Ice rock clastic flow energy dissipation and flow control structure in cold and cold mountainous area

Abstract

The invention relates to an energy dissipation and flow control structure for ice rock clastic flow in a cold and cold mountainous area, which is suitable for the technical field of geological disaster prevention and control safety and can be widely applied to disaster prevention and reduction of high ice rock clastic flow in the cold and cold mountainous area. According to the structure, at least one fluid energy dissipation structure is arranged on an ice rock clastic flow movement path; the fluid energy dissipation structure is a curved valley-to-fluid energy dissipation structure arranged for curved valley terrains, a narrow-wide valley-to-fluid energy dissipation structure arranged for narrow-wide valley terrains or a wide-narrow valley-to-fluid energy dissipation structure arranged for wide-narrow valley terrains. The invention provides three fluid energy dissipation structures depending on the valley terrain and the hydrodynamic effect. Comprising a curved valley-to-fluid energy dissipation structure arranged for curved valley terrains, a narrow-wide valley-to-fluid energy dissipation structure arranged for narrow-wide valley terrains or a wide-narrow valley-to-fluid energy dissipation structure arranged for wide-narrow valley terrains.

Description

Technical Field

[0001] This invention relates to an energy dissipation and flow control structure for ice-rock debris flows in high-altitude and cold mountainous areas. It is applicable to the field of geological disaster prevention and safety technology and can be widely used in disaster prevention and mitigation for high-altitude ice-rock debris flows in high-altitude and cold mountainous areas. Background Technology

[0002] As part of a landslide, glaciers release a large amount of heat during high-speed descent due to the collision, abrasion, and friction of debris particles. After some glaciers melt, the meltwater mixes with the debris particles, forming a solid-liquid two-phase fluid. This further reduces the frictional resistance between the debris particles and the substrate, leading to increased fluidity and travel distance. Glaciers are characterized by their enormous size, high speed, extremely long range, and chain-reaction nature, resulting in severe loss of life and property and significant engineering damage.

[0003] Statistics show that due to the low frictional resistance, this type of ice-rock debris flow typically travels over a distance of more than 5 km, making it highly susceptible to forming river dams and subsequently triggering secondary disasters such as outburst floods. Furthermore, this ice-rock debris flow not only travels a long distance but also has an average velocity often exceeding 20 m / s, far greater than that of single-phase debris flows.

[0004] Currently, traditional debris flow and debris flow control projects often employ passive control measures such as gravity dams, grid dams, pile-forest dams, and pile-beam dams near the mouth of the flow path at the end of the flow zone. These passive interception measures are only suitable for slow-moving, small-volume, single-phase fluids, and often fail to achieve ideal results in controlling ice-rock type debris flows with extremely high fluidity in large watersheds. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an energy dissipation and flow control structure for ice and rock debris flow in high-altitude and cold mountainous areas, in view of the above-mentioned problems.

[0006] The technical solution adopted in this invention is: an energy dissipation and flow control structure for ice and rock debris flow in high-altitude cold mountainous areas, wherein at least one fluid energy dissipation structure is set on the movement path of the ice and rock debris flow; The modified fluid energy dissipation structure is a curved valley modified fluid energy dissipation structure designed for curved valley terrain, a narrow-wide valley modified fluid energy dissipation structure designed for narrow-wide valley terrain, or a wide-narrow valley modified fluid energy dissipation structure designed for wide-narrow valley terrain. The curved valley water diversion energy dissipation structure includes an arc-shaped retaining wall built on the concave bank slope and the convex bank slope of the curved valley section. Drainage holes are arranged on the retaining wall. A retention and accumulation area is formed between the retaining wall and the bank slope on the same side. A vortex energy dissipation area is formed between the two retaining walls. A group of cylindrical barrier piles is arranged in the vortex energy dissipation area. The narrow-wide valley modified fluid energy dissipation structure includes a widening zone set at the junction of the wide valley section and the upstream narrow valley section. The bank slopes on both sides of the widening zone are supported by retaining walls with drainage holes. A vortex energy dissipation zone is formed on both sides of the upstream end of the widening zone and the corresponding range of the narrow valley section. A group of cylindrical barrier piles is arranged in the vortex energy dissipation zone. The wide-narrow valley energy dissipation structure includes a retaining wall I on each of the two bank slopes of the narrow valley section, forming a retention and accumulation zone between the retaining wall I and the bank slope on the same side. A widening zone is set at the junction of the wide valley section and the downstream narrow valley section. The bank slopes on both sides of the widening zone are supported by retaining walls II, which are connected to retaining walls I on the same side. Drainage holes are provided on both retaining walls I and II. A vortex energy dissipation zone is formed between the two retaining walls I. A vortex energy dissipation zone is formed on both sides of the corresponding range of the narrow valley section at the downstream end of the widening zone. A group of cylindrical barrier piles is arranged in the vortex energy dissipation zone.

