Cement dam structure with self-overflow dam body and construction method

Abstract

The invention relates to the technical field of water conservancy and hydropower engineering, in particular to a dam body self-overflow cemented dam structure which comprises a dam body, a foundation bed arranged at the bottom of the dam body, a first surface layer structure, a second surface layer structure, an overflow surface hole and a third surface layer structure, the fourth surface layer structure is arranged at the other parts of the dam body; wherein the first surface layer structure is arranged below an upstream dead water level, the second surface layer structure is arranged in an upstream water level change area, and the third surface layer structure is arranged below a downstream dead water level; a bottom plate of the overflow surface hole and the guide wall are paved with concrete, and the first surface layer structure and the third surface layer structure are paved with concrete or cemented sand gravel; and the dam body, the foundation bed, the second surface layer structure and the fourth surface layer structure are paved by adopting cemented sand gravel.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy and hydropower engineering, and in particular to a dam body self-overflowing cemented dam structure and a construction method. Background Art

[0002] In water conservancy and hydropower projects, the dam of the lower reservoir of a pumped storage power station is generally built on a river, using the river water to store water in the initial stage of the power station and to replenish the water lost due to leakage and evaporation in the later stage; after the power station is built, the lower reservoir must also have the flood discharge capacity required by the design. The panel rockfill dam is a common dam type for the lower reservoir of a pumped storage power station. Considering the settlement of the dam body during operation, a spillway is generally built on the bank of the dam. The construction of the spillway requires excavation of the bank slope, which often forms a high slope problem. The project is difficult to handle, has high safety risks, and requires a large investment scale. The investment in the spillway can account for more than 30% of the investment in the lower reservoir hub project.

[0003] The cemented dam technology is to build a dam using a small amount of cement, fly ash, admixtures and local raw materials such as unscreened and unwashed sand, gravel or stone to form a material with certain compression, shear strength and erosion resistance. The cemented dam is a new dam type between earth-rock dam and roller-compacted concrete dam. Its design concept is "suitable structure and suitable materials" and "suitable materials and suitable structure". The body shape is optimized to make full use of local materials to build the dam, and suitable materials are selected for different parts of the dam body to meet the structural requirements. The requirements of cemented gravel dam on aggregate particle size, gradation and mud content are relatively low, which can make full use of local materials and reduce waste slag; the cemented gravel dam uses less cementitious materials, has low hydration heat temperature rise, and does not need to adopt temperature control measures such as water cooling. Cemented gravel has the advantages of safety and reliability, low investment, short construction period and environmental friendliness.

[0004] The cemented dam construction materials have certain compressive and shear strengths, the dam body settlement is very small, and the safety risk of setting overflow holes on the dam body is low. It is applied to the lower reservoir dam of the pumped storage power station to avoid the setting of a shore-side spillway. Summary of the invention

[0005] The present invention provides a cemented dam structure with self-overflowing dam body and a construction method, and designs the lower reservoir dam of a pumped storage power station as a cemented dam structure with self-overflowing dam body, thereby avoiding the high slope problem caused by excavating a spillway, reducing the difficulty of engineering treatment, safety risks and saving engineering investment.

[0006] The technical solution of the present invention is: a self-overflowing cemented dam structure, comprising: a dam body, a foundation cushion layer arranged at the bottom of the dam body, a first surface structure and a second surface structure arranged on the upstream slope of the dam body, an overflow surface hole and a third surface structure arranged on the downstream slope of the dam body, and a fourth surface structure arranged at the remaining parts of the dam body; Wherein, the first surface structure is arranged below the upstream dead water level, the second surface structure is arranged in the upstream water level change zone, and the third surface structure is arranged below the downstream dead water level; The bottom plate and guide wall of the overflow surface hole are paved with concrete, and the first surface structure and the third surface structure are paved with concrete or cemented gravel; The dam body, foundation cushion layer, second surface structure and fourth surface structure are all paved with cemented gravel.

[0007] In a further solution, the cemented gravel of the foundation cushion layer needs to meet the strength and impermeability requirements; The cemented gravel of the dam body must meet the strength requirements; The concrete or cemented gravel of the first surface structure and the third surface structure must meet the strength and impermeability requirements; The cemented gravel of the second surface structure must meet the requirements of anti-seepage and anti-freezing; The cemented gravel of the fourth surface structure must meet the requirements of antifreeze and protection; The concrete of the base plate and guide wall must meet the strength and abrasion resistance requirements.

[0008] In a further solution, the cemented gravel that meets any one of the requirements of anti-seepage, anti-freezing and anti-abrasion is made of slurry-rich cemented gravel or slurry-added and vibrated cemented gravel.

[0009] In a further solution, the concrete that meets any one of the requirements of impermeability, frost resistance and abrasion resistance adopts normal concrete or rolled concrete.

