Structure for eliminating expansive force of cooling tower pool bottom plate and design method

Abstract

The invention discloses a structure for eliminating expansive force of a cooling tower pool bottom plate and a design method. The structure comprises a pile for bearing the column bottom load of a water spraying framework on the pool floor; the impermeable layer is arranged on the expansive soil foundation; an easily-compressed structural layer is arranged on the impermeable layer; and a cooling tower water pool bottom plate and a water spraying framework column are arranged on the easily-compressed structural layer. According to the characteristics and thickness of the expansive soil under the cooling tower pool floor, the dead weight of the pool floor and the water weight effect, the swelling deformation generated by water swelling of the expansive soil is calculated, meanwhile, the influence of the load in the construction period is considered, and the thickness of the needed easily-compressed structural layer is calculated; when the foundation expansive soil swells and deforms when encountering water, the expansive deformation is absorbed through the deformation of the easily-compressed structural layer, the expansive force is reduced, the expansive force is controlled within the counterforce of the bottom plate of the pool, and the effect of the expansive force on the bottom plate of the pool is eliminated; when the foundation expansive soil loses water and shrinks, the load of the pool bottom plate is borne by the piles. The problem that expansion and shrinkage circulation of the expansive soil foundation influences the pool bottom plate is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling tower design optimization and foundation treatment, and particularly relates to a structure and design method for eliminating the expansion force of the cooling tower pool bottom slab. Background Art

[0002] The pools of hyperbolic natural draft wet cooling towers and mechanical draft wet cooling towers are of open reinforced concrete structures. The water storage depth of the pools is generally 2 m. The columns of the cooling tower water spraying framework are placed on the pool bottom slab, and the spacing is 6 - 8 m. When the cooling tower is located in an expansive soil area, the swelling and shrinkage properties of the expansive soil will, on the one hand, cause swelling and shrinkage deformation of the foundation soil, and at the same time, structural cracks will be formed. Under the condition of dry-wet cycles, it is extremely easy to cause strength attenuation and a sharp reduction in bearing capacity. Therefore, when the soil layer is thick, pile foundations are generally used for foundation treatment, the pool bottom slab adopts a beam-slab structure, the load of the water spraying framework columns is directly transmitted to the piles, and the self-weight of the pool bottom slab and the weight of the water are transmitted to the piles through the floor beam-slab.

[0003] Since the water storage depth of the pool is only 2 m, the thickness of the pool bottom slab is generally 300 mm. The free swelling rate of the expansive soil is 40% - 100%, and the expansion force is 60 - 300 kPa. Since the pool bottom slab is prone to water seepage or leakage, which causes the expansive soil to expand and deform, the following two problems will occur: ① The sum of the self-weight of the pool bottom slab and the weight of the water on it is 30 kPa, which is far from being able to offset the upward expansion force under the pool bottom slab, resulting in cracking or even damage of the pool bottom slab, further leading to increased expansion. If the bearing capacity of the pool bottom slab is improved by increasing the thickness of the slab and the reinforcement, the higher the swelling grade, the greater the thickness of the slab, and the thickness can reach 600 - 700 mm, which is technically unreasonable and economically poor. ② The expansion force of the pool bottom slab is transmitted to the piles through the bottom slab beam. Since the bottom slab area is 36 - 64 m2, and the expansion force is calculated only at 130 kPa, the uplift force transmitted to the piles is 3600 - 6400 kN. After offsetting the load of the water spraying component columns, the piles still need to bear an uplift force of 1600 - 4400 kN, which is technically unreasonable.

[0004] Therefore, in view of the above problems, according to the structural characteristics of the cooling tower pool bottom slab, the load distribution characteristics, and the influence of the expansive soil, a structure for eliminating the expansion force of the expansive soil foundation of the cooling tower pool bottom slab is proposed. An anti-seepage layer is provided on the expansive soil foundation to reduce the seepage of water into the expansive soil. At the same time, an easily compressible structural layer is provided on the anti-seepage layer to eliminate the influence of the swelling deformation of the expansive soil below when it encounters water. When the expansive soil of the foundation swells and deforms when encountering water, the swelling deformation is absorbed through the deformation of the easily compressible structural layer, greatly reducing the expansion force and controlling the expansion force within the reaction force of the pool bottom slab, eliminating the action of the expansion force on the pool bottom slab; when the expansive soil of the foundation loses water and shrinks, the load of the pool bottom slab is borne by the piles. Based on the above structure, the calculation principle and design method are proposed. The problems of technical unreasonableness and poor economy are solved. Summary of the Invention

[0005] The object of the present invention is to provide a structure and design method for eliminating the expansion force of the cooling tower pool bottom slab in view of the above deficiencies, aiming to eliminate the expansion force of the expansive soil foundation under the pool bottom slab, ensuring the safety of the pool bottom slab and solving the problem of poor economy.

