CN115030114B - Natural ditch-pulling breaking method for river reservoir tributary barrier sand - Google Patents

Abstract

The invention relates to a method for breaking natural ditches for blocking sand in tributary streams of rivers and reservoirs, belonging to the field of water conservancy engineering, and its IPC classification numbers are E02B8/02 and E02B 1/00. The removal method of the present invention is based on the characteristics of low anti-scourability of tributary gate sand and the principle of beam water scour, and builds an assembled water retaining and sand retaining dam of a certain height, sand retaining and sand discharge gates distributed on the upper and lower layers, Water-retaining and sand-retaining gates and assembled diversion walls and other structures, using the ingenious application of each structure, realize the selective backflow of the low-sediment water body in the upper layer of the main stream when the water level is high, reducing the deposition of the sand-rich water flow on the tributaries in the main stream. The water body of the tributaries scours the silt in the flow channel at a high speed, resulting in sand breaks and ditches in the tributary barrage, excavation of tributary storage capacity and sustainable utilization of tributary storage capacity, maximizing the integration of flood control and silt reduction, water supply and power generation of tributary reservoirs benefit.

Description

A method for breaking natural ditch of damming sand in tributaries of rivers and reservoirs

technical field

The invention relates to a method for scouring and removing sand blocking a tributary of a reservoir, in particular to a method for removing the sand blocking a river and a tributary of a river reservoir, belonging to the field of water conservancy engineering, and its IPC classification numbers are E02B 8/02 and E02B1/00.

Background technique

Damming the river to build a reservoir makes the river drop in the reservoir area concentrate on the dam site, changes the flow rate of water and sand in the river, and causes changes in the natural environment of the river flow and the evolution of the river bed. One of the important characteristics is that the sediment is mainly deposited at the low point of the reservoir operation. The water level reaches the upstream end and the tributary mouth area where each tributary flows into the reservoir, forming gate sand. For example, the problem of sand blocking in the Guishui River, a tributary of the Guanting Reservoir, and the sand blocking problem in many tributaries of the Danjiangkou Reservoir. Especially in recent years, as the Xiaolangdi Reservoir of the Yellow River has entered the later stage of sand blocking, the reservoirs of the Yellow River had to be used at low water levels during the flood season. The multi-tributary storage capacity cannot be effectively utilized and the problem is prominent. The inter-irrigation mechanism of different flow regimes of the main and tributary streams of the reservoir, the formation of tributary gate sand and the reduction of ineffective storage capacity of tributary streams caused by engineering problems have become scientific and technological problems. The importance of in-depth research on this scientific and technological problem has become increasingly prominent. A kind of method of eliminating or destroying the sand blocking the tributary of the reservoir just seems particularly urgent and needs.

At present, in order to reduce the impact of sand blocking on the effective utilization of reservoir tributary storage capacity, reservoir management units such as Xiaolangdi, Guanting, Zhexi, Danjiangkou and Baishi have conducted long-term and multi-faceted research and exploration. The main measures and technologies are concentrated in four aspects : (1) Measures for excavating breaches, using dredgers to excavate a river channel on the gate sand to connect the two reservoir areas of the tributary and the main stream. Go to the downstream river course or use the excavated sand to silt up the beach, silt up the land, maintain the river bank, etc. However, according to the practical experience of Xiaolangdi, Guanting, and Zhexi reservoirs, the movement of the sedimentation delta near the gate sand and the sediment back-silting in the dredging tank are inevitable, and the dredging operation window is short, the project volume is large, and the construction conditions are poor , Repeated excavation and other factors, this measure is only in the experimental research stage, without mature technology and experience, and failed to solve the problem that tributary barrage sand hinders the effective use of tributary storage capacity. (2) Optimizing reservoir regulation and shaping precipitation scour measures. During the operation of the reservoir, discharge water before the flood or in case of a long-duration flood process, the reservoir will be used at a low water level, and the reservoir area will be scoured from bottom to top. When it develops to the mouth of a tributary, the barrier sand will collapse as the channel of the main stream cuts down, and the water storage and discharge of the tributary will accelerate the erosion of the barrier sand. However, due to the rare long-duration flood process, the large width of tributary barricades, and the use of water resources, the reservoir must not be used at too low water level or frequently and for a long time at low water level. According to the operating conditions and experience of Xiaolangdi Reservoir in recent years, this Measures are difficult to effectively eliminate the adverse effects of sand blocking, and cannot completely solve the problem of sand blocking in tributaries. (3) The plan of building anti-silting embankment (sand diversion embankment) is a treatment plan for Guanting Reservoir to prevent further siltation in the dredged channel connecting Guishui River Reservoir and Yongding River Reservoir. Its main purpose is to force incoming water and sand to change the flow The road will make it enter the Guishui River Reservoir or Yongding River Reservoir, and the sediment in the future will be introduced into the dead storage capacity of the Guishui River Reservoir as much as possible to slow down the siltation in front of the dam. The actual operation has not reached the expected target. However, the dredged river channel still has back-silting, and the gate sand continues to develop, which has not fundamentally solved the problem of effective utilization of the storage capacity of the Guishui River reservoir. (4) The construction of tributary water storage works is an idea put forward by the Yellow River Water Conservancy Research Institute using solid models and mathematical models to study the breaking of sand barriers in the Xiaolangdi Reservoir. There is no specific and operable construction plan. If conventional repairs are adopted The dam construction plan needs to be demonstrated and analyzed in many aspects such as environment and geology. It has not been adopted and implemented by the Xiaolangdi Administration Bureau. Even if it is implemented in the future, it will have disadvantages such as large investment, long construction period and unreasonable investment returns. Based on the comprehensive analysis of the effectiveness and application requirements of the various solutions above, it can be said that there is still a lack of reliable and effective measures and technologies for the treatment of sand blocking in tributaries of reservoirs. Fundamentally, to solve the problem, we must find a new way and invent and explore new methods and methods.

