Benefits from secondary construction engineer: key notes on water conservancy and hydropower

Benefits from secondary construction engineer: key notes on water conservancy and hydropower

The first chapter water conservancy and hydropower engineering construction technology

Type and composition of 1010 water conservancy and hydropower engineering buildings

Classification of water conservancy and hydropower projects: Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ permanent hydraulic structure: complex or new structure, 2 - 5 level buildings can improve the level of design, but the flood standard will not be improved. Belong to different levels of temporary hydraulic structures, according to the highest level; Level 3 temporary water buildings, in line with the indicators of many 2.

Hydraulic structures by use: general buildings ( spillway, sluice ) and special buildings ( water supply and drainage, fish ) by use time: permanent and temporary

Reservoir: check flood level: dam design flood level: dam flood control high water level: downstream normal water level: normal operation maximum flood control limit water level: flood discharge dead water level: normal operation minimum allowable ( dead storage capacity, beneficial storage capacity, combined storage capacity, flood control capacity, flood regulation capacity, total storage capacity ) embankments: fortification water level: flood control warning water level: fortification rise guarantee water level: design flood

Earth - rock dam according to dam height: low 30 low dam, high 70 high dam according to the construction method: roller compacted earth-rock dam, hydraulic filling dam, directional blasting rockfill dam

Earth - rock dam structure: dam crest, seepage prevention, upstream and downstream dam slope, dam drainage, foundation treatment. Wave wall 1.0 - 1.2 m sticky heart, inclined wall thickness of not less than 3 m.

Anti - seepage body function: reduce the infiltration line; Reduce the effect of seepage slope protection: prevent wave scouring, downstream erosion, freezing and other damage

Drainage of dam body: apply slope, prism, mattress, pipe type and comprehensive drainage function: reduce seepage line and void water pressure of dam body, and prevent frost heave damage of dam slope soil.

Slope drainage: the top is higher than the escape point of the infiltration line, ensuring that the infiltration line is below the freezing depth, but not reducing the infiltration line. It is used for small-sized lower waterless low-middle dam. Edge drainage can reduce the infiltration line slope protection: temporary slope should be masonry, concrete; Back water slope should be cement soil, turf ( slope protection drainage holes, deformation joints )

Seepage control material: clay, concrete, asphalt concrete, geomembrane filter layer material: sand, gravel, geotextile seepage control body high design water level of 0.5 m.

Concrete dam: longitudinal joint of gravity dam, arch dam and buttress dam: vertical joint, inclined joint and staggered joint ( vertical joint spacing is 15 - 30m )

Drainage corridor: set up upstream along the height of 15 - 30m, with minimum width of 1.2m and height of 2.2m.. Joints of gravity dam: transverse joints, longitudinal joints and construction joints

Gate room: bottom plate, gate pier, gate, breast wall, working bridge and traffic bridge ( flat bottom, low weir, inverted arch bottom plate; Integral, separate floor )

Integral bottom plate: separate bottom plate for foundation with poor geology and uneven settlement: foundation pier with good geology and large bearing capacity: separation and support function

Breast wall: water retaining effect. Simply supported and consolidated

Upstream connection section: bedding, bottom protection, slope protection, downstream connection section of upstream wing wall: apron, sea flood ( mortar, dry build by laying bricks or stones ), anti-scour tank, slope protection, downstream wing wall

Bedding: anti-seepage purpose; Clay, asphalt, reinforced concrete. Upstream wing wall: improving water flow, retaining soil, anti - scour, anti-seepage sea flood and anti-scour tank: energy dissipation

Downstream splay wing wall: total diffusion angle 14 - 24 unilateral 7 - 12 pump: volume, other, vane pump, ( centrifugal, axial flow, mixing )

Pump working lift is always greater than the actual lift. Water energy loss: water power, volume, machinery. Vacuum or air turbidity determine pump installation elevation.

Pump room structure: fixed ( sub - base, dry room, wet room, block - base type ) and mobile ( storage ship, cable car type )

Composition of hydropower station: water inlet, water diversion structure, flat water structure and water inlet of plant hub: under pressurized dead water; No pressure: water diversion structure composed of water inlet, sand flushing gate, dam retaining and grit chamber: power channel, water diversion tunnel and pressure pipeline water leveling structure: pressure front tank and pressure regulating chamber

Canal building: aqueduct, culvert, inverted siphon, falling water and steep slope

1020 water conservancy and hydropower engineering survey and measurement

Three factors of geological structure occurrence: strike, dip and dip fault structure: joint, fault ( normal fault, reverse fault and translational fault )

