Solid waste light soil composite pile and construction method thereof

Abstract

The invention belongs to the technical field of civil construction engineering foundation treatment. The method comprises the following steps: mixing and stirring drilling slag or drilling mud, a curing agent, industrial waste and water in a stirring tank to form a primary mixture, adding a foaming agent into a foaming machine to prepare foam by adopting a pre-foaming method, adding the prepared foam into the stirring tank, mixing and stirring with the primary mixture to form solid waste light soil, injecting the solid waste light soil into a pre-drilling hole, and performing extrusion molding to obtain the solid waste light soil. And after the pile body is gradually hardened to form the solid waste light soil pile, the solid waste light soil pile is pressed into the concrete precast pile to the required depth after center positioning is completed through a pile pressing machine before initial setting of the solid waste light soil pile. The solid waste light soil has the advantages of being light in weight, high in strength, excellent in vibration isolation performance, economical, environmentally friendly and the like, industrial waste and muck and slurry generated by field excavation can be fully utilized, and environmental pollution is reduced. The concrete precast pile has high rigidity, and the technical advantages of being excellent in vibration isolation performance, high in bearing capacity, small in disturbance, environmentally friendly, low in carbon and the like can be achieved through organic combination of the two kinds of pile bodies.

Description

Technical Field

[0001] The invention belongs to foundation treatment of civil engineering and relates to a solid waste lightweight soil composite pile and a construction method thereof. Background Art

[0002] In my country, where the water system is well developed along the rivers and coasts, a large number of deep and soft soil foundations have been deposited, which has brought great challenges to engineering construction. Commonly used foundation treatment methods include replacement method, dynamic tamping method, cement soil mixing pile method, concrete precast pile, bored cast-in-place pile and expanded bottom pile. However, these technologies often have defects such as high cost, high noise, shallow reinforcement depth and limited bearing capacity. To this end, scientific researchers are exploring new construction technologies or solidifying materials to improve the effect of soft soil foundation treatment. "JCJ / T327-2014 Technical Specification for Rigid Composite Piles" proposes to combine two or three of loose piles, flexible piles (such as cement soil piles) and rigid piles (such as concrete precast piles or cast-in-place piles) to form a composite pile body. Compared with a single pile body, a composite pile has significant technical advantages. Among them, the rigid composite pile formed by combining cement soil piles and concrete precast piles can give full play to the advantages of high strength and large bearing capacity of concrete precast piles and large area of ​​cement soil piles through the coordinated deformation of the two piles. The two complement each other and have been widely used in the field of deep and soft soil foundation treatment. However, the solidifying materials of the outer pile body of this type of composite pile are mainly cement and lime, which consume high energy, emit large amounts of carbon dioxide, and cause serious environmental pollution during the production process.

[0003] In addition, the highway and railway transportation network has been subjected to the effects of traffic loads for a long time, and problems such as roadbed instability, uneven settlement, and cracking and deformation of pavement structures often occur, especially causing high-speed rail tracks to become uneven and produce violent vibrations. Vibration waves may cause secondary vibrations in buildings and structures along the railway, resulting in irreversible fatigue damage to the building structure and seriously interfering with the daily lives of surrounding residents. At the same time, the construction of new lines close to existing high-speed railway subgrades and widening projects needs to consider the impact of construction disturbances on existing railway subgrades. Therefore, it is urgent to seek foundation reinforcement technologies with superior vibration isolation performance, high bearing capacity, low disturbance, and green and low-carbon.

[0004] Solid waste lightweight soil has the advantages of light weight, high strength, excellent vibration isolation performance, economy and environmental protection. It can make full use of industrial waste, slag and mud generated by on-site excavation, reduce environmental pollution, and achieve the strategic goal of sustainable development of man and nature. Combining the shortcomings and problems of the current deep soft foundation composite pile technology and solid waste lightweight soil reinforcement technology, based on the current situation of rapid development of engineering construction in my country and the demand for solid waste resource utilization, how to form a new type of composite pile foundation with pile-soil synergy, high bearing capacity, excellent vibration isolation performance and green and low-carbon has become an important topic that the industry urgently needs to develop. Summary of the invention

[0005] The object of the present invention is to provide a solid waste lightweight soil composite pile and a construction method thereof, so as to solve the problems raised in the above background technology.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a solid waste lightweight soil composite pile and a construction method thereof, comprising: a solid waste lightweight soil pile and a precast concrete pile, wherein a precast concrete pile is arranged inside the solid waste lightweight soil pile.

