A greening assembled retaining wall and its structural design method

Abstract

The present invention discloses a greenable assembled retaining wall and a structural design method thereof. The greenable assembled retaining wall consists of a main wall, a foundation cushion layer and a drainage filling layer behind the wall, and the main wall is composed of standard concrete blocks stacked and assembled. The present invention is suitable for an assembled construction method and has an ecological greening function, and is suitable for urban road slope protection and ecological construction. The structural design method of the greenable assembled retaining wall comprises calculating the earth pressure on the greenable assembled retaining wall, preliminarily formulating the design parameters of the greenable assembled retaining wall, overall anti-slip stability verification, overall anti-overturning stability verification and foundation bearing capacity verification, anti-horizontal shear bearing capacity verification, local anti-overturning stability verification, block compression verification, determining retaining wall design parameters and formulating the stacking method of the standard concrete blocks. The theory based on this method is reasonable and the calculation process is simple, and the method can be used to guide the structural design of the greenable assembled retaining wall.

Description

Technical Field

[0001] The invention belongs to the technical field of geotechnical engineering retaining wall design, and relates to a greening assembled retaining wall and a structural design method thereof. Background Art

[0002] Retaining walls are widely used in urban construction as a structure that resists soil pressure behind the wall and prevents soil deformation and instability. At present, the retaining walls commonly used in urban construction projects are still mainly mortar-laid stone, cast-in-place reinforced concrete and piles. These retaining walls have two problems in the construction and use process: (1) The production efficiency of cast-in-place construction is low, and there are problems such as numerous processes, long construction period, high labor costs and unstable construction quality; (2) The ecological and environmental protection effect is poor. The waste residues, waste materials and carbon emissions generated during cast-in-place construction will cause environmental pollution, and it is difficult to fully utilize the retaining wall body to arrange green plants in the design of urban roads, rivers and garden landscapes.

[0003] On the other hand, in the design of urban roads, rivers, garden landscapes and other projects, emphasis is usually placed on the ecological and aesthetic properties of green retaining walls, while insufficient attention is paid to the structural mechanical properties of retaining walls with a height of 4m to 7m, which can easily lead to structural safety problems such as retaining wall slippage, overturning and shear failure.

[0004] In order to solve the above technical problems, it is necessary to propose a new retaining wall that is suitable for prefabricated construction and has ecological greening functions; and in order to be suitable for prefabricated construction and have ecological greening functions, the new retaining wall must adopt a structural form that is completely different from the traditional retaining wall. This leads to the fact that traditional retaining wall structure design methods such as anti-overturning verification, anti-slip verification and shear bearing capacity verification are not sufficient to ensure the structural safety of the new retaining wall. It is necessary to propose a corresponding structural design method based on the structural characteristics of the new retaining wall. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention proposes a greenable prefabricated retaining wall and a structural design method thereof. The greenable prefabricated retaining wall is suitable for prefabricated construction and has ecological greening functions, overcoming the shortcomings of traditional cast-in-place retaining walls such as low production efficiency and poor ecological and environmental protection effects. In combination with the structural characteristics of the greenable prefabricated retaining wall, a corresponding structural design method is proposed.

[0006] The present invention provides the following technical solution: a greenable assembled retaining wall, comprising a main wall, a foundation cushion layer, and a drainage filling layer behind the wall, characterized in that: the main wall is located above the foundation cushion layer, and the vertical surface of the cross section of the main wall is arranged close to the drainage filling layer behind the wall; the main wall is composed of standard concrete blocks stacked and staggered together, and the standard concrete blocks include but are not limited to four types of blocks: single mortise and tenon blocks, double mortise and tenon blocks, single mortise and tenon green plant rack blocks, and double mortise and tenon green plant rack blocks. The bottom surfaces of the four types of blocks are all provided with one or more grooves, and the top surfaces of the three types of blocks: single mortise and tenon blocks, double mortise and tenon blocks, and double mortise and tenon green plant rack blocks are all provided with at least one tenon, and each of the tenons and each of the grooves are engaged and connected, and the number is the same.