Contents of the invention

In order to solve the deficiencies in the existing sand-blocking technology of tributaries of rivers and reservoirs, the present invention provides a low construction cost, safe and reliable method for removing sands from the rivers and reservoirs. Technical solution of the present invention is as follows:

A method for breaking the natural ditch of damming sand in tributaries of rivers and reservoirs, including the construction and operation phases of the natural damming ditch removal system of damming sand:

(1) The construction stage of the natural ditch removal system for blocking sand: when the low water level of the reservoir is used and the sand blocking the tributaries is exposed to the water surface, the natural ditch removal system for blocking sand is constructed;

The natural ditch removal system for blocking sand includes an assembled water and sand retaining dam, a gate, an assembled diversion wall, an assembled gate middle pier and a mobile crane;

The assembled water-retaining and sand-retaining dam is set on the sand-blocking deposit at the junction of the tributary and the main stream, and is composed of two rows of prestressed hollow piles, sand-filled geotechnical bags and high-strength tension belts; the prestressed hollow row The piles are prefabricated reinforced concrete hollow square piles, which are inserted into the barrier sand sedimentation body by high-pressure water injection; multiple layers of the sand-filled geotechnical bags are arranged between the two rows of prestressed hollow piles, and the sand-filled geotechnical bags are excavated The sand ship transports the nearby sand and fills it; the high-strength tension belts are set at different heights of the two rows of the hollow piles, and the two rows of the hollow piles are pulled and fixed to prevent the hollow piles from being damaged by the sand-filled geotechnical The bag is squeezed and dumped;

The assembled diversion wall and the assembled gate middle pier are both prefabricated reinforced concrete hollow square piles, which are inserted into the gate sand deposit by high-pressure jetting, and the assembled diversion wall and the assembled gate middle pier Support beams are set between;

The gate is divided into upper and lower parts, including the lower sand-retaining and sand-retaining gate and the upper water-retaining and sand-retaining gate. The sand discharge gate is located on the upstream side of the water and sand retaining gate, and the gap between the two is provided with a plugging beam gate; the sand retaining and sand discharge gate and the water and sand retaining gate are both stacked beam gates , consisting of a number of stacked beam gates; the bottom of the sand-retaining and sand-discharging gate is located on the silted river bed, the bottom of the water-retaining and sand-retaining gate is located on the support square pile, and the support square pile is located on the water retaining bar in the gate slot of the sand gate;

The hollow pile row, the assembled diversion wall and the top of the assembled gate pier are provided with a crane track, and the mobile crane is arranged on the crane track for transporting the stacker gate plate and the plugging log ram.