[0007] Furthermore, the cross-section of the precast concrete piles includes solid circle, square, ring and plum blossom shapes; the precast concrete piles along the depth direction include: nail-shaped precast concrete piles, medium-shaped precast concrete piles and soil-shaped precast concrete piles; the solid waste lightweight soil composite piles along the depth direction include: nail-shaped solid waste lightweight soil piles, medium-shaped solid waste lightweight soil piles and soil-shaped solid waste lightweight soil piles.

[0008] Furthermore, a method for constructing a solid waste light soil composite pile comprises: a rotary drilling rig, a drill rod, a rotary drilling blade, a mixing tank, a control platform, a foaming agent, a foaming machine, a solid waste light soil pile, a control valve, a precast concrete pile, a pile driver, leveling a site, using a rotary drilling rig to arrange the solid waste light soil composite pile according to specific requirements, and determining the arrangement points, drilling holes at predetermined pile positions by using the rotary drilling rig, driving the retractable rotary drilling blade to drill holes to a designed depth by using the drill rod, collecting drilling residue or mud, and putting the drilling residue or drilling mud, curing agent, industrial waste and water into a mixing tank. The mixture is mixed and stirred to form a preliminary mixture. The pre-foaming method is adopted to add a foaming agent into a foaming machine to prepare foam. The prepared foam is added into a mixing tank and mixed and stirred with the preliminary mixture to form solid waste lightweight soil. An output pipe is arranged on the mixing tank, and a control valve is arranged on the output pipe. After the preparation of the solid waste lightweight soil in the mixing tank is completed, the control valve is opened, and the solid waste lightweight soil is injected into the pre-drilled hole through the control platform, and the pile body is waited to gradually harden to form a solid waste lightweight soil pile. Before the solid waste lightweight soil pile is initially solidified, the center positioning is completed by the pile driver and the precast concrete pile is pressed into the required depth.

[0009] Furthermore, the curing agent includes: quicklime, ordinary Portland cement, magnesium oxide cement, magnesium oxide, and fly ash Portland cement.

[0010] Furthermore, the industrial waste includes: blast furnace slag, fly ash, alkali slag, red mud, serpentine, the solid waste lightweight soil raw material components include: alkali slag lightweight soil, serpentine lightweight soil, magnesium oxide lightweight soil, and the solid waste lightweight soil raw materials include, by weight: 10-120 parts of curing agent, 70-120 parts of slag or mud, and 20-400 parts of water.

[0011] Furthermore, the foaming agent includes any one or more mixtures of synthetic surfactants, proteins, composites, and nano foaming agents.

[0012] Compared with the prior art, the present invention has the following advantages: (1) The solid waste lightweight soil used in the present invention has the advantages of being green and low carbon, lightweight and high strength, and having excellent vibration isolation performance. It can effectively consume accumulated industrial waste, construction site debris and drilling mud. The on-site treatment and utilization of debris and mud can save treatment and transportation costs, reduce project costs, and at the same time have important practical significance for environmental protection and sustainable development.

[0013] (2) Solid waste lightweight soil composite piles give full play to the technical characteristics of solid waste lightweight soil piles and concrete precast piles, complementing each other's advantages and combining rigidity and flexibility. They can not only ensure a high bearing capacity, but also effectively weaken and control vibration from the vibration transmission port, thereby achieving good vibration isolation performance.

[0014] (3) The construction of solid waste lightweight soil composite piles can effectively reduce the soil squeezing effect and reduce the impact of new roadbed construction on the existing roadbed in the construction of new lines close to existing high-speed railway subgrades and side widening projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the construction process flow chart of solid waste lightweight soil composite piles.

