Sediment storage dam structure and construction method thereof
Through the design of the sand blocking structure without gates, the permeable filter body and overflow design, the safety hazards and high operation and maintenance costs caused by manual operation and high operation and maintenance costs in the existing technology are solved, and the efficient sand blocking effect is achieved without manned operation and no secondary treatment is required.
Patent Information
- Application Number
- CN202510446721.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2025-06-06
AI Technical Summary
The existing sand-blocking dam structure requires manual operation of the gate, which poses safety risks and is costly to operate and maintain. It requires secondary increase or reconstruction to achieve the design capacity.
The sand-blocking dam structure design is adopted. Through the combination of the permeable sand-blocking dam section and the water-blocking dam section, the permeable filter body and overflow design of multi-layer structure is used to achieve the separation of sediment and sand from clean water, and the erosion and erosion of the downstream river channel by the energy dissipation steps and sea flood structure are reduced.
It realizes a sand-blocking dam structure that is unmanned and does not require secondary heightening or reconstruction treatment, reduces operation and maintenance costs and engineering investment, improves the reliability and safety of the dam body, and has a long service life.
Smart Images
Figure CN120099918A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of water conservancy engineering, relates to a sand retaining dam structure, and also relates to a construction method of the sand retaining dam structure. Background Art
[0002] Sediment dams are mainly used to intercept river sediment and discharge clear water during flood season, which can reduce sediment accumulation in the downstream river and improve the downstream ecological environment. At the same time, they can create land by silting up the sediment upstream. Under the general background of ecological protection and high-quality development in the Yellow River Basin, a large number of sediment dams have been built, are under construction, and are planned in the Loess Plateau.
[0003] At present, the sand-blocking dam mainly discharges water by setting up a water release tower and controlling the gate. This method requires personnel to control the gate operation in time. Manual control depends on personnel's experience and judgment, which is easily affected by subjective factors. In addition, in emergency situations (such as sudden floods), safety hazards may be caused by insufficient response speed of personnel, especially at night or in bad weather conditions. At the same time, after the sand-blocking dam reaches the designed capacity, secondary treatment such as dam heightening or adding spillways is required. After the secondary treatment, the deformation, seepage and siltation of the dam body need to be continuously monitored, and the operation and maintenance costs increase significantly over time. Summary of the invention
[0004] The purpose of the present invention is to provide a sand retaining dam structure which has the characteristics of being unmanned in operation and not requiring secondary heightening or reconstruction.
[0005] A technical solution adopted by the present invention is that the sand-trapping dam structure includes a permeable sand-trapping dam section, which is trapezoidal in shape. An overflow weir is arranged on the top of the permeable sand-trapping dam section, retaining walls are symmetrically arranged on both sides of the trapezoidal surface of the permeable sand-trapping dam section, a traffic bridge is arranged between the two retaining walls, water retaining dam sections are arranged on the sides of the two retaining walls away from the permeable sand-trapping dam section, energy dissipation steps are arranged on one side of the slope of the permeable sand-trapping dam section, an energy dissipation pool is arranged at the bottom of the energy dissipation steps, a sea apron is arranged on the side away from the energy dissipation steps, and the other side of the sea apron is connected to the river channel.
[0006] The present invention is characterized in that: The retaining wall is trapezoidal in shape, and the contact surface between the retaining wall and the permeable sand-trapping dam section is perpendicular to the ground. The side of the retaining wall away from the permeable sand-trapping dam section forms an acute angle with the ground. The height of the retaining wall is greater than the height of the permeable sand-trapping dam section, the overflow weir and the energy dissipation step.
[0007] The permeable sand-trapping dam section includes a permeable sand-trapping dam section foundation, which is located at the bottom of the permeable sand-trapping dam section. The top of the permeable sand-trapping dam section foundation is provided with an upstream rockfill area, an upstream pebble area, an upstream gravel area, medium-coarse sand, a downstream gravel area, a downstream pebble area and a downstream rockfill area in sequence from upstream to downstream, and a geogrid is also provided in the middle of the medium-coarse sand.
[0008] The slope of the upstream rockfill area away from the medium-coarse sand side is not less than 1:1.5, and the slope of the downstream rockfill area away from the medium-coarse sand side is not less than 1:2.0. The top width of the upstream rockfill area and the downstream rockfill area is not less than 1.5m. The upstream rockfill area and the downstream rockfill area are composed of boulders with a particle size of 10-80cm and a boulders strength of not less than 30MPa. The particle size of the boulders in the upstream rockfill area and the downstream rockfill area decreases from upstream to downstream. The slope of the upstream pebble area and the downstream gravel area away from the medium-coarse sand is not less than 1:0.5, the top width of the upstream pebble area and the downstream gravel area is not less than 1.0m, and the upstream pebble area and the downstream gravel area are composed of pebbles with a particle size of 2-15cm; The slope of the upstream gravel area and the downstream pebble area away from the medium and coarse sand side is not less than 1:0.3, the vertical surface close to the medium and coarse sand side is perpendicular to the foundation of the permeable sand dam section, the top width of the upstream gravel area and the downstream pebble area is not less than 1.0m, the upstream gravel area and the downstream pebble area are composed of pebbles with a particle size of 2-15cm.
[0009] The medium-coarse sand is arranged close to the downstream facade of the upstream gravel area and is located in the middle of the permeable sand-trapping dam section foundation. The facades on both sides of the medium-coarse sand are perpendicular to the permeable sand-trapping dam section foundation. The width of the medium-coarse sand is not less than 1.0m, and the particle size of the medium-coarse sand is not less than 0.075mm; the mesh opening of the geogrid is not less than 10cm, and the tensile strength of the geogrid is not less than 20MPa.
