammering the ground soil with the weight;

[0036] (2) fill 0.2 m 3 of mixed sand and gravel, which is composed of coral reef gravel and calcareous sand with a mass ratio of 1:2.0, into the hole, then pour microbial curing liquid and complex additive, and mix the mixed sand and gravel, the microbial curing liquid, and the complex additive at a volume ratio of 1:0.4:0.2; the microbial curing liquid is composed of complex bacteria liquid and seawater at a volume ratio of 1:3.0, and the live bacteria concentration of the complex bacteria liquid is 10 10 cfu / g, the complex bacteria liquid is prepared from Bacillus pasteurii, Bacillus cereus and Bacillus mycoides, the ratio of the number of live bacteria of the three is 1:4:5; the complex additive is composed of hydroxy citronellal and eucalyptol with a mass ratio of 0.7:0.3; and the fillers are rammed by the weight again.

[0037] (3) Repeat step (2) to ram the pile hole to the ground to form the compaction pile.

[0038] Example 3

[0039] A construction method of an island reef coral filler compaction pile, comprising the following steps:

[0040] (1) clean and level the site; perform construction line laying and line checking; check and debug the construction equipment; position the pile machine so that the center of the weight is aligned with the center of the pile site; hammer to form a hole, lift the weight, and let it fall freely to impact the ground soil to form a hole to the designed depth (15 m); form a cylindrical hole by hammering the ground soil with the weight;

[0041] (2) fill 0.2 m 3The mixed sandstone is composed of coral reef gravel and calcareous sand with a mass ratio of 1:2.0, and then the microbial curing liquid and the composite additive are poured into the mixed sandstone, and the volume ratio of the mixed sandstone, the microbial curing liquid and the composite additive is 1:0.6:0.1; the microbial curing liquid is composed of the composite bacterial liquid and seawater with a volume ratio of 1:3.0, and the viable bacterial concentration of the composite bacterial liquid is 10 10 cfu / g, the composite bacterial liquid is prepared from Bacillus pasteurii, Bacillus cereus and Bacillus mycoides, and the viable bacterial quantity ratio of the three is 1:2:7; the composite additive is composed of hydroxyl citronellal and eucalyptol with a mass ratio of 0.8:0.2; and then the filler is rammed by using the weight.

[0042] (3) Repeat step (2) to ram the pile hole to the ground to form the compaction pile.

[0043] Comparative Example 1

[0044] A construction method of an island reef coral filler compaction pile, based on Example 1, the construction method is adjusted, the difference lies in that the composite bacterial liquid is not used, only a single Bacillus pasteurii liquid is used.

[0045] Comprising the following steps:

[0046] (1) Clean and level the site; carry out construction line laying and line checking; check and debug the construction equipment; position the pile driver so that the center of the weight is aligned with the center of the pile site; hammer to form a hole, lift the weight and let it fall freely, impact the ground soil to form a hole to the designed depth (15 m); form a cylindrical hole by hammering the ground soil with the weight;

[0047] (2) Fill the mixed sandstone into the hole first, the mixed sandstone is composed of coral reef gravel and calcareous sand with a mass ratio of 1:2.0, and then pour the microbial curing liquid and the composite additive into the mixed sandstone, and the volume ratio of the mixed sandstone, the microbial curing liquid and the composite additive is 1:0.5:0.15; the microbial curing liquid is composed of the Bacillus pasteurii liquid and seawater with a volume ratio of 1:3.0, and the viable bacterial concentration of the Bacillus pasteurii liquid is 10 10 cfu / g, the composite additive is composed of hydroxyl citronellal and eucalyptol with a mass ratio of 0.75:0.25; and then the filler is rammed by using the weight;

[0048] (3) Repeat step (2) to ram the pile hole to the ground to form the compaction pile.

[0049] Comparative Example 2

[0050] A construction method of an island reef coral filler compaction pile, based on Example 1, the construction method is adjusted, the difference lies in that the hydroxyl citronellal and the eucalyptol are replaced by calcium chloride and urea respectively.

[0051] (1) clean up and level the site; carry out construction line and check line; check and debug construction equipment; pile machine in place, make the center of the heavy hammer align with the center of the pile site; hammer into a hole, lift the heavy hammer and let it fall freely, impact the foundation soil to form a hole to the design depth (15m); use the heavy hammer to hammer the foundation soil to form a cylindrical hole;

[0052] (2) fill 0.2m 3 mixed sand and gravel, the mixed sand and gravel is composed of coral reef gravel and calcareous sand with a mass ratio of 1:2.0, then pour microbial curing liquid and composite additive, the volume ratio of mixed sand and gravel, microbial curing liquid and composite additive is 1:0.5:0.15; the microbial curing liquid is composed of composite bacterial liquid and seawater with a volume ratio of 1:3.0, the viable bacterial concentration of the composite bacterial liquid is 10 10 cfu / g, the composite bacterial liquid is prepared from bacillus pasteurii, bacillus cereus and bacillus mucilaginosus, the viable bacterial quantity ratio of the three is 1:3:6; the composite additive is composed of calcium chloride and urea with a mass ratio of 0.75:0.25; then use the heavy hammer to ram the fillers;

[0053] (3) repeat step (2), ram the pile hole to the ground to form a compacted pile.

