Sandy soil foundation sluice anti-scour structure

Abstract

The invention provides a sand foundation sluice anti-scour structure, and relates to the technical field of sluice engineering energy dissipation and scour prevention. According to the sand foundation water gate scour prevention structure, the reinforced concrete underground continuous scour prevention wall is arranged at the tail end of the apron, and the scour prevention wall plane is arranged in a pi shape to enclose the scour prevention groove and the river channel connecting section protection bottom, so that fine particles of a sand foundation are prevented from running off to the downstream in the scour pit forming process; the situation that the water gate safety is endangered due to the fact that the apron collapses due to the overhead bottom and further empties the gate chamber foundation is avoided; the apron adopts a roughened concrete structure, so that the residual energy behind the pool can be effectively dissipated, and meanwhile, the requirements of social development are met; a rockfill bottom protection connecting section with a slow gradient is arranged between the scour prevention groove and the downstream river channel, so that the river channel is further prevented from being scoured by turbulent swirling water flow formed near the scour prevention groove; in the scour prevention range, the riverway slope adopts the square-shaped concrete ridge to enclose the surface and is provided with the roughened anti-skid self-locking concrete precast blocks, so that the surplus energy of water flow can be effectively reduced, the scour to the river bank is reduced, and the stability of the bank slope is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of energy dissipation and erosion prevention for sluice projects, and particularly relates to an anti-erosion structure for a sluice on sandy soil foundation. Background Art

[0002] A sluice is a low-head hydraulic structure that has the dual functions of water retaining and water discharging. Appropriate energy dissipation and erosion prevention measures need to be taken to protect the safety of the sluice. The sluice often adopts bottom flow energy dissipation. The bottom flow velocity at the end of the stilling basin is still relatively large, and the water flow turbulence phenomenon is intense, which still has a strong scouring ability for the riverbed. Therefore, erosion prevention measures need to be arranged behind the stilling basin to effectively dissipate the remaining kinetic energy of the water flow, make the water flow become stable and evenly distributed, protect the riverbed and riverbank from being scoured by the water flow, and at the same time protect the safety of upstream structures such as the upstream sluice chamber. The anti-erosion engineering measures mostly adopt a filter apron and an erosion prevention trench. The filter apron is used to dissipate most of the remaining energy of the water flow after passing through the stilling basin. The water flow at the end of the filter apron still has a certain scouring ability. An erosion prevention trench is provided at the end of the filter apron to cover the upstream slope of the scouring pit when the downstream riverbed forms a scouring pit to prevent it from expanding upstream to protect the safety of the filter apron. However, for sandy soils such as silt, silty fine sand, and light sandy loam in the river channel, the anti-scouring ability is poor. During the formation of the scouring pit at the end of the filter apron, fine sediment will flow downstream, and the filter apron will collapse due to bottom voiding, which will endanger the safety of the upstream sluice chamber. There have been cases where the sluice on sandy soil foundation has accidents due to improper setting of anti-erosion measures. Therefore, the anti-erosion structure of the sluice on sandy soil foundation should be different from that of the sluice on cohesive soil foundation. An anti-erosion wall needs to be set between the filter apron and the erosion prevention trench to enhance its anti-scouring ability and protect the safety of the sluice.

[0003] Reference can be made to the Chinese invention patent with the authorized announcement number CN 203782664U, which discloses "an anti-erosion structure for a sluice on sandy soil foundation", including a filter apron rubble masonry section, a cut-off wall, a filter apron dry rubble masonry section, and an erosion prevention trench in sequence along the water flow direction. It is characterized in that a steel sheet pile cut-off wall is provided between the filter apron dry rubble masonry section and the erosion prevention trench.

[0004] Now, with the improvement of environmental protection requirements and the increasingly strict relevant environmental protection policies, it is difficult to obtain riprap with a particle size that meets the anti-scouring requirements. In addition, the manual installation cost is high, and the construction speed of the masonry filter apron is slow. In recent years, the application of the masonry filter apron in projects has been decreasing. For the steel sheet pile cut-off wall disclosed in the patent with the authorized announcement number CN 203782664U, since the steel sheet pile is a cantilever structure with a free pile top, when the scouring pit is relatively deep, the retaining stability and anti-scouring property of the steel sheet pile are poor. In addition, the penetration depth of the precast pile is limited. Therefore, based on various factors such as the requirements of the current social development and the poor anti-scouring stability of the common cantilever sheet pile anti-erosion wall, it is necessary to innovate, improve and develop the anti-erosion structure of the sluice on sandy soil foundation to protect the riverbed and the sluice safety. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides an anti-scour structure for a sluice on sandy soil foundation, which solves the problem of poor anti-scour performance of the sandy soil foundation of the sluice.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0007] An anti-scour structure for a sluice on sandy soil foundation, the anti-scour structure for a sluice on sandy soil foundation successively includes, along the water flow direction, immediately following the outlet of the stilling basin: a filter apron, an anti-scour wall, an anti-scour groove, a bottom protection, and a riverbank slope;