[0010] The energy dissipation step includes several steps with a height of 50-100cm. Several drainage holes are arranged in the steps. The drainage holes run through one end of the steps and connect to the downstream rockfill area. The diameters of the drainage holes are not less than 20cm, and the distance between the drainage holes is not more than 1.5m.
[0011] The retaining dam section includes a drainage mattress, which is located downstream of the two retaining walls. There is also an earth fill body outside the two retaining walls. A drainage prism is provided at the downstream slope foot of the earth fill body, an upstream slope protection is provided upstream of the earth fill body, and a downstream slope protection is provided downstream of the earth fill body.
[0012] The square fill is trapezoidal, with the slope ratio of the upstream slope of the square fill being 1:2.0-3.0, and the slope ratio of the downstream slope being 1:1.5-2.0; The drainage prism is trapezoidal, the slope ratio of the upstream slope of the drainage prism is 1:1.0-1.5, and the slope ratio of the downstream slope of the drainage prism is 1:2.0-2.5; The laying thickness of the drainage mattress is 50-200cm. The drainage mattress is composed of blocks and gravels. The particle size of the gravels is 2-4cm, and the particle size of the blocks is 20-50cm. The upstream slope protection and the downstream slope protection are dry masonry stones or precast concrete blocks. The laying thickness of the upstream slope protection is 20-30cm, and the laying thickness of the downstream slope protection is 10-20cm.
[0013] Another technical solution adopted by the present invention is a construction method of a sand retaining dam structure, comprising the following steps: Step 1: clean the topsoil in the site, lay the foundation of the permeable sand dam section, and cast retaining walls on both sides; Step 2: Concrete an energy dissipation step at the downstream position between the two retaining walls and simultaneously pave a permeable sand retaining dam section at the same elevation; Step 3, pouring the overflow weir on the top of the permeable sand dam section, and constructing the energy dissipation pool and sea floodplain; Step 4, setting a water retaining dam section outside the two retaining walls; Step 5. Install the traffic bridge on top of the two retaining walls.
[0014] The present invention is also characterized in that: Step 1 specifically includes the following steps: Step 101, arranging the designed section and pouring concrete, which is recorded as the foundation of the permeable sand retaining dam section; Step 102, after the concrete of the permeable sand retaining dam section foundation reaches the designed strength, formwork is set up on the left and right sides of the permeable sand retaining dam section foundation, steel bars are tied, and concrete is poured to complete the construction of the retaining wall; Step 2 specifically includes the following steps: Step 201, after the concrete of the retaining wall reaches the designed strength, pouring steps in L-shaped layers at the downstream position; Step 202, after the concrete of the energy dissipation step reaches the designed strength, a permeable sand retaining dam section is then simultaneously paved at the same elevation between two retaining walls upstream of the step; Step 203, then rolling and compacting each area of the permeable sand retaining dam section, and then constructing a number of steps layer by layer and paving and compacting them until the design elevation of the energy dissipation step is reached; Step 3 specifically includes the following steps: Step 301, after the construction of the permeable sand retaining dam section and the energy dissipation step is completed, a formwork is set up on the top of the permeable sand retaining dam section, steel bars are tied, and concrete is poured to complete the construction of the overflow weir; Step 302, setting up a formwork at the bottom of the downstream of the energy dissipation step, tying steel bars and pouring concrete to complete the construction of the energy dissipation pool; Step 303, fabricate and install a steel cage, place it at the designed location, and then fill it with stones to carry out sea cover construction; Step 4 specifically includes the following steps: Step 401, laying soil and compacting it on the downstream sides of the two retaining walls to complete the construction of the drainage mattress; Step 402, spreading soil in layers and compacting it outside the two retaining walls to complete the construction of the earth filling body; Step 403, after the earth filling body is constructed, block stones are piled and compacted at the downstream slope foot of the earth filling body to realize the construction of the drainage prism; Step 404, stacking blocks of stone upstream of the earthfill to complete the construction of upstream slope protection; Step 405, stacking blocks of stone materials downstream of the earth filling body to complete the construction of the downstream slope protection.
[0015] The beneficial effects of the present invention are: The sand-blocking dam structure of the present invention adopts a gateless solution combining a water retaining dam section and a permeable sand-blocking dam section. When the water flows through the permeable sand-blocking dam section, the permeable filter body of the multi-layer structure begins to play a role. When the water flows through these filter layers, the sediment particles cannot pass through the pores of the filter body due to their large particle size and are intercepted on the upstream side of the dam section, thereby achieving the separation of sediment and clean water. When a small amount of water comes in, the filtered clean water can be smoothly discharged through the permeable sand-blocking dam section, maintaining the ecological flow of the downstream river, meeting the water demand of the downstream area and the stability of the ecological environment. When the water volume exceeds the standard or a large amount of water comes in, when the water level of the reservoir rises to a certain height and exceeds the top of the permeable sand-blocking dam section, the water will flow directly through the overflow surface. This overflow design can not only effectively control the water level of the reservoir, but also realize energy dissipation during the water flow discharge process, reduce the scouring and erosion of the downstream river channel by the water flow, and does not require secondary heightening or reconstruction. Due to its unique gateless design, this sand dam structure does not require manual operation of the gate opening and closing, which greatly reduces the workload and cost of manual management, avoids potential safety problems such as gate failure and water leakage, and improves the reliability and safety of the dam body. In addition, this sand dam structure does not require large-scale secondary treatment or reconstruction, and has a long service life. Compared with traditional sand dams with gates, gateless sand dams have lower construction and maintenance costs and can effectively save project investment. Whether it is a small amount of water or a large amount of flood, the gateless sand dam can effectively handle it through the seepage of the permeable sand dam section and the discharge of the top overflow surface, and has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of the sand retaining dam structure of the present invention; Figure 2 It is an elevation view of a permeable sand retaining dam section of the sand retaining dam structure of the present invention; Figure 3 It is a cross-sectional view of a permeable sand retaining dam section of the sand retaining dam structure of the present invention; Figure 4 Schematic diagram of the energy dissipation step structure of the sand retaining dam structure of the present invention; Figure 5 It is a cross-sectional view of the water retaining dam section of the sand retaining dam structure of the present invention.
