Rigid-flexible composite channel debris flow blocking structure

Abstract

The invention belongs to the field of debris flow disaster prevention and reduction, and provides a rigid-flexible composite channel debris flow blocking structure which comprises a flexible protective net and a rigid protective pile group, and the rigid protective pile group comprises a plurality of protective piles; the blocking structure is arranged in a gentle slope section ditch bed of a steep and gentle connection section of a ditch. The flexible protective net is composed of a flexible net body and fixing piles, and the flexible net body is installed on the fixing piles. The lower ends of the protection piles are fixed in the gentle slope section ditch bed, the upper end faces of the protection piles are flush, the centers of the upper end faces of the protection piles are located on the same straight line, and the connecting line of the centers of the upper end faces of the protection piles is perpendicular to the linear direction of the gentle slope section; the fixed piles are fixed to the protection piles, and the flexible protection net is parallel to the plane where the axes of all the protection piles are located. Through effective combination of the rigid units and the flexible units, the impact resistance of the debris flow blocking structure is improved, and the protection capacity of the debris flow blocking structure on high-speed large-particle debris flow is enhanced.

Description

Technical Field

[0001] The invention belongs to the field of debris flow disaster prevention and reduction, and relates to a rigid-flexible composite channel debris flow blocking structure. Background Art

[0002] Debris flows, a typical geological hazard, are characterized by complex material composition, rapid movement, and strong impact. They often lead to river blockages, traffic disruptions, and the burial of infrastructure, posing a significant threat to human life and property. The complex topography, variable climate conditions, and fragile geological environment of mountainous and hilly areas provide favorable conditions for the formation of debris flows.

[0003] Given the strong destructiveness of debris flows, research on debris flow movement mechanisms and disaster-causing mechanisms has always been an important topic in the field of geological disasters. For example, Fan Xiaoyi et al. used physical model experiments to study the effect of deflection terrain on the velocity of debris flows. The experimental data showed that the particle velocity would decrease significantly near the deflection point and would rapidly increase to a peak value after passing the deflection point (see Fan Xiaoyi, Xia Guiping, Wen Xiang, et al. Experimental study on the velocity and particle distribution of landslide-debris flow under deflection terrain constraints [J]. 2024, 42(3): 389-400.). He Xurong et al. used large-scale physical model experiments to explore the influence of factors such as rock volume, channel slope, and joint development on rock mass fragmentation characteristics and energy dissipation processes (see He Xurong, Yin Yueping, Zhao Liming, et al. Disintegration and fragmentation effects of high-level rock landslide debris flow based on large-scale physical model experiments [J]. Earth Science, 2024, 49(7): 2650-2661.). To scientifically and effectively regulate debris flow hazards, numerous researchers have conducted research on various engineering measures aimed at controlling the velocity and accumulation range of debris flows, thereby mitigating their hazards. For example, Lei Ming et al. conducted numerical experiments on the interaction between multi-stage debris flows and pile groups using the discrete element method. They revealed the effects of varying the number and spacing of pile groups on the pile group forces, particle velocity, and accumulation morphology (see Lei Ming, Zhang Liang, Ye Chen, et al. Numerical Experiments on the Motion Characteristics of Multi-stage Debris Flows Blocked by Channel Pile Groups [J / OL]). Engineering Science and Technology. https: / / link.cnki.net / urlid / 51.1773.tb.20240705.1514.008.). Han Peifeng et al. conducted numerical experiments on the energy dissipation law and final accumulation characteristics of channel debris flows with different particle compositions impacting retaining structures under terrain deflection conditions using numerical simulation methods, and on this basis constructed a debris flow impact mechanics model (see Han Peifeng, Li Xingkai, Tian Shujun, et al. Study on the influence of gradation and retaining position on the movement of landslide debris flow [J]. Journal of Safety and Environment, 2024, 24(4): 1422-1433.). Although many scholars have conducted extensive research on the prevention and control of debris flow disasters, due to the complexity of debris flow problems, the interaction mechanism between debris flow and retaining structures is still in the exploratory stage, and there is currently no mature solution available for direct use in engineering.

[0004] Passive flexible protective nets, through their flexible deformation characteristics, can buffer and dissipate the impact energy of debris flows. They have the advantages of easy installation, cost-effectiveness, safety, and reliability, making them a commonly used measure for mitigating channel debris flows. However, engineering practice has shown that existing passive flexible protective nets have obvious technical deficiencies when dealing with high-speed, large-particle debris flows. For example, they are inefficient in intercepting coarse particles and are prone to structural failure under sustained strong impact loads. These limitations severely restrict the application of passive flexible protective nets in dealing with high-speed, large-particle debris flows. Therefore, it is necessary to improve the existing passive flexible protective nets to further enhance their impact resistance so that they can better cope with the impact of high-speed, large-particle debris flows. Summary of the Invention

[0005] In response to the problems of insufficient interception efficiency of coarse particles in existing passive flexible protective nets and prone to structural failure under continuous strong impact loads, the present invention provides a rigid-flexible composite channel debris flow interception structure, which improves the impact resistance of the debris flow interception structure through the effective combination of rigid units and flexible units, and strengthens the protection capability of the debris flow interception structure against high-speed large-particle debris flows.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0007] A rigid-flexible composite channel debris flow interception structure, comprising a flexible protection net and a rigid protection pile group, wherein the rigid protection pile group comprises a plurality of protection piles; the interception structure is arranged in the channel bed of the gentle slope section where the steep-gentle section connects to the gentle slope section; The flexible protective net consists of a flexible net body and fixed piles, and the flexible net body is installed on the fixed piles; the lower end of each protective pile is fixed in the ditch bed of the gentle slope section, the upper end face of each protective pile is flush, the center of the upper end face of each protective pile is located on the same straight line, and the line connecting the centers of the upper end faces of each protective pile is perpendicular to the along-the-path direction of the gentle slope section; the fixed piles are fixed on the protective piles, and the flexible protective net is parallel to the plane where the axes of all protective piles are located.

[0008] In the above technical solution, the fixed piles preferably consist of horizontal piles and vertical piles. One end of the horizontal pile is connected to one end of the vertical pile. The angle between the horizontal pile and the vertical pile is preferably 90° to 120°. There are two fixed piles, and the two fixed piles are fixed to the protective piles in a mirror-symmetrical manner via the horizontal pile. Furthermore, the two fixed piles are respectively installed on the two protective piles located closest to the riverbank on the gentle slope of the protective pile group.

[0009] In the above technical solution, the size of the flexible protective net is mainly determined according to the actual protection needs. Usually, the width of the narrowest part of the flexible protective net is 1.0~1.2 times the width of the ditch bed of the gentle slope section, and the height of the flexible protective net is 0.4~1 times the width of the ditch bed of the gentle slope section.