[0016] Figure 2 Schematic diagram of the cross-section of solid waste lightweight soil piles and precast concrete pile types.

[0017] Figure 3 It is a schematic diagram of the cross section of the concrete precast pile type.

[0018] Among them, 1. rotary drilling rig; 2. drill rod; 3. rotary drilling blade; 4. mixing tank; 5. control platform; 6. foaming agent; 7. foaming agent; 8. solid waste lightweight soil pile; 9. control valve; 10. precast concrete pile; 11. pile driver; 12. solid waste lightweight soil composite pile; 13. nail-shaped solid waste lightweight soil pile; 14. medium-shaped solid waste lightweight soil pile; 15. soil-shaped solid waste lightweight soil pile; 16. nail-shaped precast concrete pile; 17. medium-shaped precast concrete pile; 18. soil-shaped precast concrete pile; 19. solid circular section; 20. square section; 21. circular section; 22. X-shaped section. DETAILED DESCRIPTION

[0019] The present invention aims to address the deficiencies of the prior art and provide a solid waste lightweight soil composite pile and a construction method thereof, which is specifically achieved by the following technical solutions: Reference Figure 2 , Figure 3 A solid waste lightweight soil composite pile comprises: a solid waste lightweight soil pile 8 and a precast concrete pile 10. The precast concrete pile 10 is arranged inside the solid waste lightweight soil pile 8. The precast concrete pile 10 can enhance the overall strength of the solid waste lightweight soil composite pile 12.

[0020] Reference Figure 2 , Figure 3 The cross-section of the precast concrete pile 10 includes a solid circle 19, a square 20, a ring 21 and a plum blossom 22. The precast concrete pile 10 includes a nail-shaped precast concrete pile 16, a medium-shaped precast concrete pile 17 and a soil-shaped precast concrete pile 18 along the depth direction. The solid waste light soil pile 8 includes a nail-shaped solid waste light soil pile 13, a medium-shaped solid waste light soil pile 14 and a soil-shaped solid waste light soil pile 15 along the depth direction. The pile diameter ranges from 0.6m to 1.2m. In the roadbed reinforcement project, a pile cap can be arranged on the top of the pile as needed, and the pile cap is connected to the top of the precast concrete pile.

[0021] Reference Figure 1 A method for constructing a composite pile of solid waste and light soil comprises: a rotary drilling rig 1, a drill rod 2, a rotary drilling blade 3, a mixing tank 4, a control platform 5, a foaming agent 6, a foaming machine 7, a composite pile of solid waste and light soil 8, a control valve 9, a precast concrete pile 10, and a pile driver 11. The site is leveled, and the composite pile of solid waste and light soil is arranged according to specific requirements by using the rotary drilling rig 1, and the arrangement points of the piles are determined. The rotary drilling rig 1 is used to drill holes at predetermined pile positions, and the drill rod 2 drives the retractable rotary drilling blade 3 to drill holes to a designed depth. The rotary drilling blade is a retractable rotary drilling blade 3, and the blade length can be adjusted according to design requirements. The drilling residue or mud is collected, and the drilling residue or drilling mud, a curing agent, industrial waste and water are mixed and stirred in a mixing tank 4 to form a preliminary mixture. When the on-site pre-drilling process construction requires mud wall protection, and the generated drilling mud is used as the raw material of the preliminary mixture, the proportion of each raw material can be appropriately adjusted to meet the required strength requirements of the solid waste and light soil.

[0022] Reference Figure 1 , a pre-foaming method is adopted, and the foam is prepared by mixing the foaming agent and water according to a dilution multiple of 20-60 times, and the foam is prepared by a foaming machine 7 and a foaming agent 6. The foaming agent 6 is added to the foaming machine 7 to prepare the foam, and the prepared foam is added to the mixing tank 4, and mixed and stirred with the preliminary mixture to form a solid waste light soil. The mixing tank 4 is provided with an output pipe, and the output pipe is provided with a control valve 9. After the solid waste light soil is prepared in the mixing tank 4, the control valve 9 is opened, and the solid waste light soil is injected into the pre-drilled hole through the control platform 5, and the pile body is gradually hardened to form a solid waste light soil pile 8. Before the solid waste light soil pile is initially set, the pile driver 11 is used to complete the center positioning and press the concrete precast pile 10 to the required depth.

