NB/T 10344-2019Code for Design of Soil and Water Conservation for Hydropower Projects (English PDF)

5.1 General provisions

5.1.1 The design of the spoil yard shall meet the following requirements.

1 The design of the waste slag yard should be carried out simultaneously with the design of the main project, and adhere to local conditions, safety and reliability, Principles of economic rationality, combination of prevention and treatment, and process control.

2 The site selection of the waste slag yard shall be coordinated and synchronized with the design of the main project, so as to meet the requirements of water and soil conservation. At the same time, it is technically feasible.

3 The stacking of waste slag yard shall be based on topographic and geological conditions, physical and mechanical parameters of waste slag, meteorological and hydrological regulations To determine the stacking factors of parts, etc., and meet the stability of the waste slag field.

4 On the basis of the stability of the slag body, block and Design of engineering protection measures such as slope protection, flood control and drainage.

5.1.2 The basic information and results required for the design of the waste slag yard shall mainly include the following contents.

1 Topographic surveying and mapping results.

2 Topographic features, meteorological conditions, hydrological conditions, seismic fortification intensity, and environmental status quo.

3 Engineering geology and hydrogeological data.

4 The source of slag material, the composition of the slag, the amount of slag, the recovery volume, the physical and mechanical parameters of the slag.

5 The flood flow, flood level, and flow velocity corresponding to the fortification standards of the waste slag yard;

The characteristic water level of the reservoir during the travel period; rainfall, rainfall intensity, rainfall process; flood discharge atomization range.

6 The general construction layout plan, the layout plan and section plan of the pivot building.

5.1.3 The waste slag yard shall carry out corresponding engineering geological and hydrogeological surveys according to different design stages. The inspection content should meet the following requirements.

1 In the design stage of the feasibility study, the natural geographical features, meteorological features, topography and landforms of the site should be investigated Characteristics, hydrogeological characteristics, natural disaster characteristics, foundation soil characteristics, and weak foundation soil characteristics of the survey site Distribution range and characteristics, groundwater, surface water system characteristics, recharge and runoff characteristics, the distribution of soil in the site area should be ascertained.

The suitability of the site should be evaluated on the layer, gradation and physical and mechanical properties.

2 The geological data and conclusions of the feasibility study stage should be reviewed during the bidding design stage, and the remaining Provide geological information for improving and optimizing the design and preparing bidding design documents. All areas with major influences.

5.5 Safety protection

5.5.1 The safety protection distance of the spoil yard shall be determined according to the following factors.

1 Original topography and geological conditions of engineering.

2 The physical and mechanical properties of the waste slag, the stacking height and the slope of the side slope.

3 The overall stability of the waste slag yard.

4 The nature of the object of protection.

5 The relative height difference between the protection object and the waste slag yard.

5.5.2 The waste slag is stacked with waste slag that is stable overall, has good drainage, and has good engineering and hydrogeological conditions 2 The design flood level of the cofferdam during the construction period and its frequent drop.

3 The water level on the water side of the waste slag yard has dropped extremely.

4 Check the flood level and its drop.

5 Slope saturation and corresponding groundwater level changes due to rainfall, water release, rain and fog, and other reasons.

6 Under normal operating conditions, the slag body drainage fails.

5.7 Basic treatment of waste slag yard

5.7.1 Small broken zone and shallow weak interlayer should be excavated and treated.

5.7.2 For soil foundation slopes with poor stability, the original slopes should be trimmed into steps.

5.7.3 For the soft and moist soil, it is advisable to dig a trench to dry the base before piling up the slag, pour a block of crushed stone as a cushion or put a large block of The stones are stacked at the bottom.

5.7.4 The spoil yard with good surface vegetation should remove the surface vegetation before spoiling.

5.8 General arrangement of protective measures for spoil yard

5.8.1 The waste slag yard shall be based on comprehensive consideration of the type of slag yard, engineering safety, construction conditions, material sources, etc.

Based on the selection and arrangement of water and soil erosion prevention and control measures.

5.8.2 The overall arrangement of the protective measures for the flat ground spoil yard shall meet the following requirements.

1 Coffer slag weirs or foot protection measures should be arranged at the toe of the waste slag yard, and drainage measures should be arranged on the top of the slag and slope.

2 The upstream of the waste slag yard should be arranged with flood drains according to the water catchment situation.

3 Re-cultivation or planting measures should be taken on the top of the waste dump; plant measures should be given priority to the slope surface, and the slope ratio is large.