[0010] In the above technical solution, a plurality of reinforcing anchor cables are provided on the flexible protective net, and both ends of each reinforcing anchor cable are fixed on a fixed pile.

[0011] In the above technical solution, the installation position of each reinforcing anchor cable can be determined based on actual application requirements and reference to existing technologies. Preferably, each reinforcing anchor cable is arranged parallel to the width of the flexible protective net. When each reinforcing anchor cable is arranged parallel to the width of the flexible protective net, the distance between adjacent reinforcing anchor cables is mainly determined based on factors such as the actual protection requirements, the size of the flexible protective net, and the material of the flexible protective net and the reinforcing anchor cables. Preferably, the distance between adjacent reinforcing anchor cables does not exceed 2 meters.

[0012] In the above technical solution, the material and size of the reinforcing anchor cable can be determined according to the actual protection needs and with reference to the existing technology. For example, the material of the reinforcing anchor cable can be high-strength galvanized steel wire, and the diameter of the reinforcing anchor cable can be 15~25 mm.

[0013] In the above technical solution, the material of the flexible mesh of the flexible protective net, the shape and size of the grid of the flexible mesh can be determined according to the actual protection requirements with reference to the existing technology. For example, the material of the flexible mesh can be high-strength galvanized steel wire, high-strength stainless steel wire, etc., the shape of the flexible mesh can be square or diamond, and the grid side length of the flexible mesh can generally be 10~50 cm.

[0014] In the above technical solution, the lower edge of the flexible mesh is fixed to the upper end surface of each protective pile.

[0015] In the above technical solution, the height of the protective pile is related to factors such as the flow rate of the channel debris flow, particle size, and channel width. Usually, the height of the protective pile is 0.05 to 0.2 times the width of the channel bed on the gentle slope section.

[0016] In the above technical solution, the distance between adjacent protective piles is 0.1~0.4 times the width of the ditch bed on the gentle slope section.

[0017] In the above technical solution, the number of protective piles in the rigid protective pile group is related to the width of the trench in which the protective piles are arranged. The wider the trench, the more protective piles are required. Most basically, the rigid protective pile group includes at least three protective piles.

[0018] In the above technical solution, the angle between each protective pile and the bed surface of the ditch on the gentle slope section is 90° ± 5°.

[0019] In the above technical solution, the location of each protection pile mainly depends on the location of the disaster prevention and protection object on the gentle slope section, and each protection pile is set upstream of the disaster prevention and protection object on the gentle slope section.

[0020] In the above technical solution, the width of the trench bed in the gentle slope section refers to the width of the trench where the steep slope meets the gentle slope section, that is, the width at the junction of the steep slope section and the gentle slope section. The width direction of the flexible protective net refers to the width direction of the trench bed in the gentle slope section, and the height direction of the flexible protective net refers to the direction perpendicular to the width direction of the flexible protective net on the mesh surface.

[0021] Compared with the prior art, the technical solution provided by the present invention produces the following beneficial technical effects:

[0022] 1. The present invention provides a rigid-flexible composite channel debris flow intercepting structure, which includes a flexible protective net and a rigid protective pile group. The flexible protective net is arranged on the rigid protective pile group and is located above the rigid protective pile group. Since the intercepting structure rationally combines the rigid protective pile group with the flexible protective net, it can give full play to the dual advantages of the rigid structure's strong impact resistance and the flexible structure's good buffering and energy dissipation performance. The intercepting structure of the present invention, on the one hand, utilizes the rigid protective pile group to effectively resist the initial impact of coarse particles located at the front end of the debris flow surface, and on the other hand, utilizes the flexible protective net to achieve subsequent interception of flying particles and fine particles and consume their energy, giving play to the synergistic effect of "rigid interception-flexible interception energy consumption", and finally achieving the step-by-step dissipation and optimized distribution of impact energy, significantly improving the protection efficiency of the intercepting structure against channel debris flow, and effectively strengthening the intercepting structure's protection capability against high-speed large-particle debris flow. The present invention can solve the technical problem that the existing flexible protective net has insufficient impact resistance and cannot effectively cope with the impact of high-speed large-particle debris flow.

[0023] 2. The present invention has confirmed through numerical simulation that, compared to existing rigid protective pile groups, the load acting on the rigid protective pile groups of the retaining structure of the present invention when retaining channel debris flow is significantly reduced. This helps to extend the service life of the rigid protective pile groups, thereby reducing the frequency of replacement of the rigid protective pile groups, which helps to reduce the engineering costs of the retaining structure. Compared to existing flexible protective nets, the load acting on the flexible protective net of the retaining structure of the present invention when retaining channel debris flow is also significantly reduced, thereby demonstrating superior impact resistance, which helps to enhance the ability of the flexible protective net to withstand the impact of high-speed, large-particle debris flows.

[0024] 3. The rigid-flexible composite channel debris flow retaining structure provided by the present invention has good engineering adaptability and can flexibly adjust the design parameters of the retaining structure according to actual engineering needs. For example, the height and spacing of each protective pile in the rigid protective pile group, the size of the flexible protective net, and the spacing between adjacent reinforcing anchor cables and other parameters can be adjusted to adjust the protective performance of the retaining structure, so that the protective performance of the retaining structure can better meet actual engineering needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a comparison chart of the numerical simulation results of the sediment particle transport process under different sediment inflow conditions using the discrete element method and the experimental data in the literature.

[0026] Figure 2 It is a schematic diagram of the channel physical model.

[0027] Figure 3 It is a schematic diagram of the rigid-flexible composite channel debris flow blocking structure of the present invention.

[0028] Figure 4 yes Figure 3 side view.

[0029] Figure 5 It is a schematic diagram of setting a rigid-flexible composite channel debris flow barrier structure in the channel physical model.

[0030] Figure 6 This is a schematic diagram of setting up a channel debris flow pile group in the channel physical model in Comparative Example 1.

[0031] Figure 7 This is a schematic diagram of setting a flexible protective net in the channel physical model in comparative example 2.

[0032] Figure 8 yes Figure 7 Planar structure diagram of the medium flexible protective net.

[0033] Figure 9 is the particle size distribution diagram of channel debris flow.

[0034] Figure 10 This is a cloud diagram of the movement speed of particles in the channel physical model in Comparative Example 3 at different times.

[0035] Figure 11 It is a cloud diagram of the movement speed of particles in the channel physical model in Example 1 at different times.

