Pile-board type snow guide wall structure and design method thereof

Abstract

The present application provides a pile board type snow guide wall structure and a design method thereof, wherein the snow guide wall structure comprises left and right two wall bodies, the two wall bodies form an L shape, each wall body comprises an anti-skid pile and a snow guide board, the lower end of the anti-skid pile is embedded in the soil body, the upper end is exposed to the ground, the bottom of the snow guide board is placed on the ground, the top of the board is higher than the top of the anti-skid pile, and is inclined to the snow-facing side, the snow-facing surface of the snow guide board is arranged flush with the snow-facing surface of the anti-skid pile, and the design method comprises the following steps: S1, determining the protection height of the snow guide wall; S2, determining the position of the snow guide wall; S3, determining the length of the snow guide wall; S4, determining the number of the snow guide board and the anti-skid pile; S5, calculating the snow pressure load effect of the snow guide board; S6, calculating the load effect of the anti-skid pile; S7, determining the thickness of the snow guide board; S8, determining the cross-sectional height of the anti-skid pile; S9, adjusting the size and number of the snow guide wall and the anti-skid pile, repeating steps S5-S8, calculating the concrete and steel reinforcement engineering quantity, and comparing and selecting the scheme with the minimum cost.

Description

Technical Field

[0001] This invention relates to the field of avalanche prevention engineering technology for power transmission lines, and more specifically, to a pile-slab snow guide wall structure and its design method. Background Technology

[0002] With the increasing construction of power transmission lines in high-altitude areas, the impact of avalanches on these lines is becoming increasingly prominent due to limitations imposed by factors such as route, terrain, and geology. To address the avalanche problem affecting power transmission lines, a combination of avoidance and prevention measures should be adopted. Avalanche management can be implemented at the occurrence, movement, and deposition zones. However, protection in the occurrence and movement zones is typically costly, difficult to construct, and challenging to maintain year-round; therefore, priority should be given to end-point control in the avalanche deposition zone. Currently, commonly used end-point control methods include snow nets, fencing, and snow guide walls (or snow barriers). However, the protective effect of snow nets and fencing is difficult to quantify, and they often fail under the impact of avalanches exceeding a certain scale. Currently, commonly used snow guide walls are gravity structures, often using dry-laid, mortar-grouted rubble masonry, or shallow-buried reinforced concrete structures. These are unsuitable for steep slopes, require long-term maintenance, do not align with the design philosophy of low maintenance in high-altitude areas, and lack comprehensive calculation theories and systematic design methods. Summary of the Invention

[0003] The present invention aims to provide a pile-slab snow guide wall structure and its design method to solve the problems that existing snow guide wall structures are difficult to apply to steep slopes, require long-term operation and maintenance, and lack perfect calculation theory and system design methods, so as to further ensure the safety of power transmission line operation and maintenance.

[0004] This invention provides a pile-slab snow guide wall structure, including two walls, left and right, forming an L shape. Each wall includes an anti-skid pile and a snow guide plate. The lower end of the anti-skid pile is buried in the soil, and the upper end is exposed above the ground. The bottom of the snow guide plate is placed on the ground, the top of the plate is higher than the top of the anti-skid pile, and it is inclined towards the snow-facing side. The snow-facing side of the snow guide plate is flush with the snow-facing side of the anti-skid pile.

[0005] As a preferred technical solution:

[0006] The pile-slab snow guide wall structure is made of reinforced concrete.

[0007] As a preferred technical solution:

[0008] The axial angle between the left and right walls is 60°-90°.

[0009] As a preferred technical solution:

[0010] The anti-skid piles have a rectangular cross-section and are cast integrally with the snow guide plate.

[0011] This invention further provides a design method for a pile-slab snow guide wall structure, which performs avalanche erosion protection design on the above-mentioned pile-slab snow guide wall structure, including the following steps:

[0012] S1. Determine the snow guide wall protection height h1 based on the avalanche flow height h;

[0013] S2. Determine the location of the snow guide wall based on the relationship between the avalanche flow and the tower location. The snow guide wall is set above the tower location, with the left and right walls of the snow guide wall arranged in an L-shape and the corners of the snow guide wall facing the direction of the avalanche flow.