[0017] In the figure, 1. permeable sand-trapping dam section; 1-1. permeable sand-trapping dam section foundation; 1-2. upstream rockfill area; 1-3. upstream pebble area; 1-4. upstream crushed stone area; 1-5. medium-coarse sand; 1-6. geogrid; 1-7. downstream crushed stone area; 1-8. downstream pebble area; 1-9. downstream rockfill area; 1-10. overflow weir; 2. energy dissipation step; 2-1. step; 2-2. drainage hole; 3. energy dissipation pool; 4. sea floodplain; 5. retaining wall; 6. traffic bridge; 7. water retaining dam section; 7-1. earth fill; 7-2. drainage prism; 7-3. drainage mattress; 7-4. upstream slope protection; 7-5. downstream slope protection. DETAILED DESCRIPTION
[0018] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0019] Sediment dam structures, such as Figure 1 As shown, it includes a permeable sand retaining dam section 1, which is a trapezoidal body. An overflow weir 1-10 is arranged on the top of the permeable sand retaining dam section 1. The design of the overflow weir 1-10 has two purposes. One is that the overflow weir 1-10 is arranged on the top of the permeable sand retaining dam section 1, so that the top of the permeable sand retaining dam section 1 becomes a whole. The second is to overflow over the water surface and provide a water passage for excess water flow. The overflow weir 1-10 is made of reinforced concrete, and the concrete strength is not less than C30, and it should meet the requirements of impact resistance and wear resistance. Retaining walls 5 are symmetrically arranged on both sides of the trapezoidal surface of the permeable sand-trapping dam section 1. A traffic bridge 6 is arranged between the two retaining walls 5. Water retaining dam sections 7 are arranged on the two retaining walls 5 away from the permeable sand-trapping dam section 1. An energy dissipation step 2 is arranged on one side of the slope of the permeable sand-trapping dam section 1. The energy dissipation step 2 is a slope protection for the permeable sand-trapping dam section 1 to prevent erosion and damage to the structure. In addition, energy dissipation can be carried out to connect the high water level water flow to the low water level. The energy dissipation step 2 is implemented in layers to form an L shape. The energy dissipation step 2 is made of reinforced concrete with a concrete strength of not less than C30 and should meet the requirements of impact resistance and wear resistance. A dissipation pool 3 is arranged at the bottom of the energy dissipation step 2. A sea ambush 4 is arranged on the side away from the energy dissipation step 2. The sea ambush 4 is made of gabion stone cages or reinforced stone cages. The other side of the sea ambush 4 is connected to the river channel. Figure 2 As shown, the retaining wall 5 is trapezoidal, the contact surface between the retaining wall 5 and the permeable sand-trapping dam section 1 is perpendicular to the ground, the side of the retaining wall 5 away from the permeable sand-trapping dam section 1 forms an acute angle with the ground, and the height of the retaining wall 5 is greater than the height of the permeable sand-trapping dam section 1, the overflow weir 1-10 and the energy dissipation step 2.
[0020] like Figure 3As shown, the permeable sand retaining dam section 1 includes a permeable sand retaining dam section foundation 1-1, which is located at the bottom of the permeable sand retaining dam section 1. The main function of the permeable sand retaining dam section foundation 1-1 is to uniformly transfer the upper load to the foundation to prevent uneven settlement. Plain concrete is used, and the concrete strength is not less than C20. The top of the permeable sand retaining dam section foundation 1-1 is arranged from upstream to downstream in sequence with an upstream rockfill area 1-2, an upstream pebble area 1-3, an upstream crushed stone area 1-4, medium-coarse sand 1-5, a downstream crushed stone area 1-7, a downstream pebble area 1-8 and a downstream rockfill area 1-9. A geogrid 1-6 is also arranged in the middle of the medium-coarse sand 1-5.