[0007] The diameter of each cylindrical barrier pile in the group is greater than 200 mm, the ground height is 0.5 m, the underground burial depth is generally more than 1 m into the bedrock surface, and the spacing is 1 to 1.5 m.

[0008] The height of the retaining wall on the concave bank of the curved gully section is designed to be 1.2 to 1.5 times the thickness of the ice-rock debris flow, while the height of the retaining wall on the convex bank is designed to be 0.6 to 1 times the thickness of the ice-rock debris flow.

[0009] In the narrow-wide valley modified fluid energy dissipation structure, right-angle shoulders are formed on both sides of the upstream end of the widening zone. The retaining wall includes retaining wall I corresponding to the shoulder of the upstream end of the widening zone and retaining wall II corresponding to the side of the widening zone. Retaining wall I and retaining wall II are connected.

[0010] The length of retaining wall II is 2 to 3 times the length of retaining wall I.

[0011] In the narrow-wide valley modified fluid energy dissipation structure, the design height of the retaining wall is taken as 1 to 1.5 times the maximum thickness of the ice-rock debris flow.

[0012] In the wide-narrow valley fluid energy dissipation structure, right-angle shoulders are formed on both sides of the downstream end of the widening zone. The retaining wall II includes retaining wall IIa corresponding to the downstream shoulder of the widening zone and retaining wall IIb corresponding to the side of the widening zone. Retaining wall IIa and retaining wall IIb are connected.

[0013] The length of retaining wall IIb is 2 to 3 times the length of retaining wall IIa.

[0014] In the wide-narrow valley fluid-reducing energy dissipation structure, the heights of retaining walls I and II are 1 to 1.5 times the maximum thickness of previous ice-rock debris flows.

[0015] The beneficial effects of this invention are: Based on the valley topography and fluid dynamics effects, this invention proposes three types of modified fluid energy dissipation structures, including a curved valley modified fluid energy dissipation structure designed for curved valley topography, a narrow-wide valley modified fluid energy dissipation structure designed for narrow-wide valley topography, or a wide-narrow valley modified fluid energy dissipation structure designed for wide-narrow valley topography.

[0016] This invention relies on the topography of a winding valley and increases the overall curvature of the winding section by using a winding valley fluid energy dissipation structure, so that more kinetic energy of the ice-rock debris flow is consumed in the impact of debris particles with the concave bank slope.

[0017] This invention relies on the narrow-wide valley topography and increases the width of the wide valley cross section by modifying the fluid energy dissipation structure of the narrow-wide valley, so that it forms vortex motion within the concave cavity on both sides, forming a vortex energy dissipation zone.

[0018] This invention relies on the wide-narrow valley topography and reduces the width and cross-sectional area of ​​the narrow valley section by modifying the fluid energy dissipation structure of the wide-narrow valley. After the ice-rock debris fluid enters the narrow section from the wide section, it will generate four vortex motions near the boundary between the wide and narrow valleys, forming a vortex energy dissipation zone.

[0019] This invention deploys a group of reinforced concrete barrier piles in the vortex energy dissipation zone. On the one hand, this increases the frictional resistance between the debris flow and the bedrock, reducing the flow velocity while forcing turbulence and further increasing energy dissipation. On the other hand, the debris flow exhibits erosion, entrainment, and entrapment dynamics on the bedrock material during its movement. The barrier pile group embedded in the bedrock can improve the overall erosion resistance of the bedrock and reduce the increase in the volume of debris flow to a certain extent.

[0020] This invention utilizes existing topography to modify the fluid structure design, increasing energy dissipation and accumulation along the way during the high-speed movement of ice-rock debris flows, reducing the amount of substrate material scraped by the high-speed movement of ice-rock debris flows, further reducing the scale and impact velocity of river blockage, and mitigating flood damage caused by large-scale river blockage. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the technical principle of the energy dissipation and flow control structure for ice and rock debris flow in high-altitude cold mountainous areas, as shown in the embodiment.

[0022] Figure 2 This is a planar schematic diagram of the curved valley-type fluid-dissipating energy structure in the embodiment.