[0010] In a further solution, the slope of the upstream slope of the dam body ranges from 1:0.3 to 0.7, and the slope of the downstream slope of the dam body ranges from 1:0.5 to 0.7.

[0011] Another technical solution of the present invention is: a construction method for the construction of the above-mentioned cemented dam structure, comprising: S1. According to the design requirements, combined with the dam structure layout and construction conditions, the structural joints of the cemented dam structure are divided, and longitudinal joints and induced joints are not set; S2. Remove the covering layer of the dam body to expose the bedrock surface, and treat the bedrock surface to meet the construction conditions; S3. Construction of the foundation cushion on the dam foundation; S4. Install a copper sheet and rubber water stop at the structural joint. Before paving cemented gravel and stone materials, temporary protection should be installed on both sides of the water stop to ensure the integrity of the water stop. S5. Spread cemented gravel to form the dam body, and at the same time spread cemented gravel on both sides of the dam body to form the first to fourth surface structures, and make the height of the surface structure lower than the height of the rolled layer in the dam; S6. Set the filling material on the cemented gravel and stone of the dam body, dig a groove after leveling and before rolling, and fill it with the filling material; S7. Roll the cemented gravel and stone materials of the dam body and vibrate the cemented gravel and stone materials of the first to fourth surface structures; S8, performing roughening treatment on the first to fourth surface structures; S9. Install overflow surface hole reinforcement according to design requirements on the downstream side of the overflow dam section, erect formwork and pour concrete to form the overflow surface hole; Repeat steps S4 to S9 until the entire dam construction is completed.

[0012] In a further scheme, the paved cemented gravel is roughened and mortar is laid after final setting, and then the next layer of cemented gravel is constructed. The strength of cement mortar should be at least one grade higher than that of cemented gravel.

[0013] In a further solution, in step S7, during the construction of grouting and vibrating the cemented gravel at the water-stopping buried location, the water-stopping material is protected, and the large aggregates in this area should be manually removed and fully vibrated to avoid the formation of water seepage channels.

[0014] In a further plan, during the construction process, the warehouse surface is kept moist. When the sunlight is strong or the wind is dry, the surface moisture is compensated by spraying or covered with a tarpaulin to keep the surface moist without turning white. When the temperature is low, it is covered with a maintenance mat to prevent the cemented gravel from freezing.

[0015] In a further solution, in step S5, the paving materials of the first surface structure and the third surface structure can be replaced by concrete.

[0016] Compared with the prior art, the present invention has the following advantages: (1) The cemented gravel dam uses less cementitious material, has a low hydration heat temperature rise, and does not require temperature control measures such as water cooling; (2) The overflow surface hole set on the dam body has a low safety risk. When applied to the lower reservoir dam of a pumped storage power station, it can avoid the need to set up a shore spillway, reduce the difficulty of engineering treatment, safety risks, and save engineering investment; (3) The cemented gravel dam has relatively low requirements on aggregate particle size, grading, and mud content, which can make full use of local materials, reduce waste, and achieve the goal of green construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a plan view of an embodiment of the present invention.

[0018] Figure 2 It is a cross-sectional view of an overflow dam section in an embodiment of the present invention.

[0019] In the figure: water retaining dam section 1, overflow dam section 2, overflow surface hole 3, structural joint 4, foundation cushion layer 5, dam body 6, first surface structure 7, third surface structure 8, second surface structure 9, fourth surface structure 10, bottom plate 11, guide wall 12. DETAILED DESCRIPTION

[0020] In order to enable ordinary technicians in the field to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0021] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operate in a specific position, and therefore should not be understood as limiting the present invention. like Figure 1~2 As shown, the self-overflowing cemented dam structure provided in this embodiment is divided into a water retaining dam section 1 and an overflow dam section 2 according to the dam structure layout and functions, and a structural joint 4 is arranged between the dam sections. An overflow surface hole 3 is arranged on the downstream dam surface of the overflow dam section 2, and the overflow surface hole 3 includes an overflow surface hole bottom plate 11 and a guide wall 12.

[0022] The cemented dam structure includes a dam body 6, a foundation cushion layer 5 arranged at the bottom of the dam body, a first surface structure 7 and a second surface structure 9 arranged on the upstream slope of the dam body, a third surface structure 8 arranged on the downstream slope of the dam body, and a fourth surface structure 10 arranged at the rest of the dam body (mainly the top of the dam body and the downstream slope except the overflow surface hole 3 and the third surface structure). Among them, the first surface structure 7 is arranged below the upstream dead water level, the second surface structure 9 is arranged in the upstream water level change area, and the third surface structure 8 is arranged below the downstream dead water level.