[0014] S3. Determine the length of the snow guide wall based on the base of the tower. Based on the location of the snow guide wall, determine the protection range and length of the snow guide wall, ensuring that the avalanche flow does not directly impact the tower legs.

[0015] S4. Based on the length of the snow guide wall, determine the number of snow guide plates and anti-skid piles according to the assumed length of a single span of snow guide plate and the cross-sectional width of the anti-skid piles.

[0016] S5. Based on the snow pressure intensity value P obtained from numerical simulation or investigation and analysis, the snow pressure load effect on the middle span guide snow plate is calculated using a simply supported beam model based on the safety factor method, and the snow pressure load effect on the side span guide snow plate is calculated using a cantilever beam model.

[0017] S6. Based on the snow pressure intensity value P obtained from numerical simulation or survey analysis, the load effect of the anti-slide pile is calculated using a pile foundation model based on the safety factor method.

[0018] S7. Based on the snow pressure load effect borne by the snow guide plate, calculate the reinforcement of the snow guide plate as a bending member and a shear member respectively, and determine the thickness of the snow guide plate.

[0019] S8. Based on the snow pressure load effect borne by the anti-slide pile, calculate the reinforcement of the anti-slide pile as a bending member and a shear member respectively, and determine the section height of the anti-slide pile. The section height of the anti-slide pile is greater than or equal to the section width.

[0020] S9. Adjust the size and quantity of snow guide walls and anti-skid piles, repeat steps S5, S6, S7, and S8, calculate the amount of concrete and steel reinforcement, compare the economics of multiple schemes, and select the scheme with the lowest cost.

[0021] As a preferred technical solution:

[0022] In step S1, the snow guide wall protection height h1 ≥ 3h.

[0023] As a preferred technical solution:

[0024] In step S2, the axial angle between the left and right sides of the snow guide wall is consistent with the angle between the avalanche flow direction.

[0025] As a preferred technical solution:

[0026] In step S3, the shortest distances S2 and S3 between the snow guide wall and the tower leg on both sides are greater than the snow guide wall protection height h1.

[0027] As a preferred technical solution:

[0028] In step S4, the length of the middle span snow guide plate is 3.0m-5.0m, the length of the side span snow guide plate is 1.5m-2.5m, and the width of the anti-skid pile section is 1.0m-2.0m.

[0029] As a preferred technical solution:

[0030] In step S5, the maximum bending moment M of the intermediate span guide snowboard max Calculate using the following formula:

[0031]

[0032] Maximum bending moment M of the side span snow guide plate max Calculate using the following formula:

[0033]

[0034] Where L is the span of the snow guide plate, P1 is the snow pressure perpendicular to the wall, and P1=Psinθ 2 θ is the angle between the avalanche flow impact direction and the wall axial direction.

[0035] As a preferred technical solution:

[0036] When the direction of the avalanche flow is uncertain, θ can be conservatively set to 90°.

[0037] As a preferred technical solution:

[0038] In step S5, the maximum shear force V of the intermediate span guide snowboard max Calculate using the following formula:

[0039]

[0040] Maximum shear force V of the side span guide snowboard max Calculate using the following formula:

[0041] V max =P1h1L.

[0042] As a preferred technical solution:

[0043] In step S6, the maximum bending moment M of the anti-slide pile max Calculate using the following formula:

[0044] M max =1.3P1h1(L+b)(0.5h1+1);

[0045] Where b is the width of the anti-slide pile section;

[0046] Maximum shear force V of anti-slide pile max Calculate using the following formula:

[0047] V max＝ P1h1(L+b).

[0048] As a preferred technical solution:

[0049] The concrete strength of the snow guide wall is C25 or above, the longitudinal reinforcement is HRB400 and the stirrup material is HPB300. Based on the above loads, the reinforcement calculation of the normal section and oblique section of the snow guide wall and anti-slide pile and the horizontal bearing capacity calculation are carried out in accordance with the "Code for Design of Concrete Structures" and the "Code for Design of Building Pile Foundations".

