An artificial pipe gushing induced dam-break removal structure

Abstract

The utility model discloses an artificial pipe gushing inducing dam body breaching danger-removing structure, including a plurality of drilling channels in the dam body, the entrance of drilling channel is located on the slope surface of dam slope upstream of dam body, and the exit is located on the slope surface of dam slope downstream of dam body, and the drilling channel is equipped with the openwork steel wire mesh in the circumference, and the openwork steel wire mesh forms the through channel from the dam slope upstream to the dam slope downstream in the dam body, when the water level rises to the upstream entrance of drilling channel, the water body flows into the drilling channel from the entrance, and the water flow in the drilling channel continuously carries the fine particle sand and gravel and does not block the flow from the downstream drilling exit, forms the artificial pipe gushing, and continuously causes the dam body to collapse and deform, thereby realizing dam body breaching danger-removing, the utility model structure only needs a plurality of directional drilling parallel operation to form the drilling channel, and the construction efficiency is quick, and the pre-set position of overflow channel entrance can be selected below the top part of dam body, and when breaching, the maximum backwater level of reservoir water level is lower, so that the reservoir capacity and the reservoir area submergence loss are significantly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of emergency response technology for landslide dams, and in particular relates to a structure for artificially induced piping to induce landslide dam failure and eliminate risks. Background Technology

[0002] A landslide-dammed lake is formed in high-altitude canyon areas when sudden geological disasters such as landslides and debris flows enter a river channel, creating a dam that impounds water. Because the dam obstructs the river, it can easily cause the water level in the lake to rise rapidly, or even overflow and breach, resulting in an uncontrolled flood that seriously threatens the lives and property of the people and the safety of infrastructure, causing social panic or crisis. High-risk landslide-dammed lakes are characterized by harsh surrounding environments, strong water storage capacity, large landslide volumes, and great destructive power. The emergency response window is extremely short, and it is almost always possible to manually dredge and excavate the dam to restore river connectivity within a short period of time.

[0003] In response to the dangers of landslide-dammed lakes, current measures mainly involve engineering methods such as excavating diversion channels, blasting to demolish the dammed body, and pumping out the lake water. However, for high-risk landslide-dammed lakes, the volume of the dammed body typically reaches tens of millions of cubic meters, and the reservoir capacity reaches hundreds of millions or even billions of cubic meters. Currently, the maximum pumping capacity is only 10m³ / h. 3 For high-risk landslide dammed lakes with a water volume in the hundreds of millions of cubic meters per second, pumping efficiency is simply "a drop in the ocean," making the emergency response extremely inefficient and practically unsuitable. Blasting to demolish the landslide dam is highly susceptible to uncontrolled blasting, potentially causing further landslides and collapses on both sides, creating an even larger dam. Therefore, blasting is rarely used in actual emergency response for landslide dammed lakes. The diversion channel excavation technique involves manually excavating a diversion channel at the top of the dam using heavy excavation equipment to induce an overtopping flow that erodes the dam and triggers a breach. This is currently the most widely used and effective engineering measure. However, landslide dammed lakes are located in harsh environments with limited construction sites. Heavy excavation equipment typically operates in a single-point manner, resulting in extremely limited excavation efficiency. Within the very short emergency response window, the volume of diversion channel excavation is limited, and the reservoir water level remains high.

[0004] Although the diversion channel technology for landslide dammed lakes can reduce the maximum backwater level and the maximum reservoir capacity to some extent, the harsh environment of the landslide dammed lake, the short emergency response window, and the insufficient efficiency of diversion channel dredging and excavation are all significant challenges. For high-risk landslide dams with vertical heights often reaching hundreds of meters, the amount of diversion channel dredging and excavation in a very short time is extremely limited, and the geometric dimensions of the diversion channel are significantly insufficient, reaching only about 10% of the vertical height of the landslide dam. Furthermore, the reservoir water level needs to rise to the mouth of the diversion channel for the overflowing water to gradually flow over and erode the landslide dam, leading to a breach. Consequently, the maximum backwater level and reservoir capacity of the landslide dammed lake remain relatively large. Summary of the Invention

[0005] This invention addresses the engineering challenges of high reservoir water levels and large reservoir capacity during landslide dam breaches by proposing an artificial piping-induced dam breach mitigation structure. Utilizing the efficient drilling principle of horizontal directional drilling, this invention creates artificial piping channels by drilling holes at lower elevations within the dam body. The continuously rising water pressure intensifies the flow of fine-grained sand and gravel, inducing the dam body to collapse, subside, and deform, potentially leading to a breach and preventing the dam body from overflowing and breaching at higher reservoir water levels.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A structure for artificial piping-induced landslide dam failure mitigation includes multiple drilling channels within the landslide dam body. The drilling channels are inclined within the landslide dam body, with the inlet of the drilling channel located on the upstream slope of the landslide dam body and the outlet of the drilling channel located on the downstream slope of the landslide dam body. The drilling channels are circumferentially equipped with perforated wire mesh, which forms a through channel within the landslide dam body from the upstream slope to the downstream slope of the landslide dam body, and the drilling channels are not blocked during a landslide failure.