[0007] Preferably, the cross-section of the main wall also has an inclined surface opposite to the vertical surface, and the degree of inclination of the inclined surface is determined by the design parameters of the main wall. The main wall stacks the single mortise and tenon blocks, the double mortise and tenon blocks, the single mortise and tenon green plant rack blocks and the double mortise and tenon green plant rack blocks in layers and staggered positions as needed from bottom to top, and assembles them through the engagement of the tenons and the grooves.

[0008] Preferably, each layer of the layered structure includes at least one double-mortise and tenon building block, and the number of the double-mortise and tenon building blocks and the increase or decrease of the single-mortise and tenon building blocks are determined according to the inclination degree of the inclined surface.

[0009] Preferably, the layers are separated by at least one layer and the single mortise and tenon green plant rack blocks or the double mortise and tenon green plant rack blocks are assembled at the outermost edge of the layer.

[0010] Preferably, the foundation cushion layer is cast by concrete, and the upper surface of the foundation cushion layer is roughened.

[0011] Preferably, the drainage filler layer behind the wall is filled with crushed stone soil with good permeability and stable mechanical properties.

[0012] Preferably, a cavity filled with soil is provided obliquely above the single-mortise and tenon green plant rack building blocks and the double-mortise and tenon green plant rack building blocks, and green plants are arranged in the cavity according to landscape design requirements.

[0013] A structural design method for a greening assembled retaining wall specifically comprises the following steps:

[0014] S100. Calculate the earth pressure on the prefabricated retaining wall capable of greening: Based on the process characteristics of prefabricated construction and the requirements of landscape design, the cross-section of the main wall is usually a right-angled trapezoid with a narrow top and a wide bottom, and the back of the wall close to the fill is a vertical surface. Therefore, it is assumed that the back of the main wall is vertical and smooth, and the top surface of the fill behind the wall is horizontal and has a uniformly distributed load. Based on the geological data of geotechnical engineering investigation and Rankine's earth pressure theory, the active earth pressure E on the main wall of the prefabricated retaining wall capable of greening is a0 Satisfies the following expression:

[0015]

[0016] Among them, γ s is the weight of the backfill behind the wall, c is the cohesion of the backfill behind the wall, H is the height of the retaining wall, q t is the uniformly distributed load on the top surface of the backfill behind the wall, K a is the active earth pressure coefficient; the active earth pressure coefficient K a Satisfies the following expression:

[0017]

[0018] in is the internal friction angle of the fill behind the wall;

[0019] S200, preliminarily formulating design parameters for the greening prefabricated retaining wall: Preliminarily formulating geometric parameters for the greening prefabricated retaining wall based on experience, including the wall top width B0, the wall bottom width B1, and the stacking method of the standard concrete blocks;

[0020] S300, overall anti-slip stability verification, overall anti-overturning stability verification and foundation bearing capacity verification: The main wall of the greening prefabricated retaining wall must still meet the overall stability verification of the traditional retaining wall, among which the overall anti-slip stability coefficient F s Satisfies the following expression:

[0021]

[0022] Wherein, μ is the friction coefficient between the main wall and the foundation cushion, and G0 is the deadweight of the main wall;

[0023] Overall anti-overturning stability coefficient F t Satisfies the following expression:

[0024]

[0025] Among them, z G0 is the horizontal distance between the main wall's deadweight G0 and the overturning rotation point, z E0 is the active earth pressure Ea0 The vertical distance from the tipping rotation point;

[0026] The bearing capacity of the foundation satisfies the following expression:

[0027]

[0028] Among them, p k is the average pressure at the bottom of the main wall, p kmax is the maximum pressure at the bottom edge of the main wall, f a is the corrected characteristic value of foundation bearing capacity;

[0029] S400, Verification of Horizontal Shear Bearing Capacity: The difference between the greening prefabricated retaining wall and the traditional retaining wall structure is that the contact surface between the upper and lower layers of the standard concrete blocks is a shear-weak surface. The horizontal shear bearing capacity of this shear-weak surface may become a design control factor for the greening prefabricated retaining wall. Therefore, it is necessary to verify the horizontal shear bearing capacity of the contact surface between the upper and lower layers of the standard concrete blocks. The horizontal shear bearing capacity is composed of the shear bearing capacity of the tenon and the friction resistance of the contact surface. The shear bearing capacity V1 of the tenon satisfies the following expression:

[0030]

[0031] Among them, f ct is the shear strength of the standard concrete block, W ct is the bending section coefficient of the bottom surface of the tenon, h ct is the height of the tenon, A ct is the base area of ​​a single tenon;

[0032] Contact surface friction resistance V of the nth verification section 2n Satisfies the following expression:

[0033] V 2n =μ n ·G n ·(A n -m 1n ·A ct ) / A n

[0034] Among them, μ n is the friction coefficient of the nth verification section, G n is the self-weight of the main wall above the nth verification section, A n is the area of ​​the nth verification section, m 1n is the number of tenons on the nth verification section;

[0035] Horizontal shear bearing capacity V of the nth verified section 0nSatisfies the following expression;

[0036] V 0n =m 1n V1+V 2n

[0037] Active earth pressure E above the nth check section an Satisfies the following expression;

[0038]

[0039] Among them, H n is the height of the main wall above the nth verification section;

[0040] The horizontal shear resistance requirement is calculated according to the following expression:

[0041] V 0n ≥γ G ·E an

[0042] Among them, γ G is the load partial factor;

[0043] S500, local anti-overturning stability verification: The difference between the greening prefabricated retaining wall and the traditional retaining wall structure is that the upper and lower layers of the standard concrete blocks are stacked and assembled only by the deadweight of the blocks and the mortise and tenon structure. Therefore, the standard concrete blocks above any inter-layer contact surface are likely to overturn under the action of active earth pressure. Therefore, it is necessary to perform local anti-overturning stability verification on the standard concrete blocks. For the standard concrete blocks above the nth verification section, the local anti-overturning stability coefficient F tn Satisfies the following expression:

[0044]

[0045] Among them, z Gn The self-weight G of the main wall above the nth verification section n Horizontal distance from the tipping rotation point, E an is the active earth pressure on the main wall above the nth verification section, z En is the active earth pressure E on the main wall above the nth verification section an Vertical distance from the overturning rotation point;

[0046] S600, Block Compression Calculation: The standard concrete blocks bear the deadweight of the main wall above them, and the block compression calculation should be performed. Among them, the standard concrete blocks located at the bottom layer near the fill side are in the most unfavorable condition, and their compression calculation satisfies the following expression:

[0047]

[0048] Among them, f cc is the compressive strength of the standard concrete block, A cc is the most unfavorable cross-sectional area of ​​the standard concrete block in terms of compression resistance; is the influence coefficient of height-to-thickness ratio and axial force eccentricity on the bearing capacity of compression members;

[0049] S700, determine the retaining wall design parameters and formulate the stacking method of the standard concrete blocks: the retaining wall design parameters verified through all steps S200 to S600 are the final retaining wall design parameters, and the stacking method of the standard concrete blocks is formulated based on the parameters.