[0021] The slope of the upstream rockfill area 1-2 away from the medium-coarse sand 1-5 is not less than 1:1.5, the slope of the downstream rockfill area 1-9 away from the medium-coarse sand 1-5 is not less than 1:2.0, the top width of the upstream rockfill area 1-2 and the downstream rockfill area 1-9 is not less than 1.5m, the upstream rockfill area 1-2 and the downstream rockfill area 1-9 are composed of boulders with a particle size of 10-80cm, and the boulders have a strength of not less than 30MPa. The particle size of the boulders in the upstream rockfill area 1-2 and the downstream rockfill area 1-9 decreases from upstream to downstream; the slope of the upstream pebble area 1-3 and the downstream gravel area 1-7 away from the medium-coarse sand 1-5 is not less than 1:1.5, the top width of the upstream rockfill area 1-2 and the downstream rockfill area 1-9 is not less than 1.5m, the upstream rockfill area 1-2 and the downstream rockfill area 1-9 are composed of boulders with a particle size of 10-80cm, and the boulders have a strength of not less than 30MPa. The particle size of the boulders in the upstream rockfill area 1-2 and the downstream rockfill area 1-9 decreases from upstream to downstream; The gradient of the upstream pebble area 1-3 and the downstream gravel area 1-7 is not less than 1:0.5, the top width of the upstream pebble area 1-3 and the downstream gravel area 1-7 is not less than 1.0m, the upstream pebble area 1-3 and the downstream gravel area 1-7 are composed of pebbles with a particle size of 2-15cm; the slope gradient of the upstream gravel area 1-4 and the downstream pebble area 1-8 away from the medium and coarse sand 1-5 is not less than 1:0.3, the vertical surface close to the medium and coarse sand 1-5 is perpendicular to the permeable sand dam section foundation 1-1, the top width of the upstream gravel area 1-4 and the downstream pebble area 1-8 is not less than 1.0m, the upstream gravel area 1-4 and the downstream pebble area 1-8 are composed of pebbles with a particle size of 2-15cm.
[0022] The medium-coarse sand 1-5 is arranged close to the downstream vertical surface of the upstream gravel area 1-4 and is located in the middle of the permeable sand-trapping dam section foundation 1-1. The vertical surfaces on both sides of the medium-coarse sand 1-5 are perpendicular to the permeable sand-trapping dam section foundation 1-1. The width of the medium-coarse sand 1-5 is not less than 1.0m, and the particle size of the medium-coarse sand 1-5 is not less than 0.075mm; the mesh opening of the geogrid 1-6 is not less than 10cm, and the tensile strength of the geogrid 1-6 is not less than 20MPa.
[0023] like Figure 4 As shown, the energy dissipation step 2 includes a plurality of steps 2-1, the height of the step 2-1 is 50-100 cm, a plurality of drainage holes 2-2 are arranged in the step 2-1, the drainage holes 2-2 penetrate one end of the step 2-1 and are connected to the downstream rockfill area 1-9, the apertures of the plurality of drainage holes 2-2 are not less than 20 cm, and the hole spacing between the plurality of drainage holes 2-2 is not greater than 1.5 m.
[0024] like Figure 5 As shown, the retaining dam section 7 includes a drainage mattress 7-3, which is located downstream of the two retaining walls 5. An earth fill body 7-1 is also provided outside the two retaining walls 5. A drainage prism 7-2 is provided at the downstream foot of the earth fill body 7-1, an upstream slope protection 7-4 is provided upstream of the earth fill body 7-1, and a downstream slope protection 7-5 is provided downstream of the earth fill body 7-1. The square fill body 7-1 is trapezoidal, the slope ratio of the upstream slope of the square fill body 7-1 is 1:2.0-3.0, and the slope ratio of the downstream slope is 1:1.5-2.0; the drainage prism 7-2 is trapezoidal, the slope ratio of the upstream slope of the drainage prism 7-2 is 1:1.0-1.5, and the slope ratio of the downstream slope of the drainage prism 7-2 is 1:2.0-2.5; the laying thickness of the drainage mattress 7-3 is 50-200cm, the drainage mattress 7-3 is composed of blocks and gravel, the gravel particle size of the drainage mattress 7-3 is 2-4cm, and the block particle size is 20-50cm; the upstream slope protection 7-4 and the downstream slope protection 7-5 are dry-laid blocks or prefabricated concrete blocks, the laying thickness of the upstream slope protection 7-4 is 20-30cm, and the laying thickness of the downstream slope protection 7-5 is 10-20cm.
[0025] The construction method of the sand retaining dam structure comprises the following steps: Step 1, clean the topsoil in the site, lay the permeable sand dam section foundation 1-1, and cast retaining walls 5 on both sides thereof; Step 2, pouring the energy dissipation step 2 at the downstream position between the two retaining walls 5 and paving the permeable sand retaining dam section 1 at the same elevation; Step 3, pouring overflow weir 1-10 on the top of permeable sediment dam section 1, and constructing stilling pool 3 and sea cover 4; Step 4, setting a water retaining dam section 7 outside the two retaining walls 5; Step 5, installing a traffic bridge 6 on top of the two retaining walls 5.
[0026] Step 1 specifically includes the following steps: Step 101, arranging the designed section and pouring concrete, which is recorded as the permeable sand retaining dam section foundation 1-1; Step 102, after the concrete of the permeable sand retaining dam section foundation 1-1 reaches the design strength, formwork is set up on the left and right sides of the permeable sand retaining dam section foundation 1-1, steel bars are tied, and concrete is poured to complete the construction of the retaining wall 5; Step 2 specifically includes the following steps: Step 201, after the concrete of the retaining wall 5 reaches the designed strength, pour the steps 2-1 in L-shaped layers at the downstream position; Step 202, after the concrete of the energy dissipation step 2-1 reaches the designed strength, the permeable sand retaining dam section 1 is then paved simultaneously at the same elevation between the two retaining walls 5 upstream of the step 2-1; Step 203, then rolling and compacting each area of the permeable sand retaining dam section 1, and then constructing a number of steps 2-1 layer by layer and paving and compacting them until the design elevation of the energy dissipation step 2 is reached; Step 3 specifically includes the following steps: Step 301, after the construction of the permeable sand retaining dam section 1 and the energy dissipation step 2 is completed, a formwork is set up on the top of the permeable sand retaining dam section 1, steel bars are tied, and concrete is poured to complete the construction of the overflow weir 1-10; Step 302, setting up a formwork at the bottom of the downstream of the energy dissipation step 2, tying steel bars and pouring concrete to complete the construction of the energy dissipation pool 3; Step 303, fabricate and install a steel cage, place it at the designed location, and then fill it with stones to construct the seabed 4; Step 4 specifically includes the following steps: Step 401, laying soil and compacting it on the outer side and downstream of the two retaining walls 5 to complete the construction of the drainage mattress 7-3; Step 402, spreading soil in layers and compacting it outside the two retaining walls 5 to complete the construction of the earth filling body 7-1; Step 403, after the construction of the earth filling body 7-1 is completed, block stones are piled and compacted at the downstream slope foot of the earth filling body 7-1 to realize the construction of the drainage prism 7-2; Step 404, stacking blocks of stone upstream of the earthfill 7-1 to complete the construction of the upstream slope protection 7-4; Step 405, stacking blocks of stone materials downstream of the earth filling body 7-1 to complete the construction of the downstream slope protection 7-5.