[0008] The filter apron is a concrete structure, which is arranged in blocks, with roughened energy-dissipating concrete ridges on the surface, and a two-way steel mesh is laid on the surface layer;

[0009] The anti-scour wall is a reinforced concrete diaphragm wall, located at the end of the filter apron. In plan view, it is arranged in a π shape that transversely spans the river channel and longitudinally extends downstream to the end of the bottom protection at both transverse ends, enclosing the anti-scour groove and the bottom protection; the top of the anti-scour wall is rigidly connected to the adjacent filter apron by tension bar steel bars, and a concrete anti-sliding wall is provided at the front section of the block of the filter apron adjacent to the anti-scour wall; the depth of the anti-scour wall is taken as the larger value between the scour depth of the riverbed at the end of the filter apron + 1.0 m and three times the depth of the anti-scour groove;

[0010] The anti-scour groove is a rockfill structure, which is arranged immediately following the anti-scour wall, with a wide and shallow trapezoidal cross-section, and the top of the groove is flush with the end of the filter apron; the depth of the groove dc is 1.5 m to 2.5 m, and the single-width rockfill volume of the anti-scour groove, that is, the trapezoidal cross-sectional area W = Ad m , where A is an empirical coefficient, which is 3 to 4 for sandy soil foundation;

[0011] The bottom protection is a rockfill structure;

[0012] The riverbank slope within the anti-scour range is enclosed by a mouth-shaped concrete ridge on the surface, and concrete self-locking precast blocks with roughened and anti-slip surfaces are provided.

[0013] Preferably, the concrete strength grade of the filter apron is not less than C25, with a thickness of 0.2 m to 0.30 m, and it is arranged to slope downstream at a slope m1 not steeper than 1:10; the two-way steel mesh on the surface layer of the filter apron has a steel bar diameter of 8 mm to 12 mm, a spacing of 0.15 m to 0.20 m, and a concrete cover thickness of 30 mm.

[0014] Preferably, the length L of the filter apron blocks is 4.0 m to 6.0 m, a permanent joint is provided between adjacent blocks, the joint width is 0.02 m, and the joint is filled with polyethylene closed-cell board. A concrete tooth wall is provided under every two blocks of the filter apron, and the concrete tooth wall has a width of 0.4 to 0.6 m and a height of 0.8 to 1.0 m.

[0015] Preferably, two layers of filter materials are provided under the filter apron, and the two layers of filter materials from bottom to top are medium coarse sand with a thickness of 0.1 m and gravel with a thickness of 0.1 m.

[0016] Preferably, the roughened energy dissipation concrete ridge has a width of 0.5 m to 0.8 m, a height of 0.1 to 0.2 m, is arranged at intervals of 5.0 m along the water flow direction and continuously arranged perpendicular to the water flow direction. The roughened energy dissipation beam steel bars are arranged inside the ridge, with a diameter of 8 to 12 mm and a spacing of 0.15 to 0.2 m. The concrete protection layer thickness is 30 mm. The U-shaped steel bars in the roughened energy dissipation beam steel bars are inserted 0.1 m into the apron.

[0017] Preferably, the concrete strength grade of the anti-scour wall is not less than C25, the wall thickness is not less than 0.6 m, and steel bars are configured according to the stress conditions. The tension rod steel bars are HRB400, the steel bar diameter is not less than 20 mm and the spacing is 0.15 to 0.2 m, and the anchorage length is not less than 1.0 m; the concrete anti-slide wall has a width of 0.8 m and a height of not less than 2.0 m

[0018] Preferably, the riverbed scouring depth d m is obtained by the following formula:

[0019]

[0020] In the formula: q m is the unit discharge at the end of the apron, in m 2 / s;

[0021] v d is the allowable non-scouring velocity of the riverbed soil, in m / s;

[0022] h m is the water depth at the end of the apron, in m.

