Open type landslide debris flow interlaced blocking dam group

Abstract

The present application provides an open type landslide debris flow staggered blocking dam group based on the movement characteristics and accumulation deformation law of landslide debris flow, the blocking dam group comprises a plurality of blocking dams, each blocking dam is arranged staggeredly in a channel downstream of a landslide body, the intersection angle between each blocking dam and the channel is 30-60 degrees, the end of the blocking dam close to the edge of the channel is recorded as the head end, the end of the blocking dam close to the center of the channel is recorded as the tail end, and the head end of each blocking dam is located upstream of the tail end of each blocking dam. The open type landslide debris flow staggered blocking dam group can effectively reduce the movement speed and kinetic energy of the particles in the landslide debris flow, can reduce the accumulation of the landslide debris in the protection structure while achieving energy dissipation, can effectively reduce the bearing capacity of a single blocking dam, can enhance the safety and stability of the blocking dam group, and provides a new way for disaster prevention and mitigation of landslide debris flow.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of landslide disaster prevention and mitigation, and relates to an open type landslide debris flow staggered blocking dam group. BACKGROUND

[0002] Due to the extremely strong destructive power of landslide debris flow, how to establish an effective landslide debris flow prevention and control structure system has been one of the important topics in landslide dynamics research. Many scholars at home and abroad have carried out relevant researches on the disaster-causing mechanism and disaster prevention and mitigation methods of landslide debris flow. For example, Zhou et al. analyzed the influence of the changes of sediment gradation, sediment discharge and channel slope on the movement process of landslide debris flow through model test. Xiao Suyou et al. studied the collision energy dissipation effect of landslide debris flow blocking wall under different slope conditions based on three-dimensional discrete element method, and constructed a dynamic model of landslide debris flow blocking wall. Gai Yingchao et al. carried out numerical research on the landslide debris flow of Niujuangou caused by Wenchuan earthquake in 2018 through flow element model, and analyzed the influence of factors such as vegetation, blocking wall position and height on the movement and accumulation process of landslide debris flow.

[0003] At present, the research on high-speed long-range landslide debris flow prevention and control technology at home and abroad has just started, and the action mechanism between loose slope body and protection structure is still in the stage of analysis and research, and there is no mature prevention and control design method for practical engineering use. The traditional blocking structure mostly adopts a large overall blocking dam, although it can effectively block the loose slope body, but due to the limited storage capacity, when the storage capacity is filled, it loses the resistance ability, and once the upper blocking dam is damaged, it will cause a chain reaction, thereby causing more serious disaster. Therefore, it is necessary to design a landslide debris flow protection system with simple structure, safety and stability, and good blocking effect. SUMMARY

[0004] In view of the shortcomings of the existing landslide debris flow prevention and control technology, the present application provides an open type landslide debris flow staggered blocking dam group based on the movement characteristics and accumulation deformation law of landslide debris flow, so as to realize energy dissipation while reducing the accumulation of landslide debris in the protection structure, enhance the safety and stability of the blocking dam group, and realize the regulation of the downstream sediment supply process, thereby providing a new technical means for landslide debris flow disaster prevention and mitigation.

[0005] In order to achieve the above-mentioned application purposes, the technical scheme adopted by the present application is as follows:

[0006] An open type landslide debris flow staggered blocking dam group, the blocking dam group comprising a plurality of blocking dams, each blocking dam being arranged staggered in a channel downstream of a landslide body, the intersection angle θ of each blocking dam with the channel being 30°-60°, one end of the blocking dam close to the edge of the channel being recorded as the first end, one end of the blocking dam close to the center of the channel being recorded as the last end, and the first end of each blocking dam being located upstream of the last end of each blocking dam.

[0007] In the technical solution, the retaining dams are divided into a first retaining dam group and a second retaining dam group, the first ends of the retaining dams in the first retaining dam group are located on the left side of the channel, and the first ends of the retaining dams in the second retaining dam group are located on the right side of the channel. The left side and the right side of the channel herein refer to the regions close to the left boundary and the right boundary of the channel, respectively, based on the direction of water flow in the channel.