[0027] Example 1 Sediment dam structures, such as Figure 1 As shown, it includes a permeable sand-trapping dam section 1, which is trapezoidal in shape, with overflow weirs 1-10 arranged on the top of the permeable sand-trapping dam section 1, retaining walls 5 symmetrically arranged on both sides of the trapezoidal surface of the permeable sand-trapping dam section 1, a traffic bridge 6 arranged between the two retaining walls 5, and a water retaining dam section 7 arranged on the side of the two retaining walls 5 away from the permeable sand-trapping dam section 1, an energy dissipation step 2 arranged on the slope side of the permeable sand-trapping dam section 1, a stilling pool 3 arranged at the bottom of the energy dissipation step 2, a sea board 4 arranged on the side away from the energy dissipation step 2, and the other side of the sea board 4 is connected to the river channel. Figure 2 As shown, the retaining wall 5 is trapezoidal, the contact surface between the retaining wall 5 and the permeable sand-trapping dam section 1 is perpendicular to the ground, the side of the retaining wall 5 away from the permeable sand-trapping dam section 1 forms an acute angle with the ground, and the height of the retaining wall 5 is greater than the height of the permeable sand-trapping dam section 1, the overflow weir 1-10 and the energy dissipation step 2.
[0028] Example 2 Based on the sand retaining dam structure provided in Example 1, the sand retaining dam structure provided in this embodiment is as follows: Figure 3As shown, the permeable sand-trapping dam section 1 includes a permeable sand-trapping dam section foundation 1-1, which is located at the bottom of the permeable sand-trapping dam section 1, and the top of the permeable sand-trapping dam section foundation 1-1 is provided with an upstream rockfill area 1-2, an upstream pebble area 1-3, an upstream crushed stone area 1-4, medium-coarse sand 1-5, a downstream crushed stone area 1-7, a downstream pebble area 1-8 and a downstream rockfill area 1-9 in sequence from upstream to downstream, and a geogrid 1-6 is also provided in the middle of the medium-coarse sand 1-5.
[0029] The slope of the upstream rockfill area 1-2 away from the medium-coarse sand 1-5 is not less than 1:1.5, the slope of the downstream rockfill area 1-9 away from the medium-coarse sand 1-5 is not less than 1:2.0, the top width of the upstream rockfill area 1-2 and the downstream rockfill area 1-9 is not less than 1.5m, the upstream rockfill area 1-2 and the downstream rockfill area 1-9 are composed of boulders with a particle size of 10-80cm, and the boulders have a strength of not less than 30MPa. The particle size of the boulders in the upstream rockfill area 1-2 and the downstream rockfill area 1-9 decreases from upstream to downstream; the slope of the upstream pebble area 1-3 and the downstream gravel area 1-7 away from the medium-coarse sand 1-5 is not less than 1:1.5, the top width of the upstream rockfill area 1-2 and the downstream rockfill area 1-9 is not less than 1.5m, the upstream rockfill area 1-2 and the downstream rockfill area 1-9 are composed of boulders with a particle size of 10-80cm, and the boulders have a strength of not less than 30MPa. The particle size of the boulders in the upstream rockfill area 1-2 and the downstream rockfill area 1-9 decreases from upstream to downstream; The gradient of the upstream pebble area 1-3 and the downstream gravel area 1-7 is not less than 1:0.5, the top width of the upstream pebble area 1-3 and the downstream gravel area 1-7 is not less than 1.0m, the upstream pebble area 1-3 and the downstream gravel area 1-7 are composed of pebbles with a particle size of 2-15cm; the slope gradient of the upstream gravel area 1-4 and the downstream pebble area 1-8 away from the medium and coarse sand 1-5 is not less than 1:0.3, the vertical surface close to the medium and coarse sand 1-5 is perpendicular to the permeable sand dam section foundation 1-1, the top width of the upstream gravel area 1-4 and the downstream pebble area 1-8 is not less than 1.0m, the upstream gravel area 1-4 and the downstream pebble area 1-8 are composed of pebbles with a particle size of 2-15cm.
[0030] The medium-coarse sand 1-5 is arranged close to the downstream vertical surface of the upstream gravel area 1-4 and is located in the middle of the permeable sand-trapping dam section foundation 1-1. The vertical surfaces on both sides of the medium-coarse sand 1-5 are perpendicular to the permeable sand-trapping dam section foundation 1-1. The width of the medium-coarse sand 1-5 is not less than 1.0m, and the particle size of the medium-coarse sand 1-5 is not less than 0.075mm; the mesh opening of the geogrid 1-6 is not less than 10cm, and the tensile strength of the geogrid 1-6 is not less than 20MPa.