[0036] Figure 12 It is a curve showing the relationship between the average velocity of particles in the longitudinal direction and the vertical direction and time in the channel physical model in Example 1 and Comparative Examples 1 to 3; wherein, Figure (a) is a curve showing the relationship between the average velocity of particles in the longitudinal direction and time, and Figure (b) is a curve showing the relationship between the average velocity of particles in the vertical direction and time.

[0037] Figure 13Figure 3 is the cumulative mass of particles of different particle sizes passing through the characteristic monitoring section changing over time, among which (a) is the cumulative mass of the total particles of the debris flow passing through the characteristic monitoring section changing over time, (b) is the cumulative mass of particles with a particle size of 10 cm passing through the characteristic monitoring section changing over time, (c) is the cumulative mass of particles with a particle size of 30 cm passing through the characteristic monitoring section changing over time, and (d) is the cumulative mass of particles with a particle size of 40 cm passing through the characteristic monitoring section changing over time.

[0038] Figure 14 It is the change over time of the average interaction force between the rigid protection pile group in the rigid-flexible composite channel debris flow retaining structure in Example 1 and the protection pile group and the debris flow in Comparative Example 1.

[0039] Figure 15 Figures (a) and (b) show the displacement response characteristics of the reinforced anchor cables of the flexible protective net of comparative example 2 and the flexible protective net of the retaining structure of embodiment 1, respectively.

[0040] Figure 16 Figures (a) and (b) respectively show the changes in the tension of the reinforcing anchor cables of the flexible protective net 1 of comparative example 2 and the flexible protective net of the retaining structure of embodiment 1 over time.

[0041] Figure 17 This is the effect of different types of blocking structures in the physical models of Example 1 and Comparative Examples 1-3 on the accumulation morphology of channel debris flow.

[0042] In the figure, 1 is the protection net, 101 is the flexible net, 102 is the fixed pile, 2 is the protection pile, 3 is the reinforced anchor cable, 4 is the steep slope section, 5 is the gentle slope section, V is the width of the protection net, B is the width of the steep slope section, L1 is the length of the steep slope section, L2 is the length of the gentle slope section, α —The angle between the ditch bed surface and the horizontal plane on the steep slope, x —horizontal distance of the trench, a—the distance between two adjacent reinforcing anchor cables, b—the height of the protective pile, d—the width of the bottom surface of the protective pile, c—the length of the bottom surface of the protective pile. DETAILED DESCRIPTION

[0043] The following examples, combined with the accompanying drawings, further illustrate the rigid-flexible composite channel debris flow intercepting structure of the present invention. It is important to note that the following examples are intended only to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Based on the above disclosure, non-essential improvements and adjustments made by persons skilled in the art to the present invention and to implement the present invention remain within the scope of protection of the invention.

[0044] In the following embodiments, in order to analyze the influence of the rigid-flexible composite channel debris flow blocking structure on the channel debris flow transport and accumulation process and the blocking effect, it is necessary to use the discrete element method to numerically simulate the channel debris flow transport and accumulation process under different working conditions. Therefore, it is necessary to verify the reliability and accuracy of the discrete element method in simulating the channel debris flow transport and accumulation process. Specifically, based on the verification method provided in the literature [Cheng Hao, Han Peifeng, Su Youwen. Analysis of sliding accumulation characteristics and influencing factors of loose bodies based on discrete element method [J]. Acta Physica Sinica, 2020, 69(16): 164501], numerical calculations were carried out on two sets of physical model tests with different sediment loads (0.005 m³ and 0.015 m³) in the literature [Zhou JW, Yang XG, Hou TX. An analysis of the supply process of loose materials to mountainous rivers and gullies as a result of dry debris avalanches [J]. Environmental Earth Sciences, 2017, 76(13): 452.], that is, the discrete element method was used to numerically simulate the transport process of sediment particles with a particle size of 20~60 mm under the conditions of sediment loads of 0.005 m³ and 0.015 m³. The comparison between the numerical simulation results and the experimental data in the literature is shown in the figure. Figure 1 As shown by Figure 1 The time-dependent curve of the cumulative particle volume obtained from the numerical simulation agrees well with the experimental results, and the overall trend is consistent. This demonstrates that the discrete element method is effective and reliable for simulating the transport process of channel debris flow.

[0045] In the following Examples 2 to 7, when the numerical simulation of the transport process of the channel debris flow in the channel physical model of Example 1 with a rigid-flexible composite channel debris flow blocking structure, the channel physical model of Comparative Example 1 with a protective pile group, and the channel physical model of Comparative Example 3 without any channel debris flow blocking structure is performed, the numerical simulation is based on the method in the literature [Cheng Hao, Han Peifeng, Su Youwen. Analysis of the sliding accumulation characteristics and influencing factors of loose bodies based on the discrete element method [J]. Acta Physica Sinica, 2020, 69(16): 164-501]. When the numerical simulation of the transport process of the channel debris flow in the channel physical model of Comparative Example 2 with a flexible protective net is performed, the numerical simulation is based on the method in the literature [Xiao Siyou, Su Lijun, Jiang Yuanjun. Discrete element simulation study of debris flow impacting flexible net [J]. Chinese Journal of Geotechnical Engineering, 2019, 41(3): 526-533.]. The particle size distribution of the channel debris flow used in the numerical simulation is as follows: Figure 9The relevant calculation parameters used in the numerical simulation are shown in Tables 1 to 3. The mesh in Tables 1 to 3 refers to the flexible mesh and the anchor cable refers to the reinforced anchor cable.

[0046] Table 1 Material parameters

[0047]

[0048] Table 2 Bonding parameters

[0049]

[0050] Table 3 Contact parameters

[0051]

[0052] Example 1

[0053] In this embodiment, a rigid-flexible composite channel debris flow blocking structure is provided.

[0054] Considering that most actual channels are in the form of steep slopes and gentle slopes, this embodiment adopts a channel physical model in which a steep slope section 4 and a gentle slope section 5 are connected to each other based on an actual natural channel topography. Figure 2 As shown in the physical model of the channel, the widths of the steep slope section 4 and the gentle slope section 5 are equal, the width B of the steep slope section 4 is 10 m, the length L1 of the steep slope section 4 is 50 m, the length L2 of the gentle slope section 5 is 60 m, the angle between the ditch bed surface of the gentle slope section 5 and the horizontal plane is 0°, and the angle between the ditch bed surface of the steep slope section 4 and the horizontal plane is α =40°, there is loose accumulation at the top of the steep slope section 4, which will be transformed into channel debris flow under the impact of the incoming flow.