[0023] The bottom plate 11 and guide wall 12 of the overflow surface hole are paved with concrete, the first surface structure 7 and the third surface structure 8 are paved with concrete or cemented gravel; the dam body 6, foundation cushion layer 5, second surface structure 9 and fourth surface structure 10 are all paved with cemented gravel.

[0024] The cemented gravel of the foundation cushion 5 must meet the strength and anti-seepage requirements; the cemented gravel of the dam body 6 must meet the strength requirements; the concrete or cemented gravel of the first surface structure 7 and the third surface structure 8 must meet the strength and anti-seepage requirements; the cemented gravel of the second surface structure 9 must meet the anti-seepage and anti-freezing requirements; the cemented gravel of the fourth surface structure 10 must meet the anti-freezing and protection requirements; the concrete of the bottom plate 11 and the guide wall 12 must meet the strength and anti-impact requirements. In addition, in this embodiment, the cemented gravel with any one of the requirements of anti-seepage, anti-freezing, and anti-impact uses slurry-rich cemented gravel or slurry-added vibrated cemented gravel; the concrete with any one of the requirements of anti-seepage, anti-freezing, and anti-impact uses normal concrete or roller-compacted concrete.

[0025] In this embodiment, the slope of the upstream slope of the dam body 6 ranges from 1:0.3 to 0.7, and the slope of the downstream slope of the dam body ranges from 1:0.5 to 0.7.

[0026] Cemented gravel dam is an innovative dam type with great advantages over concrete. Concrete dams need to be located on weakly weathered bedrock, while cemented gravel dams can be located on strongly weathered bedrock. Cemented gravel has low requirements for material sources, and the strongly weathered materials excavated from the material yard can be used to build dams, greatly reducing the amount of waste and excavation.

[0027] This embodiment also provides a construction method, which is applied to the construction of the above-mentioned dam body self-overflow cemented dam structure, comprising the following steps: S1. According to the design requirements, combined with the dam structure layout and construction conditions, the cemented gravel retaining dam section 1 and the overflow dam section 2 are divided, and a structural joint 4 is set between the dam structures, and no longitudinal joints and induced joints are set; S2. Remove the covering layer of the dam body to expose the bedrock surface, remove the steep slopes, sharp corners and loose rocks on the bedrock surface; clean the soil, rust spots, calcium film, etc. on the structural surface; if there are faults, cracks, and weak interlayers, they must be removed and backfilled according to the design requirements; S3, constructing the foundation cushion layer 5 on the dam foundation. The foundation cushion layer 5 can be constructed by anti-seepage rolling with rich slurry cemented gravel; S4. Install a copper sheet and rubber water stop at each of the 4 structural joints. Before paving the cemented gravel and stone materials, temporary protection should be installed on both sides of the water stop to ensure the integrity of the water stop and leave enough cavities to be filled with self-compacting concrete; S5, paving the cemented gravel and stone materials of the dam body 6. The cemented gravel and stone materials can be transported to various positions parallel to the axis of the dam by dump trucks, and then transported to the upstream position by loaders arranged in the warehouse surface. In the area about 1m away from the template, water stop and other details, manual auxiliary paving is required to avoid mechanical impact on the template and water stop. At the same time, stones are paved on both sides of the rolling layer in the dam to form the first to fourth surface structures, and the height of the surface structure is lower than the height of the rolling layer in the dam; The paving materials of the first surface structure 7 and the third surface structure 8 may also be replaced by concrete; S6. Set up the filling material, which can be asphalt fir wood board. After leveling and before rolling, you can use an excavator to dig a groove and fill it with asphalt fir wood board. The spacing of the joints shall not be greater than 100mm, and the height shall be 30mm~50mm lower than the compacted thickness; S7. Roll the cemented gravel of the dam body 6 and vibrate the first to fourth surface structures 7 to 10. The junction of the cemented gravel 6 of the dam body and the first to fourth surface structures 7 to 10 should be cross-paved (i.e., at the junction of the cemented gravel dam body and the surface structure, the two materials need to cross each other and rise synchronously layer by layer), and vibrate the parts of the dam body 6 where the cemented gravel cannot be rolled in place; in the process of adding mortar and vibrating the cemented gravel at the water-stop buried place, protect the water-stop material, and the large aggregates at this part should be artificially removed reasonably, and fully vibrated to avoid the formation of water seepage channels; S8, performing a roughening process on the first to fourth surface structures 7 to 10; S9. On the downstream side of the overflow dam section 2, the overflow surface hole reinforcement is manufactured and installed according to the design requirements, and the mold is erected and the concrete of the bottom plate 11 and the guide wall 12 is poured to form the overflow surface hole; Repeat steps S4 to S9 until the entire dam construction is completed.