[0007] Furthermore, the multiple drilling channels are spaced out from bottom to top within the dam body.

[0008] Furthermore, each of the aforementioned drilling channels is oriented as an inclined straight line within the dam body.

[0009] Furthermore, the multiple drilling channels are actually three, and the three drilling channels are arranged at intervals from bottom to top within the dam body.

[0010] Furthermore, the drilling channel is located in a part of the dammed body where the material structure includes sand, gravel, or fine clay particles.

[0011] Furthermore, the outlet of the drilling channel is located within 1 / 5 of the vertical height of the toe of the downstream slope of the landslide dam.

[0012] Furthermore, the diameter of the perforated wire mesh is 25-30cm.

[0013] Compared with the traditional method of dredging and excavating diversion channels for landslide-dammed lakes, this utility model has the following advantages: 1. The project investment cost of this utility model is low: The existing technology uses a huge amount of diversion channel dredging and excavation work, which requires the organization of multiple excavation and transportation vehicles to carry out the work, which takes a long time and requires a high investment of manpower and material resources. This utility model only requires multiple directional drills to work in parallel, which is more efficient and requires less manpower and material resources.

[0014] 2. Significantly reduced maximum backwater level in the reservoir area: The emergency response window for landslide dammed lakes is short. Existing technologies have limited excavation depth for diversion channels, and the maximum backwater level in the reservoir area generally reaches about 3-5m above the breach of the diversion channel. This utility model has faster construction efficiency, and the preset position of the drilling channel inlet can be selected at a lower elevation. When the breach occurs, the maximum backwater level in the reservoir will be lower, and the water storage capacity and reservoir area inundation losses will be significantly reduced. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the dam structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the dam body of this utility model.

[0017] Figure 3 This is a schematic diagram of the drilling process of the horizontal directional drilling bit of this utility model.

[0018] Figure 4 This is a schematic diagram of the back-drilling process of the horizontal directional drilling reamer of this utility model.

[0019] Wherein: 1 represents the top of the landslide dam, 2 represents the downstream slope of the landslide dam, 3 represents the upstream slope of the landslide dam, 4 represents the drilling channel, 5 represents the inlet of the drilling channel, 6 represents the bottom of the upstream reservoir, H0 represents the vertical height of the downstream outlet of the drilling channel from the toe of the downstream slope of the landslide dam, and H1 represents the initial water level of the landslide-dammed lake. H 2 represents the inlet elevation of the drilling channel, H3 represents the highest elevation of the landslide dammed lake reservoir, D represents a schematic diagram of the horizontal directional drilling installation, and S represents a schematic diagram of the perforated wire mesh installation. H 0 represents the borehole exit elevation. h 0 represents the vertical height of the borehole from the downstream toe of the slope. h 1 represents the vertical height of the landslide dam; 4-1, 4-2, and 4-3 represent multiple drilling channels; 5-1, 5-2, and 5-3 represent the inlets of each drilling channel; L1 represents the drilling distance of the horizontal directional drill per unit time; 6 represents the horizontal directional drill bit; 7 represents the drill rod; 8 represents the reamer; 9 represents the connecting rod; 10 represents the perforated wire mesh; and 11 represents the protective sleeve. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific examples described herein are only some embodiments of this utility model, not all embodiments, and are not intended to limit the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0021] This invention proposes an artificial "piping" induced landslide dam collapse and risk mitigation structure. It utilizes the basic principle of efficient horizontal directional drilling to drill holes at a lower elevation within the landslide dam to form an artificial piping channel. The continuous rise in water pressure intensifies the piping and carries fine-grained sand and gravel, thereby inducing the landslide dam to collapse, settle, deform, or even collapse, thus preventing the landslide dam from overflowing and collapsing when the reservoir water level is higher.