[0050] The structural design method for a prefabricated retaining wall capable of greening is based on the following principle: the main wall of the prefabricated retaining wall is constructed from staggered, stacked, and assembled standard concrete blocks. The blocks interlock with each other through the mortise and tenon joints, forming a single unit to resist the earth pressure of the backfill behind the wall. The prefabricated retaining wall is characterized by the absence of mortar as a bonding material between the blocks. The stacking and assembly of the upper and lower layers of blocks is achieved solely through the deadweight of the blocks and the mortise and tenon joints. Consequently, the contact surface between the upper and lower layers of blocks is a shear-weak surface. The horizontal shear bearing capacity of this shear-weak surface may become a design control factor for the prefabricated retaining wall. Therefore, in addition to conventional retaining wall calculations, it is necessary to perform a horizontal shear bearing capacity calculation for the contact surface between the upper and lower layers of the standard concrete blocks. Furthermore, the portion of the main wall above the contact surface between any two layers of blocks is subject to potential overturning under active earth pressure, necessitating a local anti-overturning stability calculation. Furthermore, the standard concrete blocks should also undergo a block compression calculation.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows: a greenable prefabricated retaining wall is proposed, the greenable prefabricated retaining wall consists of a main wall, a foundation cushion layer and a drainage filling layer behind the wall, and the main wall is composed of stacked and assembled standard concrete blocks; the process of the present invention is simple and the construction efficiency is high, it is suitable for prefabricated construction and has ecological greening functions, and is suitable for urban road slope protection and ecological construction; a structural design method for a greenable prefabricated retaining wall is proposed, which is suitable for the greenable prefabricated retaining wall, and overcomes the shortcomings of the traditional gravity retaining wall structure verification method that fails to reflect the horizontal shear bearing capacity, local anti-overturning stability and block compressive bearing capacity of the greenable prefabricated retaining wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a flow chart of a structural design method for a greening prefabricated retaining wall;

[0053] Figure 2 This is a schematic cross-sectional view of the greening assembled retaining wall of the present invention;

[0054] Figure 3 Schematic diagram of a single mortise and tenon building block according to the present invention;

[0055] Figure 4 is a schematic diagram of a double mortise and tenon building block according to the present invention;

[0056] Figure 5 This is a schematic diagram of the single mortise and tenon green plant rack building block of the present invention;

[0057] Figure 6 This is a schematic diagram of the double-mortise and tenon green plant rack building block of the present invention;

[0058] Figure 7 A force diagram of the main wall above the nth verification section;

[0059] Figure numerals: 10-main wall, 11-single mortise and tenon block, 12-double mortise and tenon block, 13-single mortise and tenon green plant rack block, 14-double mortise and tenon green plant rack block, 15-cavity, 16-groove, 17-tenon, 20-foundation cushion layer, 30-drainage filler layer behind the wall. DETAILED DESCRIPTION

[0060] The following is combined with Figure 1-7 The embodiments of the present invention are described in more detail with reference to the accompanying drawings so that those skilled in the art can implement the invention after studying the specification. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0061] A greenable assembled retaining wall comprises: a main wall 10, a foundation cushion layer 20, and a drainage filling layer 30 behind the wall; the main wall 10 is located above the foundation cushion layer 20, and the vertical surface of the cross section of the main wall 10 is arranged close to the drainage filling layer 30 behind the wall; the main wall 10 is composed of standard concrete blocks stacked and staggered together, and the standard concrete blocks include but are not limited to four types of blocks: single mortise and tenon blocks 11, double mortise and tenon blocks 12, single mortise and tenon green plant rack blocks 13, and double mortise and tenon green plant rack blocks 14. The bottom surfaces of the four types of blocks are each provided with one or more grooves 16, and the top surfaces of the three types of blocks: single mortise and tenon blocks 11, double mortise and tenon blocks 12, and double mortise and tenon green plant rack blocks 14 are each provided with at least one tenon 17, and each tenon 17 is engaged with each groove 16 and the number is the same.

[0062] In a specific implementation, the cross-section of the main wall 10 also has an inclined surface opposite to the vertical surface. The degree of inclination of the inclined surface is determined by the design parameters of the main wall 10. The main wall 10 stacks the single mortise and tenon building blocks 11, the double mortise and tenon building blocks 12, the single mortise and tenon green plant rack building blocks 13 and the double mortise and tenon green plant rack building blocks 14 from bottom to top in layers and staggered manner as needed, and assembles them through the engagement of the convex tenon 17 and the groove 16.

[0063] In a specific implementation, each layer of the layered structure includes at least one double-mortise and tenon building block 12 , and the number of the double-mortise and tenon building blocks 12 and the increase or decrease of the single-mortise and tenon building blocks 11 are determined according to the inclination degree of the inclined surface.

[0064] The layers are separated by at least one layer and the single mortise and tenon green plant rack building blocks 13 or the double mortise and tenon green plant rack building blocks 14 are assembled on the outermost edge of the layer.