[0006] The present invention is achieved by the following solutions:

[0007] A structure for eliminating the expansion force of the cooling tower pool bottom slab includes piles that bear the bottom loads of the sprinkler framework columns on the pool floor; an anti-seepage layer provided on the expansive soil foundation; an easily compressible structural layer provided on the anti-seepage layer to eliminate the influence of the expansive soil under it from swelling and deforming when encountering water; and the sprinkler framework columns of the cooling tower pool bottom slab are provided on the easily compressible structural layer.

[0008] For the above disclosed structure, calculate the expansion deformation amount generated by the expansive soil swelling when encountering water according to the characteristics, thickness of the expansive soil under the cooling tower pool floor, and the self-weight and water weight of the pool bottom slab, and at the same time consider the influence of the construction period load to calculate the required thickness of the easily compressible structural layer; when the expansive soil in the foundation swells and deforms when encountering water, the expansion deformation is absorbed through the deformation of the easily compressible structural layer, greatly reducing the expansion force and controlling the expansion force within the reaction force of the pool bottom slab, eliminating the action of the expansion force on the pool bottom slab; when the expansive soil in the foundation shrinks due to water loss, the load of the pool bottom slab is borne by the piles. Solve the problem of the influence of the expansion and shrinkage cycle of the expansive soil foundation on the pool bottom slab.

[0009] Further, the anti-seepage layer provided on the expansive soil foundation in the present invention is preferably laid after improving the original soil excavated from the cooling tower and using lime to eliminate the expansibility. The anti-seepage layer includes a lime soil layer with a thickness of 200 - 400 mm, or non-expansive cohesive soil can also be used to reduce the seepage or leakage of water from the pool into the expansive soil foundation. When laying, compact the anti-seepage layer and level the top surface.

[0010] Further, the easily compressible structural layer used in the present invention can be laid with a variety of materials, which is not uniquely limited. Porous foam boards, cinder, loose sand and other easily compressible materials with large pores can be used for paving; when using porous foam boards for paving, sand can be used to level its top surface to facilitate the pouring of the plain concrete cushion layer of the pool reinforced concrete bottom slab.

[0011] Further, the compressive bearing capacity of the formed easily compressible structural layer is not less than 12 kPa, and the deformation modulus is less than 0.3 MPa;

[0012] Further, the thickness of the easily compressible structural layer used in the present invention is calculated and determined according to the characteristics, thickness of the expansive soil, and the self-weight and water weight of the pool bottom slab to calculate the expansion deformation amount generated by the expansive soil swelling when encountering water, and at the same time considering the influence of the construction period load.

[0013] Furthermore, the top pressure of the easily compressible structure layer used in the present invention is 30 kPa. The greater the swelling rate of the expansive soil, the thicker the layer thickness, and the layer thickness is 100 - 300 mm.

[0014] The above content discloses a structure for eliminating the expansive force of the expansive soil foundation of the cooling tower pool bottom slab. The present invention also discloses a design method for this kind of structure. Now, a specific description is given. A structure and design method for eliminating the expansive force of the expansive soil foundation of the cooling tower pool bottom slab includes:

[0015] According to the structural characteristics of the cooling tower pool bottom slab, the load distribution characteristics, and the influence of the expansive soil, determine the sharing principle of the load acting on the foundation treatment.

[0016] According to the characteristics, thickness, and mechanical parameters of the easily compressible structure layer, considering the self - weight of the pool bottom slab and the weight of water, calculate the thickness of the easily compressible structure layer.

[0017] Calculate and check the deformation amount of the pool bottom slab during the construction period. If the deformation amount meets the deformation requirements during the construction period, the easily compressible structure layer meets the requirements; otherwise, increase its thickness until the deformation requirements during the construction period are met.