Slope deformation and failure types: relaxation crack, creep deformation, collapse you, landslide

Factors affecting slope stability: topographic and geomorphic conditions, rock type, geological structure, water effect; Manual excavation; Earthquake

Soft soil foundation pit engineering geological problems: soil slope stability and foundation pit drainage ( open drainage, artificial precipitation - light well point, tube well mode )

Seepage deformation: piping, flow soil, contact erosion, contact piping or contact flow soil

Earth dam construction lofting content: dam axis test, dam body control survey, clear foundation excavation line, toe line lofting, dam slope line lofting and slope repair pile layout

Dam body control survey: plane and elevation clear foundation excavation line lofting: sleeve drawing or theodolite dam body side slope line lofting: wheelbase rod or slope scale

Slope pile layout: level or theodolite level ruler: second - class precision, third-class and fourth-class common

Use of level: setting, coarse leveling, focusing and sighting, fine leveling and reading theodolite: centering, leveling, sighting and reading

Error: system error, accidental error, gross error ( human, instrument, environmental reasons )

1030 water conservancy and hydropower engineering construction materials

Apparent density, bulk density, compactness, porosity, filling rate, porosity, water absorption: water absorption; Hygroscopicity: moisture content; Water resistance: water content

Hydrophilicity: brick and concrete. Hydrophobic: asphalt. Impermeability: k, concrete and mortar, w4: 0.4 MPa frost resistance: f25, 25 cycles

Fine aggregate particle size: 0.15 - 4.75 mm coarse aggregate particle size great than 4.75 mm sand: river, sea, mountain and lake sand; Class I, class ii, class iii

Class I sand and gravel: greater than C60 concrete class ii: C30 - C60 concrete class iii: less than C30 concrete fineness modulus: m in 3.0 - 2.3, medium

When the amount of aggregate is fixed, the specific surface area decreases with the increase of particle size, thus saving cement. Crushed stone strength: cube strength and crush index crush smaller, stronger

Water content of aggregate: dry, air dry, saturated surface dry and wet. Ordinary concrete: dry state large water conservancy: saturated surface dry state

Workability: fluidity, cohesiveness and water retention; Slump said, low plasticity, plasticity 50 - 90 mm, fluidity, large fluidity concrete 160 mm or more

Dry hard concrete mixture, slump < 10 mm, d wave consistency as workability index.

Factors affecting workability concrete mixture: cement slurry content, consistency, sand content size, raw material type, sand content additive: sand and stone percentage

C15 … c75, c80, 14 prestressed not less than C30 100 cube: coefficient of 0.95 200 cube: coefficient of 1.05 150 * 150 * 300, 0.67

The tensile strength of concrete is generally 1 / 10 - 1 / 20 of compressive strength. Impermeability: dense and void, structure w2,... w12, 4 in grade 6, impervious to 0.2 MPa

Frost resistance: f50 … f300, f400, grade 7 f400 freeze-thaw cycles to improve frost resistance: concrete compactness, water cement ratio reduction, additive addition, vibrating, maintenance

Cementitious materials: organic and inorganic ( gas hardening: lime; Hydraulic cement: cement according to the purpose: general, special ( low, medium, large volume ), characteristics

Quick setting and quick hardening: emergency rescue shall not be mixed up. Aluminate: emergency rescue and early strength, without structural engineering

Water reducer: increase fluidity, increase concrete strength, reduce cement, increase compactness air entrainer: improve workability, increase impermeability, frost resistance, slightly reduce concrete strength, not suitable for steam and prestressed concrete. Retarding agent: retarding, reducing water, reducing hydration heat; Is use for large-volume and hot construction

Accelerator: used in mine shaft, railway tunnel, diversion culvert, underground engineering expansion agent: to improve the permeability and crack resistance of concrete

Admixture adding method: soluble water soluble, immiscible cement or sand. Water reducing agent: same mixing method, after mixing method, divided mixing method

Steel: carbon structural steel and low carbon steel of common low alloy steel: carbon content less than 0.25 %, grade I steel. High carbon steel: carbon content greater than 0.6 %, steel wire.

Ordinary steel: plasticity of grade ii, iii and iv steel bars: quality inspection of elongation and cold bending properties: yield, limit, elongation and cold bending properties

Geosynthetics: geotextiles, geomembrane, geosynthetics, geotextiles: woven and non-woven shapes

Geotechnical composite: composite geomembrane, plastic drainage board, soft drainage pipe geotechnical special: grid, geonet, membrane bag, compartment, geotechnical pipe, geotechnical bag

Diversion 2010

Task of construction diversion design: select diversion scheme, select diversion standard and design flow rate, determine buildings and formulate construction methods.