[0065] In a specific implementation, the foundation cushion layer 20 is cast by concrete and is used to bear the load transmitted from the main wall 10 ; the upper surface of the foundation cushion layer 20 is roughened to enhance the friction between it and the main wall 10 .

[0066] In a specific implementation, the drainage filling layer 30 behind the wall is filled with crushed stone soil with good water permeability and stable mechanical properties.

[0067] In a specific implementation, a cavity 15 filled with soil is provided obliquely above the single mortise and tenon green plant rack block 13 and the double mortise and tenon green plant rack block 14 , and green plants are arranged in the cavity 15 according to landscape design requirements.

[0068] In a specific implementation, the shapes of the single mortise and tenon building block 11, the double mortise and tenon building block 12, the single mortise and tenon green plant rack building block 13 and the double mortise and tenon green plant rack building block 14 are as shown in the attached drawings. Figure 3-6 Taking into account the deviations in block production and hoisting construction, the size of the groove 16 is slightly larger than the size of the tenon 17 to ensure that the tenon 17 can be embedded in the groove 16 and form a mortise and tenon fixing relationship during implementation.

[0069] This embodiment relies on a city road slope protection and greening project. According to the relative relationship between the city road and the terrain conditions along the road, it is required to adopt a vertical retaining wall with a height H of 6m. The backfill behind the wall is sandy soil with a density of γ s 19.6kN / m 3 , internal friction angle is 38°; the top surface load of the fill behind the wall q t 20kN / m 2The uniformly distributed load of the retaining wall is 160 kPa after correction of the foundation bearing capacity characteristic value. The vertical retaining wall is designed using the greening prefabricated retaining wall and its structural design method of the present invention.

[0070] S100. Calculate the earth pressure on the greening prefabricated retaining wall: Based on the process characteristics of prefabricated construction and the requirements of landscape design, the cross-section of the main wall 10 is usually a right-angled trapezoid with a narrow top and a wide bottom, and the back of the wall close to the fill is a vertical surface. Therefore, it is assumed that the back of the main wall 10 is vertical and smooth, and the top surface of the fill behind the wall is horizontal and has a uniformly distributed load. Based on the geological data of geotechnical engineering investigation and Rankine's earth pressure theory, the active earth pressure coefficient K of the fill behind the wall is a Satisfies the following expression:

[0071]

[0072] in is the internal friction angle of the fill behind the wall;

[0073] The active earth pressure E on the main wall 10 of the greening assembled retaining wall a0 Satisfies the following expression:

[0074] E a0 =γ s ·K a ·H 2 / 2+q t ·K a H = 19.6 × 0.238 × 6 2 / 2+20×0.238×6=112.5kN / m(2)

[0075] Among them, γ s is the weight of the backfill behind the wall, c is the cohesion of the backfill behind the wall, H is the height of the retaining wall, q t The load is evenly distributed on the top surface of the fill behind the wall;

[0076] According to the Technical Specification for Slope Engineering (GB 50330-2013), for a gravity retaining wall with a height of 5 to 8 meters, the active earth pressure increase coefficient should be 1.1. At this time, the active earth pressure E a0 Satisfies the following expression;

[0077] E a0 =112.5×1.1=123.7kN / m (3)

[0078] S200, preliminarily formulate the design parameters of the greening assembled retaining wall: Based on experience, preliminarily formulate the geometric parameters of the greening assembled retaining wall, and propose that the wall top width B0 is 1.25m, the wall bottom width B1 is 2.5m, the bottom elevation of the main wall 10 is 0.5m lower than the ground elevation; the stacking method of the standard concrete blocks is as follows: Figure 2 As shown; the material of the standard concrete block is C20 concrete with a weight of 24kN / m 3 The main wall 10 has a deadweight of 270 kN / m per meter. 3 ;

[0079] S300, overall anti-slip stability verification, overall anti-overturning stability verification and foundation bearing capacity verification: the main wall 10 of the greening prefabricated retaining wall still needs to meet the overall stability verification of the traditional retaining wall, among which the overall anti-slip stability coefficient F s Satisfies the following expression:

[0080]

[0081] Wherein, μ is the friction coefficient between the main wall 10 and the foundation cushion 20, and G0 is the deadweight of the main wall 10;

[0082] From formula (4), it can be seen that the overall anti-slip stability verification meets the requirements;

[0083] The potential overturning rotation point of the main wall 10 is the wall toe point, and the overall anti-overturning stability coefficient F t Satisfies the following expression:

[0084]

[0085] Among them, z G0 is the horizontal distance between the main wall's deadweight G0 and the overturning rotation point, z E0 is the active earth pressure E a0 The vertical distance from the tipping rotation point;

[0086] From formula (5), it can be seen that the overall anti-slip stability verification meets the requirements;

[0087] The foundation bearing capacity verification is conservative and does not consider the beneficial effect of the foundation cushion on load transfer. The foundation bearing capacity verification satisfies the following expression:

[0088]

[0089] Among them, p k is the average pressure at the bottom of the main wall, p kmax is the maximum pressure at the bottom edge of the main wall, f a is the corrected characteristic value of foundation bearing capacity;

[0090] From formula (6), we can see that the foundation bearing capacity verification meets the requirements;

[0091] S400, Verification of Horizontal Shear Capacity: The difference between the greening prefabricated retaining wall and the traditional retaining wall structure is that the contact surface between the upper and lower layers of the standard concrete blocks is a shear-weak surface. The horizontal shear capacity of this shear-weak surface may become a design control factor for the greening prefabricated retaining wall. Therefore, it is necessary to verify the horizontal shear capacity of the contact surface between the upper and lower layers of the standard concrete blocks. The horizontal shear capacity is composed of the shear capacity of the tenon 17 and the friction resistance of the contact surface. The shear capacity V1 of a single tenon 17 satisfies the following expression:

[0092]

[0093] Among them, f ct is the shear strength of the standard concrete block, W ct is the bending section coefficient of the bottom surface of the tenon 17, h ct is the height of the tenon 17, A ct is the bottom area of ​​a single tenon 17;

[0094] Contact surface friction resistance V 2n and horizontal shear bearing capacity V 0n The friction resistance V of the contact surface varies with different verification sections. Taking the contact surface between the second and third layers of blocks counted upward from the bottom layer of the main wall 10 as an example, the friction resistance V of the contact surface is 21 Satisfies the following expression:

[0095] V 21 =μ1·G1·(A1-m 11 ·A ct ) / A1=0.6×210×(2.25-18×0.05) / 2.25=75.6kN / m(8)

[0096] Among them, μ1 is the friction coefficient of the first verification section, G1 is the deadweight of the main wall 11 above the first verification section, A1 is the area of ​​the first verification section, m 11 is the number of the tenons 17 on the first verification section;

[0097] Horizontal shear bearing capacity V of the first verified section 0n Satisfies the following expression:

[0098] V 01 =m 11 V1+V 21=18×10.63+75.6=267.00kN / m (9)

[0099] Active earth pressure E above the first check section a1 Satisfies the following expression:

[0100] E a1 =γ s ·K a H1 2 / 2+q t ·K a H1=19.6×0.238×5 2 / 2+20×0.238×5=82.1kN / m(10)

[0101] The horizontal shear resistance requirement is calculated according to the following expression:

[0102] V 01 =267.0≥γ G ·E a1 =1.35×82.1=110.79kN / m (11)

[0103] Among them, γ G is the load partial factor;

[0104] From formula (11), it can be seen that the horizontal shear bearing capacity of the first verification section meets the requirements;

[0105] The results of the horizontal shear bearing capacity verification of each verification section are shown in Table 1:

[0106] Table 1. Horizontal shear bearing capacity and local anti-overturning stability verification results of each verification section

[0107]

[0108] The nth calculated section in Table 1 is the contact surface between the 2nth and 2n+1th layers of blocks, counting upward from the bottom layer of the main wall 10. As can be seen from Table 1, the calculated horizontal shear bearing capacity of each calculated section meets the requirements.

