1 scope
This technology is applicable to industrial
and civil construction of groundwater in the General clay, sand and Auger hole
filling pile in artificial filled soil Foundation.
2 construction preparation
2.1 materials and equipment:
2.1.1 cement: appropriate uses, No. 425
Portland slag cement.
2.1.2 sand: sand or coarse sand, clay is
less than 5%.
2.1.3 the gravel: gravel or crushed rock,
size 5~32mm, clay is less than 2%.
2.1.4 steel: steel grade, diameter must
conform to the design requirements, certificate and retest report of the
factory, the surface should be free of old rust and grease.
2.1.5 blocks: 1:3 cement mortar buried wire
preformed in advance, 22nd or plastic cards.
2.1.6 wire: wire specifications 18~20,
firing.
2.1.7 admixtures: admixtures; under
construction need determined through experiments.
2.1.8 main equipment:
2.1.8.1 Auger boring machine: common
technical parameters is shown in table 2-7.
Auger boring machine main technical
parameter table 2-7
Motor power
(KW) rotary speed
(R/min) Rotary torque
(N • m) into the pressure
(N) the drilling speed
(M/min) external dimension
Length x width x height (m)
Crawler-LZ-30 81 3400 2800 2 8.0x3.21x21.78
-Auto-QZ~4 17 120 1400-1 7.3x2.65
2.1.8.2 maneuvering small dump trucks or
carts, load and unload earth-moving or transport of concrete.
2.1.8.3, short Rod-type vibrators. Some
long flexible shaft, concrete mixers, flat-nosed shovel, hose, etc.
2.1.8.4 slipped cylinder, cover, measuring
line, hand lamps, low voltage transformers and lines, and so on.
2.2 operating conditions:
2.2.1 aboveground and underground obstacles
were processed to achieve "three connections and one leveling".
Temporary facilities are ready for construction.
2.2.2 landmarks in general we should cap
the epithelium of the beam elevation and rammed or rolled.
2.2.3 good fabricated steel cage, its
length to 5~8M is appropriate.
2.2.4 released axis according to the
drawing and pile points, Gao Mujue horizontally on the copy, and pre-screened
visa.
2.2.5 construction hole should be made before
trial, the number of not less than two.
2.2.6 to select and determine the order of
access routes and drilling drilling machine, and formulate programmes,
technical clarification.
3 operational processes
3.1 process:
3.1.10% hole process:
Drilling machine in place → drill
bottom cleaning →
→ quality → hole orifice plate → drilling machine
3.1.2 concrete process:
Move cover plates measuring depth, vertical
→ slip →
→ concrete pouring of concrete of steel cage (with the cast with
vibration) → Insert pile head reinforcing bar
3.2 drill in place: drilling machine in
place, must remain stable, do not tilt and displacement, for control and
accurate drilling depth should be made at the rack or pipe control rods, to
observe, record in the construction.
3.3 borehole: straightening racks tappet,
good position (on), start the machine drilling, unearthed, to control the depth
after drilling, drilling.
3.4 checking the quality of hole:
3.4.1 drilling depth determination.
Sounding-line (hammer) or Lantern holes deep and tilled soil thickness.
Difference of the imaginary depth equal to drill deep. Tilled soil thickness
should not exceed 10cm.
3.4.2 aperture control. Drilling of soil
containing more blocks whenever, or when large water content soft plastic clay
stratum, we must prevent the pipe shaking caused aperture to expand, resulting
in holes wall attachment of disturbed soil and the hole end of fall.
3.5 hole the subsoil cleanup. After
drilling to a predetermined depth, must be idling in the hole at the end of Qing
dynasty, and then stopped, carry the pipe may not be music Kelly. Thickness of
downhole deficiency exceeds quality standards, to analyze the causes and take
measures to deal with. Scattered on the ground of the soil in the drilling
process, must be cleared away.
3.6 moving the drilling rig to the next
pile. Through hole inspection, should fill in the pile hole construction
records. Then, cover the orifice plate, and to prevent the cover driving, or on
leave. Finally, remove the drilling rig to the next pile.
3.7 concrete:
3.7.1 removing Burr hole cover plate once
again review the depth, diameter, bubble wall, vertical and hole bottom of
tilled soil thickness. When you do not meet the quality standards, should be
qualified, then the next procedure.
3.7.2 dipping steel cage: steel cage should
tie before in mortar blocks (or plastic card); dipping steel cage, must aim at
the hole, hanging straight steady, slow down, avoid collision wall. Steel cage
to design position, should be fixed immediately. In case of two-stage
connection of steel cage, weld should be taken in order to ensure that the bar
is correctly positioned to ensure the thickness meets the requirements.
3.7.3 on slip tube pouring concrete. In
front of the sliding tube should be checked again and measure virtual depth.
Concrete should be continuous, layered vibration compacting, lamination height
to tamping tools may be. Must not be greater than 1.5M.
3.7.4 when pouring concrete pile, due over
the pile design elevation to ensure cut after removal of laitance, top level
meets the design requirements.