[0008] Further, the first ends of the retaining dams in the first retaining dam group are arranged close to the left edge of the channel, and the first ends of the retaining dams in the second retaining dam group are arranged close to the right edge of the channel. The left edge and the right edge of the channel herein refer to the left boundary and the right boundary of the channel, respectively, based on the direction of water flow in the channel.

[0009] Further, in the technical solution, the retaining dams in the first retaining dam group and the retaining dams in the second retaining dam group are staggered, which means that, except for the two retaining dams located at the most upstream and the most downstream, any retaining dam in the first retaining dam group is located between two adjacent retaining dams in the second retaining dam group, and any retaining dam in the second retaining dam group is located between two adjacent retaining dams in the first retaining dam group.

[0010] In the technical solution, the interval between the adjacent retaining dams in the first retaining dam group and the interval between the adjacent retaining dams in the second retaining dam group are determined according to the actual engineering conditions, for example, according to the topographic features (such as channel size, channel gradient, etc.) of the actual channel and the features of the landslide mass (loose accumulation). Preferably, the interval between the adjacent retaining dams in the first retaining dam group is 10-20 m, and the interval between the adjacent retaining dams in the second retaining dam group is 10-20 m.

[0011] In the technical solution, the number of retaining dams is determined according to the actual engineering conditions, for example, according to the topographic features (such as channel size, channel gradient, etc.) of the actual channel and the features of the landslide mass (loose accumulation). In order to effectively reduce the movement speed and kinetic energy of the particles in the landslide debris flow, the number of retaining dams is at least 2, for example, the number of retaining dams can be 2-10.

[0012] In the technical solution, the length D of the retaining dam is 0.2-0.4 times the width of the channel, and the length of the retaining dam refers to the distance from the first end to the end of the retaining dam.

[0013] In the technical solution, the height of the retaining dam is preferably 0.5-0.8 times the length of the retaining dam.

[0014] In the above technical solution, the length and height of the barrier dam satisfy the above conditions, and the thickness and specific shape of the barrier dam generally only need to satisfy that the strength of the barrier dam can resist the impact of the debris flow of the landslide body, without other special requirements, for example, the shape of the barrier dam in the cross section perpendicular to the length direction of the barrier dam can be rectangular, trapezoidal or other shapes.

[0015] In the above technical solution, the face of each barrier dam facing the incoming flow of the landslide debris flow is perpendicular or close to perpendicular to the bottom surface of the channel, and generally, the included angle between the face of each barrier dam facing the incoming flow of the landslide debris flow and the bottom surface of the channel is 90°±5°.

[0016] In the above technical solution, the arrangement position of the barrier dam in the channel generally only needs to satisfy that the barrier dam is located downstream of the landslide body in the channel, further, the slope of the channel section where the barrier dam is located is smaller than the slope of the channel section where the landslide body is located, and further, the channel section where the barrier dam is located and the channel section where the landslide body is located are connected to each other, and the slope of the channel section where the barrier dam is located is smaller than the slope of the channel section where the landslide body is located.

[0017] Compared with the prior art, the technical solution provided by the present application has the following beneficial technical effects:

[0018] 1. The present application provides an open type landslide debris flow staggered barrier dam group, which comprises a plurality of barrier dams, each barrier dam being staggered arranged in the channel downstream of the landslide body, one end of the barrier dam close to the edge of the channel being marked as the first end, one end of the barrier dam close to the center of the channel being marked as the last end, and the first end of each barrier dam being located upstream of the last end of each barrier dam. The open type arrangement adopted by the present application has strong water permeability, and compared with the whole type barrier dam in the prior art, the open type arrangement of the present application can reduce the accumulation of landslide debris in the protection structure while achieving energy dissipation, and can make up for the deficiency that the landslide debris in the existing barrier structure is not easy to clean, and the barrier effect will be significantly reduced once the landslide occurs again. At the same time, the barrier dam in the present application is at a certain angle with the channel, and each barrier dam is staggered arranged, which can effectively reduce the bearing capacity of a single barrier dam, is conducive to enhancing the safety and stability of the barrier dam group, can solve the problems of limited storage capacity and limited structural stability of the large whole type barrier dam used in the prior art, and is a landslide debris flow protection system with simple structure, safety and stability.

