CN216892261U - Closed debris flow drainage structure - Google Patents

Abstract

The utility model provides a closed debris flow drainage and guide structure, which comprises a drainage guide hole arranged in a mountain body on the bank side of a branch ditch, a layered grid arranged at the inlet of the drainage guide hole and a blocking dam positioned on the downstream side of the inlet of the drainage guide hole; the inlet of the layered grating corresponding to the row of guide holes is provided with a grating, and a distributed water inlet hole is arranged above the elevation A, wherein the elevation A is the water depth height of the debris flow under the designed peak flow; the height of the layered grating meets the height B, and the height B is the maximum sedimentation height of the total amount of certain fixed objects of the debris flow in front of the retaining dam according to the fortification standard; the height of the blocking dam is higher than the height C, and the height C is the maximum water level of the primary fixed substance total amount of the debris flow in the fortification standard after the blocking dam is silted. The scheme realizes 'water stone' diversion treatment, can meet the silt stopping requirement of solids and can ensure that the discharge guide tunnel has enough discharge capacity under the condition of local silt blockage at the inlet; meanwhile, the section of the guide hole can be obviously reduced, and the engineering difficulty and cost are reduced.

Description

Closed debris flow drainage structure

Technical Field

The utility model relates to a closed debris flow drainage structure suitable for mountainous valley.

Background

Debris flow is the flood flow formed by saturated dilution of soft soil mountain bodies containing sand and stones in gullies due to heavy rain and flood, and has large area, volume and flow, and typical debris flow is composed of viscous slurry which is suspended with coarse solid debris and is rich in silt and clay. The debris flow has high solid content and contains huge stones, the debris flow moves along the steep terrain and slope surface of the mountain high slope, the flow speed can reach several meters or even dozens of meters per second, high potential energy is converted into strong kinetic energy, and the destructive power is very large; and in gentle slope areas, the sludge can be rapidly accumulated and deposited. It has a very different movement mechanism from that of general flood and water flow. Because the composition is not uniform, the flow of the mud-rock flow is unstable, even the mud level (water level) passing through the same section is not changed, the passing quality of the mud-rock flow in unit time is changed along with time, the general mud-rock flow has a gust flow and a front (faucet), the movement of the mud-rock flow has obvious straight-moving property, and the mud-rock flow is difficult to disturb or change direction when meeting obstacles or passing through a bend, so that a violent impact action or climbing and impacting and blocking phenomena are generated. According to the current national standard, the debris flow prevention and control needs to meet the prevention and control standards of ditch water and debris flow at the same time, and the prevention and control standards and the treatment of the ditch water are finished together. The flood source in the debris flow composition is rainfall (rainstorm), the rainfall brings continuous supply to the flood, the total amount is large, and if the rainfall is timely discharged, secondary disasters can be avoided. At present, rainfall and flood calculation and analysis models are mature, calculation and prediction results of flood peaks and flood volumes are verified through practice of a large number of projects, design of a diversion tunnel section is carried out by utilizing a mature hydraulic calculation theory, timely flood drainage can be reliably achieved, and related technical problems are clear. And solid particulate matters carried in debris flow flood water have various formation mechanisms, the body types and the movement mechanisms are changed at multiple ends, the impact damage to the discharge and guide structure under the impact and impact effects is large, the discharge and guide difficulty is large, and the secondary influence is large. In particular, the phenomenon that particles with over diameters appear in debris flow cannot be eliminated, the phenomenon that a drainage channel is blocked in a closed channel cannot be eliminated, and then the normal drainage of rainstorm and flood is influenced, so that the whole rainstorm, flood drainage and debris flow control system fails and malfunctions are caused, and the difficulty and pain point of debris flow drainage design are caused.

At present, debris flow prevention and control projects tend to be comprehensively managed. If the circulation area of the debris flow is a protected object, the circulation path of the debris flow is generally controlled and changed, and the drainage scheme is an important scheme and engineering measure for preventing and treating the debris flow. The drainage scheme can preferentially select an open drainage scheme, namely a discharge chute, and the top of the discharge chute is not provided with a potential barrier and is relatively difficult to be blocked by the solid particles of the carried over-diameter debris flow. However, debris flow prevention and control projects are all in deep cutting ditches and valleys in mountain areas, most potential drainage lines are arranged on two sides of the ditches and are tall in mountain shapes, and excavation conditions of open drainage and drainage grooves are not usually implemented, so that the buried drainage and guidance tunnel becomes the only option for treating debris flow by adopting a drainage and guidance scheme. In order to improve the super drainage capacity and prevent the blocking risk, the traditional method of the buried drainage tunnel is to enlarge the section of the tunnel and simulate and achieve the operation effect and the working condition of the open drainage chute as much as possible. However, the increase of the section of the tunnel inevitably brings about a great increase of the scale and investment of the drainage engineering, and the operation effect and the working condition of the open type drainage chute can be achieved only by increasing the section to a certain extent. The phenomenon is a big problem of debris flow prevention and control because the buried type discharging and guiding tunnel scheme has the defects of poor economy and reliability.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art and provide a small-section debris flow drainage structure which reduces the construction difficulty and can effectively reduce the risk of clogging of a drainage channel.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