(2) Operation stage:

(1) Before the reservoir resumes its water storage operation status and the water level of the reservoir rises to the top elevation of the assembled water retaining and sand retaining dam, use a mobile crane to hoist the stacking beam gates of the sand blocking and sand discharge gates and block the stacking beam gates in sequence Plate and the stacking beam slab of the water and sand retaining gate to complete the closing operation of the sand retaining and sand discharging gate and the water retaining and sand retaining gate; then, evacuate the mobile crane;

(2) The water level of the reservoir continues to rise, and the low-sedinity water body in the upper layer of the main stream overflows the top of the assembled water-retaining and sediment-retaining dam, and the overflow flows back into the tributaries. Keep the water and sand retaining gate closed;

(3) Before the flood season, the reservoir discharges water to meet the flood, and the reservoir is operated at a low water level. The dam crest of the assembled water and sand retaining dam is exposed to the water surface, and the mobile crane enters the assembled diversion wall and the assembled dam. The top of the middle pier of the gate; when the water level of the tributary stream is higher than that of the main stream, the mobile crane will lift all the stacked beam gates and the blocking stacked beam gates of the water retaining and sand retaining gate, and open the water retaining and sand retaining gate The gate, the tributary water body passes through the flow channel formed by the assembled diversion wall, and the silt and sand in the channel are washed away by the beam of water; until the silt and sand near the logger gate on the upper part of the sand-blocking and sand-discharging gate is washed away , reducing the lifting resistance of the stacking beam gate of the sand-blocking and sand-discharging gate, moving the crane to lift the stacking beam gate of the sand-blocking and sand-discharging gate, and putting the stacked beam gate of the suspended sand-blocking and sand-discharging gate on the In the gate groove of the water-retaining and sand-retaining gate; the tributary water body flows out along the gate hole through the sand-retaining and sand-discharging gate, scouring the sediment in the channel at high speed, and extending the upstream and downstream ditches to scour and destroy the gate sand To realize the barrier-free connection of the main and tributary stream storage capacity and the synchronous rise and fall of the main and tributary stream water level under the low water level operation condition of the reservoir;

(4) Before the reservoir resumes its water storage operation status and the water level of the reservoir begins to rise, use a mobile crane to hoist the stacking beam gate of the sand-blocking and sand-discharging gate that was previously hoisted in the gate groove of the water-retaining and sand-blocking gate to the sand-blocking row In the door groove of the sand gate, then hoist the blocking beam gate and the stacking beam gate of the water retaining and sand retaining gate in order, and complete the closing operation of the sand retaining and sand retaining gate and the water retaining and sand retaining gate; Then, evacuate the mobile crane; this step should be completed before the water level of the reservoir rises to the crest elevation of the assembled water retaining dam.

Further, the supporting square piles are installed in the gate groove of the water and sand retaining gate by high-pressure water jetting.

Invention point of the present invention and technical effect thereof are:

(1) The natural ditch removal method of the river reservoir tributary dam silt of the present invention is closely combined with the formation of the river dam tributary dam silt, hindering the inter-irrigation and connection mechanism of different flow states of the main and tributary reservoirs and the reservoir flood control dispatching application practice, according to the tributary dam Due to the low anti-scouring ability of sand and the principle of water scouring, an assembled water-retaining and sand-retaining dam of a certain height, sand-retaining and sand-discharging gates distributed on the upper and lower layers, water-retaining and sand-retaining gates and assembled guiding Structures such as flow walls, using the ingenious use of various structures, realize the selective backflow of the low-sedinity water body in the upper layer of the main stream at high water levels to reduce the sedimentation of the tributary stream by the sandy water flow in the main stream, and the tributary water body washes away the silt in the flow channel at a high speed when the water level is low As a result, tributary barrage sand breaks and ditches are formed, tributary storage capacity is excavated and tributary storage capacity is continuously utilized, and the comprehensive benefits of tributary reservoirs such as flood control and silt reduction, water supply and power generation are maximized.

(2) The natural ditch removal method for blocking sand adopted by the removal method of the present invention, the main structure includes a dam body, a stacked beam gate, a diversion wall and a middle pier of the gate, all of which are assembled structures, and adopt hydraulic pile insertion and hydraulic filling and other construction operation modes, water and sand are obtained locally, and the construction can be completed quickly within a short operation window. Destroying and penetrating the gate-blocking sand-silting body, the investment is small, the effect is quick, and once and for all, it has high promotion and application value.

Description of drawings

Fig. 1 is the planar layout diagram of the system planar layout of the door-blocking sand natural pulling ditch that the present invention adopts;

Fig. 2 is the right elevation view of Fig. 1;

Fig. 3 is A-A sectional view among Fig. 1;

Fig. 4 is the plan view of the sluice chamber structure of the door-blocking sand natural ditch removal system adopted in the present invention;

Fig. 5 is a B-B sectional view of the lock chamber structure in Fig. 4 .