[0019] 2. The open type landslide debris flow staggered barrier dam group combines efficiency and barrier, has simple structure, and can flexibly adjust the size, number of barrier dams and the intersection angle of each barrier dam with the channel according to the actual engineering situation and the prevention and control requirements of landslide debris flow, so as to regulate and control the barrier and efficiency effect on the landslide debris flow, and is easy to be applied in engineering. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Figure 1 is a comparison chart of the numerical simulation results of different particle sizes and the results of the indoor physical model test in the literature.

[0021] Figure 2 Figure 2 is a schematic diagram of a channel physical model composed of three grades of slopes.

[0022] Figure 3 Figure 3 is a schematic diagram of arranging an open-type landslide debris flow staggered dam group in a channel physical model.

[0023] Figure 4 Figure 4 is a schematic diagram of one arrangement of an open-type landslide debris flow staggered dam group.

[0024] Figure 5 Figure 5 is a schematic diagram of another arrangement of an open-type landslide debris flow staggered dam group.

[0025] Figures 3 to 5 In the figure, 1—dam, D—length of the dam, n r —spacing between two adjacent dams in the same dam group along the channel direction, θ—intersection angle of the dam and the channel.

[0026] Figure 6 Figure 6 is a particle size distribution diagram of a landslide debris flow.

[0027] Figure 7 Figure 7 is a particle velocity cloud chart at different times in the channel physical model of Example 1 arranged according to the first arrangement of the dam group.

[0028] Figure 8 Figure 8 is a particle velocity cloud chart at different times in the channel physical model of Comparative Example 1.

[0029] Figure 9 Figure 9 is a relationship between the average kinetic energy of the particles and time in the channel physical model of Example 1 arranged with the dam group and the channel physical model of Comparative Example 1 without the dam group.

[0030] Figure 10 Figure 10 is a relationship between the cumulative mass of the particles entering the downstream and time in the channel physical model of Example 1 arranged with the dam group and the channel physical model of Comparative Example 1 without the dam group.

[0031] Figure 11 Figure 11 is a final accumulation pattern of the particles in the channel in the channel physical model of Example 1 arranged with the dam group and the channel physical model of Comparative Example 1 without the dam group. DETAILED DESCRIPTION

[0032] The open-type landslide debris flow staggered blocking dam group according to the present application is further described below in connection with the drawings by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above description of the present application, and the specific implementation still belongs to the protection scope of the present application.

[0033] In the following examples, in order to analyze the influence of the open-type staggered blocking dam group on the movement characteristics of the landslide debris flow, the discrete element method is used to numerically simulate the sliding and depositing process of the landslide debris flow under different working conditions. Here, the reliability and accuracy of the discrete element method in simulating the movement process of the landslide debris flow are verified first.

[0034] The indoor physical model test 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.] is numerically simulated by using the discrete element method. Specifically, the movement process of the sediment particles with a particle size of 5-20 mm and a particle size of 20-60 mm is numerically simulated under the condition of a sediment supply of 0.015 m 3 . Figure 1 The comparison between the numerical simulation results of different particle sizes and the indoor physical model test results in the literature under the condition of a sediment supply of 0.015 m 3 is given. It can be found that the numerical simulation results by using the discrete element method are consistent with the indoor physical test results in the literature, which shows that the discrete element method can better simulate the movement process of the landslide debris flow.

[0035] Example 1

[0036] In this embodiment, various open-type landslide debris flow staggered blocking dam groups in different forms are provided.

[0037] Considering the characteristics of the natural channel with steep and gentle sections, in this embodiment, a channel physical model composed of three levels of slopes is used according to the topography of a certain natural channel, as shown in Figure 2As shown, in the channel physical model, the width of the channel B = 20 m, the length of the first slope L1 = 60 m, the length of the second slope L2 = 60 m, the length of the third slope L3 = 200 m, the angle between the first slope and the horizontal plane a1 = 50°, the angle between the second slope and the horizontal plane a2 = 20°, and the angle between the third slope and the horizontal plane a3 = 0°. The top end of the first slope of the channel physical model is accumulated with a landslide body (loose accumulation body), which will be converted into a landslide debris flow under the impact of the incoming flow.