Diversion standard: diversion building grade, design flood, flood during flood season and flood during flood season after plugging standard 3 - 5

Diversion method: stage cofferdam method diversion ( narrow riverbed, through the existing construction ), one-time stop riverbed cofferdam diversion ( open channel, smooth, tunnel, narrow, culvert )

Cofferdam type: horizontal and vertical. Or overflow, but water cofferdam cofferdam construction: water seal filling, rolling construction; Last flood season for underwater occupation demolition

Danger of cofferdam: loopholes, piping and overflow

Methods of protection for loopholes: plug method, cover method ( hole more concentrated ), kung dike method ( hole more small wide )

Piping: the principle of stopping water and sand gushing; Overflow of filter well ( small concentration ) and filter layer gland ( large area and sufficient material ): additional sub-embankments shall be built at weir top

2020 closure

Closure process: basic methods of intake, longkou, closure and gas closing: throwing block material ( large flow ), blasting ( canyon ), lower gate and hydraulic filling

Throwing block material: flat plugging ( easy to flush foundation ), vertical plugging ( large flow, rock foundation ), mixed plugging ( first flat and then stand and then flat )

Longkou position: main stream position, scour - resistant riverbed and wide ground. Longkou width: protective bottom and wrapping head protection. Determination of flow rate and orifice impact velocity

3010 earth and stone excavation works

Soil is divided into four categories: class I soil: sand, slightly add feet; Class ii soil silt, with the foot step; Class iii soil: clay, with strong feet; Four types of soil: gravel soil, pick

Excavation method: top - down, top-down combination, front groove back bank slope and stage section excavation method: manual, mechanical ( digging, pushing, shoveling, loading )

Single bucket excavator: forward shovel, backhoe shovel, cable shovel, grab shovel forward shovel: forward upward, forced cutting soil, I - iii soil, lateral and forward excavation mode

Backhoe: backward downward, forced cut soil, I - iii soil, trench end and trench side excavation method. Cable shovel: underwater earth and rock, grab shovel: up and down, I - ii soil

Multi - bucket excavator features: light weight, high productivity, simple operation; Class 1 - iii earthmover: class I - iii earthmover unloading: compulsory, semi - free

Channel excavation: manual excavation, mechanical excavation ( bulldozer, shovel transport vehicle ) shovel transport vehicle: circular operation and 8 - shaped operation ( front line length, high elevation difference )

Rock classification: igneous rock ( flower, flash, glow, Xuan ), water diagenesis ( lime, sand ), metamorphic rock ( gneiss, Dali, quartzite ) rock classification: grade 12

Stonework excavation method: open-pit stonework and underground engineering blasting: shallow hole, deep hole, cavern, presplitting underground engineering: drilling blasting, tunneling, shield, pipe jacking

3020 foundation and foundation treatment

Soil foundation excavation: when the slope is smooth and steep, the variable slope angle is less than 20, the slope should not be steep at 1: 1.5, and the protective layer of 0.2 - 0.3m shall be reserved for manual excavation

Foundation excavation of concrete dam: high dam is excavated to fresh and fresh breeze rock foundation; Middle dam excavation to breeze or weak weathering rock foundation; Dig into a large step shape, 0.2 - 03m protective layer to the upstream, dig out when pouring concrete; Dig to rock 0.5 - 1.0 m, hand pneumatic drill, blasting, lest cause bedrock cracks.

Basic methods of foundation treatment: consolidation, curtain, contact, chemistry, high pressure jet grouting, cut-off wall, replacement, drainage, squeezing, pile foundation

Different foundation treatment applicable methods: rock foundation: grouting gravel: cut-off wall, curtain soft soil: excavation, pile, replacement, drainage, compaction method

Grouting method: pure pressure type and circulation type or one-time grouting and segmented grouting ( large crack ) process: drilling, water pressure test, grouting, hole sealing, inspection

3030 earth and rockfill dams and embankments

Yard planning: time planning, space planning ( low material low use, high material high use ), quality and quantity planning

Time planning: when the dam strength is high, use the near material, the near material and the upstream easily flooded material yard, the dry season with high water content material yard, and the rainy season with low water content material yard.