[0055] The structural diagram of the rigid-flexible composite channel debris flow intercepting structure is shown in the figure. Figures 3 and 4 As shown, it consists of a flexible protective net 1 and a rigid protective pile group, and the rigid protective pile group includes four protective piles 2; the retaining structure is arranged in the ditch bed of the gentle slope section 5 of the steep-to-gentle transition section of the ditch; the flexible protective net 1 consists of a flexible net body 101 and fixed piles 102, and the flexible net body 101 is installed on the fixed piles 102; the lower end of each protective pile 2 is fixed in the ditch bed of the gentle slope section 5, and the upper end face of each protective pile 2 is flush, and the center of the upper end face of each protective pile 2 is located on the same straight line, and the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5; the fixed piles 102 are fixed on the protective piles 2, and the flexible protective net 1 is parallel to the plane where the axes of all protective piles 2 are located.

[0056] Specifically, the fixed piles 102 consist of horizontal and vertical piles, one end of which is connected to the other end of the vertical pile, with the angle between the horizontal and vertical piles being 90°. There are two fixed piles 102, which are fixed to the two outermost protective piles 2 of the protective pile group in a mirror-symmetrical manner via the horizontal piles. The flexible mesh 101 is mounted on the vertical piles of the fixed piles 102. The flexible mesh is a high-strength galvanized steel wire mesh with a plurality of square grids with a grid size of 30 cm x 30 cm. The lower edge of the flexible mesh 101 is fixed to the upper end surface of each protective pile 2. The flexible protective net 1 is equipped with five reinforcing anchor cables 3 made of high-strength galvanized steel wire. The two ends of each reinforcing anchor cable 3 are respectively fixed to the vertical piles of the two fixed piles 102. Each reinforcing anchor cable 3 is arranged parallel to the width of the flexible protective net 1, and the distance a between adjacent reinforcing anchor cables 3 is 1 m. The flexible net 101 of the flexible protection net 1 is rectangular, with a height of 4 m and a width of 10 m. The protection piles 2 are cubes with a side length of 1 m, and the distance between adjacent protection piles 2 is 1.5 m.

[0057] like Figure 5 As shown, when the rigid-flexible composite channel debris flow blocking structure is set in the channel, the lower end of each protective pile 2 is fixed in the channel bed of the gentle slope section 5, the angle between each protective pile 2 and the bed surface of the channel bed of the gentle slope section 5 is 90°, the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-course direction of the gentle slope section 5, and the distance between each protective pile 2 and the steep-to-gentle junction of the steep-to-gentle junction of the channel is 0 m, that is, the edge of the upstream side of each protective pile 2 is located at the steep-to-gentle junction of the steep-to-gentle junction of the channel.

[0058] Comparative Example 1

[0059] In this comparative example, a group of protective piles is set in the channel physical model.

[0060] exist Figure 2 The protective pile group is arranged in the channel physical model shown in FIG. The schematic diagram after the protective pile group is arranged in the channel physical model is shown in FIG. Figure 6 The structural diagram of the protective pile group is shown in Figure 7 As shown, the protective pile group consists of four identical protective piles 2, each of which is a regular quadrangular prism with a square base. Each pile 2 is 5 m tall and has a base side length of 1 m. The centers of the upper end faces of each pile are aligned, and the line connecting the centers of the upper end faces of each pile 2 is perpendicular to the direction of travel along the gentle slope section 5. The distance between adjacent piles 2 is 1.5 m. The lower end of each pile 2 is fixed to the bed of the gentle slope section 5, and each pile 2 is perpendicular to the bed of the gentle slope section 5. The distance between each pile 2 and the steep-to-gentle transition point of the channel is 0 m, that is, the upstream edge of each pile 2 is located at the steep-to-gentle transition point of the channel.

[0061] Comparative Example 2

[0062] In this comparative example, a flexible protective net is set in the channel physical model.

[0063] exist Figure 2 A flexible protective net is set in the channel physical model shown in FIG. The schematic diagram after setting the flexible protective net in the channel physical model is as shown in FIG. Figure 7 As shown, the structural diagram of the flexible protective net is as follows Figure 8 As shown. Similar to the flexible protective net in Example 1, the flexible protective net 1 in this comparative example consists of a flexible mesh body and fixed piles. The fixed piles consist of horizontal piles and vertical piles. One end of the horizontal pile is connected to the end of the vertical pile, and the angle between the horizontal and vertical piles is 90°. There are two fixed piles, which are fixed in the ditch bed of the gentle slope section 5 in a mirror-symmetrical manner through the horizontal piles. After being fixed, the vertical piles are perpendicular to the bed surface of the ditch bed of the gentle slope section 5. The flexible mesh body is installed on the vertical piles of the fixed piles. The flexible mesh is a high-strength galvanized steel wire mesh with several square grids with a grid size of 30 cm × 30 cm. The distance between the lower edge of the flexible mesh body and the bed surface of the ditch bed of the gentle slope section 5 is 2 cm. The flexible protective net is equipped with six reinforcing anchor cables 3 made of high-strength galvanized steel wire. The two ends of each reinforcing anchor cable are fixed to the vertical piles of two fixed piles. Each reinforcing anchor cable is arranged parallel to the width of the flexible protective net, and the distance between adjacent reinforcing anchor cables is 1 meter. The flexible net body of the flexible protective net is rectangular with a height of 5 m and a width of 10 m.

[0064] The flexible protective net 1 is installed on the bed of the gentle slope section 5, perpendicular to the bed of the gentle slope section 5. The width of the flexible protective net is aligned with the width of the ditch bed of the gentle slope section. The upstream edge of the flexible protective net is located at the steep-to-gentle transition between the steep-to-gentle transition section. Multiple inclined cables are installed on the upstream and downstream sides of the flexible protective net to enhance the fixed stability of the flexible protective net. One end of the inclined cable is connected to the longitudinal pile of the fixed pile, and the other end is fixed to the bed of the steep slope section 4 or the gentle slope section 5.

[0065] Comparative Example 3

[0066] In this comparative example, the same channel physical model as that of Example 1 is used, and no channel debris flow blocking structure is arranged in the channel physical model. Example 2

[0067] In this embodiment, numerical simulations are performed on the transport process of the channel debris flow in the channel physical model of the rigid-flexible composite channel debris flow blocking structure in Example 1 and the channel physical model in Example 3 to compare their effects on the movement law of the channel debris flow. The specific simulation method and parameter settings are as described above.