[0022] This utility model discloses a structure for artificial piping-induced landslide dam breaching and hazard mitigation. The landslide dam body includes multiple drilling channels 4, which are inclinedly arranged within the landslide dam body. The inlet of the drilling channel 4 is located on the slope of the upstream dam slope of the landslide dam body, and the outlet of the drilling channel 4 is located on the slope of the downstream dam slope of the landslide dam body. The drilling channel 4 is circumferentially equipped with a perforated wire mesh 10, forming a through channel within the landslide dam body from the upstream dam slope to the downstream dam slope. Each drilling channel 4 is generally inclined and straight within the landslide dam body.

[0023] The design method for realizing the artificial "piping" induced landslide dam failure and hazard mitigation structure of this utility model is as follows: (1) Select the type with the most fine particles (D) 50 ≤3mm dammed bodies are used as typical application objects.

[0024] (2) Measuring the underwater and above-water topography upstream of the landslide dammed lake reservoir area allows for the quantification of the reservoir capacity V as a function of the reservoir water level H, i.e. Let the initial water level of the landslide dam be H1. The reservoir capacity V varies with the reservoir water level H, which depends on the actual measurement or calculation of the specific topography. Usually, a water level-capacity curve is established through hydrological mapping such as topographic maps, remote sensing data, or field measurements, or based on a digital elevation model (DEM), the reservoir capacity at different water levels is calculated by integration, generating a discrete VH correspondence table.

[0025] (3) Measure the material structure and geometric shape of the landslide dam, and record the vertical height of the landslide dam as h1, the upstream slope of the landslide dam as 1:m1, the downstream slope of the landslide dam as 1:m2, and the length of the top 1 of the landslide dam as L0.

[0026] (4) Measure the inflow rate Q0 of the landslide dammed lake. As the upstream water flow continues to enter the landslide dammed lake, the water level of the reservoir gradually rises. Record the time for the water level to rise as t, i.e. V1 is the initial reservoir capacity, V2 is the current reservoir capacity, H1 is the initial water level, and H2 is the current reservoir water level.

[0027] The landslide dammed lake experiences a water storage process as its water level rises. The construction work of this utility model begins after rocks have fallen from the mountain but before the water level rises, or simultaneously with water storage at the edge of the landslide dammed lake and the construction team's work. Figure 1 and Figure 2As shown in this embodiment of the invention, the dam body includes multiple drilling channels. Among these channels, drilling channel 4-3 has the lowest elevation. Construction begins before the water level rises to drilling channel 4-3. The duration of the water level rise is defined as t to determine the construction operation time.

[0028] (5) Select the top pass of the landslide dam and use boreholes to explore the material structure of the landslide dam. Select the location where the material structure of the landslide dam is dominated by fine particles such as sand and gravel or clay as the drilling axis for horizontal directional drilling.

[0029] The term "predominantly fine-particle location" refers to selecting the location with the highest concentration of fine particles after surveying the material structure of multiple parts of the landslide dam. If three drilling channels are set up within the landslide dam, the three locations with the highest number of fine particles are selected as the predominantly fine-particle locations.

[0030] (6) With the help of local emergency response departments, multiple horizontal directional drilling (WD) machines were deployed. The WD machines included a horizontal directional drilling bit 6 and a drill rod 7. The WD efficiency was denoted as . a 1. The efficiency of horizontal directional drilling re-drilling and reaming is: a 2. It should be noted that this process includes the horizontal directional drilling process from upstream to downstream and the horizontal directional drilling process from downstream to upstream. For ease of calculation, the time spent on the installation and connection of the perforated wire cage is ignored.

[0031] (7) Select the initial drilling point on the slope of the upstream slope 3 of the landslide dam and select the drilling inlet and outlet on the slope of the downstream slope 2 of the landslide dam.

[0032] Drilling channel 4 is located within the landslide dam body, extending from the slope surface of the upstream dam slope 3 to the slope surface of the downstream dam slope 2. In one specific embodiment of this utility model, drilling channel 4 includes three drilling channels: 4-1, 4-2, and 4-3. These three drilling channels are arranged vertically and alternately within the landslide dam body, with 4-1, 4-2, and 4-3 serving as the inlets of the three drilling channels located on the upstream dam slope.

[0033] Select the initial drilling point on the upstream slope of the landslide dam, and denote the corresponding water level elevation as H2. Within 1 / 5 of the vertical height of the downstream slope toe, select the drill inlet and outlet on the downstream slope. Denote the vertical height of the drill inlet and outlet from the slope toe as h0, corresponding to elevation H0. Denote the distance between the drill inlet and outlet as L2.