In the figure, sand-retaining and sand-discharging gate 1, water-retaining and sand-retaining gate 2, assembled diversion wall 3, prestressed hollow row pile 4, middle pier of assembled gate 5, supporting beam 6, sand-filled geotechnical bag 7, stacked beam Flashboard 8, mobile crane 9, crane track 10, lifting lug 11, blocking stacked beam flashboard 12, supporting square pile 13, high-strength tie bar 14.

Detailed ways

Below in conjunction with Fig. 1-Fig. 5, the method for removing the sand natural ditch of the tributary of rivers and reservoirs of the present invention will be described in detail.

A method for breaking the natural ditch of damming sand in tributaries of rivers and reservoirs, including the construction and operation phases of the natural damming ditch removal system of damming sand:

(1) The construction stage of the natural ditch removal system for blocking sand: when the low water level of the reservoir is used and the sand blocking the tributaries is exposed to the water surface, the natural ditch removal system for blocking sand is constructed;

The system for breaking the sand-blocking natural ditch includes an assembled water-retaining and sand-retaining dam, a gate, an assembled diversion wall 3, an assembled gate middle pier 5, and a mobile crane 9;

The assembled water-retaining and sand-retaining dam is set on the sand-blocking deposit at the junction of the tributary reservoir and the main river, and consists of two rows of prestressed hollow piles 4, sand-filled geotechnical bags 7 and high-strength tension belts 14. The above-mentioned prestressed hollow piles 4 are prefabricated reinforced concrete hollow square piles, the length of which is mainly determined according to the thickness change of the barricade deposit, the optional length is 3.0-40.0m, and the cross section is mainly determined according to the retaining height and construction requirements. Prefabricated reinforced concrete hollow square piles of 0.6×0.6m are used, and are inserted into the sand deposit body of the barrier by means of high-pressure water injection. Multiple layers of sand-filled geotechnical bags 7 are arranged between the two rows of prestressed hollow piles 4. The sand-filled geotechnical bags 7 can be selected in various specifications. Geotechnical bags are filled with sand transported nearby by dredgers, and the high-strength tie bands 14 are set at different heights of the two rows of hollow piles 4, and the two rows of hollow piles 4 are fixed to prevent the hollow The row of piles 4 topples because of the extrusion of the sand-filled geotechnical bag 7 .

The assembled diversion wall 3 and the assembled gate middle pier 5 are made of prefabricated reinforced concrete hollow square piles, which are inserted into the gate-blocking sand deposits by means of high-pressure water injection. A supporting beam 6 is arranged between the assembled diversion wall 3 and the middle pier 5 of the assembled gate.

The gate is divided into upper and lower parts, including the lower sand-retaining and sand-retaining gate 1 and the upper water-retaining and sand-retaining gate 2. The sand-retaining and sand-discharging gate 1 and the water and sand retaining gate 2 are not in the same plane above, and arranged at intervals front and rear, the sand-retaining and sand-discharging gate 1 is located on the upstream side of the water- and sand-retaining gate 2, and the gap between the two is provided with a plugging beam ram 12 . Both the sand-retaining and sand-discharging gate 1 and the water-retaining and sand-retaining gate 2 are stacked beam gates, which are composed of several stacked beam gates 8 . The bottom of the sand-retaining and sand-discharging gate 1 is located on the silted river bed, and the bottom of the water-retaining and sand-retaining gate 2 is located on the supporting square pile 13, and the supporting square pile 13 is arranged on the water-retaining and sand-retaining gate by high-pressure water jetting. 2. Set the depth in the gate slot.

A crane track 10 is provided on the top of the hollow pile row 4, the assembled diversion wall 3 and the middle pier 5 of the assembled gate, and the mobile crane 9 is arranged on the crane track 10 for The stacking beam ram 8 and the blocking stacking beam ram 12 are dispatched. A crane track 10 is set on the crest of the assembled water retaining and sand retention dam to provide a passage for moving the crane 9 to enter or evacuate.