[0023] Preferably, the upstream and downstream slopes m2 of the anti-scour trough are 1:3 to 1:4, and the two side slopes m4 are 1:2 to 1:3; the rockfill particle size d in the anti-scour trough needs to meet the anti-scouring requirements, d = 0.05V 2 , V is the water flow velocity at the end of the apron, and the rockfill particle size d is not less than 0.3 m; four layers of filter materials are arranged under the anti-scour trough. The four layers of filter materials are geotextile 300 - 400 g / m 2 , medium coarse sand with a thickness of 0.15 m to 0.25 m, pea gravel with a thickness of 0.15 m to 0.25 m, and crushed stone 0.15 m to 0.25 m.

[0024] Preferably, the bottom protection is a rockfill bottom protection for the river channel connection section. The rockfill has a thickness of 1.0 m to 1.5 m, the rockfill particle size is 0.3 m to 0.5 m, the slope ratio m3 of the connection section is 1:4 to 1:6, and the top horizontal section extends 5.0 m to 8.0 m downstream.

[0025] Preferably, for the slope protection within the range of the anti-scour measures corresponding to the riverbed of the river channel slope, concrete self-locking precast blocks with a thickness of 0.10 m to 0.15 m are used, and a crushed stone cushion layer with a thickness of 0.1 m is arranged below. The slope ratio m4 of the river channel slope is not greater than 1:3;

[0026] The weight of each concrete self-locking precast block is not less than 65 kg, and anti-slip ribs are provided on the surface, with the protruding height of the anti-slip ribs being 5 mm - 8 mm;

[0027] A concrete capping is provided at the upper end of the river channel slope, and a concrete foot groove is provided at the lower end. Concrete partition ridges are arranged longitudinally at intervals of 8.0 m - 15 m to form an "O"-shaped enclosed concrete self-locking precast block.

[0028] The present invention provides an anti-scouring structure for a sluice on sandy soil foundation. Compared with the prior art, it has the following beneficial effects:

[0029] In the present invention, for the anti-scouring structure of the sluice on sandy soil foundation, a reinforced concrete underground continuous anti-scouring wall is provided at the end of the apron. The anti-scouring wall is arranged in a "π" shape on the plane to enclose the anti-scouring groove and the bottom protection of the river channel connection section, preventing the fine particles of the sandy foundation from flowing downstream during the formation of the scouring pit, and avoiding the apron from collapsing due to bottom voiding and further hollowing out the foundation of the sluice chamber, thus endangering the safety of the sluice; the apron adopts a roughened concrete structure, which can effectively dissipate the remaining energy after the pool, and at the same time meet the needs of social development; a rockfill bottom protection connection section with a gentle slope is arranged between the anti-scouring groove and the downstream river channel to further prevent the turbulent swirling flow formed near the anti-scouring groove from scouring the river channel; the river channel slope within the anti-scouring range is enclosed by an "O"-shaped concrete ridge, and self-locking concrete precast blocks with roughened anti-slip surfaces are provided on the surface, which can effectively reduce the remaining energy of the water flow, reduce the scouring of the river bank, and protect the stability of the river bank slope. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is the plan layout drawing of the anti-scouring structure of the sluice on sandy soil foundation in the embodiment of the present invention.

[0032] Figure 2 It is Figure 1 the sectional view of A-A in

[0033] Figure 3 It is Figure 2 the partial enlarged view of

[0034] Figure 4 It is the assembly schematic diagram of the concrete self-locking precast block in the embodiment of the present invention.

[0035] The reference numerals in the figure are set as follows: stilling basin 0, apron 1, anti-scour wall 2, anti-scour groove 3, bottom protection 4, river slope 5, roughened energy dissipation concrete ridge 6, steel bars of roughened energy dissipation beam 7, double-layer steel mesh 8, permanent joint 9, concrete tooth wall 10, concrete anti-sliding wall 11, tie rod steel bars 12, two-layer filter material 13, four-layer filter material 14, concrete capping 15, concrete foot trough 16, concrete partition ridge 17, concrete self-locking precast block 18. Detailed implementation manners

[0036] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] The embodiment of the present application provides a scour prevention structure for a sluice on sandy soil foundation, solving the problem of poor anti-scour performance of the sandy soil foundation of the sluice.