a closed debris flow drainage structure comprises a drainage guide hole arranged in a mountain body on the bank side of a branch ditch, a layered grating arranged at an inlet of the drainage guide hole and a blocking dam positioned on the downstream side of the inlet of the drainage guide hole; the layered grating is arranged at the position corresponding to the inlet of the row of guide holes and is provided with distributed water inlet holes above the elevation A, and the elevation A is the water depth height of the debris flow under the designed peak flow; the height of the layered grating meets an elevation B, and the elevation B is the maximum sedimentation height of the total amount of certain fixed objects of the debris flow in the fortification standard in front of the retaining dam; the height of the blocking dam is higher than the height C, and the height C is the maximum water level of the certain fixed total amount of substances of the debris flow in the fortification standard after the blocking dam is silted.

Furthermore, the height difference between the blocking dam and the elevation C is not less than 0.3-0.5 m.

Furthermore, the size of the holes of the grating is smaller than 1/2-1/3 of the width of the row guide holes.

Furthermore, the size of the opening of the water inlet hole is smaller than 1/2-1/3 of the width of the row guide hole.

Further, the grid is of a concrete structure, a steel structure or a reinforced concrete structure.

According to the technical scheme, the grid structure is arranged at the inlet of the drainage and guide hole according to the composition and the movement characteristics of the debris flow, so that the debris flow can be effectively limited and controlled to carry large-particle solid matters into the closed drainage and guide hole, the clogging risk of the closed drainage and guide hole is reduced and avoided, the reliability and the adaptability of the closed drainage and guide hole are obviously improved, and the manufacturing cost of drainage and guide engineering is reduced. And moreover, the blocking dam is arranged on the downstream side of the inlet, the layered water inlet structure is arranged at the inlet of the drainage and guide tunnel, so that the diversion treatment of the water stone is realized, the silt stopping requirement of solid matters can be met, the drainage and guide tunnel can be ensured to have enough drainage capacity under the condition of local silting of the inlet, and rainstorm and flood drainage channels can be kept smooth to reduce the requirement on the storage capacity of the blocking dam, the scale of the blocking dam and the implementation difficulty. Meanwhile, the scheme can remarkably reduce the section of the drainage guide tunnel under the condition that the safety and the reliability are not reduced, the requirement of a protection structure needing to be arranged is weakened, and the selectable drainage guide scheme under the condition that the high and steep terrains do not have the function of excavating the open-air chute is added on both sides.

Drawings

FIG. 1 is a floor plan of the present invention.

Fig. 2 is a cross-sectional layout of the present invention.

Detailed Description

The utility model is further described below with reference to the accompanying drawings.

The embodiment comprises a row guide tunnel 3 arranged in a mountain body 4 at the shore of the branch trench 1, a layered grating 2 arranged at the shore of the branch trench 1 at the inlet of the row guide tunnel 3 and a blocking dam 5 positioned at the downstream side of the inlet of the row guide tunnel 3. This technical scheme can bypass potential protection zone 7 with the rivers that mobility is strong (the mud-rock flow after containing the large granule solid is planed) and arrange and lead to low reaches main river course 8, stops becoming silted up in the district 6 that silts up with the solid matter total amount of mud-rock flow under the standard of seting up defences.

Specifically, the layered grating 2 can realize the separation of 'water and stone', the grating 21 is arranged at the inlet of the corresponding row guide hole 3 and below the elevation A, the distributed water inlet holes 22 are arranged above the elevation A, and the elevation A is the water depth height of the debris flow under the design peak flow under the condition of non-siltation. The grid 21 can adopt various permeable structures such as a concrete structure, a steel structure or a reinforced concrete structure, and the opening size of the holes of the grid 21 is smaller than 1/2-1/3 of the width of the row guide hole 3, and is generally selected to be 0.2-5.0 m. The water inlet hole 22 is generally a hole of a reinforced concrete structure (or plain concrete structure), the size of the hole is smaller than 1/2-1/3 of the width of the row guide hole 3, the hole is preferably 0.2-5.0 m generally, the hole can be in various forms such as a round hole and a square hole, a steel grid, a reinforcing mesh and the like can be added in the middle of the hole, and the total flow area meets the water flow demand of debris flow under the fortification standard. The maximum silt stopping elevation of the total amount of certain solid matters of the debris flow in the siltation area 6 under the fortification standard is elevation B, and the maximum water level under the siltation condition is elevation C.