(2) Operation stage:

(1) Before the reservoir is restored to the state of water storage and the water level of the reservoir is raised to the top elevation of the assembled water retaining and sand retaining dam, use the mobile crane 9 to sequentially hoist the stacking beam ram 8 of the sand retaining and sand discharging gate 1, and block The stoplog ram 12 and the stoplog ram 8 of the water-retaining and sand-retaining gate 2 complete the closed-door operation of the silt-retaining and sand-retaining gate 1 and the water-retaining and sand-retaining gate 2; then, evacuate the mobile crane 9;

(2) The water level of the reservoir continues to rise, and the low-sedinity water body in the upper layer of the main stream overflows the top of the assembled water-retaining and sediment-retaining dam, and the overflow flows back into the tributaries. 1 and the water and sand retaining gate 2 remain closed;

(3) Before the flood season, the reservoir discharges water to evacuate the reservoir to meet the flood, and the reservoir is operated at a low water level. The dam crest of the assembled water and sand retaining dam is exposed to the water surface, and the mobile crane 9 enters the assembled diversion wall 3 and the described dam. The top of the pier 5 of the assembled gate; when the water level of the tributary is higher than the water level of the main stream, the mobile crane 9 lifts all the stacking beam gates 8 and the blocking stacking beam gates 12 of the water-retaining and sand-retaining gate 2, Open the water-retaining and sand-retaining gate 2, the tributary water passes through the flow channel formed by the assembled diversion wall 3, and the silt in the channel is washed away by the beam of water; The silt around the gate 8 is washed away, reducing the lifting resistance of the stacked beam gate 8 of the sand-blocking and sand-discharging gate 1, and the mobile crane 9 lifts the stacking beam gate 8 of the sand-blocking and sand-discharging gate 1, and Put the stacked beam ram 8 of the lifted sand-blocking and sand-discharging gate 1 into the gate groove of the water-retaining and sand-retaining gate 2; the tributary water flows out of the gate hole along the sand-blocking and sand-discharging gate 1, and the high-speed Scour the sediment in the channel, and extend the ditch upstream and downstream to scour and destroy the barricade sand body, so as to realize the unobstructed connection of the storage capacity of the main and tributary streams and the synchronous rise and fall of the water level of the main and tributary streams under the low water level operation condition of the reservoir;

(4) Before the reservoir resumes its water storage operation state and the water level of the reservoir begins to rise, use the mobile crane 9 to hoist the stacking beam ram 8 of the sand-blocking and sand-discharging gate that was previously hoisted in the 2-door groove of the water-retaining and sand-blocking gate to the In the door slot of the sand-blocking and sand-discharging gate 1, the blocking beam gate 12 and the stacking beam gate 8 of the water-retaining and sand-retaining gate 2 are hoisted in sequence to complete the sand-blocking and sand-discharging gate 1 and the water retaining gate. The closed-door operation of the sand-retaining gate 2; then, evacuate the mobile crane 9. This step should be completed before the water level of the reservoir rises to the crest elevation of the assembled water and sand retaining dam.

Claims (2)