[0050] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0051] The pile-slab snow guide wall structure proposed in this invention adopts a combination of anti-slide piles and snow guide plates. The number and size of anti-slide piles and snow guide plates can be freely adjusted according to the tower base and avalanche conditions. It has strong applicability and high safety, and is especially suitable for steep mountain terrain.

[0052] The design method for pile-slab snow guide wall structures proposed in this invention rationally designs the setting location, arrangement, length, and height of the pile-slab snow guide wall structure, fully considering the impact height and impact angle of the avalanche flow to protect the tower base from avalanche impacts. Furthermore, the method reduces the angle between the avalanche flow direction and the retaining wall axis during snow guide wall arrangement, ensuring uniform stress on the left and right sides of the snow guide walls and maximizing their snow guiding function. The invention also proposes calculation formulas for the bending moment and shear force of the snow guide slab and anti-slide piles, as well as methods for calculating the reinforcement of the normal and oblique sections of the snow guide wall and anti-slide piles, and for calculating the horizontal bearing capacity. The design method of this invention has a sound calculation theory, meets the requirements of avalanche prevention design and safe operation and maintenance, and ensures the safety and economic rationality of the snow protection structure.

[0053] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0055] Figure 1 This is a flowchart of the design method for the pile-slab snow guide wall structure described in this invention.

[0056] Figure 2 This is a three-dimensional structural diagram of the pile-slab snow guide wall structure described in this invention.

[0057] Figure 3 This is a plan view of the pile-slab snow guide wall structure described in this invention.

[0058] Figure 4 This is a schematic elevation view of the pile-slab snow guide wall structure described in this invention.

[0059] Figure 5 This is a side view of the pile-slab snow guide wall structure described in this invention.

[0060] in, Figures 1 to 5 The correspondence between the reference numerals and component names in the attached diagram is as follows: 1-Avalanche flow direction; 2-Anti-skid pile; 3-Middle span snow guide plate; 4-Side span snow guide plate; 6-Tower foundation; 7-Tower root opening. Detailed Implementation

[0061] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Example 1

[0064] like Figures 1-5 As shown in the figure, this embodiment proposes a design method for a pile-slab snow guide wall structure, including the following steps:

[0065] S1. Determine the snow guide wall protection height based on the avalanche flow height;

[0066] Based on the avalanche flow height h determined by field investigation, numerical simulation or empirical methods, calculate the snow guide wall protection height h1, h1≥3h, where h is the avalanche flow height.

[0067] S2. Determine the location of the snow guide wall based on the relationship between the avalanche flow and the tower location;

[0068] The snow guide wall is set above the tower, with the left and right walls arranged in an L-shape, with the corners facing the direction of the avalanche flow. In order to make the left and right walls more evenly stressed, the axial direction of the left and right walls is as consistent as possible with the impact direction of the avalanche flow; the angle between the left and right walls is 60°-90°.

[0069] S3. Determine the length of the snow guide wall based on the 7-meter opening at the base of the tower. Based on the location of the snow guide wall, and taking into account the principle that the avalanche flow does not directly impact the tower leg, i.e., satisfying θ1>0 and θ2>0, lay out the snow guide wall protection range and length.

[0070] The shortest distances S2 and S3 between the two side walls and the tower legs should satisfy S2≥h1 and S3≥h1, so as to prevent the walls from falling towards the tower and damaging the tower materials in extreme cases.

[0071] S4. Based on the length of the snow guide wall, assume the length of the single-span snow guide plate and the cross-sectional width of the anti-skid pile, and determine the number of snow guide plates and anti-skid piles according to the assumed length of the single-span snow guide plate and the cross-sectional width of the anti-skid pile.

[0072] In this embodiment, the lengths L1 and L3 of the middle span snow guide plate are generally 3.0m-5.0m, the lengths L2 and L4 of the side span snow guide plate are generally 1.5m-2.5m, and the widths b1, b2, and b3 of the anti-skid pile section are generally 1.0m-2.0m.