[0031] Example 3 Based on the sand retaining dam structure provided in Example 2, the sand retaining dam structure provided in this embodiment is as follows: Figure 4 As shown, the energy dissipation step 2 includes a plurality of steps 2-1, the height of the step 2-1 is 50-100 cm, a plurality of drainage holes 2-2 are arranged in the step 2-1, the drainage holes 2-2 penetrate one end of the step 2-1 and are connected to the downstream rockfill area 1-9, the apertures of the plurality of drainage holes 2-2 are not less than 20 cm, and the hole spacing between the plurality of drainage holes 2-2 is not greater than 1.5 m.
[0032] Example 4 Based on the sand retaining dam structure provided in Example 3, the sand retaining dam structure provided in this embodiment is as follows: Figure 5 As shown, the retaining dam section 7 includes a drainage mattress 7-3, which is located downstream of the two retaining walls 5. An earth fill body 7-1 is also provided outside the two retaining walls 5. A drainage prism 7-2 is provided at the downstream foot of the earth fill body 7-1, an upstream slope protection 7-4 is provided upstream of the earth fill body 7-1, and a downstream slope protection 7-5 is provided downstream of the earth fill body 7-1. The square fill body 7-1 is trapezoidal, the slope ratio of the upstream slope of the square fill body 7-1 is 1:2.0-3.0, and the slope ratio of the downstream slope is 1:1.5-2.0; the drainage prism 7-2 is trapezoidal, the slope ratio of the upstream slope of the drainage prism 7-2 is 1:1.0-1.5, and the slope ratio of the downstream slope of the drainage prism 7-2 is 1:2.0-2.5; the laying thickness of the drainage mattress 7-3 is 50-200cm, the drainage mattress 7-3 is composed of blocks and gravel, the gravel particle size of the drainage mattress 7-3 is 2-4cm, and the block particle size is 20-50cm; the upstream slope protection 7-4 and the downstream slope protection 7-5 are dry-laid blocks or prefabricated concrete blocks, the laying thickness of the upstream slope protection 7-4 is 20-30cm, and the laying thickness of the downstream slope protection 7-5 is 10-20cm.
[0033] Example 5 This embodiment provides a construction method for a sand retaining dam structure, comprising the following steps: Step 1, clean the topsoil in the site, lay the permeable sand dam section foundation 1-1, and cast retaining walls 5 on both sides thereof; Step 101, arranging the designed section and pouring concrete, which is recorded as the permeable sand retaining dam section foundation 1-1; Step 102, after the concrete of the permeable sand retaining dam section foundation 1-1 reaches the design strength, formwork is set up on the left and right sides of the permeable sand retaining dam section foundation 1-1, steel bars are tied, and concrete is poured to complete the construction of the retaining wall 5; Step 2, pouring the energy dissipation step 2 at the downstream position between the two retaining walls 5 and paving the permeable sand retaining dam section 1 at the same elevation; Step 201, after the concrete of the retaining wall 5 reaches the designed strength, pour the steps 2-1 in L-shaped layers at the downstream position; Step 202, after the concrete of the energy dissipation step 2-1 reaches the designed strength, the permeable sand retaining dam section 1 is then paved simultaneously at the same elevation between the two retaining walls 5 upstream of the step 2-1; Step 203, then rolling and compacting each area of the permeable sand retaining dam section 1, and then constructing a number of steps 2-1 layer by layer and paving and compacting them until the design elevation of the energy dissipation step 2 is reached; Step 3, pouring overflow weir 1-10 on the top of permeable sediment dam section 1, and constructing stilling pool 3 and sea cover 4; Step 301, after the construction of the permeable sand retaining dam section 1 and the energy dissipation step 2 is completed, a formwork is set up on the top of the permeable sand retaining dam section 1, steel bars are tied, and concrete is poured to complete the construction of the overflow weir 1-10; Step 302, setting up a formwork at the bottom of the downstream of the energy dissipation step 2, tying steel bars and pouring concrete to complete the construction of the energy dissipation pool 3; Step 303, fabricate and install a steel cage, place it at the designed location, and then fill it with stones to construct the seabed 4; Step 4, setting a water retaining dam section 7 outside the two retaining walls 5; Step 401, laying soil and compacting it on the outer side and downstream of the two retaining walls 5 to complete the construction of the drainage mattress 7-3; Step 402, spreading soil in layers and compacting it outside the two retaining walls 5 to complete the construction of the earth filling body 7-1; Step 403, after the construction of the earth filling body 7-1 is completed, block stones are piled and compacted at the downstream slope foot of the earth filling body 7-1 to realize the construction of the drainage prism 7-2; Step 404, stacking blocks of stone upstream of the earthfill 7-1 to complete the construction of the upstream slope protection 7-4; Step 405, stacking blocks of stone at the downstream of the earth filling body 7-1 to complete the construction of the downstream slope protection 7-5; Step 5, installing a traffic bridge 6 on top of the two retaining walls 5.
[0034] Example 6 On the basis of the construction method of the sand retaining dam structure provided in Example 5, the construction method of the sand retaining dam structure provided in this embodiment includes specific construction conditions for the traffic bridge 6 and the energy dissipation step 2 .