[0109] S500, local anti-overturning stability verification: The difference between the greening prefabricated retaining wall and the traditional retaining wall structure is that the upper and lower layers of the standard concrete blocks are stacked and assembled only by the deadweight of the blocks and the mortise and tenon structure. Therefore, the standard concrete blocks above any inter-layer contact surface are likely to overturn under the action of active earth pressure. Therefore, it is necessary to perform local anti-overturning stability verification on the standard concrete blocks. For the standard concrete blocks above the nth verification section, the local anti-overturning stability coefficient F tn Satisfies the following expression:

[0110]

[0111] Among them, z Gn The self-weight G of the main wall 10 above the nth verification section n Horizontal distance from the tipping rotation point, E an is the active earth pressure on the main wall 10 above the nth verification section, z En is the active earth pressure E on the main wall 10 above the nth verification section an Vertical distance from the overturning rotation point;

[0112] The local anti-overturning stability verification results of each verification section are shown in Table 1. It can be seen from Table 1 that the local anti-overturning stability verification results of each verification section meet the requirements;

[0113] S600, block compression calculation: The standard concrete blocks bear the deadweight pressure of the main wall 10 above them, and the block compression calculation should be performed. The standard concrete blocks located at the bottom layer near the fill side are in the most unfavorable compression condition, and their compression calculation satisfies the following expression:

[0114]

[0115] Among them, f cc is the compressive strength of the standard concrete block, A cc is the most unfavorable cross-sectional area of ​​the standard concrete block in terms of compression resistance; is the influence coefficient of height-to-thickness ratio and axial force eccentricity on the bearing capacity of compression members;

[0116] From formula (13), we can see that the compression calculation meets the requirements;

[0117] S700, determine the retaining wall design parameters and formulate the stacking method of the standard concrete blocks: the retaining wall design parameters calculated from step S200 to step S600 are the final retaining wall design parameters, and the stacking method of the standard concrete blocks is determined accordingly. Figure 2 shown.