[0038] To better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0039] Embodiment 1:

[0040] As Figure 1 、 Figure 2 shown, the present invention provides a scour prevention structure for a sluice on sandy soil foundation, which successively includes, along the water flow direction, immediately following the outlet of the stilling basin 0: apron 1, anti-scour wall 2, anti-scour groove 3, bottom protection 4 and river slope 5.

[0041] The apron 1 is a rough concrete apron with a thickness of 0.20m - 0.30m. The concrete strength grade is not less than C25 and it is arranged to slope downstream at a slope m1 not steeper than 1:10. To prevent deformation cracks caused by factors such as uneven foundation settlement and temperature difference, the block length L of the apron 1 is 4.0m - 6.0m. A permanent joint 9 is provided between adjacent blocks with a width of 0.02m, and the joint is filled with polyethylene closed-cell board. A two-way HRB400 steel bar mesh 8 is laid on the surface of the apron 1, with the steel bar diameter of 8mm - 12mm and the spacing of 0.15m - 0.2m, and the concrete cover thickness is 30mm. To improve the energy dissipation effect, rough energy dissipation concrete ridges 6 are set on the surface of the apron 1, with a width of 0.5m - 0.8m and a height of 0.1m - 0.2m, arranged at intervals perpendicular to the water flow direction, with a center distance of 5.0m in the direction of the water flow. HRB400 rough energy dissipation beam steel bars 7 with a diameter of 8mm - 12mm and a spacing of 0.15m - 0.2m are arranged in the ridges, and the concrete cover thickness is 30mm. The U-shaped steel bars in the rough energy dissipation beam steel bars 7 are inserted 0.1m into the apron 1. The apron 1 is provided with concrete cut-off walls 10 every two blocks to improve the anti-sliding stability of the apron 1 structure. The concrete cut-off walls 10 have a width of 0.4m - 0.6m and a height of 0.8m - 1.0m. Two layers of filter materials 13 are arranged under the apron 1, which are medium coarse sand with a thickness of 0.1m and gravel with a thickness of 0.1m from bottom to top.

[0042] The scour prevention wall 2 is a reinforced concrete diaphragm wall located at the end of the apron 1. In plan view, it is arranged in a "π" shape that transversely crosses the river channel and longitudinally extends downstream to the end of the bottom protection 4 at both ends of the transverse direction, enclosing the scour trough 3 and the bottom protection 4 to protect the apron 1 and the river bank slope 5 when the scour pit is formed. The concrete strength grade of the scour prevention wall 2 is not less than C25, and the wall thickness is not less than 0.6m, and the steel bars are configured according to the stress conditions. To improve the safety and stability of the scour prevention wall 2, control the displacement of the wall top and improve its stress conditions, the wall top is rigidly connected to the adjacent apron 1 block. The HRB400 grade tie rod steel bars 12 have a diameter of not less than 20mm and a spacing of 0.15 - 0.2m, and the anchorage length is not less than 1.0m. A concrete anti-sliding wall 11 with a width of 0.8m and a height of not less than 2.0m is arranged in the front section of the adjacent apron 1 block. The depth (m) of the scour prevention wall 2 is taken as the larger value between the scour depth d of the river bed at the end of the apron 1 m +1.0(m) and three times the depth d of the scour trough 3, and d c is obtained from the following formula: m is obtained from the following formula:

[0043]

[0044] where: q m is the unit discharge (m 2 / s) at the end of the apron 1, v d is the allowable non-scouring velocity (m / s) of the river bed soil, and h m is the water depth (m) at the end of the apron 1.

[0045] The anti-scour trough 3 is a rockfill anti-scour trough, which is arranged immediately following the anti-scour wall 2. The anti-scour trough 3 has a wide and shallow trapezoidal cross-section, and the trough top is flush with the end of the apron 1. The height difference between the trough top and the trough bottom in the sandy soil foundation, i.e., the trough depth d c is 1.5 m to 2.5 m. The upstream and downstream slopes m2 of the anti-scour trough 3 are 1:3 to 1:4, and the two side slopes m4 are 1:2 to 1:3. The single-width rockfill volume (trapezoidal cross-sectional area) W of the anti-scour trough 3 = Ad m , where A is an empirical coefficient, which is 3 to 4 for the sandy soil foundation; the rockfill particle size d (m) in the anti-scour trough 3 needs to meet the anti-scour requirement, d = 0.05V 2 , where V is the water flow velocity (m 2 / s) at the end of the apron 1, and the rockfill particle size d is not less than 0.3 m. Four layers of filter materials 14 are arranged under the anti-scour trough 3 to protect the soil and allow water to permeate. From bottom to top, they are geotextiles (300 - 400 g / m 2 ), medium coarse sand with a thickness of 0.2 m, pebble chips with a thickness of 0.2 m, and crushed stones with a thickness of 0.2 m.