[0068] Figure 10 This is a cloud diagram of the movement speed of particles at different times in the channel physical model of Comparative Example 3. Figure 11 This is a cloud diagram of the particle movement speed at different times in the channel physical model of the embodiment 1 in which a rigid-flexible composite channel debris flow blocking structure is set. Figures 10-12 It can be seen that in the steep slope section, particles (debris flow) accelerate along the ditch bed under the action of gravity. When it enters the gentle slope section, the movement speed of the particles gradually decreases and eventually accumulates. Figure 10 As shown in Figure 2, when there is no blocking structure in the channel, the debris flow exhibits high-speed and strong impact movement characteristics. Figure 11 As shown in the figure, after the rigid-flexible composite channel debris flow intercepting structure is arranged in the channel, the movement process of the debris flow shows obvious staged blocking characteristics. First, the coarse particles moving at high speed at the front of the debris flow surface collide with the rigid protection pile group, and the kinetic energy is significantly dissipated. At the same time, the particles splashed from the bed surface are effectively intercepted by the flexible protection net; then, with the continuous accumulation of a large number of particles, the bed surface gradually rises, and the subsequent fine particles moving at low speed are successfully blocked by the flexible protection net.

[0069] This demonstrates that the rigid-flexible composite channel debris flow interception structure integrates the synergistic effects of a rigid protective pile group and a flexible protective net. The rigid protective pile group provides strong initial impact resistance, while the flexible protective net effectively intercepts debris flow. The flexible protective net intercepts particles that are ejected from the bed surface after colliding with the rigid protective piles, as well as particles that subsequently accumulate and move at low speeds after the bed surface is elevated. This combined design effectively addresses the technical challenges of existing flexible protective nets in intercepting high-speed, large particles, such as insufficient impact resistance and poor durability. Furthermore, the rigid-flexible composite channel debris flow interception structure also exhibits excellent water permeability and stability. Example 3

[0070] In this embodiment, numerical simulations are performed on the channel physical models in Example 1 and Comparative Examples 1-2, which are equipped with a rigid-flexible composite channel debris flow blocking structure, a protective pile group and a flexible protective net, as well as the channel debris flow transport process in the channel physical model in Comparative Example 3, to compare their effects on the average particle movement velocity. The specific simulation method and parameter settings are as described above.

[0071] Figure 12 Figures (a) and (b) are the curves showing the relationship between the average velocity of particles in the longitudinal and vertical directions and time in the channel physical model under the working conditions of Example 1 and Comparative Examples 1 to 3, respectively. In the figure, the pile group represents the working condition of Comparative Example 1, the flexible protective net represents the working condition of Comparative Example 2, the non-blocking structure represents the working condition of Comparative Example 3, and the new blocking structure represents the working condition of Example 1. Figure 12As can be seen, under the four operating conditions of Example 1 and Comparative Examples 1-3, the average velocity of particles (debris flow) in both the longitudinal and transverse directions increases first and then decreases, a pattern consistent with the fundamental dynamics of debris flow motion. Compared to the operating condition of Comparative Example 3, where no retaining structure was placed within the channel, the inclusion of a retaining structure reduced the velocity of the debris flow. However, under the condition of consistent retaining structure height, the average velocity of particles in both the longitudinal and transverse directions was not sensitive to the type of retaining structure. Example 4

[0072] In this example, the channel physical model of Example 1 and Comparative Examples 1-2, which is equipped with a rigid-flexible composite channel debris flow blocking structure, a protective pile group, and a flexible protective net, as well as the channel physical model of Comparative Example 3, is numerically simulated to compare their effects on the downstream sediment replenishment process. The specific simulation method and parameter settings are as described above. When analyzing the data, particles with a diameter of 10 cm, 30 cm, and 40 cm are selected as the research objects, and the channel horizontal distance is used as the reference. x =39 m (the horizontal projection length of the steep slope section is 39 m) is the characteristic monitoring section, and the accumulation of particles in the characteristic monitoring section is analyzed.

[0073] Figure 13 Figure 1 is the cumulative mass of particles of different particle sizes passing through the characteristic monitoring section over time, where (a) is the cumulative mass of the total particles of the debris flow passing through the characteristic monitoring section over time, (b) is the cumulative mass of particles with a particle size of 10 cm passing through the characteristic monitoring section over time, (c) is the cumulative mass of particles with a particle size of 30 cm passing through the characteristic monitoring section over time, and (d) is the cumulative mass of particles with a particle size of 40 cm passing through the characteristic monitoring section over time. Figure 13 It can be seen that the rate of increase of the cumulative mass of the particles shows a nonlinear change characteristic of first increasing and then decreasing. When a retaining structure is set in the channel, the cumulative mass of the particles passing through the characteristic monitoring section will be significantly reduced. Compared with the working condition in which no retaining structure is set in the channel in Comparative Example 3, under the working conditions of Example 1, Comparative Example 1 and Comparative Example 2, the cumulative mass of the particles is reduced by 83.9%, 68.0% and 97.3%, respectively.

[0074] Further analysis showed that under the operating conditions of Example 1 and Comparative Examples 1-2, the interception structure exhibited high interception efficiency for particles with a diameter of 10 cm. The interception efficiency of the flexible protective net 1 in Comparative Example 2 was 98.1%, the interception efficiency of the rigid-flexible composite channel debris flow interception structure in Example 1 was 90.0%, and the interception efficiency of the protective pile group in Comparative Example 1 was 84.8%. However, the interception efficiency for coarse particles with a diameter of 40 cm showed a different pattern: the interception efficiency of the rigid-flexible composite channel debris flow interception structure in Example 1 was 87.3%, the interception efficiency of the flexible protective net in Comparative Example 2 was 98.0%, and the interception efficiency of the protective pile group in Comparative Example 1 was 57.3%. This demonstrates the superiority of the flexible protective net in intercepting large particles. Example 5

[0075] In this embodiment, a numerical simulation is performed on the transport process of the channel debris flow in the channel physical model of Example 1 and Comparative Example 1, in which a rigid-flexible composite channel debris flow retaining structure and a protective pile group are set. The changes in the force of the protective pile groups of the two retaining structures and the debris flow over time during the debris flow impact process are compared. The specific simulation method and parameter settings are as described above.