[0073] S5. Based on the snow pressure intensity value P obtained from numerical simulation or investigation and analysis, the snow pressure load effect on the middle span guide snow plate is calculated using a simply supported beam model based on the safety factor method, and the snow pressure load effect on the side span guide snow plate is calculated using a cantilever beam model.

[0074] Maximum bending moment M of the middle span snowboard max The calculation method is as follows:

[0075]

[0076] Maximum bending moment M of the side span snow guide plate max The calculation method is as follows:

[0077]

[0078] Where L is the span of the snow guide plate, P1 is the snow pressure perpendicular to the wall, and P1=Psinθ 2 θ is the direction of the avalanche flow impact, and θ is the angle between the axial direction of the wall. When the direction of the avalanche flow is uncertain, it can be conservatively taken as 90°.

[0079] Maximum shear force V of the middle span guide snowboard max The calculation method is as follows:

[0080]

[0081] Maximum shear force V of the side span snow guide plate max The calculation method is as follows:

[0082] V max =P1h1L.

[0083] S6. Based on the snow pressure intensity value P obtained from numerical simulation or survey analysis, the load effect of the anti-slide pile is calculated using a pile foundation model based on the safety factor method.

[0084] Maximum bending moment M of anti-slide pile maxThe calculation method is as follows:

[0085] M max =1.3P1h1(L+b)(0.5h1+1);

[0086] Where b is the width of the anti-slide pile section.

[0087] Maximum shear force V of anti-slide pile max The calculation method is as follows:

[0088] V max＝ P1h1(L+b).

[0089] S7. Based on the snow pressure load effect borne by the snow guide plate, calculate the reinforcement of the snow guide plate as a bending member and a shear member respectively, and determine the thickness of the snow guide plate.

[0090] The concrete strength of the snow guide plate can be C30, and the longitudinal reinforcing steel should be HRB400 and the stirrups should be HPB300.

[0091] S8. Based on the snow pressure load effect borne by the anti-slide pile, calculate the reinforcement of the anti-slide pile as a bending member and a shear member respectively, and determine the section height of the anti-slide pile. The section height of the anti-slide pile should be greater than or equal to the section width.

[0092] The concrete strength of the anti-slide pile can be C30, and the longitudinal reinforcing steel should be HRB400 and the stirrups should be HPB300.

[0093] S9. Adjust the size and quantity of snow guide walls and anti-skid piles, repeat steps S5, S6, S7, and S8, calculate the amount of concrete and steel reinforcement, compare the economics of multiple schemes, and select the scheme with the lowest cost.

[0094] Example 2

[0095] like Figures 2-5 As shown in the figure, this embodiment proposes a pile-slab snow guide wall structure, which is a reinforced concrete structure. Specifically, it includes two walls, left and right, forming an L-shape. The included angle between the axes of the left and right walls is 60°-90°. Each wall includes anti-skid piles 2 and snow guide plates. The snow guide plates include a middle span snow guide plate 3 and a side span snow guide plate 4.