[0018] Furthermore, in the method disclosed by the present invention, according to the structural characteristics of the cooling tower pool bottom slab, the load distribution characteristics, and the influence of the expansive soil, determine the sharing principle of the load acting on the foundation treatment; the load at the bottom of the sprinkler structure column on the cooling tower pool bottom slab is directly transmitted to the pile, and the 20 kPa water weight and self - weight on the pool bottom slab are transmitted to the pile through the bottom slab beam. The vertical load of the pile is large and can offset the action of the pile expansion force. By absorbing the expansion deformation through the easily compressible structure layer, the top pressure of the easily compressible structure layer can be controlled not to be greater than 30 kPa, the pool bottom slab does not bear the expansion force of the expansive soil foundation, and neither the pool bottom slab nor the pile is affected by the expansion force.

[0019] Furthermore, according to the characteristics, thickness, and mechanical parameters of the easily compressible structure layer, considering the self - weight of the pool bottom slab and the weight of water, calculate the thickness of the easily compressible structure layer according to the following formula:

[0020]

[0021] Δp = P z - 30000

[0022] ΔS1 = ΔS2

[0023]

[0024] Among them, h0 is the thickness of the easily compressible layer (m); e0 is the initial void ratio of the easily compressible layer; φ is the empirical coefficient for calculating the deformation amount of the expansive soil, and it is recommended to take 1.0; n is the number of expansive soil layers divided within the calculation depth from the bottom surface of the pool bottom slab. Considering the factors of pool leakage and the presence of an anti - seepage layer under the easily compressible layer, the calculation depth is taken as the depth of the atmospheric influence; δi The swelling rate of the i-th layer of soil under the pool bottom slab; h i is the thickness of the i-th layer of soil (m); α v is the compression coefficient of the easily compressible soil layer (Pa-1); p z is the swelling force (Pa).

[0025] Furthermore, calculate and check the deformation of the pool bottom slab during the construction period. The deformation during the construction period is calculated based on the self-weight of the pool bottom slab and the construction period load to calculate the foundation soil deformation (ΔS). The deformation during the construction period is less than L / 1000 (L is the calculated span of the slab).

[0026]

[0027] ΔS = ΔS3 + ΔS4

[0028] where, ΔS is the foundation soil deformation during the construction period (m); ΔS3 is the deformation of the easily compressible layer during the construction period (m); ΔS4 is the deformation of the soil layer within the calculated depth under the easily compressible layer during the construction period (m); α is an empirical coefficient, which can be taken as 0.3 - 0.54; b is the width of a single slab during construction, generally 6m; p is the construction period pressure, p can be taken as 10000Pa; E0 is the deformation modulus of the easily compressible layer (Pa); E1 is the comprehensive deformation modulus of the soil within the calculated depth of the foundation under the easily compressible layer (Pa), and the calculated depth is 0.5b.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0030] The present invention aims at the structural characteristics, load distribution characteristics of the cooling tower pool bottom slab and the influence of expansive soil, and at the same time considers the influence of the construction period load, and calculates the required thickness of the easily compressible structural layer; when the expansive soil in the foundation undergoes water swelling deformation, the swelling deformation is absorbed through the deformation of the easily compressible structural layer, greatly reducing the swelling force and controlling the swelling force within the reaction force of the pool bottom slab, eliminating the effect of the swelling force on the pool bottom slab; when the expansive soil in the foundation loses water and shrinks, the load of the pool bottom slab is borne by the piles. It solves the problem of the influence of the expansion and shrinkage cycle of the expansive soil foundation on the pool bottom slab. The structural materials of the present invention are easily available, the cost is low, and the design method is simple. If the pool bottom slab is used to bear the swelling force, the pool bottom slab needs to be thickened, but the depth of the pool is only 2m. Thickening the pool bottom slab is technically unreasonable, and at the same time, the engineering quantity of the pool bottom slab increases, and the load of the piles also needs to be increased. Calculated according to a 2×600MW unit power plant, it can save investment of tens of millions, solving the problems of technical unreasonableness and poor economy. It has great economic and safety significance. Description of the Drawings

[0031] Figure 1 is a partial typical plan layout diagram of the cooling tower pool bottom slab;

[0032] Figure 2It is a partial typical sectional view of the bottom slab of the cooling tower pool;

[0033] Figure 3 It is a process schematic diagram of the design method;

[0034] Markings in the figure: 1. Pile; 2. Impervious layer; 3. Easily compressible structural layer; 4. Bottom slab of the cooling tower pool; 5. Column of the water spraying framework. Specific implementation manners

[0035] All features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.