[0076] Figure 14 The average force between the rigid protective pile group in the rigid-flexible composite channel debris flow blocking structure in Example 1 and the protective pile group in Comparative Example 1 and the debris flow changes over time. Figure 14 It can be seen that during the debris flow impact, when the leading edge of the debris flow collides with the retaining structure, the interaction force between the protective pile group and the debris flow of the retaining structures of Example 1 and Comparative Example 1 quickly reaches a peak value. The peak interaction force between the protective pile group and the debris flow of Comparative Example 1 is 1.39 times the peak interaction force between the rigid protective pile group and the debris flow in the retaining structure of Example 1. Over time, the interaction force between the protective pile group and the debris flow of the retaining structures of Example 1 and Comparative Example 1 gradually decays and reaches a stable state. In the stable state, the interaction force between the protective pile group and the debris flow of Comparative Example 1 is 1.21 times the interaction force between the rigid protective pile group and the debris flow in the retaining structure of Example 1. This mechanical response characteristic verifies that the rigid-flexible composite channel debris flow retaining structure of the present invention can effectively reduce the impact load of the rigid protective pile group by more than 30% through the energy dissipation and load redistribution mechanism of its flexible protective net, demonstrating a superior load transfer path and excellent impact resistance. That is, the load acting on the rigid protection pile group is effectively reduced, which is beneficial to extending the service life of the rigid protection pile group. Example 6

[0077] In this embodiment, a numerical simulation is performed on the transport process of the channel debris flow in the channel physical model of Example 1 and Comparative Example 2, in which a rigid-flexible composite channel debris flow retaining structure and a flexible protective net are set. The displacement response characteristics and the tension characteristics of the reinforced anchor cables of the flexible protective nets of the two retaining structures during the debris flow impact are compared. The specific simulation method and parameter settings are as described above.

[0078] Figure 15 Figures (a) and (b) show the displacement response characteristics of the reinforcing anchor cables of the flexible protective net of comparative example 2 and the flexible protective net of the barrier structure of embodiment 1. In the figures, anchor cables 1 to 5 represent the reinforcing anchor cables arranged on the flexible protective net in sequence from the upper end to the lower end of the flexible protective net. Figure 15 As shown in Figure (a), the flexible protection net of comparative example 2 shows an obvious stratification effect during the impact of high-speed debris flow. The flexible protection net at the bottom first bears the impact and triggers the corresponding reinforcement anchor cable ( Figure 15 The anchor cables 4 and 5 in (a) are displaced. As the particles at the leading edge continue to accumulate to form a natural buffer layer, the subsequent particles gradually rise and impact the flexible protective net in the middle and upper parts, eventually resulting in the maximum displacement of the reinforced anchor cables in the longitudinal direction showing a distribution characteristic of "large in the middle and small at both ends" from bottom to top along the height direction. Figure 15 As shown in Figure (b), due to the pre-intercepting effect of the rigid protection pile group, the particle impact mode of the retaining structure of Example 1 is significantly changed. The maximum displacement of the reinforced anchor cables of the flexible protection net of the retaining structure of Example 1 in the longitudinal direction shows a gradient decreasing distribution from bottom to top along the height direction. The maximum displacement of the reinforced anchor cables in the flexible protection net of the retaining structure of Example 1 in the longitudinal direction is reduced by 39.2% compared with the reinforced anchor cables in the flexible protection net of the comparative example 2. The reinforced anchor cables ( Figure 15 The displacement of anchor cable 1 in Figure (b) exhibits a distinct oscillatory characteristic along the path, indicating that residual energy continues to dissipate even after particle accumulation stabilizes. This phenomenon demonstrates that the flexible protective net of the rigid-flexible composite channel debris flow interceptor structure described herein has a longer energy dissipation time course. These experimental results demonstrate that the synergistic working mechanism of "rigid interception and flexible interception energy dissipation" in the rigid-flexible composite channel debris flow interceptor structure described herein achieves a cascaded dissipation and optimized distribution of impact energy, significantly enhancing the interceptor structure's protection against channel debris flows.

[0079] Figure 16 Figures (a) and (b) show the change of tension of the reinforcing anchor cables of the flexible protective net of comparative example 2 and the flexible protective net of the barrier structure of embodiment 1 over time. In the figures, anchor cables 1 to 5 respectively represent the reinforcing anchor cables arranged on the flexible protective net in the direction from the upper end to the lower end of the flexible protective net. Figure 16 As shown in Figure (a), the stress process of the flexible protection net of comparative example 2 is a typical bottom impact mode. The debris flow first impacts the bottom of the flexible protection net, causing the reinforced anchor cable ( Figure 16 The tension of anchor cables 4 and 5 in Figure (a) increases first; under the continuous particle supply from upstream, the tension of the reinforced anchor cables quickly reaches a peak value, and its peak tension shows a non-monotonic trend of increasing first and then decreasing along the height direction; then, due to the deceleration and sedimentation of particles, the tension of the reinforced anchor cables gradually decays and eventually stabilizes. Figure 16 As shown in (b), for the retaining structure of Example 1, the high-speed debris flow first collides with the rigid protective pile group of the retaining structure. This interaction significantly changes the load distribution pattern in the retaining structure. Under the action of the rigid protective pile group, the peak tension of the reinforcing anchor cables of the flexible protective net shows a regular distribution along the height direction, monotonically increasing from top to bottom. Its maximum peak load is 38.6% lower than that of the flexible protective net of Comparative Example 2. This experimental result shows that the rigid-flexible composite channel debris flow retaining structure of the present invention can effectively reduce the load borne by the flexible protective net by optimizing the force transmission path, showing superior impact resistance. Example 7

[0080] In this embodiment, numerical simulations are performed on the channel physical models in Example 1 and Comparative Examples 1-2, which are equipped with a rigid-flexible composite channel debris flow retaining structure, a protective pile group and a flexible protective net, as well as the channel debris flow transport process in the channel physical model in Comparative Example 3, to compare their effects on the accumulation morphology of the channel debris flow. The specific simulation method and parameter settings are as described above.

[0081] Figure 17 This is the accumulation form of channel debris flow in the channel physical model with different types of retaining structures. In the figure, the pile group represents the working condition of comparative example 1, the flexible protection net represents the working condition of comparative example 2, the non-retaining structure represents the working condition of comparative example 3, and the new retaining structure represents the working condition of embodiment 1. Figure 17 It can be seen that when there is no retaining structure in the channel, the debris flow accumulation body presents a relatively flat morphological feature. After the retaining structure is set, the particle accumulation position moves toward the upstream direction of the channel as a whole, and the accumulation thickness in the area with a horizontal distance greater than 40 m is significantly reduced compared with when there is no retaining structure, while the accumulation thickness in the area near the foot of the steep slope section is significantly increased. By comparing the sedimentation profiles of different retaining structures, it can be found that the sedimentation body formed after the protective pile group is set in Example 1 has the widest extension range, and the sedimentation body formed after the rigid-flexible composite channel debris flow retaining structure is set in Example 1 has a smaller extension range. In the area with a horizontal distance greater than 40 m, the sedimentation thickness after the protective pile group is set in Example 1 is the largest, and the sedimentation thickness after the rigid-flexible composite channel debris flow retaining structure is reduced in Example 1.