[0023] Figure 3 for Figure 2 A schematic diagram of the cross-section of a medium-bending valley-type fluid-dissipating energy structure.

[0024] Figure 4 This is a planar schematic diagram of the narrow-wide valley modified fluid energy dissipation structure in the embodiment.

[0025] Figure 5 for Figure 4 A schematic diagram of the cross-section of a medium-narrow to wide valley modified fluid energy dissipation structure.

[0026] Figure 6 This is a planar schematic diagram of the wide-narrow valley modified fluid energy dissipation structure in the embodiment.

[0027] Figure 7 for Figure 6 A schematic diagram of the cross-section of a medium-wide-narrow valley modified fluid energy dissipation structure.

[0028] 1. Arched retaining wall; 2. Retention and accumulation zone; 3. Drainage hole; 4. Concrete barrier pile; 5. Vortex energy dissipation zone; 6. Concave bank slope; 7. Convex bank slope; 8. Ice-rock debris flow; 9. Free surface of ice-rock debris flow; 10. Lateral velocity profile of ice-rock debris flow; 11. Lateral circulation velocity direction; 12. Concave bank area; 13. Convex bank area; 14. L-shaped retaining wall; 15. Original topographic line of narrow-wide gully; 16. Topographic line of narrow-wide gully after widening; 17. Z-shaped retaining wall; 18. Original topographic line of wide-narrow gully. Detailed Implementation

[0029] In hydraulics, energy loss is generally expressed as the energy lost per unit weight of fluid. In a channel with a straight solid boundary, the mechanical energy lost per unit weight of fluid flowing from one cross-section to another is called the head loss between those two cross-sections. The head loss that increases with the length of the channel is called friction head loss, expressed as... In addition, hydraulic losses caused by topographic changes are called local hydraulic losses, often referred to as local hydraulic losses. This is represented as follows. Assuming the fluid is incompressible and its motion follows a constant-field flow, with gravity as the only body force, the Bernoulli equation for the overall flow of a viscous fluid is: In the formula: For hydraulic loss, This refers to hydraulic losses along the friction path (caused by viscous friction). This refers to localized hydraulic losses (caused by topographical changes). The average velocity is K, and the local loss factor is K, the magnitude of which is determined by the geometry and size of the gully.

[0030] In the above formula, under the same hydraulic loss along the route, the greater the local hydraulic loss caused by topographic changes, the greater the overall energy consumption will be.

[0031] This embodiment investigates the topography of several ice-rock type debris flow valleys in the lower reaches of the Yarlung Tsangpo River. The flow paths are characterized by complex terrain combinations of various types, including tortuous, straight, wide-narrow, and narrow-wide. From the perspective of modifying the fluid energy dissipation structure, the tortuous, wide-narrow, and narrow-wide terrain types can be further modified to form active energy dissipation structures.

[0032] like Figure 1 As shown in Figure a, when ice-rock debris flow enters a winding valley, under the centrifugal force of the bend, the fluid particles form a secondary flow with double vortices on the inner and outer slopes of the cross-section, exhibiting a spiral motion. In the first half of the bend, the pressure of the debris flow increases along the outer side and decreases along the inner side, while the velocity decreases on the outer side and increases on the inner side. Therefore, in the first half of the bend, the fluid decelerates and pressurizes along the outer wall, forming a vortex region. The fluid motion in the vortex region is similar to rotation around a rigid body, increasing energy dissipation. In the second half of the bend, due to inertia, with a larger Reynolds number and a larger bend angle and smaller radius of curvature, a vortex region appears on the inner side of the bend. However, in terms of strength and size, the vortex on the inner side is larger than that on the outer side. The local loss factor (Kc) is related to the total bend angle of the bend. The curvature radius (R) of the curve centerline and the valley width (B) are related, and their expressions are as follows: As shown in the above formula, the magnitude of the local loss factor is positively correlated with the channel turning angle and the valley width, while it is negatively correlated with the radius of curvature. That is, in a curved channel of the same length, a smaller radius of curvature results in a relatively larger centrifugal force on the fluid particles, leading to greater energy consumption. Therefore, when designing fluid topography, increasing the valley width and curvature can be considered to improve overall energy consumption.