[0118] The above is a description of one or more embodiments of the present invention, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A structural design method for a greening assembled retaining wall, characterized in that: Applied to a greening assembled retaining wall, the greening assembled retaining wall comprises a main wall, a foundation cushion layer and a drainage filling layer behind the wall; The main wall is located above the foundation cushion layer, and the vertical surface of the cross section of the main wall is arranged adjacent to the drainage filler layer behind the wall; the main wall is composed of standard concrete blocks stacked and staggered together, and the standard concrete blocks include four types of blocks: single-mortise and tenon blocks, double-mortise and tenon blocks, single-mortise and tenon green plant rack blocks, and double-mortise and tenon green plant rack blocks. The bottom surfaces of the four types of blocks are each provided with one or more grooves, and the top surfaces of the three types of blocks: single-mortise and tenon blocks, double-mortise and tenon blocks, and double-mortise and tenon green plant rack blocks are each provided with at least one tenon, and each tenon is engaged with each groove; The cross section of the main wall further comprises an inclined surface opposite to the vertical surface, the degree of inclination of the inclined surface being determined by the design parameters of the main wall. The main wall comprises the single mortise and tenon blocks, the double mortise and tenon blocks, the single mortise and tenon green plant rack blocks, and the double mortise and tenon green plant rack blocks, stacked in layers and staggered as needed from bottom to top, and assembled by engaging the tenons and grooves. Each layer comprises at least one double mortise and tenon block, and the number of double mortise and tenon blocks and the number of single mortise and tenon blocks are determined according to the degree of inclination of the inclined surface. The single mortise and tenon green plant rack blocks or the double mortise and tenon green plant rack blocks should be arranged at least every other layer on the outermost side of the inclined surface of the cross section of the main wall. The structural design method includes the following steps: S100, calculating the earth pressure on the greening assembled retaining wall: the active earth pressure E on the main wall of the greening assembled retaining wall a0 Satisfies the following expression: Among them, γ s is the weight of the backfill behind the wall, c is the cohesion of the backfill behind the wall, H is the height of the retaining wall, q t is the uniformly distributed load on the top surface of the backfill behind the wall, K a is the active earth pressure coefficient; the active earth pressure coefficient K a Satisfies the following expression: in is the internal friction angle of the fill behind the wall; S200, preliminarily formulating design parameters for the greening prefabricated retaining wall: Preliminarily formulating geometric parameters for the greening prefabricated retaining wall based on experience, including the wall top width B0, the wall bottom width B1, and the stacking method of the standard concrete blocks; S300, overall anti-slip stability verification, overall anti-overturning stability verification and foundation bearing capacity verification: the overall anti-slip stability coefficient F s Satisfies the following expression: Wherein, μ is the friction coefficient between the main wall and the foundation cushion, and G0 is the deadweight of the main wall; Overall anti-overturning stability coefficient F t Satisfies the following expression: Among them, z G0 is the horizontal distance between the main wall's deadweight G0 and the overturning rotation point, z E0 is the active earth pressure E a0 The vertical distance from the tipping rotation point; The bearing capacity of the foundation satisfies the following expression: Among them, p k is the average pressure at the bottom of the main wall, p kmax is the maximum pressure at the bottom edge of the main wall, f a is the corrected characteristic value of foundation bearing capacity; S400, horizontal shear bearing capacity verification: The horizontal shear bearing capacity of the contact surface between the upper and lower layers of the standard concrete block is composed of the tenon shear bearing capacity and the contact surface friction resistance, wherein the tenon shear bearing capacity V1 satisfies the following expression: Among them, f ct is the shear strength of the standard concrete block, W ct is the bending section coefficient of the bottom surface of the tenon, h ct is the height of the tenon, A ct is the base area of ​​a single tenon; Contact surface friction resistance V of the nth verification section 2n Satisfies the following expression: V 2n =μ n ·G n ·(A n -m 1n ·A ct ) / A n Among them, μ n is the friction coefficient of the nth verification section, G n is the self-weight of the main wall above the nth verification section, A n is the area of ​​the nth verification section, m 1n is the number of tenons on the nth verification section; Horizontal shear bearing capacity V of the nth verified section 0n Satisfies the following expression; In 0n =m 1n ·V1+V 2n Active earth pressure E above the nth check section an Satisfies the following expression; Among them, H n is the height of the main wall above the nth verification section; The horizontal shear resistance requirement is calculated according to the following expression: V 0n ≥γ G ·E an Among them, γ G is the load partial factor; S500, local anti-overturning stability verification: For the standard concrete blocks above the nth verification section, the local anti-overturning stability coefficient F tn Satisfies the following expression: Among them, z Gn The self-weight G of the main wall above the nth verification section n Horizontal distance from the tipping rotation point, E an is the active earth pressure on the main wall above the nth verification section, z En is the active earth pressure E on the main wall above the nth verification section an Vertical distance from the overturning rotation point; S600, Block Compression Calculation: Under the most unfavorable conditions, the compression calculation of the standard concrete blocks located at the bottom layer near the fill side satisfies the following expression: Among them, f cc is the compressive strength of the standard concrete block, A cc is the most unfavorable cross-sectional area of ​​the standard concrete block in terms of compression resistance; is the influence coefficient of height-to-thickness ratio and axial force eccentricity on the bearing capacity of compression members; S700, determine the retaining wall design parameters and formulate the stacking method of the standard concrete blocks: all the retaining wall design parameters verified through steps S200 to S600 are the final retaining wall design parameters, and the stacking method of the standard concrete blocks is formulated based on them.

2. The structural design method of a greening assembled retaining wall according to claim 1, characterized in that: The foundation cushion layer is cast by concrete, and the upper surface of the foundation cushion layer is roughened.

3. The structural design method of a greening assembled retaining wall according to claim 1 is characterized in that: The drainage filling layer behind the wall is filled with crushed stone soil.

4. The structural design method of a greening assembled retaining wall according to claim 1 is characterized in that: A cavity filled with soil is provided obliquely above the single-mortise and tenon green plant rack building block and the double-mortise and tenon green plant rack building block, and green plants are arranged in the cavity according to landscape design requirements.

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