[0038] The open landslide debris flow staggered check dam group is arranged on the second slope of the channel physical model, as shown in Figure 3 As shown, the specific arrangement form of the open landslide debris flow staggered check dam group is described as follows:

[0039] The first arrangement form: the schematic diagram (top view) of the first arrangement form is shown in Figure 4 As shown, an open landslide debris flow staggered check dam group includes four check dams, each check dam is arranged on the second slope in the channel, each check dam is arranged vertically to the second slope, the four check dams are divided into a first check dam group and a second check dam group, and each of the first check dam group and the second check dam group includes two check dams; each check dam has the same shape, which is a cuboid, one end of the check dam close to the edge of the channel is marked as the head end, and the other end of the check dam close to the center of the channel is marked as the tail end, the height of each check dam l = 3 m, and the length of the check dam (the distance between the head end and the tail end of the check dam) D = 5 m; the head end of each check dam is located upstream of the tail end of each check dam; the head end of each check dam in the first check dam group is in contact with the left side edge of the channel, and the head end of each check dam in the second check dam group is in contact with the right side edge of the channel, wherein the left side edge and the right side edge of the channel refer to the left side boundary and the right side boundary of the channel based on the direction of the water flow in the channel; the two check dams in the first check dam group are parallel to each other, the distance between the two adjacent check dams in the channel direction n r = 20 m, the two check dams in the second check dam group are parallel to each other, the distance between the two adjacent check dams in the channel direction n r = 20 m; the intersection angle between each check dam and the channel θ = 60°; the check dams in the first check dam group and the check dams in the second check dam group are arranged alternately, specifically, the head end of one check dam in the first check dam group is located at the midpoint of the line connecting the head ends of the two check dams in the second check dam group, and the head end of one check dam in the second check dam group is located at the midpoint of the line connecting the head ends of the two check dams in the first check dam group.

[0040] The second arrangement is basically the same as the first arrangement, except that the length D of the barrier dam is 4 m, the intersection angle θ of each barrier dam with the channel is 30°, the distance n between two adjacent barrier dams in the first group of barrier dams along the direction of the channel is 12 m, and the distance n between two adjacent barrier dams in the second group of barrier dams along the direction of the channel is 12 m. r r

[0041] The third arrangement is basically the same as the second arrangement, except that the distance n between two adjacent barrier dams in the first group of barrier dams along the direction of the channel is 16 m, and the distance n between two adjacent barrier dams in the second group of barrier dams along the direction of the channel is 16 m. r r

[0042] The fourth arrangement is basically the same as the second arrangement, except that the distance n between two adjacent barrier dams in the first group of barrier dams along the direction of the channel is 20 m, and the distance n between two adjacent barrier dams in the second group of barrier dams along the direction of the channel is 20 m. r r

[0043] The fifth arrangement is basically the same as the second arrangement, except that the intersection angle θ of each barrier dam with the channel is 45°.

[0044] The sixth arrangement is basically the same as the second arrangement, except that the intersection angle θ of each barrier dam with the channel is 60°.

[0045] The seventh arrangement is basically the same as the second arrangement, except that the length D of the barrier dam is 5 m.

[0046] The eighth arrangement is basically the same as the second arrangement, except that the length D of the barrier dam is 6 m. Figure 4 ​​​​​​As shown, the second arrangement is basically the same as the first arrangement, except that the dam group includes six dams, the six dams are divided into a first dam group and a second dam group, and the first dam group and the second dam group each include three dams; the dams in the first dam group and the dams in the second dam group are staggered, specifically, the first and second dams in the first dam group have their first ends located at the midpoint of the line connecting the first and second, and the second and third, dams in the second dam group, and the third and second dams in the second dam group have their first ends located at the midpoint of the line connecting the third and second, and the second and first, dams in the first dam group.

[0047] The ninth arrangement is basically the same as the second arrangement, except that the length of each dam D = 5 m, and the intersection angle between each dam and the channel θ = 60°.

[0048] The tenth arrangement is basically the same as the second arrangement, except that the length of each dam D = 5 m, the intersection angle between each dam and the channel θ = 60°, the two dams in the first dam group are parallel to each other, the distance between the two adjacent dams in the channel direction n r = 16 m, and the two dams in the second dam group are parallel to each other, the distance between the two adjacent dams in the channel direction n r = 16 m.