[0054] Comparative example

[0055] A construction method of island reef coral filler compacted pile, based on example 1, adjust the construction method, the difference lies in: without using composite bacterial liquid, directly using bacillus pasteurii liquid, and the use amount of bacillus pasteurii liquid is equal to the volume of mixed sand and gravel; also without adding composite additive.

[0056] (1) clean up and level the site; carry out construction line and check line; check and debug construction equipment; pile machine in place, make the center of the heavy hammer align with the center of the pile site; hammer into a hole, lift the heavy hammer and let it fall freely, impact the foundation soil to form a hole to the design depth, the depth of this example is 15m; use the heavy hammer to hammer the foundation soil to form a cylindrical hole;

[0057] (2) fill 0.2m 3 mixed sand and gravel, the mixed sand and gravel is composed of coral reef gravel and calcareous sand with a mass ratio of 1:2.0, then pour microbial curing liquid, the volume ratio of mixed sand and gravel and microbial curing liquid is 1:1; the microbial curing liquid is composed of bacillus pasteurii liquid and seawater with a volume ratio of 1:3.0, the viable bacterial concentration of bacillus pasteurii liquid is 10 10 cfu / g; then use the heavy hammer to ram the fillers;

[0058] (3) repeat step (2), ram the pile hole to the ground to form a compacted pile.

[0059] Test examples

[0060] The test was carried out on the island, and the single pile bearing capacity of the compaction pile formed according to Examples 1-3 and Comparative Examples 1-2 was tested respectively, and compared with the control example, and the single pile bearing capacity improvement rate was calculated. According to the Technical Code for Detection of Building Foundation Pile (JGJ106-2014), the single pile vertical compression static load test was carried out. The single pile bearing capacity improvement rate = (the single pile vertical bearing capacity of the compaction pile formed according to the examples or comparative examples - the single pile vertical bearing capacity of the compaction pile formed according to the control example) / the single pile vertical bearing capacity of the compaction pile formed according to the control example × 100%.

[0061] The results are shown in Table 1 below:

[0062] Table 1: Results of single pile vertical compression static load test

[0063]

[0064] As can be seen from Table 1, the single pile bearing capacity of the compaction pile obtained according to the construction methods of Examples 1-3 and Comparative Examples 1-2 is improved. Among them, the single pile bearing capacity improvement rate of Example 1-3 is relatively obvious. The construction method of the present application can not only effectively and significantly improve the single pile bearing capacity of the compaction pile, but also greatly reduce the use amount of microbial solidification liquid.

[0065] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method of an island coral fill compaction pile, characterized by, The method comprises the following steps: (1) hammering the ground body with a heavy hammer to form a cylindrical hole; (2) filling mixed sand and stone into the hole, wherein the mixed sand and stone is composed of coral reef gravel and calcareous sand, pouring composite additives and microbial curing liquid, wherein the microbial curing liquid is composed of composite bacterial liquid and seawater, the composite bacterial liquid is prepared from Bacillus pasteurii, Bacillus cereus and Bacillus mucilaginosus, and the composite additives are composed of hydroxyl citronellal and eucalyptol; and then ramming the fillers with the heavy hammer; (3) repeating step (2) to ram the pile hole to the ground to form a compacted pile; In step (2), the ratio of the viable bacterial quantity of Bacillus pasteurii, Bacillus cereus and Bacillus mucilaginosus in the composite bacterial liquid is 0.5-1.5:2-4:5-7; In step (2), the mass ratio of hydroxyl citronellal and eucalyptol in the composite additives is 0.7-0.8:0.2-0.

3.

2. The construction method of the island coral filler compaction pile according to claim 1, characterized in that, In step (1), the diameter of the heavy hammer is 200-600 mm, the length is 1-5 m, and the weight is 1.5-3.5 tons.

3. The method of constructing an island-coral fill compaction pile according to claim 1, characterized in that, In step (2), the viable cell concentration of the complex bacteria solution is (8-10) x 10 9 cfu / g.

4. The method of constructing an island-coral fill compaction pile according to claim 1, characterized in that, In step (2), the mass ratio of coral reef gravel and calcareous sand in the mixed sand and stone is 1:1.5-2.

5.

5. The method of constructing an island-coral fill compaction pile according to claim 1, wherein, In step (2), the volume ratio of the mixed sand and stone to the microbial curing liquid is 1:0.4-0.

6.

6. The method of constructing an island-coral fill compaction pile according to claim 1, wherein, In step (2), the volume ratio of the mixed sand and stone to the composite additives is 1:0.1-0.

2.

7. The method of constructing an island-coral fill compaction pile according to claim 1, wherein In step (2), the volume ratio of the bacterial liquid to seawater in the microbial curing liquid is 1:2.5-3.

5.

8. An island reef coral infill compaction pile characterized by, The compacted pile is prepared by the method of any one of claims 1-7.

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