Comprehensive slope protection measures should be taken at the slope of 1.1.5.

4 For waste slag to fill recessed land, priority should be given to re-cultivation after leveling or planting measures should be taken.

5.8.3 The overall arrangement of protective measures for slope-type spoil yard shall meet the following requirements.

1 Slag retaining walls or foot protection measures should be arranged at the foot of the slag pile, and drainage measures should be arranged on the top and slope of the slag.

2 If there is water catchment upstream of the waste slag yard, flood drainage facilities shall be arranged.

3 Re-cultivation or vegetation measures should be taken on the top of the waste slag yard; vegetation measures should be taken first on the slope surface, and the slope ratio is large.

In the ratio of 1.1.5, comprehensive slope protection measures should be adopted.

5.8.4 According to flood disposal methods and slag dumping methods, trench-type spoil yards can be divided into flood interception type, flood detention type and Fill the ditch. The overall arrangement of protective measures for trench-type spoil yard shall meet the following requirements.

1 The upstream flood of the flood interception spoil yard can be discharged into the adjacent channel through the flood discharge tunnel, or through Flood drainage tunnels, flood drainage culverts, flood drainage canals and other methods are discharged to the downstream of the site. The foot of the slag slope should be equipped with a slag retaining wall or guard Foot measures, drainage measures should be arranged on the top of the slag and slope.

2 A slag blocking dam should be arranged downstream of the flood detention spoil yard. The slag dam should be equipped with flood overflow, energy dissipation and other facilities.

3 Ditch-filling waste slag yards should arrange flood drains according to upstream catchment conditions. Slag retaining wall should be set at the foot of the slag slope Or foot protection measures, drainage measures should be arranged on the top of the slag and slope.

4 The trench-type waste slag yard should be filled with large rocks with hard lithology and good water resistance at the bottom of the ditch. The formation of drainage blind ditch or drainage base.

5.8.5 The overall arrangement of protective measures for Linhe type spoil yard shall meet the following requirements.

1 The protective measures of the slag foot facing the water surface shall meet the requirements of anti-impact stability.

2 It is advisable to lay a slag-blocking embankment at the foot of the slope on the water-incoming side, or set up mortar masonry, dry masonry, riprap, firewood pillows, etc. Foot measures.

3 Slope protection measures should be taken for the water-incoming slope below the design flood level; slopes above the design flood level Plant measures should be taken first, and comprehensive slope protection measures should be taken if the slope ratio is greater than 1.1.5.

4 Cut-off and drainage measures should be arranged on the top of the slag and the slope.

5 Re-cultivation or planting measures should be taken on the top of the spoil yard.

5.8.6 The overall arrangement of protective measures for the reservoir-type spoil yard shall meet the following requirements.

1 According to the topography and landform, the flood during the construction period, and the impact of water and soil erosion caused by water storage inundation, the mining Take corresponding engineering and temporary protective measures; plant measures are not required for the bottom-type waste slag yard and the middle-sized slag yard of the warehouse.

When necessary, it should be determined in conjunction with the analysis of the impact of water and soil loss before the water storage inundation.

2 When the overflow of the top of the silo bottom-type spoil yard and the middle-sized slag yard may cause water and soil loss, the response should be Take capping measures for the slag top.

3 When the slag slope is affected by the fall of water level, slope protection measures should be taken.

5.8.7 The slag field with the amount of discarded slag greater than 500,000 m³ or the slag pile height greater than 20m shall be based on the stability analysis.

The protection design shall be carried out on the basis and shall include the following contents.

1 Determining factors and basis for the level of waste slag yard and design standards.

2 Basic treatment design of waste slag yard and protection engineering.

3 Hydrological calculation and scouring calculation of the flood control and drainage facilities of the spoil yard.

4 Blocking engineering design of spoil yard.

5 Slope protection engineering design of spoil yard.

6 Design of flood control and drainage engineering of waste slag yard.

7 Design of plant measures for waste slag yard.

8 Design of temporary measures for spoil yard.

(Code for design of water and soil conservation in hydropower projects)

ICS 27.140

NB P 59 Energy Industry Standards of the People's Republic of China Design Code for Water and Soil Conservation of Hydropower Projects Released on.2019-12-30 Implemented on 2020-07-01 Issued by the National Energy Administration