[0036] Any feature disclosed in this specification (including any additional claims, abstract) can be replaced by other equivalent or similar-purpose alternative features unless specifically stated. That is, unless specifically stated, each feature is only an example of a series of equivalent or similar features.

[0037] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined orientation, be constructed and operated in a predetermined orientation, and therefore should not be construed as a limitation to the present invention.

[0038] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0039] Embodiment 1

[0040] As Figure 1 shown, the present invention provides a technical solution:

[0041] Aiming at the problem that the swelling force of the expansive soil foundation of the bottom slab of the cooling tower pool is greater than the self-weight of the bottom slab and the water weight on it, resulting in poor economy, this embodiment discloses a structure for eliminating the swelling force of the expansive soil foundation of the bottom slab of the cooling tower pool to solve the above problem.

[0042] Specifically, the technical solution adopted in this embodiment is as follows:

[0043] A structure for eliminating the expansive force of the expansive soil foundation of the cooling tower pool bottom plate, comprising piles 1 that bear the loads at the bottom of the pool floor and the columns of the water spraying framework; an anti-seepage layer 2 provided on the expansive soil foundation; an easily compressible structural layer 3 provided on the anti-seepage layer to eliminate the influence of the expansive deformation of the expansive soil below when it encounters water; a cooling tower pool bottom plate 4 and water spraying framework columns 5 are provided on the easily compressible structural layer.

[0044] For the above disclosed structure, calculate the expansive deformation amount generated by the expansive soil when it encounters water according to the characteristics, thickness of the expansive soil under the cooling tower pool floor, and the self-weight of the pool bottom plate and the water weight, and at the same time consider the influence of the construction period load to calculate the required thickness of the easily compressible structural layer 3; when the expansive soil in the foundation encounters water and expands and deforms, the expansion deformation is absorbed through the deformation of the easily compressible structural layer 3, greatly reducing the expansive force and controlling the expansive force within the reaction force of the pool bottom plate 4, eliminating the action of the expansive force on the pool bottom plate; when the expansive soil in the foundation loses water and shrinks, the load of the pool bottom plate is borne by the piles 1. It solves the problem of the influence of the expansion and shrinkage cycle of the expansive soil foundation on the pool bottom plate 4.

[0045] In this embodiment, the anti-seepage layer 2 provided on the expansive soil foundation is preferably laid after improving the original soil excavated from the cooling tower, and lime is added to eliminate the expansibility. The anti-seepage layer includes a lime soil layer with a thickness of 200 - 400 mm, or non-expansive cohesive soil can also be used to reduce the seepage or leakage of the pool water into the expansive soil foundation. When laying, compact the anti-seepage layer and level the top surface.

[0046] In this embodiment, the easily compressible structural layer 3 can be laid with a variety of materials, which is not uniquely limited, and easily compressible materials with large pores such as porous foam boards, carbon slag, and loose sand can be used for paving; when using a porous foam board for paving, sand can be used to level its top surface to facilitate the pouring of the plain concrete cushion layer of the pool reinforced concrete bottom plate. The compressive bearing capacity of the paved easily compressible structural layer is not less than 12 kPa, and the deformation modulus is less than 0.3 MPa;

[0047] In this embodiment, the thickness of the easily compressible structural layer 3 is calculated and determined according to the characteristics, thickness of the expansive soil, and the self-weight of the pool bottom plate and the water weight to calculate the expansive deformation amount generated by the expansive soil when it encounters water, and at the same time considering the influence of the construction period load.

[0048] In this embodiment, the top pressure of the easily compressible structural layer 3 is 30 kPa. The greater the expansion rate of the expansive soil, the thicker the layer thickness, and the layer thickness is 100 - 300 mm.

[0049] Embodiment 2

[0050] Based on the structure of the above Embodiment 1, this solution provides a technical solution;

[0051] The content of the above embodiments discloses a structure for eliminating the expansive force of the expansive soil foundation of the cooling tower pool bottom slab. This embodiment discloses the design method of this kind of structure, and specific descriptions are as follows. A structure design method for eliminating the expansive force of the expansive soil foundation of the cooling tower pool bottom slab includes:

[0052] S01: Determine the sharing principle of the load acting on the foundation treatment according to the structural characteristics of the cooling tower pool bottom slab, the load distribution characteristics, and the influence of the expansive soil.

