A device for reducing earth pressure transmission in bauxite stockpiles

Abstract

This utility model relates to the field of structural design and civil construction technology, and in particular to a device for reducing soil pressure transmission in a bauxite stockpile. The device includes a fixed unit, a sliding unit, and a rubber granule composite. The fixed unit is located on the side of the factory foundation. The top and bottom of the sliding unit are slidably connected to the fixed unit, and the hollow area formed by the sliding unit and the fixed unit is filled with the rubber granule composite. The device is installed between the bauxite stockpile and the factory foundation. When horizontal deformation of the soil is transmitted to the device, the sliding unit can move horizontally on the fixed unit, causing shear deformation of the rubber granule composite, absorbing most of the horizontal thrust, leaving only a small amount of force transmitted to the fixed unit, thus reducing the force transmitted to the fixed unit and consequently reducing the force on the factory foundation.

Description

Technical Field

[0001] This utility model relates to the field of structural design and civil construction technology, and in particular to a device for reducing soil pressure transmission in bauxite stockpiles. Background Technology

[0002] The bauxite stockpile workshop in the alumina project is one of the core production workshops in the entire aluminum plant. The main building of the bauxite stockpile workshop is a large-span space frame structure. The main equipment in the workshop is a stacker-reclaimer (gauge 30-45m), and auxiliary equipment includes belt conveyors. The maximum stockpile height in the workshop is approximately 20m, generating a ground load of approximately 280kPa (calculated based on γ=14kN / m³). Analysis using geotechnical finite element software shows that under large-area load, the soil below ground level will experience both vertical and horizontal displacements, with a horizontal displacement of 200-300mm at the top of the pile foundations under the columns of the workshop near the edge of the stockpile.

[0003] The foundations of stacker-reclaimers, space frames, and belt conveyors mostly use Φ800mm cast-in-place piles, with a designed vertical bearing capacity of approximately 5000kN, but the horizontal bearing capacity only reaches 10% of the vertical capacity (approximately 500kN). Finite element analysis results show that under a 280kPa ground load, the horizontal thrust at the top of a single pile is approximately 1200kN, far exceeding the horizontal bearing capacity of the pile foundation. In some projects, significant horizontal displacement of the foundations has led to excessive horizontal displacement of the retaining walls and stacker-reclaimer tracks, causing equipment malfunctions and posing safety hazards to the superstructure.

[0004] Based on the assessment of external loads and pile foundation bearing capacity, reducing the transmission of earth pressure to the plant's pile foundations is more rational and economical than simply increasing the pile foundation bearing capacity or the number of piles. This device is an effective means of reducing earth pressure transmission. Utility Model Content

[0005] To address the problems existing in the prior art, this utility model provides a device for reducing soil pressure transmission in bauxite stockpiles, thereby reducing the adverse effects of horizontal soil forces on building foundations under large-area loading, ensuring the structural safety of buildings and the stable operation of internal equipment.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A device for reducing soil pressure transmission in a bauxite stockpile includes a fixed unit, a sliding unit, and a rubber particle composite. The fixed unit is located on the foundation side of the plant. The top and bottom of the sliding unit are slidably connected to the fixed unit, and the hollow area formed by the fixed unit and the sliding unit is filled with the rubber particle composite.

[0007] The fixed unit includes a foundation slab and a fixed retaining wall. The foundation slab is fixedly connected above the concrete base slab, and the fixed retaining wall is fixedly connected above the foundation slab. The foundation slab and the fixed retaining wall are an integrated reinforced concrete structure.

[0008] The sliding unit includes a sliding retaining wall and a top plate. The top of the sliding retaining wall is fixedly connected to the top plate to form an L-shaped structure. The bottom of the sliding retaining wall is slidably connected to the foundation plate. The bottom of the free end of the top plate is slidably connected to the top of the fixed retaining wall. The sliding retaining wall and the top plate are an integrated reinforced concrete structure.

[0009] A PTFE sliding pad is provided at the connection between the top plate and the fixed retaining wall; a PTFE sliding pad is provided at the connection between the sliding retaining wall and the foundation plate, and the PTFE sliding pad extends a certain distance on the upper surface of the foundation plate towards the fixed retaining wall side.

[0010] A polystyrene foam board is provided between the top plate and the rubber particle composite.

[0011] The beneficial effects of this utility model are as follows: 1. The device of this utility model is set between the bauxite stockpile and the factory foundation. When the horizontal deformation of the soil is transmitted to the device of this utility model, the sliding unit can move horizontally on the fixed unit, which will cause the rubber particle composite to undergo shear deformation, absorb most of the horizontal thrust, and only a small amount of force is transmitted to the fixed unit, thereby reducing the force transmission to the fixed unit and thus reducing the force on the factory foundation.