[0033] like Figure 1 As shown in Figure b, when ice-rock debris fluid enters a narrow-to-wide valley, it's similar to a fluid entering a large-diameter channel from a small-diameter channel. It enters the large-diameter pipe as a jet, and the flow interface gradually widens. After a certain distance, it re-engages with the flow, establishing a fully developed flow. Debris flows typically exhibit vortices at the corners of the pipe wall where the flow suddenly widens. These vortices are mainly driven by the main flow, consuming some of the main flow's energy. Due to viscosity, this energy is dissipated as heat. Furthermore, because the fluid has a higher velocity in the small-diameter pipe, it inevitably collides with the lower-velocity fluid in the large-diameter pipe, resulting in energy loss through collisions. The expression for the local loss factor (Kb) is as follows: In the formula: A1 and A2 are the cross-sectional areas of the narrow and wide valleys, respectively.

[0034] As can be seen from the above formula, for valley terrain with a sudden widening of the cross section, it is necessary to further increase the width and area of ​​the cross section, expand the range of the vortex zone, and increase energy consumption.

[0035] like Figure 1 As shown in Figure c, when ice-rock debris flow enters a wide-narrow valley terrain, it is similar to the process of fluid flowing from a large-diameter pipe into a small-diameter pipe, where the streamlines bend and the flow cross-section contracts. Due to inertia, after the debris flow enters the small-diameter pipe, the flow stream contracts to its minimum cross-section; this phenomenon is called necking. Subsequently, the fluid fills the entire cross-section. Near the necking, a low-pressure zone filled with small vortices appears between the flow stream and the bank wall, and vortices also form near the shoulder at the junction of the two pipes. The vortices consume some of the mainstream energy, and during the bend of the streamlines, the acceleration and deceleration of the fluid, the fluid particles collide with each other, and their velocities change, resulting in energy loss. When the cross-section suddenly narrows, the local loss factor (Ks) is: In the formula: A1 and A2 are the cross-sectional areas of the narrow and wide valleys, respectively.

[0036] As can be seen from the above formula, when designing fluid dynamics for wide and narrow valleys, it is necessary to reduce the ratio of narrow to wide cross-sectional area, that is, reduce the width of the narrow cross-section and increase the width of the wide cross-section. This can not only increase the collision between particles, but also expand the range of the vortex zone, resulting in more energy dissipation.

[0037] Based on the aforementioned principle of modified fluid energy dissipation, this embodiment provides an energy dissipation and flow control structure for ice-rock debris flow in high-altitude and cold mountainous areas. The valley terrain along the movement path of the ice-rock debris flow is evaluated, and terrain sections with low construction difficulty and easy access by manpower are selected. Modified fluid energy dissipation structures are designed and constructed for constructable curved valley terrain, narrow-wide valley terrain (with narrow and wide valley sections in sequence along the direction of ice-rock debris flow movement), and wide-narrow valley terrain (with wide and narrow valley sections in sequence along the direction of ice-rock debris flow movement).

[0038] like Figure 2 , 3As shown, this embodiment employs a curved gully-type fluid diversion and energy dissipation structure tailored to the curved gully terrain. This includes constructing arched retaining walls on both the concave and convex bank slopes, using reinforced concrete cantilever retaining walls, which are characterized by strong impact resistance. Due to the superelevation phenomenon caused by the ice-rock debris flow under centrifugal force (i.e., the liquid level on the concave bank is higher than on the convex bank), the height of the retaining wall on the convex bank can be slightly lower than that on the concave bank, reducing material consumption. The retaining wall on the concave bank forms a dissipation zone, increasing energy dissipation; furthermore, it resists the erosion and damage of the ice-rock debris flow to the toe of the concave bank slope, fundamentally reducing the increase in the disaster volume. The design height of retaining walls is generally based on the thickness and freeboard of the ice-rock debris flow. The height of retaining walls on concave banks is typically designed to be 1.2 to 1.5 times the thickness, while on convex banks it is typically designed to be 0.6 to 1 times the thickness. Other parameters can be designed according to actual conditions. Crack width is controlled at 0.2 mm. Reinforcement grade: HRB400; Concrete strength grade: C30. Drainage holes are also installed on the retaining walls.

[0039] An accumulation zone is formed between the arched retaining wall and the bank slope on the same side. When the ice-rock debris flow overflows the retaining wall due to its superelevation or thickness being greater than the height of the retaining wall, the overflowing part will enter the accumulation zone between the retaining wall and the slope, thereby reducing the flow volume of the debris flow.