[0053] S02: Calculate the thickness of the easily compressible structural layer according to the characteristics, thickness of the expansive soil, and mechanical parameters of the easily shrinkable structural layer, considering the self-weight of the pool bottom slab and the weight of water.

[0054] S03: Calculate and check the deformation amount of the pool bottom slab during the construction period. If the deformation amount meets the deformation requirements during the construction period, the easily compressible structural layer meets the requirements; otherwise, increase its thickness until the deformation requirements during the construction period are met.

[0055] In the method disclosed in this embodiment, according to the structural characteristics of the cooling tower pool bottom slab, the load distribution characteristics, and the influence of the expansive soil, determine the sharing principle of the load acting on the foundation treatment; the column bottom load of the sprinkling structure column on the cooling tower pool bottom slab is directly transmitted to the pile, and the 20 kPa water weight and self-weight on the pool bottom slab are transmitted to the pile through the bottom slab beam. The vertical load of the pile is large, which can offset the action of the pile expansion force. By absorbing the expansion deformation through the easily compressible structural layer, the pressure on the top of the easily compressible structural layer can be controlled not to be greater than 30 kPa, and the pool bottom slab does not bear the expansion force of the expansive soil foundation, and neither the pool bottom slab nor the pile is affected by the expansion force.

[0056] According to the characteristics, thickness of the expansive soil, and mechanical parameters of the easily shrinkable structural layer, considering the self-weight of the pool bottom slab and the weight of water, calculate the thickness of the easily compressible structural layer according to the following formula:

[0057]

[0058] Δp = P z -30000

[0059] ΔS1 = ΔS2

[0060]

[0061] Among them, h0 is the thickness of the easily compressible layer (m); e0 is the initial void ratio of the easily compressible layer; φ is the empirical coefficient for calculating the deformation amount of the expansive soil, and it is recommended to take 1.0; n is the number of expansive soil layers divided within the calculation depth from the bottom surface of the pool bottom slab. Considering the factors of pool leakage and the presence of an anti-seepage layer under the easily compressible layer, the calculation depth is taken as the depth of atmospheric influence; δ i is the expansion rate of the i-th layer of soil under the pool bottom slab; h i is the thickness of the i-th layer of soil (m); α vis the compression coefficient of the easily compressible soil layer (Pa-1); p z is the swelling force (Pa).

[0062] Calculate and review the deformation of the pool bottom slab during the construction period. The deformation during the construction period is calculated as the foundation soil deformation (ΔS) based on the self-weight of the pool bottom slab and the construction period load. The deformation during the construction period is less than L / 1000 (L is the calculated span of the slab).

[0063]

[0064] ΔS = ΔS3 + ΔS4

[0065] Among them, ΔS is the foundation soil deformation during the construction period (m); ΔS3 is the deformation of the easily compressible layer during the construction period (m); ΔS4 is the deformation of the soil layer within the calculated depth below the easily compressible layer during the construction period (m); α is an empirical coefficient, which can be taken as 0.3 - 0.54; b is the width of a single slab during construction, generally 6m; p is the construction period pressure, and p can be taken as 10000Pa; E0 is the deformation modulus of the easily compressible layer (Pa); E1 is the comprehensive deformation modulus of the soil within the foundation calculated depth below the easily compressible layer (Pa), and the calculated depth is 0.5b.

[0066] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A structure for eliminating the expansion force of the bottom plate of a cooling tower pool, characterized in that: The invention comprises a pile (1) for bearing the column bottom load of a water sprinkling frame column (5) on the pool floor; an anti-seepage layer (2) arranged on an expansive soil foundation; a compressible structural layer (3) arranged on the anti-seepage layer to eliminate the influence of the expansive soil below it swelling and deforming when it encounters water; and a cooling tower pool bottom plate (4) and a water sprinkling frame column are arranged on the compressible structural layer.

2. The structure for eliminating the expansion force of the bottom plate of a cooling tower water pool according to claim 1, characterized in that: The anti-seepage layer (2) comprises a lime soil anti-seepage layer with a thickness of 200 to 400 mm.

3. The structure for eliminating the expansion force of the bottom plate of a cooling tower water pool according to claim 1, characterized in that: The easily compressible structural layer (3) is formed by paving with easily compressible materials such as porous foam boards, carbon slag or loose sand.

4. The structure for eliminating the expansion force of the bottom plate of a cooling tower water pool according to claim 1, characterized in that: The compressive bearing capacity of the easily compressible structural layer (3) is not less than 12 kPa, and the deformation modulus is less than 0.3 MPa.