[0049] The eleventh arrangement is basically the same as the ninth arrangement, except that the intersection angle between each dam and the channel θ = 30°.

[0050] The twelfth arrangement is basically the same as the ninth arrangement, except that the intersection angle between each dam and the channel θ = 45°.

[0051] The thirteenth arrangement is basically the same as the eighth arrangement, except that the intersection angle between each dam and the channel θ = 60°, and the length of each dam D = 5 m.

[0052] The fourteenth arrangement is basically the same as the fourth arrangement, except that the intersection angle between each dam and the channel θ = 45°

[0053] The fifteenth arrangement is basically the same as the fourth arrangement, except that the intersection angle between each dam and the channel θ = 60°

[0054] The arrangement parameters of the open landslide debris flow staggered blocking dam group in the above various arrangement forms are listed in Table 1.

[0055] Table 1 Arrangement parameters of open landslide debris flow staggered blocking dam group

[0056]

[0057]

[0058] Comparative Example 1

[0059] In the present comparative example, the same channel physical model as in Example 1 is used, and the difference from Example 1 is that no blocking dam is arranged in the channel.

[0060] Example 2

[0061] In the present example, the discrete element method is used to simulate the sliding and accumulation process of the landslide debris flow. The sliding and accumulation process of the landslide debris flow is simulated under the conditions that the blocking dam group is arranged in the channel in Example 1 and no blocking dam is arranged in the channel in Comparative Example 1, in order to compare and investigate the influence of the open landslide debris flow staggered blocking dam group on the movement law of the landslide debris flow.

[0062] In the present example, the numerical simulation calculation is carried out by referring to the method in the literature [Zhao C, Fu C H, Zou H M, et al. Three-dimensional landslide process numerical simulation analysis based on discrete element method [J]. People's Pearl River, 2015, 4(2): 11-15.]. The calculation parameters used are shown in Table 2. In the calculation process, the cohesion between the particles of the landslide debris flow is not considered, and the particle size distribution of the landslide debris flow is shown in Table 2. Figure 6

[0063] Table 2 Calculation parameters

[0064]

[0065] 1. Numerical simulation of the first arrangement form in Example 1 and Comparative Example 1 is carried out to compare the influence of setting the open landslide debris flow staggered blocking dam group on the movement law of the landslide debris flow

[0066] The first arrangement form in Example 1 and Comparative Example 1 is numerically simulated under the condition that the sliding friction coefficient μ = 0.4 by using the aforementioned method of the present example. Figure 7 is the particle motion velocity cloud chart in the channel physical model of Example 1 arranged according to the first arrangement form of the blocking dam group at different times. Figure 8 ​is the velocity cloud of the particles in the physical model of the channel in Comparative Example 1 at different times. The particles start to move under the influence of gravity and accelerate downward along the slope. Since the particles in the front section are less constrained, the particles move at a higher speed. After the particles in the front section collide with the slope bottom, the particles lose a large amount of kinetic energy, and the speed of the particles gradually decreases and the particles accumulate near the slope toe. Figure 7 and Figure 8 It can be found that after the open-type landslide debris flow staggered block dam group is arranged in the channel, the block dam has a significant hindering effect on the movement of the particles. When the particles collide with the block dam, the kinetic energy of the particles is greatly lost, and the speed of the particles is significantly reduced.

[0067] 2. Numerical simulation is performed on the second to eighth arrangement forms in Example 1 and Comparative Example 1 to investigate the influence of the arrangement form of the open-type landslide debris flow staggered block dam group on the energy dissipation effect

[0068] The second to eighth arrangement forms in Example 1 and Comparative Example 1 are numerically simulated by using the aforementioned method of the present embodiment under the condition that the sliding friction coefficient μ is 0.2. Figure 9 is the change relationship between the average kinetic energy of the particles and time in the channel physical model in which the block dam group is arranged in Example 1 and the channel physical model in which no block dam group is arranged in Comparative Example 1. In the figure, (A) is the change relationship between the average kinetic energy of the particles of the landslide debris flow and time in the second to fourth arrangement forms in Example 1 and Comparative Example 1, (B) is the change relationship between the average kinetic energy of the particles of the landslide debris flow and time in the second, fifth and sixth arrangement forms in Example 1 and Comparative Example 1, (C) is the change relationship between the average kinetic energy of the particles of the landslide debris flow and time in the second, seventh arrangement form in Example 1 and Comparative Example 1, and (D) is the change relationship between the average kinetic energy of the particles of the landslide debris flow and time in the second, eighth arrangement form in Example 1 and Comparative Example 1.