[0040] Under centrifugal force, the ice-rock debris flow will create a lateral circulation effect in the curved section. A group of small-diameter cylindrical bollards is installed at the bottom of the curved valley. Each bollard has a diameter greater than 200 mm, a ground height of 0.5 m, and is generally buried more than 1 m into the bedrock surface, with a spacing of 1–1.5 m. The purpose of these small-diameter bollards is primarily to increase the frictional resistance between the base and the debris particles, reduce the lateral circulation velocity, and increase energy dissipation.

[0041] like Figure 4 , 5 As shown, the narrow-wide valley energy dissipation structure designed for narrow-wide valley terrain in this embodiment includes widening the connection between the wide valley section and the upstream narrow valley section to form a widening zone, increasing the local loss factor (Kb), and forming right-angle shoulders on both sides of the upstream end of the widening zone. The widening width can be determined according to the actual situation.

[0042] In this embodiment, retaining walls are used to support the widened area. The retaining walls include retaining wall I, which is set on the shoulder of the upstream end of the widened area, and retaining wall II, which is set on the side of the widened area. Retaining wall I and retaining wall II are connected to form an L-shaped retaining wall.

[0043] In this example, a gravity retaining wall is used. This type of support relies on the wall's own weight to resist soil pressure. It is generally constructed using mortar-lined rubble (block) stone masonry, which is simple in form, can use local materials, and is easy to construct.

[0044] In this example, the support length (Lc) of the L-shaped retaining wall in the wide valley section can generally be taken as 2 to 3 times the width of the narrow section (Lb). The height of the retaining wall can be designed according to the actual maximum ice-rock debris flow height in the valley over the years, and the design height can generally be taken as 1 to 1.5 times the maximum thickness of the ice-rock debris flow. Drainage holes are set in the retaining wall to prevent the bank slope from becoming unstable and failing due to saturation of the rock and soil.

[0045] In this embodiment, the retaining wall primarily serves to prevent the debris flow vortex in the energy dissipation zone from eroding the toe of the bank slope and causing an amplification of the disaster volume. To further increase energy dissipation, a group of small-diameter cylindrical barrier piles is deployed in the vortex energy dissipation zone on both sides of the wide cross-section. The deployment method, spacing, and burial depth are consistent with the aforementioned principles for the deployment in the winding gully.

[0046] like Figure 6 , 7 As shown, in this embodiment, a wide-narrow valley energy dissipation structure is set up to modify the flow of the wide-narrow valley. This includes constructing a retaining wall I on each of the two bank slopes of the narrow valley section. A retention and accumulation zone is formed between the retaining wall I and the bank slope on the same side. A widening zone is set up at the junction of the wide valley section and the downstream narrow valley section. The bank slopes on both sides of the widening zone are supported by retaining walls II. Retaining walls II are connected to retaining walls I on the same side. Drainage holes are arranged on both retaining walls I and II. A vortex energy dissipation zone is formed between the two retaining walls I. A vortex energy dissipation zone is formed on both sides of the corresponding range of the narrow valley section at the downstream end of the widening zone.

[0047] In the wide-narrow valley fluid energy dissipation structure, right-angle shoulders are formed on both sides of the downstream end of the widening zone. The retaining wall II includes retaining wall IIa corresponding to the downstream shoulder of the widening zone and retaining wall IIb corresponding to the side of the widening zone. Retaining wall IIb, retaining wall IIa and retaining wall I are connected in sequence to form a Z-shaped retaining wall.

[0048] In this embodiment, the type and structure of the retaining wall are consistent with the above-mentioned principles for the layout of the winding valley terrain. The height is generally 1 to 1.5 times the maximum height of the previous ice and rock debris flows, and the length is generally 2 to 3 times the shoulder width (Ld). Drainage holes are also provided.

[0049] In narrow valley sections, the width of the valley is further reduced by retaining walls I on both sides. The cross-sectional width is generally designed to be 0.5 to 0.8 times the width of the valley, and the length is generally designed according to the actual situation. It is recommended to take more than 3 times the width of the valley.

[0050] For this type of wide-narrow valley terrain, after the ice-rock debris flow enters, it will form vortex energy dissipation zones at the right-angle shoulders on both sides of the wide valley and on both sides of the near-narrow valley section. Therefore, small-diameter cylindrical barrier pile groups are set up at these locations. The layout method, spacing and burial depth are consistent with the above-mentioned principles for the layout of winding valleys.

[0051] When the height of the ice-rock debris flow exceeds the height of the retaining wall, an overflow will occur. The space between retaining wall I and the slope can serve as a retention area to accumulate some debris, thereby reducing the overall scale of the disaster to a certain extent.