[0082] The numerical simulation process of the above embodiments 2 to 7 confirms that the rigid-flexible composite channel debris flow retaining structure of the present invention is set in the gentle slope section of the steep-gentle transition section of the channel. The rigid protection pile group in the retaining structure can effectively resist the initial impact of coarse particles located in the front section of the debris flow surface, and the flexible protection net in the retaining structure can realize the subsequent interception of flying particles and fine particles. The synergistic effect of the two can effectively solve the technical problem of insufficient impact resistance of traditional flexible protection nets. Example 8

[0083] In this embodiment, a rigid-flexible composite channel debris flow blocking structure is provided.

[0084] The rigid-flexible composite channel debris flow barrier structure is arranged in an actual natural channel. The channel includes a steep slope section 4 and a gentle slope section 5. The steep slope section 4 and the gentle slope section 5 have the same width. The width of the steep slope section 4 is B = 16 m. The angle between the channel bed surface of the gentle slope section 5 and the horizontal plane is 1.5°, and the angle between the channel bed surface of the steep slope section 4 and the horizontal plane is α =35°, there is loose accumulation at the top of the steep slope section 4, which will be transformed into channel debris flow under the impact of the incoming flow.

[0085] The rigid-flexible composite channel debris flow blocking structure consists of a flexible protective net 1 and a rigid protective pile group, and the rigid protective pile group includes four protective piles 2; the blocking structure is arranged in the ditch bed of the gentle slope section 5 of the steep-to-gentle transition section of the channel; the flexible protective net 1 consists of a flexible net body 101 and fixed piles 102, and the flexible net body 101 is installed on the fixed piles 102; the lower end of each protective pile 2 is fixed in the ditch bed of the gentle slope section 5, and the upper end face of each protective pile 2 is flush, and the center of the upper end face of each protective pile 2 is located on the same straight line, and the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5; the fixed piles 102 are fixed on the protective piles 2, and the flexible protective net 1 is parallel to the plane where the axes of all protective piles 2 are located.

[0086] Specifically, the fixed piles 102 consist of horizontal and vertical piles, one end of which is connected to the other end of the vertical pile, with the angle between the horizontal and vertical piles being 90°. There are two fixed piles 102, which are fixed to the two outermost protective piles 2 of the protective pile group in a mirror-symmetrical manner via the horizontal piles. The flexible mesh 101 is installed on the vertical piles of the fixed piles 102. The flexible mesh 101 is a high-strength galvanized steel wire mesh with a plurality of square grids with a grid size of 30 cm x 30 cm. The lower edge of the flexible mesh 101 is fixed to the upper end surface of each protective pile 2. The flexible protective net 1 is equipped with five reinforcing anchor cables 3 made of high-strength galvanized steel wire. The two ends of each reinforcing anchor cable 3 are respectively fixed to the vertical piles of the two fixed piles 102. Each reinforcing anchor cable 3 is arranged parallel to the width of the flexible protective net 1, and the distance a between adjacent reinforcing anchor cables 3 is 1 meter. The flexible net 101 of the flexible protection net 1 is rectangular, with a height of 8 m and a width of 16 m. The protection piles 2 are cubes with a side length of 1 m, and the distance between adjacent protection piles 2 is 4 m.

[0087] When the rigid-flexible composite channel debris flow retaining structure is set in the channel, the lower end of each protective pile 2 is fixed in the channel bed of the gentle slope section 5, the angle between each protective pile 2 and the bed surface of the channel bed of the gentle slope section 5 is 85°, the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5, the distance between each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 3 m, that is, the distance between the edge of the upstream side of each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 3 m. Example 9

[0088] In this embodiment, a rigid-flexible composite channel debris flow blocking structure is provided.

[0089] The rigid-flexible composite channel debris flow barrier structure was arranged in an actual natural channel. The channel includes a steep slope section 4 and a gentle slope section 5. The steep slope section 4 and the gentle slope section 5 are of equal width. The width B of the steep slope section 4 is 16 m. The angle between the channel bed surface of the gentle slope section 5 and the horizontal plane is 1.5°, and the angle α between the channel bed surface of the steep slope section 4 and the horizontal plane is 35°. Loose accumulation is accumulated at the top of the steep slope section 4, which will be transformed into channel debris flow under the impact of the incoming flow.

[0090] The rigid-flexible composite channel debris flow blocking structure consists of a flexible protective net 1 and a rigid protective pile group, and the rigid protective pile group includes four protective piles 2; the blocking structure is arranged in the ditch bed of the gentle slope section 5 of the steep-to-gentle transition section of the channel; the flexible protective net 1 consists of a flexible net body 101 and fixed piles 102, and the flexible net body 101 is installed on the fixed piles 102; the lower end of each protective pile 2 is fixed in the ditch bed of the gentle slope section 5, and the upper end face of each protective pile 2 is flush, and the center of the upper end face of each protective pile 2 is located on the same straight line, and the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5; the fixed piles 102 are fixed on the protective piles 2, and the flexible protective net 1 is parallel to the plane where the axes of all protective piles 2 are located.

[0091] Specifically, the fixed piles 102 consist of horizontal and vertical piles, with one end of the horizontal pile connected to the other end of the vertical pile, forming a 100° angle between them. There are two fixed piles 102, each secured to the two outermost protective piles 2 of the protective pile group in a mirror-symmetrical manner via the horizontal pile. The flexible mesh 101 is mounted on the vertical piles of the fixed piles 102. The flexible mesh 101 is a high-strength galvanized steel wire mesh with a plurality of square grids measuring 30 cm x 30 cm. The lower edge of the flexible mesh 101 is secured to the upper end surface of each protective pile 2. The flexible protective net 1 is equipped with five reinforcing anchor cables 3 made of high-strength galvanized steel wire. Each anchor cable 3 is secured at both ends to the vertical piles of the two fixed piles 102. Each anchor cable 3 is arranged parallel to the width of the flexible protective net 1, with a distance a = 1 m between adjacent anchor cables 3. Flexible mesh 101 of flexible protective net 1 is an isosceles trapezoid, 12 meters high and 16 meters wide at its narrowest point. That is, the width of flexible mesh 101 at its lower end is 16 meters. Protective piles 2 are 3.2 meters high and are specifically rectangular parallelepipeds measuring 2 meters by 2 meters by 3.2 meters. Adjacent protective piles 2 are 1.6 meters apart.

[0092] When the rigid-flexible composite channel debris flow retaining structure is set in the channel, the lower end of each protective pile 2 is fixed in the channel bed of the gentle slope section 5, the angle between each protective pile 2 and the bed surface of the channel bed of the gentle slope section 5 is 90°, the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5, and the distance between each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 4 m, that is, the distance between the edge of the upstream side of each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 4 m. Example 10

[0093] In this embodiment, a rigid-flexible composite channel debris flow blocking structure is provided.