[0012] 2. This utility model is not only applicable to bauxite stockpiles, but can also be extended to large coal yards, iron ore stockpiles, foundation protection of buildings in fill areas, and protection of existing structures near deep foundation pits. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a device for reducing soil pressure transmission in a bauxite stockpile according to the present invention. Figure 2 This is a cross-sectional view of the application of the bauxite stockpile reducing soil pressure transmission device of this utility model in a bauxite stockpile project. In the attached diagram, 1 is the fixed unit; 101 is the foundation plate; 102 is the fixed retaining wall; 2 is the sliding unit; 201 is the sliding retaining wall; 202 is the top plate; 3 is the rubber particle composite; 4 is the concrete base plate; 5 is the PTFE sliding pad; and 6 is the polystyrene foam board. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0015] like Figures 1-2 As shown, a device for reducing soil pressure transmission in a bauxite stockpile includes a fixed unit 1, a sliding unit 2, and a rubber particle composite 3. The fixed unit 1 is located on the foundation side of the plant. The top and bottom of the sliding unit 2 are slidably connected to the fixed unit 1, and the hollow area formed by the fixed unit 1 is filled with the rubber particle composite 3.

[0016] In this embodiment, the device is positioned between the bauxite stockpile and the factory foundation, within 2-4m of the factory foundation edge. It is used to absorb and reduce the transmission of surcharge earth pressure to the pile foundation and reduce the impact of horizontal displacement of the foundation soil on the structure. The fixed unit 1 is close to the factory foundation to protect it. The sliding unit 2 serves as the face facing the earth pressure under surcharge. The two units can slide between each other. The rubber particle composite 3 serves as a buffer area. When the horizontal deformation of the soil is transmitted to the sliding unit 2 of this invention, the sliding unit 2 can move horizontally on the fixed unit 1, causing the rubber particle composite to undergo shear deformation, absorbing most of the horizontal thrust, reducing the force transmission to the fixed unit 1, and thus reducing the force on the factory foundation.

[0017] In this embodiment, the width of the hollow area between the fixed unit 1 and the sliding unit 2 is 1000-2000mm, the particle size of the rubber particle composite 3 is 5-20mm, the density is 1.2-1.5g / cm³, and the rubber particle composite 3 needs to be compacted in layers (each layer ≤300mm), with a compaction coefficient >0.9.

[0018] The fixed unit 1 includes a foundation plate 101 and a fixed retaining wall 102. The foundation plate 101 is fixedly connected above the concrete base plate 4, and the fixed retaining wall 102 is fixedly connected above the foundation plate 101. The foundation plate 101 and the fixed retaining wall 102 are an integrated reinforced concrete structure.

[0019] In this embodiment, the foundation slab 101 and the fixed retaining wall 102 are fabricated on site. The foundation slab 101 is reserved with the fixed wall 102 reinforcement bars to form an integral whole with the foundation slab 101. The concrete section thickness and reinforcement are determined after calculation and analysis according to different working conditions. In this embodiment, the foundation slab 101 has a thickness of 500~800mm, and a graded sand and gravel cushion layer (thickness 300mm) is set at the bottom with a compaction coefficient ≥95%. The foundation slab 101 is equipped with a double-layer bidirectional steel mesh (Φ16@200), and a fixed retaining wall 102 with dowel bars (Φ16@150) is reserved at the top with an extension length ≥800mm. The fixed retaining wall 102 has a thickness of 400~600mm and is connected to the foundation slab 101 through the reserved dowel bars to form an integral load-bearing system. The fixed retaining wall 102 is reinforced with vertical main bars Φ16@150, horizontal distribution bars Φ12@200, and horizontal tie bars Φ8@600.

[0020] The sliding unit 2 includes a sliding retaining wall 201 and a top plate 202. The top of the sliding retaining wall 201 is fixedly connected to the top plate 202 to form an L-shaped structure. The bottom of the sliding retaining wall 201 is slidably connected to the foundation plate 101. The bottom of the free end of the top plate 202 is slidably connected to the top of the fixed retaining wall 102. The sliding retaining wall 201 and the top plate 202 are an integrated reinforced concrete structure. A polystyrene foam board (EPS) 6 is provided between the top plate 202 and the rubber particle composite 3 for sealing and as a permanent template during the pouring of the top plate 202. The polystyrene foam board (EPS) 6 is 100mm thick.