5. The structure for eliminating the expansion force of the bottom plate of a cooling tower water pool according to claim 1, characterized in that: The thickness of the material of the easily compressible structural layer (3) is determined by calculating the expansion deformation of the expansive soil caused by the expansion of the expansive soil when it encounters water, based on the properties and thickness of the expansive soil and the deadweight of the pool bottom plate and the weight of water, while also taking into account the influence of the load during the construction period.

6. A structure for eliminating the expansion force of the bottom plate of a cooling tower water pool according to any one of claims 1 to 5, characterized in that: The top pressure of the easily compressible structural layer (3) is 30 kPa. The greater the expansion rate of the expansive soil, the thicker the layer thickness, and the layer thickness is 100 to 300 mm.

7. A structural design method for eliminating the expansion force of the bottom plate of a cooling tower pool, characterized in that: include: S01: Determine the load sharing principle for foundation treatment based on the structural characteristics of the cooling tower pool bottom plate, load distribution characteristics and the influence of expansive soil; S02: Based on the characteristics and thickness of the expansive soil and the mechanical parameters of the easily compressible structural layer, the thickness of the easily compressible structural layer is calculated taking into account the deadweight of the pool bottom plate and the weight of water; S03: Calculate and verify the deformation of the pool bottom plate during the construction period. If the deformation meets the deformation requirements during the construction period, the compressible structure layer meets the requirements; otherwise, increase its thickness until it meets the deformation requirements during the construction period.

8. A structural design method for eliminating the expansion force of the bottom plate of a cooling tower pool according to claim 7, characterized in that: According to the structural characteristics of the cooling tower pool bottom plate, load distribution characteristics and the influence of expansive soil, the load sharing principle of foundation treatment is determined; specifically, the bottom load of the sprinkler frame column on the cooling tower pool bottom plate is directly transmitted to the pile, and the 20kPa water weight and deadweight on the pool bottom plate are transmitted to the pile through the bottom plate beam. The pile has a large vertical load, which offsets the effect of the pile expansion force; the expansion deformation is absorbed by the compressible structural layer, and the top pressure of the compressible structural layer is controlled to be no more than 30kPa. The pool bottom plate does not bear the expansion force of the expansive soil foundation, and the pool bottom plate and piles are not affected by the expansion force.

9. A structural design method for eliminating the expansion force of a cooling tower pool bottom plate according to claim 7, characterized in that: According to the characteristics, thickness and mechanical parameters of the expansive soil and the easily compressible structural layer, the thickness of the easily compressible structural layer is calculated according to the following formula, taking into account the deadweight of the pool bottom plate and the weight of water: Δp=P z -30000 ΔS1=ΔS2 Wherein, h0 is the thickness of the easily compressible layer, in m; e0 is the initial porosity of the easily compressible layer; The empirical coefficient for calculating the deformation of expansive soil is taken as 1.0; n is the number of expansive soil layers from the bottom of the pool floor to the calculated depth. Considering the leakage of the pool and the anti-seepage layer under the compressible layer, the calculated depth is the atmospheric influence depth; δ i The expansion rate of the i-th layer of soil under the pool bottom plate; h i is the thickness of the i-th soil layer, in m; α v is the compression coefficient of the compressible soil layer, in Pa -1 ;p z It is the expansion force, and its unit is Pa.

10. A structural design method for eliminating the expansion force of a cooling tower pool bottom plate according to claim 7, 8 or 9, characterized in that: Calculate and verify the deformation of the pool bottom plate during the construction period. The deformation during the construction period is calculated based on the self-weight of the pool bottom plate and the load during the construction period. The deformation during the construction period is less than L / 1000, where L is the calculated span of the plate. ΔS=ΔS3+ΔS4 Among them, ΔS is the deformation of the foundation soil during the construction period, in m; ΔS3 is the deformation of the compressible layer during the construction period, in m; ΔS4 is the deformation of the soil layer within the calculated depth under the compressible layer during the construction period, in m; α is the empirical coefficient, which is 0.3~0.5; b is the width of a single plate during construction, which is 6~8m; p is the pressure during the construction period, which is 10000Pa; E0 is the deformation modulus of the compressible layer, in Pa; E1 is the comprehensive deformation modulus of the soil within the calculated depth of the foundation under the compressible layer, in Pa, and the calculated depth is 0.5b.

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