[0023] Curing agents include, but are not limited to, quicklime, ordinary Portland cement, magnesium oxide cement, magnesium oxide, and fly ash Portland cement.

[0024] Industrial waste includes but is not limited to: blast furnace slag, fly ash, alkali slag, red mud, serpentine, solid waste light soil raw material components include but are not limited to: alkali slag light soil, serpentine light soil, magnesium oxide light soil, solid waste light soil raw materials include by weight: 10-120 parts of curing agent, 70-120 parts of slag or mud and 20-400 parts of water. In actual projects, according to indoor tests and project requirements, the proportion of solid waste light soil can be flexibly adjusted to obtain solid waste light soil of different densities and strengths. The common density is generally 400-1600kg / m3, and the compressive strength is generally 0.5-2MPa.

[0025] The foaming agent 6 includes any one or more mixtures of synthetic surfactant, protein, composite and nano foaming agents.

[0026] Embodiment 1: Leveling the site and positioning the rotary drilling rig 1: Selecting a square pile layout form according to the design requirements to lay out the solid waste lightweight soil composite piles, and determining the pile layout points; Drilling a hole at a predetermined pile position by means of a rotary drilling rig 1, the hole diameter being 800 mm and the hole depth being 12 m, and collecting the drilled soil into a mixing tank 4; Preparation of solid waste lightweight soil: Alkali slag lightweight soil in solid waste lightweight soil is used, and the raw materials of alkali slag lightweight soil are piled up every 50m, and alkali slag lightweight soil with a wet density of 500-900kg / m3 and a flow value of 200mm is prepared according to the proportion. First, the rotary excavation slag is collected and crushed through a 5-10mm sieve, and mixed evenly with alkali slag, silicate cement and blast furnace slag mixed in a mass ratio of 3:4:3 in a mixing tank 4, and tap water is added according to a water-solid ratio of 0.5-0.7 to stir into slurry; then the polymer composite foaming agent 6 is diluted with water at a ratio of 1:100 to form a foaming liquid, and foam is prepared using a foaming machine 7 and the foaming liquid, and the foam is injected into the slurry and mixed evenly to form solid waste lightweight soil.

[0027] Solid waste light soil pile construction: open the control valve 9, inject the solid waste light soil into the pre-drilled hole through the control platform 5, and wait for the pile body to gradually harden to form a solid waste light soil pile 8; Construction of solid waste light soil composite piles: Before the solid waste light soil piles are initially set, a prefabricated concrete pipe pile with an inner diameter of 95 mm and an outer diameter of 400 mm is pressed into the pile driver 11 after completing the center positioning, and a construction operation of a solid waste light soil composite pile 12 is completed; Repeat steps ae until all solid waste lightweight soil composite piles are constructed.

[0028] Embodiment 2: Leveling the site and positioning the rotary drilling rig 1: Selecting a plum blossom-shaped pile arrangement form according to design requirements to arrange the solid waste lightweight soil composite piles, and determining the pile arrangement points; Drill holes at the predetermined pile positions by means of a rotary drilling rig 1, with the upper hole diameter being 1000 mm and the depth being 4 m, and the lower hole diameter being 600 mm and the depth being 8 m, and collecting the drilled soil into a mixing tank 4; Preparation of solid waste lightweight soil: Serpentine lightweight soil is used in solid waste lightweight soil. Serpentine lightweight soil raw materials are piled up every 50m to prepare solid waste lightweight soil with a wet density of 600-1000kg / m3 and a flow value of 200mm according to the proportion. First, the rotary excavation slag is collected and crushed through a 5mm sieve. The slag, ground serpentine powder and lightweight magnesium oxide are mixed evenly in a stirring device at a mass ratio of 3:3.5:3.5, and tap water is added at a water-solid ratio of 0.5-0.7 to stir into slurry; then the special cement foaming agent 6 is diluted with water at a ratio of 1:40 to form a foaming liquid, and foam is prepared using a foaming machine 7 and the foaming liquid, and the foam is injected into the slurry and mixed evenly to form solid waste lightweight soil.