[0069] From Figure 9 It can be seen that with the passage of time, the average kinetic energy of the particles presents a trend of first increasing and then decreasing. Since the open-type landslide debris flow staggered block dam group is arranged on the second slope in the channel, the particles do not contact the block dam in the first 4s after the particles start to move, and therefore the time at which the average kinetic energy of the particles reaches the peak value and the peak value of the average kinetic energy of the particles are independent of the arrangement form of the block dam. After the particles contact the block dam, the average kinetic energy and the speed of the particles are significantly reduced, which indicates that the open-type landslide debris flow staggered block dam group has a good energy dissipation effect. In the same block dam group, the spacing n between the adjacent two block dams in the channel direction is rThe influence on the change relationship of the average kinetic energy of the particles with time is small. The average kinetic energy of the particles decreases with the increase of the intersection angle θ of the dam and the channel. With the increase of the number of the dams and the increase of the length of the dam, the average kinetic energy of the particles gradually decreases.

[0070] 2. Numerical simulation is performed on the first to thirteenth arrangement forms in embodiment 1 and the comparative example 1 to explore the relationship between the downstream sediment supply process and the arrangement form of the open landslide debris flow staggered dam group.

[0071] The aforementioned method of the embodiment is used to perform numerical simulation on part of the first to thirteenth arrangement forms in embodiment 1 and the comparative example 1 under the condition that the sliding friction coefficient μ is 0.4. Figure 10 is the change relationship of the cumulative mass of the particles entering the downstream with time in the channel physical model in which the dam group is arranged in embodiment 1 and the channel physical model in which the dam group is not arranged in the comparative example 1, wherein (A) is the change relationship of the cumulative mass of the particles entering the downstream with time in the first, ninth and tenth arrangement forms in embodiment 1 and the comparative example 1, (B) is the change relationship of the cumulative mass of the particles entering the downstream with time in the ninth, eleventh and twelfth arrangement forms in embodiment 1 and the comparative example 1, (C) is the change relationship of the cumulative mass of the particles entering the downstream with time in the sixth and ninth arrangement forms in embodiment 1 and the comparative example 1, and (D) is the change relationship of the cumulative mass of the particles entering the downstream with time in the ninth and thirteenth arrangement forms in embodiment 1 and the comparative example 1.

[0072] From Figure 10 It can be seen that with the increase of time, the increase rate of the sediment mass entering the downstream presents the change feature of first increasing and then decreasing. Arranging the open landslide debris flow staggered dam group in the channel can delay the starting time of the particles entering the downstream, and the sediment supply mass is greatly reduced. The increase of the spacing n between the adjacent two dams in the same dam group along the channel direction causes the starting time of the downstream sediment supply to be slightly advanced, and the cumulative mass of the particles entering the downstream to be reduced. r The increase of the intersection angle of the dam and the channel, the increase of the number of the dam and the increase of the length of the dam can delay the starting time of the downstream sediment supply, increase the energy loss of the particles, slow down the movement speed of the particles, and cause the accumulation position of the particles to be closer to the slope toe, which makes many particles stay in the slope channel and fail to enter the downstream, so that the sediment supply mass in the downstream is obviously reduced.

[0073] 4. Numerical simulation is performed on the first to fifteenth arrangement forms in embodiment 1 and the comparative example 1 to investigate the influence of the arrangement form of the open landslide debris flow staggered dam group on the particle accumulation law in the branch channel.