[0046] The bottom protection 4 is a rockfill bottom protection for the river channel connection section. The rockfill thickness is 1.0 m to 1.5 m, the rockfill particle size is 0.3 m to 0.5 m, the slope ratio m3 of the connection section is 1:4 to 1:6, and the top horizontal section extends 5.0 m to 8.0 m downstream.

[0047] For the river channel slope 5, the slope protection within the range of the corresponding river bottom anti-scour measures uses C25 concrete self-locking precast blocks 18 with a thickness of 0.10 m to 0.12 m, and a 0.1 m thick crushed stone cushion layer is arranged below. The slope ratio m4 of the river channel slope 5 is determined according to slope stability and is not greater than 1:3. The structure of the C25 concrete self-locking precast block 18 is shown in Figure 3 , the weight of a single block is not less than 65 kg, and anti-slip and anti-skid strips are arranged on the surface with a protruding height of 5 mm to 8 mm; at the upper end of the river channel slope 5, there is a C25 concrete capping 15 (width 0.4 m × height 0.6 m), and a C25 concrete foot trough 16 (width 0.5 m × height 0.8 m) is arranged below. A C25 concrete partition dike 17 (width 0.4 m × height 0.6 m) is arranged longitudinally every about 10 m to form a "mouth"-shaped enclosed concrete precast block to ensure the stability of the river channel slope 5.

[0048] Example 2:

[0049] The flood inlet sluice of the Shouxihu Flood Diversion Area in the Huaihe River is a large-scale sluice, and the designed flood inlet flow is 2000 m 3 / s. The sluice chamber is an open-type flat-bottom structure with a total of 17 holes. The net width of a single hole is 12.0 m, and the total net width is 204.0 m. The foundation surface of the sluice is located on silty loam and fine sand. The elevation of the bottom sill of the sluice chamber is 19.0 m, and the elevations of the upstream and downstream canal bottoms are 19.0 m and 18.5 m respectively. The beginning width of the first apron is 240.0 m and the elevation is 16.9 m, while the end width is 258.0 m and the elevation is 14.9 m. During the flood discharge condition, the upstream water level is 26.05 m and the downstream water level is 25.95 m. During the energy dissipation and scour prevention condition, the upstream water level is 26.5 m and the downstream water level is 19.0 m. The anti-scour structure after connecting to the stilling basin 0 is, in the water flow direction, successively the first apron 1, the reinforced concrete diaphragm anti-scour wall 2, the scour prevention trough 3, the bottom protection 4, and the riverbank slope 5 within the scope of the corresponding river bottom anti-scour measures. After being built and put into use, no cracks have occurred in the structure, the energy dissipation effect is good, no obvious scouring and damage phenomena have occurred to the downstream riverbed and bank slopes, and the sluice operates safely.

[0050] See Figure 1 and Figure 2 A set of anti-scour structure for a sluice on sandy soil foundation includes, successively in the water flow direction along the outlet of the stilling basin 0, the first apron 1, the anti-scour wall 2, the scour prevention trough 3, the bottom protection 4, and the riverbank slope 5 within the scope of the corresponding river bottom anti-scour measures. See Figure 1 and Figure 2 The first apron 1 is 0.3 m thick and is arranged with a slope m1 of 1:25 sloping downstream. The length of the first apron 1 in the water flow direction is 60.0 m, and the block length L is 5.0 m. A permanent joint 9 is provided between adjacent blocks, with a joint width of 0.02 m. The joint is filled with polyethylene closed-cell board. A two-way HRB400 steel bar mesh 8 with a steel bar diameter of 12 mm and a spacing of 0.2 m is laid on the surface of the first apron 1, and the concrete cover thickness is 30 mm. To improve the energy dissipation effect, roughened concrete ridges 6 with a width of 0.8 m and a height of 0.1 m are arranged at intervals perpendicular to the water flow direction, with a center distance of 5.0 m in the water flow direction. HRB400 roughened energy dissipation beam steel bars 7 with a diameter of 10 mm and a spacing of 0.2 m are arranged in the ridges, and the concrete cover thickness is 30 mm. The U-shaped steel bars in the roughened energy dissipation beam steel bars 7 are inserted 0.1 m into the first apron 1. Concrete cut-off walls 10 are provided under the first apron 1 at an interval of two blocks to improve the anti-sliding stability of the concrete first apron 1 structure. The concrete cut-off walls 10 are 0.5 m wide and 0.8 m high. Two layers of filter materials 13 are provided under the first apron 1, which are medium coarse sand with a thickness of 0.1 m and gravel with a thickness of 0.1 m from bottom to top.