[0029] Solid waste light soil pile construction: open the control valve 9, inject the solid waste light soil slurry into the pre-drilled hole through the control platform 5, and wait for the pile body to gradually harden to form a solid waste light soil pile 13; Solid waste lightweight soil composite pile construction: before the solid waste lightweight soil pile is initially set, a prefabricated concrete square pile with a side length of 400 is pressed into place by a pile driver 11 after completing center positioning, and a solid waste lightweight soil composite pile 12 is constructed; Repeat steps ae until all the solid waste lightweight soil composite piles 12 are constructed.

Claims

1. A solid waste lightweight soil composite pile, characterized in that: include: Solid waste lightweight soil piles (8), precast concrete piles (10), A prefabricated concrete pile (10) is arranged inside the solid waste lightweight soil pile (8).

2. The solid waste lightweight soil composite pile according to claim 1, characterized in that: The cross-sections of the precast concrete piles (10) include solid round, square, annular and plum blossom shapes. The precast concrete piles (10) include nail-shaped precast concrete piles, medium-shaped precast concrete piles and soil-shaped precast concrete piles along the depth direction. The solid waste light soil piles (8) include, along the depth direction, nail-shaped solid waste light soil piles, medium-shaped solid waste light soil piles and soil-shaped solid waste light soil piles.

3. A solid waste lightweight soil composite pile construction method, characterized in that: include: Rotary drilling rig (1), drill rod (2), rotary drilling blade (3), mixing tank (4), control platform (5), foaming agent (6), foaming machine (7), solid waste lightweight soil pile (8), control valve (9), precast concrete pile (10), pile driver (11), Level the site, use a rotary drilling rig (1) to lay out the solid waste lightweight soil composite piles according to specific requirements, and determine the pile placement points. A hole is drilled at a predetermined pile position by a rotary drilling rig (1), a retractable rotary drilling blade (3) is driven by a drill rod (2) to drill the hole to a designed depth, and drilling residue or mud is collected. Drilling cuttings or drilling mud, a curing agent, industrial waste and water are mixed and stirred in a mixing tank (4) to form a preliminary mixture. A pre-foaming method is adopted, wherein a foaming agent (6) is added to a foaming machine (7) to prepare foam, and the prepared foam is added to a mixing tank (4) and mixed with a preliminary mixing material to form a solid waste lightweight soil. The mixing tank (4) is provided with an output pipe, and the output pipe is provided with a control valve (9). After the solid waste light soil is prepared in the mixing tank (4), the control valve (9) is opened, and the solid waste light soil is injected into the pre-drilled hole through the control of the control platform (5), and the pile body is gradually hardened to form a solid waste light soil pile (8). Before the solid waste lightweight soil pile is initially set, the pile driver (11) completes the center positioning and then drives the precast concrete pile (10) into place to a desired depth.

4. The solid waste lightweight soil composite pile construction method according to claim 3 is characterized in that: Curing agents include: Quicklime, ordinary Portland cement, magnesium oxide cement, magnesium oxide, fly ash Portland cement.

5. The solid waste lightweight soil composite pile and construction method thereof according to claim 3, characterized in that: Industrial waste includes: blast furnace slag, fly ash, alkali residue, red mud, serpentine, Solid waste light soil raw material components include: alkali residue light soil, serpentine light soil, magnesium oxide light soil, The solid waste lightweight soil raw material includes, by weight: 10-120 parts of a curing agent, 70-120 parts of slag or mud, and 20-400 parts of water.

6. The solid waste lightweight soil composite pile and construction method thereof according to claim 3, characterized in that: The foaming agent (6) includes any one or more mixtures of synthetic surfactants, proteins, composites, and nano foaming agents.

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