[0074] The aforementioned method of the present embodiment was used to perform numerical simulation on some of the first to fifteenth arrangements in Example 1 and Comparative Example 1 under the condition of a sliding friction coefficient μ = 0.4. Figure 11 are diagrams of the final accumulation of particles in the channel in the channel physical model of Example 1 with the arrangement of the set of check dams and the channel physical model of Comparative Example 1 without the arrangement of the set of check dams, wherein (A) is a diagram of the final accumulation of particles in the channel in the first, ninth and tenth arrangements in Example 1 and Comparative Example 1, (B) is a diagram of the final accumulation of particles in the channel in the fourth, fourteenth and fifteenth arrangements in Example 1 and Comparative Example 1, (C) is a diagram of the final accumulation of particles in the channel in the sixth and ninth arrangements in Example 1 and Comparative Example 1, and (D) is a diagram of the final accumulation of particles in the channel in the ninth and thirteenth arrangements in Example 1 and Comparative Example 1.

[0075] From Figure 11 It can be seen that after the set of check dams of the open landslide debris flow is arranged in the channel, the accumulation position of the particles moves towards the channel as a whole, and the accumulation thickness at the toe of the slope is smaller than the deposition thickness when the set of check dams is not arranged. As the spacing n r between the adjacent two check dams in the same set of check dams increases along the channel direction, the accumulation thickness of the particles in the region where the set of check dams is arranged and upstream thereof increases, while the accumulation thickness of the particles in the region downstream of the region where the set of check dams is arranged decreases, as shown in (A) of Figure 11 The greater the intersection angle of the check dam and the channel, the farther the accumulation position of the particles from the channel, and in the region with a horizontal distance of less than 75 m, the accumulation thickness of the particles gradually increases as the intersection angle of the check dam and the channel increases, while near the toe of the slope, the accumulation thickness of the particles gradually decreases as the intersection angle of the check dam and the channel increases, as shown in (B) of Figure 11 The increase in the length of the check dam increases the efficiency of the check dam in hindering the movement of the particles, resulting in that most of the particles are accumulated in the channel, and thus the mass of the sediment entering the channel is greatly reduced. In the region with a horizontal distance of less than 75 m, the accumulation thickness and volume of the particles gradually increase as the length of the check dam increases, while near the toe of the slope, the accumulation thickness and volume of the particles gradually decrease as the length of the check dam increases, as shown in (C) of Figure 11 The increase in the number of the check dams improves the check dam effect on the particles, and the more the number of the check dams, the closer the accumulation position of the particles to the channel. In the channel, the accumulation volume and thickness of the particles are positively correlated with the number of the check dams, while near the toe of the slope, the accumulation volume and thickness of the particles are negatively correlated with the number of the check dams, as shown in (D) of Figure 11

[0076] ​The embodiment proves by the above numerical simulation process that the application can effectively reduce the particle movement speed and kinetic energy of the landslide debris flow, adjust the sediment supply process downstream, and thus can produce disaster prevention and mitigation effect on the landslide by arranging the open landslide debris flow staggered check dam group in the channel.

Claims

1. An open-type landslide debris flow interlocking dam set, characterized by, The retaining dam group includes several retaining dams (1), which are staggered in the gully downstream of the landslide body. The gully section where the retaining dam is located is connected to the gully section where the landslide body is located. The slope of the gully section where the retaining dam is located is less than the slope of the gully section where the landslide body is located. The angle of intersection between each retaining dam and the gully is ( θ The angle is 30°~45°. The end of the barrier dam closest to the edge of the gully is called the beginning end, and the end of the barrier dam closest to the center of the gully is called the end end. The beginning end of each barrier dam is located upstream of the end end of each barrier dam. The barrier dams are divided into a first barrier dam group and a second barrier dam group, the first ends of the barrier dams in the first barrier dam group are located near the left side of the gully, and the first ends of the barrier dams in the second barrier dam group are located on the right side of the gully; The barrier dams in the first barrier dam group and the barrier dams in the second barrier dam group are staggered arranged; The spacing between each adjacent barrier dam in the first barrier dam group along the gully direction is 12-20 m, and the spacing between each adjacent barrier dam in the second barrier dam group along the gully direction is 12-20 m; The shapes of the barrier dams are the same, and each barrier dam is in the shape of a cuboid; the length (D) of each barrier dam is 0.2-0.25 times the width of the gully; the height of the barrier dam is 0.5-0.8 times the distance from the first end to the end of the barrier dam; and the angle between the face of each barrier dam facing the incoming debris flow and the gully bottom surface is 90°±5°.

2. The open landslide debris flow interlocking dam set of claim 1, wherein, The number of the barrier dams is at least 2.

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