[0035] The traffic bridge 6 is located at the top of the two retaining walls 5 and is a rectangular plate made of reinforced concrete. The concrete strength is not less than C30. There should be enough clearance between the traffic bridge 6 and the overflow weir 1-10. The clearance is not less than 3m and meets the following calculation formula: H = h + 1.0 (1) H is the clearance between the traffic bridge and the overflow weir, and h is the water depth at the top of the weir for verifying the flood discharge level of the sand dam.
[0036] After the concrete of the retaining wall 5 reaches the design strength, the energy dissipation step 2 is poured at the downstream position between the two retaining walls 5, and the concrete of the permeable sand dam section 1 is paved at the same elevation at the same time. Specifically, the step 2-1 is poured in L-shaped layers at the downstream position between the two retaining walls 5. After reaching the design strength, the upstream rockfill area 1-2, the upstream pebble area 1-3, the upstream crushed stone area 1-4, the medium-coarse sand 1-5, the geogrid 1-6, the downstream crushed stone area 1-7, the downstream pebble area 1-8 and the downstream rockfill area 1-9 are paved at the same elevation inside the upstream. The paving layer thickness is 30-50cm, which is also called flat construction. At the same time, the following formula must be met: H 1 =H 0 / N(2) H 1 H is the thickness of the paving layer for level construction; 0 is the height of the steps; N is the number of segments, which is a natural number (1, 2, 3…).
[0037] After the construction is completed, each area of the permeable sand retaining dam section 1 will be rolled and compacted, and then several steps 2-1 will be constructed layer by layer and laid and compacted until the design elevation of the energy dissipation step 2 is reached.
Claims
1. A sediment dam structure, characterized in that: The invention comprises a permeable sand retaining dam section (1), the permeable sand retaining dam section (1) is in a trapezoidal shape, an overflow weir (1-10) is arranged at the top of the permeable sand retaining dam section (1), retaining walls (5) are symmetrically arranged on both sides of the trapezoidal surface of the permeable sand retaining dam section (1), a traffic bridge (6) is arranged between the two retaining walls (5), a water retaining dam section (7) is arranged on the side of the two retaining walls (5) away from the permeable sand retaining dam section (1), an energy dissipation step (2) is arranged on one side of the slope of the permeable sand retaining dam section (1), a stilling pool (3) is arranged at the bottom end of the energy dissipation step (2), a sea board (4) is arranged on the side away from the energy dissipation step (2), and the other side of the sea board (4) is connected to the river channel.
2. The sediment retaining dam structure according to claim 1, characterized in that: The retaining wall (5) is trapezoidal in shape, the contact surface between the retaining wall (5) and the permeable sand retaining dam section (1) is perpendicular to the ground, the side of the retaining wall (5) away from the permeable sand retaining dam section (1) forms an acute angle with the ground, and the height of the retaining wall (5) is greater than the height of the permeable sand retaining dam section (1), the overflow weir (1-10) and the energy dissipation step (2).
3. The sediment retaining dam structure according to claim 1, characterized in that: The permeable sand-trapping dam section (1) comprises a permeable sand-trapping dam section foundation (1-1), the permeable sand-trapping dam section foundation (1-1) being located at the bottom end of the permeable sand-trapping dam section (1), and the top of the permeable sand-trapping dam section foundation (1-1) being provided with an upstream rockfill area (1-2), an upstream pebble area (1-3), an upstream crushed stone area (1-4), medium-coarse sand (1-5), a downstream crushed stone area (1-7), a downstream pebble area (1-8) and a downstream rockfill area (1-9) in order from upstream to downstream, and a geogrid (1-6) being further provided in the middle of the medium-coarse sand (1-5).
4. The sediment retaining dam structure according to claim 3, characterized in that: The slope of the upstream rockfill area (1-2) away from the medium-coarse sand (1-5) is not less than 1:1.5, and the slope of the downstream rockfill area (1-9) away from the medium-coarse sand (1-5) is not less than 1:2.
0. The top widths of the upstream rockfill area (1-2) and the downstream rockfill area (1-9) are not less than 1.5 m. The upstream rockfill area (1-2) and the downstream rockfill area (1-9) are composed of boulders with a boulders particle size of 10-80 cm and a boulders strength of not less than 30 MPa. The boulders particle size of the upstream rockfill area (1-2) and the downstream rockfill area (1-9) decreases from upstream to downstream. The slope of the upstream pebble area (1-3) and the downstream gravel area (1-7) away from the medium-coarse sand (1-5) is not less than 1:0.5, the top width of the upstream pebble area (1-3) and the downstream gravel area (1-7) is not less than 1.0 m, and the upstream pebble area (1-3) and the downstream gravel area (1-7) are composed of pebbles with a particle size of 2-15 cm; The slope of the upstream gravel area (1-4) and the downstream pebble area (1-8) away from the medium-coarse sand (1-5) is not less than 1:0.3, and the vertical surface close to the medium-coarse sand (1-5) is perpendicular to the permeable sand dam section foundation (1-1). The top width of the upstream gravel area (1-4) and the downstream pebble area (1-8) is not less than 1.0m. The upstream gravel area (1-4) and the downstream pebble area (1-8) are composed of pebbles with a pebble particle size of 2-15cm.
5. The sediment retaining dam structure according to claim 3, characterized in that: The medium-coarse sand (1-5) is arranged close to the downstream vertical surface of the upstream gravel area (1-4) and is located in the middle of the permeable sand retaining dam section foundation (1-1). The vertical surfaces on both sides of the medium-coarse sand (1-5) are perpendicular to the permeable sand retaining dam section foundation (1-1). The width of the medium-coarse sand (1-5) is not less than 1.0m, and the particle size of the medium-coarse sand (1-5) is not less than 0.075mm; the mesh opening of the geogrid (1-6) is not less than 10cm, and the tensile strength of the geogrid (1-6) is not less than 20MPa.