[0028] During the construction process, the paved cemented gravel is roughened and mortar is laid after final setting, and then the next layer of cemented gravel is constructed. The strength of cement mortar should be at least one level higher than that of cemented gravel. During the construction process, the warehouse surface needs to be kept moist. When the light is strong or the wind is dry, the surface moisture is compensated by spraying or covered with tarpaulin to keep the surface moist without turning white; when the temperature is low, cover it with a maintenance mat to prevent the cemented gravel from freezing.

[0029] The above is only a preferred embodiment of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A self-overflowing cemented dam structure, characterized in that: include: The dam body, the foundation cushion layer arranged at the bottom of the dam body, the first surface structure and the second surface structure arranged on the upstream slope of the dam body, the overflow surface hole and the third surface structure arranged on the downstream slope of the dam body, and the fourth surface structure arranged on the remaining parts of the dam body; Wherein, the first surface structure is arranged below the upstream dead water level, the second surface structure is arranged in the upstream water level change zone, and the third surface structure is arranged below the downstream dead water level; The bottom plate and guide wall of the overflow surface hole are paved with concrete, and the first surface structure and the third surface structure are paved with concrete or cemented gravel; The dam body, foundation cushion layer, second surface structure and fourth surface structure are all paved with cemented gravel.

2. A self-overflowing cemented dam structure according to claim 1, characterized in that: The cemented gravel of the foundation cushion layer must meet the strength and impermeability requirements; The cemented gravel of the dam body must meet the strength requirements; The concrete or cemented gravel of the first surface structure and the third surface structure must meet the strength and impermeability requirements; The cemented gravel of the second surface structure must meet the requirements of anti-seepage and anti-freezing; The cemented gravel of the fourth surface structure must meet the requirements of antifreeze and protection; The concrete of the base plate and guide wall must meet the strength and abrasion resistance requirements.

3. A self-overflowing cemented dam structure according to claim 2, characterized in that: For cemented gravel that meets any of the requirements of anti-seepage, anti-freezing and anti-abrasion, slurry-rich cemented gravel or slurry-added vibrated cemented gravel can be used.

4. A self-overflowing cemented dam structure according to claim 2, characterized in that: Concrete that meets any of the requirements of anti-seepage, anti-freezing and anti-abrasion shall adopt normal concrete or roller-compacted concrete.

5. A self-overflowing cemented dam structure according to claim 1, characterized in that: The slope of the upstream slope of the dam body ranges from 1:0.3 to 0.7, and the slope of the downstream slope of the dam body ranges from 1:0.5 to 0.

7.

6. A construction method for the construction of the cement dam structure according to any one of claims 1 to 5, characterized in that: include: S1. According to the design requirements, combined with the dam structure layout and construction conditions, the structural joints of the cemented dam structure are divided, and longitudinal joints and induced joints are not set; S2. Remove the covering layer of the dam body to expose the bedrock surface, and treat the bedrock surface to meet the construction conditions; S3. Construction of the foundation cushion on the dam foundation; S4. Install a copper sheet and rubber water stop at the structural joint. Before paving cemented gravel and stone materials, temporary protection should be installed on both sides of the water stop to ensure the integrity of the water stop. S5. Spread cemented gravel to form the dam body, and at the same time spread cemented gravel on both sides of the dam body to form the first to fourth surface structures, and make the height of the surface structure lower than the height of the rolled layer in the dam; S6. Set the filling material on the cemented gravel and stone of the dam body, dig a groove after leveling and before rolling, and fill it with the filling material; S7. Roll the cemented gravel and stone materials of the dam body and vibrate the cemented gravel and stone materials of the first to fourth surface structures; S8, performing roughening treatment on the first to fourth surface structures; S9. Install overflow surface hole reinforcement according to design requirements on the downstream side of the overflow dam section, erect formwork and pour concrete to form the overflow surface hole; Repeat steps S4 to S9 until the entire dam construction is completed.

7. The construction method according to claim 5, characterized in that: After the paved cemented gravel has finally set, the roughening and mortar are carried out before the next layer of cemented gravel is constructed. The strength of the cement mortar should be at least one grade higher than that of the cemented gravel.

8. The construction method according to claim 5, characterized in that: In step S7, during the construction of grouting and vibrating the cemented gravel at the water-stopping buried location, the water-stopping material is protected, and the large aggregates at this location should be manually removed and vibrated sufficiently to avoid the formation of water seepage channels.

9. The construction method according to claim 5, characterized in that: During the construction process, keep the warehouse surface moist. When the sunlight is strong or the wind is dry, compensate the surface moisture by spraying or cover it with a tarpaulin to keep the surface moist without turning white. When the temperature is low, cover it with a maintenance mat to prevent the cemented sand and gravel from freezing.

10. The construction method according to claim 5, characterized in that: In step S5, the paving materials of the first surface structure and the third surface structure may be replaced with concrete.

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