[0096] The anti-slide pile 2 has a rectangular cross-section, with the lower end buried in the soil. In mountainous terrain, the burial depth should be ≥5m, and the upper end is exposed above the ground. It is cast integrally with the corresponding middle span snow guide plate 3 and side span snow guide plate 4. The bottom of the snow guide plate is placed on the ground, and the top of the plate is 0.5-1.0m higher than the top of the anti-slide pile 2. It is tilted at a certain angle (between 45° and 90°) towards the snow-facing side to prevent the avalanche flow from being blocked by the snow guide wall and rushing out and over the wall. The avalanche flow is confined within the wall. The snow-facing side of the snow guide plate is arranged flush with the snow-facing side of the anti-slide pile 2. The purpose is to facilitate snow guidance and avoid forming a concave angle, so that the avalanche flow accumulates within the wall and increases the avalanche impact height.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for a pile-slab snow guide wall structure, characterized in that: The snow guide wall structure is designed for avalanche protection. The snow guide wall structure consists of two walls, left and right, forming an L-shape. Each wall includes anti-skid piles and snow guide plates. The lower end of the anti-skid piles is buried in the soil, while the upper end is exposed above the ground. The bottom of the snow guide plate is placed on the ground, and the top of the plate is higher than the top of the anti-skid piles and is inclined towards the snow-facing side. The snow-facing side of the snow guide plate is flush with the snow-facing side of the anti-skid piles. The design methodology includes the following steps: S1, based on avalanche flow height Determine the height of the snow guide wall ; S2. Determine the location of the snow guide wall based on the relationship between the avalanche flow and the tower location. The snow guide wall is set above the tower location, with the left and right walls of the snow guide wall arranged in an L-shape and the corners of the snow guide wall facing the direction of the avalanche flow. S3. Determine the length of the snow guide wall based on the base of the tower. Based on the location of the snow guide wall, determine the protection range and length of the snow guide wall, ensuring that the avalanche flow does not directly impact the tower legs. S4. Based on the length of the snow guide wall, determine the number of snow guide plates and anti-skid piles according to the assumed length of a single span of snow guide plate and the cross-sectional width of the anti-skid piles. S5. Snow pressure intensity value based on numerical simulation or survey analysis. P Based on the safety factor method, the snow load effect on the middle span guide snow plate is calculated using a simply supported beam model, and the snow load effect on the side span guide snow plate is calculated using a cantilever beam model. S6. Snow pressure intensity value based on numerical simulation or survey analysis. P Based on the safety factor method, the load effect of anti-slide piles is calculated using a pile foundation model; S7. Based on the snow pressure load effect borne by the snow guide plate, calculate the reinforcement of the snow guide plate as a bending member and a shear member respectively, and determine the thickness of the snow guide plate. S8. Based on the snow pressure load effect borne by the anti-slide pile, calculate the reinforcement of the anti-slide pile as a bending member and a shear member respectively, and determine the section height of the anti-slide pile. The section height of the anti-slide pile is greater than or equal to the section width. S9. Adjust the size and quantity of snow guide walls and anti-skid piles, repeat steps S5, S6, S7, and S8, calculate the amount of concrete and steel reinforcement, compare the economics of multiple schemes, and select the scheme with the lowest cost.

2. The design method for a pile-slab snow guide wall structure according to claim 1, characterized in that: In step S1, the snow guide wall protection height .

3. The design method for a pile-slab snow guide wall structure according to claim 1, characterized in that: In step S2, the axial angle between the left and right sides of the snow guide wall is consistent with the angle between the avalanche flow direction.

4. The design method for a pile-slab snow guide wall structure according to claim 1, characterized in that: In step S3, the shortest distances S2 and S3 between the snow guide wall and the tower legs on both sides are greater than the protective height of the snow guide wall. .

5. The design method for a pile-slab snow guide wall structure according to claim 1, characterized in that: In step S4, the length of the middle span snow guide plate is 3.0m-5.0m, the length of the side span snow guide plate is 1.5m-2.5m, and the width of the anti-skid pile section is 1.0m-2.0m.

6. The design method for a pile-slab snow guide wall structure according to claim 5, characterized in that: In step S5, the maximum bending moment of the intermediate span guide snowboard. Calculate using the following formula: ； Maximum bending moment of the side span snow guide plate Calculate using the following formula: ； in, L For the span of the snow guide, The snow pressure is perpendicular to the wall. , The angle between the direction of the avalanche flow impact and the axial direction of the wall.

7. The design method for a pile-slab snow guide wall structure according to claim 6, characterized in that: In step S5, the maximum shear force of the intermediate span guide snowboard Calculate using the following formula: ； Maximum shear force of side span guide snowboard Calculate using the following formula: 。 8. The design method for a pile-slab snow guide wall structure according to claim 7, characterized in that: In step S6, the maximum bending moment of the anti-slide pile Calculate using the following formula: ； Where b is the width of the anti-slide pile section; Maximum shear force of anti-slide pile Calculate using the following formula: 。 9. The design method for a pile-slab snow guide wall structure according to claim 1, characterized in that: The axial angle between the left and right walls is 60°-90°.

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