6. The sediment retaining dam structure according to claim 4, characterized in that: The energy dissipation step (2) comprises a plurality of steps (2-1), the height of the steps (2-1) is 50-100 cm, a plurality of drainage holes (2-2) are arranged in the steps (2-1), the drainage holes (2-2) penetrate one end of the steps (2-1) and are connected to the downstream rockfill area (1-9), the diameters of the plurality of drainage holes (2-2) are not less than 20 cm, and the hole spacing between the plurality of drainage holes (2-2) is not greater than 1.5 m.
7. The sediment retaining dam structure according to claim 1, characterized in that: The retaining dam section (7) comprises a drainage cushion (7-3), the drainage cushion (7-3) being arranged downstream of the outer sides of the two retaining walls (5), an earth filling body (7-1) being arranged outside the two retaining walls (5), a drainage prism (7-2) being arranged at the downstream slope foot of the earth filling body (7-1), an upstream slope protection (7-4) being arranged upstream of the earth filling body (7-1), and a downstream slope protection (7-5) being arranged downstream of the earth filling body (7-1).
8. The sediment retaining dam structure according to claim 7, characterized in that: The square fill body (7-1) is trapezoidal, the slope ratio of the upstream slope of the square fill body (7-1) is 1:(2.0-3.0), and the slope ratio of the downstream slope is 1:(1.5-2.0); The drainage prism (7-2) is a trapezoidal body, the slope ratio of the upstream slope of the drainage prism (7-2) is 1:(1.0-1.5), and the slope ratio of the downstream slope of the drainage prism (7-2) is 1:(2.0-2.5); The laying thickness of the drainage mattress (7-3) is 50-200 cm. The drainage mattress (7-3) is composed of blocks and crushed stones. The particle size of the crushed stones in the drainage mattress (7-3) is 2-4 cm, and the particle size of the blocks is 20-50 cm. The upstream slope protection (7-4) and the downstream slope protection (7-5) are dry masonry blocks or prefabricated concrete blocks. The laying thickness of the upstream slope protection (7-4) is 20-30 cm, and the laying thickness of the downstream slope protection (7-5) is 10-20 cm.
9. A construction method for a sand-trapping dam structure, applied to the sand-trapping dam structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: clean the topsoil in the site, lay the foundation of the permeable sand dam section (1-1), and cast retaining walls (5) on both sides thereof; Step 2, pouring an energy dissipation step (2) at a downstream position between the two retaining walls (5) and simultaneously paving a permeable sand retaining dam section (1) at the same elevation; Step 3, pouring an overflow weir (1-10) on the top of the permeable sediment retaining dam section (1), and constructing an energy dissipation pool (3) and a sea cover (4); Step 4, setting a water retaining dam section (7) outside the two retaining walls (5); Step 5, installing a traffic bridge (6) on top of the two retaining walls (5).
10. The construction method of the sediment dam structure according to claim 9, characterized in that: The step 1 specifically comprises the following steps: Step 101, arranging the designed section and pouring concrete, which is recorded as the permeable sediment dam section foundation (1-1); Step 102, after the concrete of the permeable sand retaining dam section foundation (1-1) reaches the designed strength, formwork is set up on the left and right sides of the permeable sand retaining dam section foundation (1-1), steel bars are tied, and concrete is poured to complete the construction of the retaining wall (5); The step 2 specifically includes the following steps: Step 201, after the concrete of the retaining wall (5) reaches the designed strength, pouring steps (2-1) in L-shape layers at the downstream position; Step 202, after the concrete of the energy dissipation step (2-1) reaches the designed strength, a permeable sand retaining dam section (1) is then simultaneously paved at the same elevation between two retaining walls (5) upstream of the step (2-1); Step 203, then rolling and compacting each area of the permeable sand retaining dam section (1), and then constructing a number of steps (2-1) layer by layer and laying and compacting the materials until the design elevation of the energy dissipation step (2) is reached; The step 3 specifically includes the following steps: Step 301, after the construction of the permeable sand retaining dam section (1) and the energy dissipation step (2) is completed, a formwork is set up on the top of the permeable sand retaining dam section (1), steel bars are tied, and concrete is poured to complete the construction of the overflow weir (1-10); Step 302, setting up a formwork at the bottom of the downstream of the energy dissipation step (2), tying steel bars and pouring concrete to complete the construction of the energy dissipation pool (3); Step 303, fabricate and install a steel cage, place it at the designed location, and then fill it with stones to construct the seawall (4); The step 4 specifically comprises the following steps: Step 401, laying soil and compacting it on the downstream sides of the two retaining walls (5) to complete the construction of the drainage mattress (7-3); Step 402, spreading and compacting the soil in layers outside the two retaining walls (5) to complete the construction of the earth filling body (7-1); Step 403, after the construction of the earth filling body (7-1) is completed, block stones are piled and compacted at the foot of the downstream slope of the earth filling body (7-1) to achieve the construction of the drainage prism (7-2); Step 404, stacking blocks of stone upstream of the earth filling body (7-1) to complete the construction of the upstream slope protection (7-4); Step 405, stacking blocks of stone materials downstream of the earth filling body (7-1) to complete the construction of the downstream slope protection (7-5).