3.7.5 withdrawal slip tube and plug the top
bar. Concrete poured pile 1.5M, pull out the sliding tube, directly into
concrete. Steel inserted perpendicular to the rail must be inserted at the top
of, there is enough cover and anchorage length to prevent Plug and insert
diagonal.
3.7.6 the slump of concrete suitable for
8~10cm; to ensure its workability and slump, should adjust the rate and the
addition of superplasticizer sand and fly ash.
3.7.7 the same mix of blocks, each class
shall not be less than a set.
3.8 in winter and rain during construction:
3.8.1 in winter when the temperature is
lower than 0 ℃ when pouring concrete, heating and insulation measures should be
taken. When pouring, temperature of concrete in winter construction programmes
shall apply. Top of the pile is not to design strength 50% must not be frozen.
When the temperature is higher than 30 ℃, the retarded
should be taken depending on the situation of the concrete measures.
3.8.2 strictly adhere with the drill with
the rain pouring concrete provisions in case of rain into hole collapse caused
by irrigation. Rainy days drilling is not possible. Site must have drainage
measures, prevent surface water into the tank, so as to avoid collapse or the
base of the slope and soil subsidence, drilling machine incline.
4 quality criteria
4.1 project:
4.1.1 piles of raw material and concrete
provisions must comply with the design requirements and specifications.
4.1. the 20% hole depth must meet the
design requirements. Pile dominated by friction, sediment thickness no greater
than 300mm; end-bearing piles, sediment thickness no greater than 100mm.
4.1.3 the actual pouring of concrete, no
less than the calculated size.
4.1.4 top elevation of pouring concrete
pile and treatment of laitance must meet the requirements of specification for
design and construction.
4.2 allowable deviation, as shown in table
2-8.
5 finished product protection
5.1 during the process of fabrication,
transportation and installation of reinforcement cage, measures should be taken
to prevent deformation. Into the drilling, there should be protection pad.
Tubes and the pad or pad.
5.2 reinforcement cage in the hanger into
the holes, no collision hole. When pouring concrete, should take steps to fix
its position.
5.3 basic excavation pile construction is
completed, should formulate a reasonable construction and technical measures in
order to prevent displacement and tilt. And review the level of vertical and
horizontal deviation of each pile.
Auger drill hole filling pile tolerance
table 2-8
Project tolerance (mm) test method
1 steel cage reinforcement spacing ± 10 '
check
2 Stirrup spacing of reinforcement cage ±
20 foot check
3 steel cage diameter ± 10 ' check
4 length of steel cage ± 100 foot check
1~2 pile
Perpendicular to the center line of the
pile of single rank of piles d/6 and not more than 200 cable and check
5 positional deviation of group piles
foundation piles
Strip foundation piles
The Middle pile of pile foundation
H/100 hanging wire and vertical 6 foot
check
Note: d for diameter of the piles, and h is
the length.
5.4 after the hole in the steel cage, to
pour concrete in the 4H. In the pouring process, and there should be no
reinforcement cage floating mud pollution prevention measures.
5.5 installing the drill when the
reinforcement cage, transport and pouring of concrete, should pay attention to
protect the scene of the axis, elevation.
5.6 external reinforcement inserted iron to
protect, not any bending or breaking.
5.7 strength of pile head concrete, without
up to 5MPa shall not be laminated to prevent damage.
6 quality problems to be noticed
6.1 well tilled soil by the end of excess:
drilling is completed, should cover the openings in a timely manner, and
prevent the cover on a car and walk. Operations should be cleared up in Virtual
Earth. If necessary, second vote for drilling soil of Qing dynasty.
6.2 collapse crater: note changes in soil,
sand and gravel, or plastic mud, perched water leakage and so on, should be
studied in conjunction with the relevant authorities.
6.3 quality of pile concrete difference:
necking, empty, folder and so on, must be strictly according to the operating
regulations of the pouring process of concrete vibrated. No debris mixed with
soil and pouring in concrete.
6.4 deformation of steel cage: steel cage
stacking, transporting, lifting, into the hole in the process, there is no
strict according to the operating regulations. Technology gives the low-down on
workers must be strengthened, strict implementation of the reinforcement of the
quality measures.
6.5 when the drill pipe to beat Hoang,
rack, shaking, drilling footage and other anomalies, should immediately stop
checking.
6.6 when the water closer to the pile of
concrete, to measure elevation at the top, so as to avoid cutting off too much
and remedial piling.
6.7 drilling into sand when groundwater is
encountered, drilling depth should not exceed initial water level in case of
collapse.
7 quality records
This standard shall meet the following
quality records:
7.1 cement factory prove and retest proved.
7.2 certificates or certificates of steel
bar and shop test of steel bar single-copy.
7.3 test pressure test records.
7.4 repair sketch pile.
7.5 pile construction records.
7.6 test of concrete application form and
mix orders issued by the laboratory.
7.7 28D compressive strength of standard
curing concrete block test report.
7.8 factory certification of ready-mixed
concrete.
No comments:
Post a Comment