Ratio of actual total exploitable amount to dam filling amount: soil material 2 - 2.5; Underwater gravel: 2 - 3; Gravel: 1.5 - 2; Stone: 1.5 - 2; The filter material is not less than 3

Earthwork filling compaction machinery: static pressure rolling ( horn, pneumatic tire ), vibration rolling, ramming soil compaction standard: clay dry density; Non - clay relative density

Compaction parameters: weight of rolling machine, water content, number of rolling passes and thickness of paving soil vibration grinding shall also include vibration frequency and walking speed

Compaction water content of cohesive soil: w = w + 2 %, w = w, w = w - 2 % w plastic limit non-cohesive soil: paving thickness, times, dry density test

Earth - rock dam: dry fill compaction, water fill, hydraulic fill compaction earth-rock dam construction operations: preparation, basic, auxiliary and additional operations

Preparation work: four - way - one - level auxiliary work: dam surface drainage, stone removal additional work: slope protection and finishing basic work: paving and compaction

Dam surface operation: paving, leveling and compacting cohesive soil, adding water to the material yard; Non - cohesive soil, dam surface water. Rolling method: advance and retreat offset and rotary sleeve

Joint treatment: quality control of earth-rock dam with soil before sand, sand before earth: water content of material yard and dam surface is high: overturning, rotation of working face, improvement of drainage and rainproof

Low water cut: ridge construction, irrigation, rotation of soil dam surface quality inspection: cohesive soil 200 - 500 ring knife sand 500 ring knife gravel, reverse filter material irrigation sand filling

Division of rockfill dam body material: cushion layer, transition, main rockfill, downstream rockfill ( secondary rockfill area ) dam body filling: occupying method and retreating method

Cushion material, transition material and main pile of Shi Ping construction cushion material: back method of rock-fill compaction: porosity, test pit method

Earth - rock dam seepage prevention: upper section and lower section

Upstream cut-off seepage method: clay inclined wall, throwing soil and silting method, grouting, cut-off wall, cut-off wall downstream drainage seepage guide method: seepage guide ditch, slope drainage, drainage ditch

3040 concrete works

Dismantle: cantilever plate and beam: span ≤ 2m, 70 %; Span > 2m, 100 %. Other beam, plate span 2 m or less, 50 %, span 2 - 8 m, 70 %;

* 8m 100 % first after the demolition, after the first demolition.

Steel tensile test: cold bending test piece with yield point, tensile strength and elongation: no crack or fracture after bending

Reinforcement replacement: strength replacement, area replacement reinforcement connection: welding, machinery, binding welding: flash, arc, electroslag, resistance

Joint distribution requirements: welding: tensile area of bending member shall not exceed 50 %, and compression is not restricted. Binding: should not be 25 %, pressure should not be more than 50 %

Mechanical connection: should not exceed 50 %, compression zone a joint is not restricted binding and welding joint distance elbow starting point shall not be less than 10 D.

Secondary feeding method: the strength of concrete is increased by 15 % compared with the same period of last year, and the cement is saved by 15 - 20 %. Cement sand coating method: 20 - 30 % higher strength than that of the same year and no segregation of concrete

Horizontal transportation of concrete: rail and trackless; Vertical transportation: gantry crane, tower crane, cable crane, crawler crane

Principle for selecting concrete transportation and pouring scheme: less transportation times, whole control, peak meeting, other lifting work and less equipment type

Construction process of concrete building: preparation before pouring, material laying in warehouse, vibrating after unwinding and maintenance after pouring

Construction joint treatment: high pressure water scouring for 5 - 20h, wind sand gun sanding for 1 - 2 days. Cold seam, layer permeability, shear, tensile ability is reduced

Mass concrete temperature crack: surface, penetration, deep temperature control measures: reduce fever, reduce warehouse temperature, speed up the heat dissipation

Reduce fever: reduce cement, reduce warehouse entry temperature with low fever cement: reasonably arrange time, add water and ice, pre-cool aggregate ( water, air, vacuum )

Accelerate heat dissipation: thin layer casting, precooling thick block, water cooling seam: vertical and horizontal seam width: 1.0 - 2.5 cm; Impervious scope: water stop

Joint crossing treatment: vertical flexible connection, horizontal rigid connection dam split joint: horizontal joint 15 - 24m; Longitudinal seam block or no seam through warehouse casting

Transverse seam section, grouting requirements of keyways. Vertical seam block, longitudinal seam keyways, grouting processing inclined seam can not grouting, not straight to the upstream face of the dam

Concrete quality problems: surface damage ( cause: quality defects, carbonization, chemical erosion ), cracks, structural leakage, structural instability ( steel plate, fiber )

Surface damage reinforcement: cement mortar, shotcrete, shotcrete, steel fiber shotcrete, grouting concrete, epoxy material repair

Crack: settlement joint, temperature joint, dry shrinkage joint, stress joint and construction joint crack repair: crack epoxy mortar, leakage cement mortar, sink temperature grouting