[0051] See Figure 1 and Figure 2, the anti-scour wall 2 of C25 reinforced concrete diaphragm wall is located at the end of the apron 1. In plan view, it is arranged in a "π" shape that spans the river channel horizontally and extends downstream to the end of the bed protection 4 longitudinally at both ends of the horizontal direction, enclosing the anti-scour trough 3 and the bed protection 4 to protect the apron 1 and the river channel slope 5; the wall thickness of the anti-scour wall 2 is 0.6m, and vertical steel bars with a diameter of 18mm and a spacing of 0.2m and horizontal steel bars with a diameter of 14mm and a spacing of 0.2m are configured according to the structural calculation of the force conditions; to improve the safety and stability of the anti-scour wall 2, control the displacement of the wall top and improve its force conditions, the top of the wall is rigidly connected to the adjacent apron 1 block. The HRB400 grade tie rod steel bars with a diameter of 22mm and a spacing of 0.2m have an anchorage length of 1.2m, and a concrete anti-sliding wall 11 is provided at the front section of the adjacent apron 1 block, with a wall width of 0.8m and a height of 2.0m; the depth (m) of the anti-scour wall 2 is taken as the larger value between the scour depth d of the riverbed at the end of the apron 1 plus 1.0 (m) and not less than 3 times the depth d of the anti-scour trough 3. According to the calculated scour depth d m +1.0 (m) and not less than 3 times the depth d of the anti-scour trough 3 c , and the larger value of the two is taken. According to the calculated scour depth d m is 8.5m, the depth d of the trough c is 2.5m, and the depth of the anti-scour wall 2 is 10.0m.

[0052] See Figure 1 and Figure 2 , the anti-scour trough 3 is located behind the anti-scour wall 2. The anti-scour trough 3 has a wide and shallow trapezoidal cross-section, with the trough top flush with the end of the apron 1. The depth d of the trough c is 2.5m. The upstream and downstream slopes m2 of the anti-scour trough 3 are 1:4, and the two side slopes m4 are 1:3. According to the calculation, the single-width rockfill volume (trapezoidal cross-sectional area) of the anti-scour trough 3 is 42.0m 3 / m. Therefore, the bottom width of the trough is 10.0m and the top width is 24.0m; the rockfill particle size d (m) in the anti-scour trough 3 needs to meet the anti-scour requirements. According to the calculation, the rockfill particle size d is 0.3m to 0.5m. Four layers of filter materials 14 are provided under the anti-scour trough 3 to protect the soil and allow water to permeate. From bottom to top, they are geotextile (350g / m 2 ), medium coarse sand with a thickness of 0.2m, pea gravel with a thickness of 0.2m, and crushed stone with a thickness of 0.2m.

[0053] See Figure 1 and Figure 2 , the bed protection 4 of the anti-scour trough 3 and the downstream river channel is 0.8m to 1.0m thick, the rockfill particle size is 0.3m to 0.5m, the slope ratio m3 of the connection section is 1:6, and the horizontal section at the top extends 5.0m downstream.

[0054] See Figure 1 , for the slope protection of the river channel slope 5 within the range of the corresponding river bottom anti-scour measures, C25 concrete self-locking precast blocks 18 with a thickness of 0.12m are used, and a 0.1m thick crushed stone cushion is provided below. The slope ratio m4 of the river channel slope 5 is determined to be 1:3 according to slope stability. The structure of the C25 concrete self-locking precast block is shown in Figure 3, the single-piece weight is not less than 65 kg, and anti-slip ribs with a protrusion height of 6 mm are provided on the surface; at the upper end of the slope protection 5, a C25 concrete capping 15 (width 0.4 m × height 0.6 m) is provided, and at the lower end, a C25 concrete foot groove 16 (width 0.5 m × height 0.8 m) is provided. A C25 concrete partition ridge 17 (width 0.4 m × height 0.6 m) is provided every about 10 m longitudinally to form a "mouth"-shaped enclosed concrete precast block to ensure the stability of the slope protection.