[0052] In this embodiment, the small-diameter reinforced concrete barrier pile group deployed in the vortex zone of curved, wide-narrow, and narrow-wide valleys needs to be embedded in the bedrock. This serves two purposes: firstly, it increases the frictional resistance between the debris flow and the bedrock, reducing the flow velocity while forcing turbulence and further increasing energy dissipation; secondly, the debris flow exhibits erosion, entrainment, and entrapment dynamics on the bedrock material, and the barrier pile group embedded in the bedrock can comprehensively improve the bedrock's erosion resistance and reduce the increase in debris flow volume to a certain extent.

Claims

1. A structure for energy dissipation and flow control of ice-rock debris flow in high-altitude cold mountainous areas, characterized in that: At least one fluid energy dissipation structure should be installed along the movement path of the ice-rock debris flow; The modified fluid energy dissipation structure is a curved valley modified fluid energy dissipation structure designed for curved valley terrain, a narrow-wide valley modified fluid energy dissipation structure designed for narrow-wide valley terrain, or a wide-narrow valley modified fluid energy dissipation structure designed for wide-narrow valley terrain. The curved valley water diversion energy dissipation structure includes an arc-shaped retaining wall built on the concave bank slope and the convex bank slope of the curved valley section. Drainage holes are arranged on the retaining wall. A retention and accumulation area is formed between the retaining wall and the bank slope on the same side. A vortex energy dissipation area is formed between the two retaining walls. A group of cylindrical barrier piles is arranged in the vortex energy dissipation area. The narrow-wide valley modified fluid energy dissipation structure includes a widening zone set at the junction of the wide valley section and the upstream narrow valley section. The bank slopes on both sides of the widening zone are supported by retaining walls with drainage holes. A vortex energy dissipation zone is formed on both sides of the upstream end of the widening zone and the corresponding range of the narrow valley section. A group of cylindrical barrier piles is arranged in the vortex energy dissipation zone. The wide-narrow valley energy dissipation structure includes a retaining wall I on each of the two bank slopes of the narrow valley section, forming a retention and accumulation zone between the retaining wall I and the bank slope on the same side. A widening zone is set at the junction of the wide valley section and the downstream narrow valley section. The bank slopes on both sides of the widening zone are supported by retaining walls II, which are connected to retaining walls I on the same side. Drainage holes are provided on both retaining walls I and II. A vortex energy dissipation zone is formed between the two retaining walls I. A vortex energy dissipation zone is formed on both sides of the corresponding range of the narrow valley section at the downstream end of the widening zone. A group of cylindrical barrier piles is arranged in the vortex energy dissipation zone.

2. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: The diameter of each cylindrical barrier pile in the group is greater than 200 mm, the ground height is 0.5 m, the underground burial depth is generally more than 1 m into the bedrock surface, and the spacing is 1 to 1.5 m.

3. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: The height of the retaining wall on the concave bank of the curved gully section is designed to be 1.2 to 1.5 times the thickness of the ice-rock debris flow, while the height of the retaining wall on the convex bank is designed to be 0.6 to 1 times the thickness of the ice-rock debris flow.

4. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: In the narrow-wide valley modified fluid energy dissipation structure, right-angle shoulders are formed on both sides of the upstream end of the widening zone. The retaining wall includes retaining wall I corresponding to the shoulder of the upstream end of the widening zone and retaining wall II corresponding to the side of the widening zone. Retaining wall I and retaining wall II are connected.

5. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 4, characterized in that: The length of retaining wall II is 2 to 3 times the length of retaining wall I.

6. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: In the narrow-wide valley modified fluid energy dissipation structure, the design height of the retaining wall is taken as 1 to 1.5 times the maximum thickness of the ice-rock debris flow.

7. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: In the wide-narrow valley fluid energy dissipation structure, right-angle shoulders are formed on both sides of the downstream end of the widening zone. The retaining wall II includes retaining wall IIa corresponding to the downstream shoulder of the widening zone and retaining wall IIb corresponding to the side of the widening zone. Retaining wall IIa and retaining wall IIb are connected.

8. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 7, characterized in that: The length of retaining wall IIb is 2 to 3 times the length of retaining wall IIa.

9. The energy dissipation and flow control structure for ice-rock debris flow in high-altitude cold mountainous areas according to claim 1, characterized in that: In the wide-narrow valley fluid-reducing energy dissipation structure, the heights of retaining walls I and II are 1 to 1.5 times the maximum thickness of previous ice-rock debris flows.

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