The height of the layered grating 2 satisfies the elevation B. The siltation area 6 is formed by a blocking dam 5 arranged at the downstream, the elevation of the blocking dam 5 is higher than the elevation C, and the height difference between the blocking dam 5 and the elevation C is not less than 0.3-0.5 m. The blocking dam 5 can adopt various dam types such as a concrete gravity dam, an earth-rock dam and the like, and meets the requirements of water retaining and seepage prevention. The section of the row guide hole 3 can be a plurality of conventional hydraulic tunnel sections such as a city gate hole type and the like, and the equivalent hole diameter is 3.0-15.0 m. The diameter of the 3 conventional debris flow discharge guide holes is usually limited by the largest solid particulate matter to be discharged, and is not less than 2.5 times of the largest solid particulate matter according to the standard requirement and is often more than 2-3 times of the cross section area required by the peak flow of the discharged debris flow, so that the technical scheme can effectively prevent large solid particles with the largest potential hazard to the closed space from entering the closed discharge guide holes 3 through debris flow 'water-stone' separation treatment, thereby reducing the cross section area of the discharge guide holes 3, forming a reliable and relatively economic closed discharge guide hole 3 scheme, increasing the selectable discharge guide scheme under the condition that the two sides of the closed space do not have open-air excavation chute for high and steep terrains, increasing the diversity of debris flow prevention and control means, and being beneficial to reducing the total investment of debris flow prevention and control engineering and improving the comprehensive benefit.

The construction method of the embodiment comprises the following steps:

a, step a: firstly, excavating a hole body of the row guide tunnel 3 in a mountain body 4 of a potential row guide line, and then completing pouring construction of a hole body structure of the row guide tunnel 3;

step b: cofferdams are implemented around the water inlet structures of the layered grids 2 on the shore of the branch ditches 1 (if the floor of the water inlet structures of the layered grids 2 is higher than the height of a flood level in the construction period, the cofferdams do not need to be changed), and dry land construction conditions are realized. Excavating a foundation of a water inlet structure of the layered grating 2, and pouring a concrete structure and a grating of the water inlet structure of the layered grating 2;

step c: and (3) after the water inlet structures of the guide discharging tunnels 3 and the layered grating 2 have running conditions (overflowing), arranging a cofferdam in a construction period at the front edge of the blocking dam 5, and then performing foundation excavation and dam body construction of the blocking dam 5.

It should be noted that the above describes exemplifying embodiments of the utility model. It will be understood by those skilled in the art, however, that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, but that various changes and modifications may be made without departing from the scope of the utility model as defined by the appended claims.

Claims (5)

1. A closed debris flow drainage structure is characterized by comprising a drainage guide hole arranged in a mountain body on the bank side of a branch ditch, a layered grating arranged at an inlet of the drainage guide hole and a blocking dam positioned on the downstream side of the inlet of the drainage guide hole; the layered grating is arranged at the position corresponding to the inlet of the row of guide holes and is provided with distributed water inlet holes above the elevation A, and the elevation A is the water depth height of the debris flow under the designed peak flow; the height of the layered grating meets the height B, and the height B is the maximum sedimentation height of the total amount of certain fixed objects of debris flow in the fortification standard in front of the retaining dam; the height of the blocking dam is higher than the height C, and the height C is the maximum water level of the certain fixed total amount of substances of the debris flow in the fortification standard after the blocking dam is silted.

2. The enclosed debris flow diversion structure as claimed in claim 1, wherein the height difference between said barrage and said elevation C is 0.3-0.5 m.

3. A closed debris flow deflector according to claim 1, wherein the size of the openings in said grating is less than 1/2 of the width of said deflector opening.

4. A closed debris flow deflector according to claim 1, wherein the opening size of said inlet opening is smaller than 1/2 of the width of said deflector.

5. The enclosed debris flow guide structure as claimed in claim 1, wherein the grating is a concrete structure, a steel structure or a reinforced concrete structure.

Images