[0055] In this way, in this embodiment, by providing a reinforced concrete underground continuous anti-scour wall 2 at the end of the apron 1, the fine particles of the sandy foundation are prevented from flowing downstream during the formation of the scour pit, avoiding the collapse of the apron 1 due to bottom voiding and further hollowing out the foundation of the sluice chamber and endangering the safety of the sluice; the use of a roughened concrete structure apron 1 can effectively dissipate the remaining energy after the pool and meet the needs of social development at the same time; a connection section of riprap revetment with a gentle slope is provided between the anti-scour trough 3 and the downstream river channel to further prevent the turbulent rolling water flow formed near the anti-scour trough 3 from scouring the river channel; the river slope 5 within the anti-scour range is enclosed by a "mouth"-shaped concrete ridge, and self-locking concrete precast blocks with roughened and anti-slip surfaces are provided, which can effectively reduce the remaining energy of the water flow, reduce the scouring of the river bank, and protect the stability of the river bank slope.

[0056] The present invention provides a complete set of anti-scour structures for sluices on sandy soil foundations, effectively solving the problem of sluice scouring on sandy soil foundations, protecting the safety of structures such as the apron and the upstream sluice chamber, accelerating the construction progress, reducing the length of the apron, saving project investment, meeting the needs of social development at the same time, and being environmentally friendly and economical.

[0057] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. In the embodiment of the present invention, the anti-scour structure of the sluice on the sandy soil foundation is arranged in a "π" shape in plan by providing a reinforced concrete underground continuous anti-scour wall at the end of the apron to enclose the anti-scour trough and the revetment of the river channel connection section, preventing the fine particles of the sandy foundation from flowing downstream during the formation of the scour pit, avoiding the collapse of the apron due to bottom voiding and further hollowing out the foundation of the sluice chamber and endangering the safety of the sluice; the apron adopts a roughened concrete structure, which can effectively dissipate the remaining energy after the pool and meet the needs of social development at the same time; a connection section of riprap revetment with a gentle slope is provided between the anti-scour trough and the downstream river channel to further prevent the turbulent rolling water flow formed near the anti-scour trough from scouring the river channel; the river slope within the anti-scour range is enclosed by a "mouth"-shaped concrete ridge, and self-locking concrete precast blocks with roughened and anti-slip surfaces are provided, which can effectively reduce the remaining energy of the water flow, reduce the scouring of the river bank, and protect the stability of the river bank slope.

[0059] 2. By comprehensively adopting the above measures, the problem of sluice scouring on sandy soil foundations is effectively solved, the safety of structures such as the apron and the upstream sluice chamber is protected, the construction progress is accelerated, the length of the apron is reduced, the project investment is saved, the needs of social development are met at the same time, and it is environmentally friendly and economical.

[0060] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sand foundation sluice anti-scour structure, characterized in that: The sand foundation sluice anti-scouring structure is immediately adjacent to the outlet of the stilling pool (0) and comprises, in sequence along the water flow direction: a floodplain (1), an anti-scouring wall (2), an anti-scouring groove (3), a bottom protection (4) and a river channel slope (5); The seawall (1) is a concrete structure, which is arranged in blocks, with a roughened energy dissipation concrete ridge (6) on the surface and a bidirectional steel mesh (8) laid on the surface layer; The anti-scouring wall (2) is a reinforced concrete underground continuous wall, located at the end of the apron (1), and is arranged in a π-shape in plane, horizontally spanning the river channel and longitudinally extending downstream at both ends to the end of the bottom protection (4), enclosing the anti-scouring groove (3) and the bottom protection (4); the top of the anti-scouring wall is rigidly connected to the adjacent apron (1) by means of tension rod steel bars (12), and a concrete anti-slip wall (11) is provided in the front section of the apron (1) adjacent to the anti-scouring wall (2); the wall depth of the anti-scouring wall (2) is the larger value of the riverbed scouring depth at the end of the apron (1) + 1.0 m and three times the groove depth of the anti-scouring groove (3); The anti-scour groove (3) is a rockfill structure, which is set immediately after the anti-scour wall (2) and has a wide shallow trapezoidal cross section. The groove top is flush with the end of the sea apron (1); the groove depth dc is 1.5m to 2.5m, and the single width rockfill volume of the anti-scour groove (3), that is, the trapezoidal cross-sectional area W = Ad m , A is the empirical coefficient, and the sand foundation is 3 to 4; The bottom protection (4) is a rockfill structure; The river channel slope (5) is enclosed by a U-shaped concrete embankment within the anti-scouring range, and the surface is provided with roughened and anti-skid concrete self-locking prefabricated blocks (18).

2. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The concrete strength grade of the apron (1) is not less than C25, the thickness is 0.2m-0.30m, and it is arranged to be inclined downstream with a slope m1 not steeper than 1:10; the diameter of the steel bars of the bidirectional steel mesh (8) on the surface layer of the apron (1) is 8mm-12mm, the spacing is 0.15m-0.20m, and the thickness of the concrete protective layer is 30mm.

3. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The block length L of the seawall (1) is 4.0m-6.0m, and a permanent seam (9) is arranged between adjacent blocks, with a seam width of 0.02m, and the seam is filled with a polyethylene closed-cell board. A concrete tooth wall (10) is arranged under every two blocks of the seawall (1), and the concrete tooth wall (10) is 0.4-0.6m wide and 0.8-1.0m high.

4. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: Two layers of filter material (13) are arranged below the seafloor (1), and the two layers of filter material (13) are 0.1m thick medium-coarse sand and 0.1m thick crushed stone from bottom to top.

5. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The roughened energy dissipation concrete embankment (6) is 0.5m-0.8m wide and 0.1-0.2m high, and is arranged continuously with a spacing of 5.0m in the direction of water flow and perpendicular to the direction of water flow. Roughened energy dissipation beam steel bars (7) are arranged in the embankment with a diameter of 8-12mm and a spacing of 0.15-0.2m. The thickness of the concrete protective layer is 30mm. The U-shaped steel bars in the roughened energy dissipation beam steel bars (7) are inserted into the sea apron (1) by 0.1m.

6. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The concrete strength grade of the anti-collision wall (2) is not less than C25, the wall thickness is not less than 0.6m, and the steel bars are arranged according to the stress conditions. The tension rod steel bars (12) are HRB400, the steel bar diameter is not less than 20mm, the spacing is 0.15-0.2m, and the anchor length is not less than 1.0m; the concrete anti-slip wall (11) has a wall width of 0.8m and a height of not less than 2.0m.

7. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: Riverbed scour depth d m It is obtained by the following formula: Where: q m is the single width flow rate at the end of Haiman (1) m 2 / s; v d The soil quality of the riverbed allows a non-concussive flow velocity of m / s; h m is the water depth at the end of the floodplain (1) m.

8. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The upstream and downstream slopes m2 of the anti-scour groove (3) are 1:3-1:4, and the slopes m4 on both sides are 1:2-1:3; the rockfill particle size d in the anti-scour groove (3) must meet the anti-scour requirements, d=0.05V 2 , V is the water flow velocity at the end of the sea flood (1), and the rockfill particle size d is not less than 0.3m; the anti-scouring groove (3) is provided with four layers of anti-filter materials (14), and the four layers of anti-filter materials (14) are geotextiles of 300-400g / m from bottom to top. 2 , medium-coarse sand thickness 0.15m~0.25m, melon seed slice thickness 0.15m~0.25m, gravel 0.15m~0.25m.

9. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The bottom protection (4) is a rockfill bottom protection in the river channel connection section, the rockfill thickness is 1.0m to 1.5m, the rockfill particle size is 0.3m to 0.5m, the connection section slope ratio m3 is 1:4 to 1:6, and the top horizontal section extends 5.0m to 8.0m downstream.

10. The sand foundation sluice anti-scour structure according to claim 1, characterized in that: The river channel slope (5) is provided with a slope protection of 0.10m to 0.15m thick concrete self-locking prefabricated blocks (18) within the scope of the corresponding river bottom anti-scouring measures, and a crushed stone cushion layer of 0.1m thick is arranged underneath, and the slope ratio m4 of the river channel slope (5) is not greater than 1:3; The weight of a single concrete self-locking prefabricated block (18) is not less than 65 kg, and a roughened anti-slip strip is provided on the surface, and the protruding height of the roughened anti-slip strip is 5 mm to 8 mm; The upper end of the river channel slope (5) is provided with a concrete capping (15), the lower end is provided with a concrete footing groove (16), and concrete partition ridges (17) are arranged at longitudinal intervals of 8.0m to 15m to form a U-shaped enclosure concrete self-locking prefabricated block (18).

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