[0021] In this embodiment, the sliding retaining wall 201 and the top plate 202 are fabricated on site. A PTFE sliding pad 5 is set between the sliding retaining wall 201 and the foundation plate 101. The sliding retaining wall 201 is reserved for the top plate 202 reinforcement. After the rubber particle composite 3 in the middle area is filled, the top plate 202 is poured. The concrete section thickness and reinforcement are determined after calculation and analysis according to different working conditions. In this embodiment, the sliding retaining wall 201 has a thickness of 400~600mm, with vertical main reinforcement Φ14@150, horizontal distribution reinforcement Φ12@200, and horizontal tie reinforcement Φ8@600; the top slab 202 has a thickness of 300~500mm and is equipped with double-layer bidirectional reinforcement (Φ14@150). The reinforcement of the top slab 202 has pre-reserved dowel bars at the top of the sliding retaining wall 201 and is cast into one piece with the sliding retaining wall 201.

[0022] A PTFE sliding pad 5 is provided at the connection between the top plate 202 and the fixed retaining wall 102; a PTFE sliding pad 5 is provided at the connection between the sliding retaining wall 201 and the foundation plate 101, and the PTFE sliding pad 5 extends a distance on the upper surface of the foundation plate 101 toward the fixed retaining wall 102.

[0023] In this embodiment, before installing the PTFE sliding pad 5, the surface of the installation structure (top plate, fixed retaining wall, sliding retaining wall, foundation plate) needs to be cleaned to ensure that the flatness deviation is ≤2mm / 2m, the thickness of the PTFE sliding pad 5 is ≥3mm, the friction coefficient is ≤0.08, and the PTFE sliding pad 5 is sealed with polyurethane elastic sealant to prevent soil intrusion from affecting the sliding performance.

[0024] The basic working principle of this novel earth pressure transmission reduction mechanism is as follows: When bauxite stockpiling begins, as the stockpile height increases, the pressure on the soil below the stockpile area continuously increases. In the initial stage, the soil mainly undergoes elastic compression deformation, the pore volume shrinks, and the stress-settlement curve shows an approximately linear relationship. At this time, the soil particles do not undergo significant displacement, the deformation is small, and it increases linearly with the increase of load. When the load further increases, the shear stress in local areas exceeds the shear strength, and a plastic deformation zone appears. As the load continues to increase, the plastic zone expands, the deformation rate accelerates, and the stress-settlement curve becomes nonlinear. At this time, the soil still has a certain bearing capacity, but the plastic deformation is significant. Soil deformation develops in both vertical and horizontal directions. When the horizontal deformation of the soil is transmitted to the sliding retaining wall 201 of this utility model, since the sliding retaining wall 201 and the top plate 202 can move horizontally on the foundation plate 101 and the fixed retaining wall 102, the rubber particle composite 3 will undergo shear deformation, absorbing most of the horizontal thrust, and only 20%-30% of the force will be transmitted to the fixed retaining wall 102, thereby reducing the impact on the factory foundation.

[0025] The present invention was applied to a bauxite stockpile in an alumina plant (stockpile height 20m, γ=14kN / m³), and the comparison results with the traditional solution are as follows:

[0026] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for reducing earth pressure transmission in bauxite stockpiles, characterized in that, It includes a fixed unit, a sliding unit, and a rubber granule composite. The fixed unit is located on the foundation side of the factory building. The top and bottom of the sliding unit are slidably connected to the fixed unit, and the hollow area formed by the fixed unit and the sliding unit is filled with the rubber granule composite.

2. The bauxite stockpile earth pressure reduction device according to claim 1, characterized in that, The fixed unit includes a foundation slab and a fixed retaining wall. The foundation slab is fixedly connected above the concrete base slab, and the fixed retaining wall is fixedly connected above the foundation slab. The foundation slab and the fixed retaining wall are an integrated reinforced concrete structure.

3. The bauxite stockpile earth pressure reduction device according to claim 2, characterized in that, The sliding unit includes a sliding retaining wall and a top plate. The top of the sliding retaining wall is fixedly connected to the top plate to form an L-shaped structure. The bottom of the sliding retaining wall is slidably connected to the foundation plate. The bottom of the free end of the top plate is slidably connected to the top of the fixed retaining wall. The sliding retaining wall and the top plate are an integrated reinforced concrete structure.

4. The bauxite stockpile earth pressure reduction device according to claim 3, characterized in that, A PTFE sliding pad is provided at the connection between the top plate and the fixed retaining wall; a PTFE sliding pad is provided at the connection between the sliding retaining wall and the foundation plate, and the PTFE sliding pad extends a certain distance on the upper surface of the foundation plate towards the fixed retaining wall side.

5. A device for reducing earth pressure transmission in a bauxite stockpile according to claim 1, characterized in that, A polystyrene foam board is provided between the top plate and the rubber particle composite.

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