1. A kind of river reservoir tributary damming sand natural ditch breaking method is characterized in that, comprises damming sand natural ditch breaking system construction stage and operation stage: (1) The construction stage of the natural ditch removal system for blocking sand: when the low water level of the reservoir is used and the sand blocking the tributaries is exposed to the water surface, the natural ditch removal system for blocking sand is constructed; The system for breaking the sand-blocking natural ditch includes an assembled water-retaining and sand-retaining dam, a gate, an assembled diversion wall (3), an assembled gate middle pier (5) and a mobile crane (9); The assembled water-retaining and sand-retaining dam is set on the sand-blocking deposit at the junction of the tributary and the main stream, and consists of two rows of prestressed hollow piles (4), sand-filled geotechnical bags (7) and high-strength tension belts (14 ) composition; the prestressed hollow row piles (4) are prefabricated reinforced concrete hollow square piles, which are inserted into the gate sand deposit body by means of high-pressure water injection; multi-layered piles are arranged between two rows of the described prestressed hollow row piles (4) The sand-filled geotechnical bag (7), the sand-filled geotechnical bag (7) is filled with sand transported nearby by a dredging ship; the high-strength tension bars are set at different heights of the two rows of prestressed hollow piles (4) belt (14), the two rows of prestressed hollow piles (4) are pulled and fixed to prevent the prestressed hollow piles (4) from toppling over due to the extrusion of the sand-filled geotechnical bag (7); The assembled diversion wall (3) and the assembled gate middle pier (5) are both prefabricated reinforced concrete hollow square piles, which are inserted into the gate sand deposit by high-pressure jetting, and the assembled diversion wall (3 ) and the middle pier (5) of the assembled gate is provided with a support beam (6); The gate is divided into upper and lower parts, including a lower sand-retaining and sand-retaining gate (1) and an upper water-retaining and sand-retaining gate (2). The gates (2) are arranged at intervals front and rear, and the sand-retaining and sand-discharging gate (1) is located on the upstream side of the water-retaining and sand-retaining gate (2), and the gap between the two is provided with a plugging beam gate (12) ; The described sand-blocking and sand-discharging gate (1) and the described water-retaining and sand-retaining gate (2) are all stacked beam gates, consisting of several stacked beam gates (8); the described sand-blocking and sand-discharging gate (1) The bottom is located on the silted river bed, and the bottom of the water-retaining and sand-retaining gate (2) is located on a supporting square pile (13), and the supporting square pile (13) is located in the gate groove of the water-retaining and sand-retaining gate (2) middle; A crane track (10) is provided on the top of the prestressed hollow pile row (4), the assembled diversion wall (3) and the middle pier (5) of the assembled gate, and the mobile crane (9) It is arranged on the crane track (10) and is used for transporting the stacking beam gate (8) and the blocking stacking beam gate (12); (2) Operation stage: (1) Before the reservoir resumes its water storage operation state and the water level of the reservoir rises to the top elevation of the assembled water retaining and sand retaining dam, use the mobile crane (9) to hoist the stacked beam gates of the sand retaining and sand discharging gates (1) in sequence (8), plugging the stacked beam ram (12) and the water-retaining and sand-retaining gate (2) of the stacking-beam ram (8), and completing the construction of the silt-retaining and sand-discharging gate (1) and the water-retaining and sand-retaining gate (2) Closed door operation; Then, evacuate mobile crane (9); (2) The water level of the reservoir continues to rise, and the low-sedinity water body in the upper layer of the main stream overflows the top of the assembled water-retaining and sediment-retaining dam, and the overflow flows back into the tributaries. (1) and the water-retaining and sand-retaining gate (2) remain closed; (3) Before the flood season, the reservoir discharges water to evacuate the reservoir to meet the flood, and the reservoir is operated at a low water level. The dam crest of the assembled water retaining and sand retaining dam is exposed to the water surface, and the mobile crane (9) enters the assembled diversion wall (3 ) and the top of the middle pier (5) of the assembled gate; when the water level of the tributary is higher than the water level of the main stream, the mobile crane (9) will move the stacked beam gate (8) and the All the above-mentioned blocking stacking beam gates (12) are hoisted, the water-retaining and sand-retaining gates (2) are opened, and the tributary water body passes through the overflow channel formed by the assembled diversion wall (3), and the water in the channel is flushed. until the silt near the stacking beam gate (8) on the upper part of the sand-blocking and sand-discharging gate (1) is washed away, reducing the stacking beam gate of the sand-blocking and sand-discharging gate (1) plate (8) lifting resistance, the mobile crane (9) lifts the stacker gate (8) of the sand-blocking and sand-discharging gate (1), and will lift the stacking beam gate (8) of the sand-blocking and sand-discharging gate (1) 8) Put it into the gate groove of the water-retaining and sand-retaining gate (2); the tributary water body flows out of the gate hole along the described sand-retaining and sand-discharging gate (1), and silt deposits in the channel are washed at high speed, and upward The downstream extended ditch scours and destroys the barricade sand body, realizing the barrier-free connection of the storage capacity of the main and tributary streams and the synchronous rise and fall of the water level of the main and tributary streams under the low water level operation condition of the reservoir; (4) Before the reservoir resumes its water storage operation state and the water level of the reservoir begins to rise, use the mobile crane (9) to hoist the stacked beam gate of the sand-blocking and sand-discharging gate that was previously placed in the door groove of the water-retaining and sand-blocking gate (2) The board (8) is hoisted into the door slot of the sand-retaining and sand-discharging gate (1), and then the blocking logger gate (12) and the stacking beam gate of the water-retaining and sand-retaining gate (2) are hoisted in sequence (8), complete the closing operation of the sand-retaining and sand-retaining gate (1) and the water-retaining and sand-retaining gate (2); then, evacuate the mobile crane (9); it should be raised to the assembled water-retaining and sand-retaining dam when the water level of the reservoir Complete this step before the dam crest elevation. 2. a kind of river reservoir tributary gate-blocking sand natural ditch breaking method according to claim 1, is characterized in that, described support square pile (13) adopts high-pressure jetting method to be arranged on described water-retaining sand-blocking gate (2 ) in the gate slot.

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