[0034] (8) Lay 2-4 horizontal directional drilling rigs parallel to the horizontal directional drilling axis. The reaming diameter of the horizontal directional drilling rig is D0, which can be 20-40cm. The average drilling distance between each horizontal directional drill is A0, which is 30-50 times the reaming diameter. Then the drilling time of the horizontal directional drilling rig is... .

[0035] (9) To ensure the safety of on-site horizontal directional drilling, record , For safety, a value of 1.2-1.5 is used, meaning that when the duration of the reservoir water level rise coincides with the drilling time of the horizontal directional drill, the horizontal directional drill inlet elevation H2 can reach its minimum.

[0036] (10) In order to avoid collapse and blockage when fine sand and gravel flows through, a perforated iron mesh with a diameter of 25-30cm is followed at the end of the horizontal directional drilling back drill bit. The mesh size of the perforated iron mesh is 2-5cm. A protective sleeve is put on the outer layer of the perforated iron mesh. When the horizontal directional drilling back drills to the upstream dam slope inlet, the protective sleeve 11 can be pulled out as a whole, and the perforated iron mesh can be retained in the dam body.

[0037] Horizontal Directional Drilling (HDD) Working Principle: HDD is a trenchless underground pipeline laying technology. Its core principle is to achieve underground horizontal or curved path construction through directional drilling, borehole reaming, and pipeline pullback. Its main construction stages include: pilot hole drilling, which uses a directional drill to advance along the designed trajectory and drill a small-diameter (usually 10-20cm) initial hole; borehole reaming: when the directional drill reaches the opposite stratum, a reamer is used to reverse the drilling along the pilot hole's path and enlarge the small-diameter initial hole to a diameter suitable for pipeline laying; pipeline pullback: a rotary joint (to prevent pipeline twisting) is connected to the rear end of the reamer, and the drilling rig rotates in the opposite direction and pulls back, dragging the pipeline into the hole along the initial hole path.

[0038] The technical principle of this utility model is as follows: Utilizing the basic principle of efficient and rapid horizontal directional drilling, a flow channel is longitudinally drilled along the loose and weak parts inside the dam body. When the drilling reaches the slope of the downstream dam slope 2 of the dam body, a perforated steel wire mesh 10 is connected to the end of the reamer 8. A connecting rod 9 is provided between the end of the reamer 8 and the perforated steel wire mesh 10. One end of the connecting rod 9 is connected to the end of the reamer 8, and the other end is connected to the perforated steel wire mesh 10. The perforated steel wire mesh 10 is set along the circumference of the drilling channel 4 and is set inside the dam body, closely attached to the inner wall of the dam body. When the reamer 8 is used to drill back and pull back the perforated wire mesh to the inlet of the flow channel, the perforated wire mesh 10 can form a through hole from upstream to downstream in the dam body. When the reservoir water level rises and submerges the inlet of the flow channel, the reservoir water level will flow along the through flow channel due to the gravitational potential energy. As the reservoir water level rises, the head difference between upstream and downstream gradually increases. The water flow in the flow channel continuously carries fine sand and gravel to the downstream, causing the dam body to continuously collapse and deform. Moreover, due to the supporting effect of the perforated wire mesh skeleton, the collapsed sand and gravel in the dam body will not block the flow channel. The water flow in the flow channel can continuously carry and transport sand and gravel, causing the dam body to gradually show soil erosion and damage, forming a piping effect similar to that of a levee, causing the dam body to gradually collapse and deform, or even break.

[0039] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A structure for mitigating the risk of landslide dam failure induced by artificial piping, characterized in that: The dam body includes multiple drilling channels (4), which are inclinedly set in the dam body. The inlet of the drilling channel (4) is located on the slope of the upstream dam slope of the dam body, and the outlet of the drilling channel (4) is located on the slope of the downstream dam slope of the dam body. The drilling channel (4) is circumferentially equipped with a perforated wire mesh (10), which forms a through channel from the upstream dam slope to the downstream dam slope of the dam body in the dam body.

2. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: The multiple drilling channels (4) are spaced out from bottom to top within the dam body.

3. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: Each of the aforementioned drilling channels (4) is in a straight, inclined shape within the dam body.

4. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: The multiple drilling channels (4) are three in number, and the three drilling channels (4) are arranged at intervals from bottom to top in the dam body.

5. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: The drilling channel (4) is located in the part of the dam body where the material structure includes sand, gravel or clay particles.

6. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: The outlet of the drilling channel (4) is located within 1 / 5 of the vertical height of the slope toe of the downstream slope of the landslide dam.

7. The artificial piping-induced dam breaching and hazard mitigation structure according to claim 1, characterized in that: The diameter of the perforated wire mesh (10) is 25-30cm.

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