[0094] The rigid-flexible composite channel debris flow barrier structure is arranged in an actual natural channel. The channel includes a steep slope section 4 and a gentle slope section 5. The steep slope section 4 and the gentle slope section 5 have the same width. The width of the steep slope section 4 is B = 20 m. The angle between the channel bed surface of the gentle slope section 5 and the horizontal plane is 2.1°, and the angle between the channel bed surface of the steep slope section 4 and the horizontal plane is α =43°, there is loose accumulation at the top of the steep slope section 4, which will be transformed into channel debris flow under the impact of the incoming flow.

[0095] The rigid-flexible composite channel debris flow blocking structure consists of a flexible protective net 1 and a rigid protective pile group, and the rigid protective pile group includes four protective piles 2; the blocking structure is arranged in the ditch bed of the gentle slope section 5 of the steep-to-gentle transition section of the channel; the flexible protective net 1 consists of a flexible net body 101 and fixed piles 102, and the flexible net body 101 is installed on the fixed piles 102; the lower end of each protective pile 2 is fixed in the ditch bed of the gentle slope section 5, and the upper end face of each protective pile 2 is flush, and the center of the upper end face of each protective pile 2 is located on the same straight line, and the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5; the fixed piles 102 are fixed on the protective piles 2, and the flexible protective net 1 is parallel to the plane where the axes of all protective piles 2 are located.

[0096] Specifically, the fixed piles 102 consist of horizontal and vertical piles, one end of which is connected to the other end of the vertical pile, with the angle between the horizontal and vertical piles being 120°. There are two fixed piles 102, which are fixed to the two outermost protective piles 2 of the protective pile group in a mirror-symmetrical manner via the horizontal piles. The flexible mesh 101 is mounted on the vertical piles of the fixed piles 102. The flexible mesh 101 is a high-strength galvanized steel wire mesh with a plurality of square grids measuring 30 cm x 30 cm. The lower edge of the flexible mesh 101 is fixed to the upper end surface of each protective pile 2. The flexible protective net 1 is equipped with five reinforcing anchor cables 3 made of high-strength galvanized steel wire. Each reinforcing anchor cable 3 is fixed to the vertical piles of the two fixed piles 102 at both ends. Each reinforcing anchor cable 3 is arranged parallel to the width of the flexible protective net 1, with a distance a = 1 m between adjacent reinforcing anchor cables 3. Flexible mesh 101 of flexible protective net 1 is an isosceles trapezoid, 20 meters high and 24 meters wide at its narrowest point. That is, the width of flexible mesh 101 at its lower end is 24 meters. Protective piles 2 are 3 meters high and are specifically rectangular parallelepipeds measuring 2 meters by 2 meters by 3 meters. Adjacent protective piles are 4 meters apart.

[0097] When the rigid-flexible composite channel debris flow retaining structure is set in the channel, the lower end of each protective pile 2 is fixed in the channel bed of the gentle slope section 5, the angle between each protective pile 2 and the bed surface of the channel bed of the gentle slope section 5 is 95°, the line connecting the centers of the upper end faces of each protective pile 2 is perpendicular to the along-direction of the gentle slope section 5, the distance between each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 5 m, that is, the distance between the edge of the upstream side of each protective pile 2 and the steep-to-gentle connection of the steep-to-gentle connection section of the channel is 5 m.

Claims

1. A rigid-flexible composite channel debris flow blocking structure, characterized in that: The retaining structure comprises a flexible protective net (1) and a rigid protective pile group, wherein the rigid protective pile group comprises a plurality of protective piles (2); the retaining structure is arranged in a gentle slope ditch bed of a steep-gentle transition section of a ditch; The flexible protective net (1) is composed of a flexible net body (101) and a fixed pile (102), wherein the flexible net body (101) is installed on the fixed pile (102); the lower end of each protective pile (2) is fixed in the ditch bed of the gentle slope section, the upper end surface of each protective pile (2) is flush, the center of the upper end surface of each protective pile (2) is located on the same straight line, and the line connecting the centers of the upper end surfaces of each protective pile (2) is perpendicular to the along-course direction of the gentle slope section; the fixed pile (102) is fixed on the protective pile (2), and the plane where the axes of the flexible protective net (1) and all the protective piles (2) are located is parallel to each other.

2. The rigid-flexible composite channel debris flow blocking structure according to claim 1, characterized in that: The fixing pile (102) consists of a horizontal pile and a vertical pile, one end of the horizontal pile is connected to one end of the vertical pile, and the angle between the horizontal pile and the vertical pile is 90° to 120°. There are two fixing piles (102), and the two fixing piles are fixed to the protective pile (2) through the horizontal pile in a mirror-symmetrical manner.

3. The rigid-flexible composite channel debris flow blocking structure according to claim 1, characterized in that: The width of the narrowest part of the flexible protective net (1) is 1.0 to 1.2 times the width of the ditch bed of the gentle slope section, and the height of the flexible protective net (1) is 0.4 to 1 times the width of the ditch bed of the gentle slope section.

4. The rigid-flexible composite channel debris flow blocking structure according to claim 1, characterized in that: A plurality of reinforcing anchor cables (3) are provided on the flexible protective net (1), and both ends of each reinforcing anchor cable (3) are fixed on a fixed pile (102).

5. The rigid-flexible composite channel debris flow blocking structure according to claim 4, characterized in that: Each reinforced anchor cable (3) is arranged parallel to the width direction of the flexible protective net (1).

6. The rigid-flexible composite channel debris flow blocking structure according to claim 1, characterized in that: The lower edge of the flexible net (101) is fixed to the upper end surface of each protection pile (2).

7. The rigid-flexible composite channel debris flow blocking structure according to any one of claims 1 to 6, characterized in that: The height of the protection pile (2) is 0.05 to 0.2 times the width of the ditch bed in the gentle slope section.

8. The rigid-flexible composite channel debris flow blocking structure according to any one of claims 1 to 6, characterized in that: The distance between adjacent protection piles (2) is 0.1 to 0.4 times the width of the ditch bed in the gentle slope section.

9. The rigid-flexible composite channel debris flow blocking structure according to any one of claims 1 to 6, characterized in that: The angle between each protective pile (2) and the bed surface of the ditch bed in the gentle slope section is 90°±5°.

10. The rigid-flexible composite channel debris flow blocking structure according to any one of claims 1 to 6, characterized in that: Each protection pile (2) is arranged upstream of the disaster prevention protection object on the gentle slope section.

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