CN110374094A

CN110374094A - Construction method of mechanical pore-forming cast-in-place pile

Info

Publication number: CN110374094A
Application number: CN201910459792.1A
Authority: CN
Inventors: 李冉; 廖富兴; 许兴成; 唐建淞; 龚颖康; 刘振宇; 张恒; 倪元春; 孙缙环; 王洋; 郑佳蕊
Original assignee: China Construction Second Engineering Bureau Co Ltd
Current assignee: China Construction Second Engineering Bureau Co Ltd
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2019-10-25

Abstract

The invention discloses a construction method of a mechanical pore-forming cast-in-place pile, which comprises the following specific steps of leveling a field, removing sundries, lofting a pile position, embedding a steel casing, drilling, cleaning holes, hoisting a steel reinforcement cage, pouring concrete to obtain a cast-in-place pile foundation, and detecting the pile foundation; the pile foundation is detected by adopting a method combining the single-pile vertical compression static load test and the low-strain method integrity detection, so that the detection is more complete, and the detection data is more complete; the construction method can be well suitable for special terrains, such as environments of mountainous areas, underground water flows and the like, and has strong adaptability and high construction efficiency; the automation degree is high, and the shifting is flexible and convenient; low noise, low vibration, large torque, high hole forming speed and high efficiency; the safety performance is high; no slurry circulation and little environmental pollution; is a green construction process.

Description

A kind of construction method of mechanical hole perfusion post

Technical field

The present invention relates to a kind of construction methods of mechanical hole perfusion post, belong to construction bored concrete pile technology field.

Background technique

Bored concrete pile system refers in engineering site through means such as machine drilling, steel pipe soil compaction or manpower excavations in foundation soil Stake holes is formed, and places steel reinforcement cage, concrete perfusion and the stake being made into it, according to forming hole method difference, bored concrete pile again may be used It is divided into several classes such as driven cast-in-place pile, cast-in-situ bored pile and digging hole filling pile.The construction of cast-in-situ bored pile, because retaining wall selected by it is formed Difference, have mud off mode method and without two kinds of mud off construction method.Its advantage of constructing is: 1, and sinking to the hammering in stake Method is compared, and construction noise and vibration are much smaller；2, the more stakes bigger than the diameter of prefabricated pile can be built；3, on various grounds It can be used；4, the shortcomings that quality of construction quality influences the bearing capacity of stake very big, but there is also increasings, such as because of coagulation Soil is to be perfused in muddy water, therefore concrete quality is more difficult to control；Time-consuming, speed of fulfiling hole is slow, and body refuse pollutes environment etc..

Non- intellectual, the complexity of geological conditions certainly will cause to dig the uncontrollable to influence and restrict whole work of stake progress Cheng Jindu, karst cave treatment, the special geomorphology processing difficulty of work progress are all very big, and make and obtain in special circumstances at these Pile measurement difficulty it is also very large, so being badly in need of developing the construction method and pile measurement method of a kind of new bored concrete pile.

Summary of the invention

The present invention provides a kind of construction method of mechanical hole perfusion post, specifically includes the following steps:

(1) it preparation: removes sundries and carries out place leveling again, smooth location size will be able to satisfy rotary drilling rig construction Position, earthwork levelling of the land are directly excavated to raft plate bed course bottom absolute altitude, and the stake position for being intended to drilling releases, and fix cross protection Stake；

(2) stake position setting-out: by the position setting-out for carrying out pile foundation " from entirety to the principle of part ", the absolute altitude to drill is put When sample, the absolute altitude of setting-out should be checked in time, using the position of each stake point of total station accurate settingout, standardizing its error In it is required that, construction drill places the pile foundation construction direction from the inside to the outside, from top to bottom for needing every building, that is to say, that every building Stake is played outward from innermost stake, principle construction direction, upper → left and right → in → under (builder's road entrance)；

(3) it buries steel pile casting: guaranteeing that steel pile casting gradient is not more than by the control stake setting-out of positioning, when burying steel pile casting 1%；

(4) drilling construction: first landing drilling bucket, when aperture, is self-possessed using drilling bucket and is pressurizeed as drilling power, when drilling bucket quilt It squeezes full of after boring mud, is proposed earth's surface, transport boring mud, return to bore operation position, hanging down for pore-forming is checked in drilling process Straight degree, bore operation is until meeting the socket length designed；After pore-forming reaches designed elevation, to hole depth, aperture, hole wall, hang down Straight degree is checked；

Encountered in boring procedure hard boulder, geological condition it is more complex when, 1~2m will check a verticality；Remaining is just During normal drilling construction, every 5~8m checks a verticality；It creeps into middle decomposed rock, then drilled through out completely with straight tube pick Core, to meet design socket length until；Solution cavity is encountered in boring procedure, boulder Special Geological Condition should take perfusion C20 concrete drills again.

(5) borehole cleaning: carrying out borehole cleaning using circulation drilling technology: behind stake holes end hole, drilling tool being replaced with dedicated scouring bit, By scouring bit, borehole cleaning, borehole cleaning number are no less than 3 times repeatedly, are measured under drilling tool to below ground length as bottom hole depth (note: the length of the bit generally takes its 2/3 calculating), then sediment thickness is detected by the method for sash weight measurement (lining rope), lining rope measures Depth is sediment thickness as sediment top surface depth, the difference between the two, until clear complete sediment, it is ensured that Chen slag Hou Du≤5cm；

(6) lifting of steel reinforcement cage:

First segment hang load hole steel reinforcement cage framework of steel reinforcement center and stake holes centering after insert in the hole, to be protected in decentralization process It holds that steel reinforcement cage is vertical, and steel reinforcement cage is stuck at aperture using inserting thick stick method by the steel reinforcement cage being inserted into, then by the second section reinforcing bar Cage is temporarily hung with crane and is suspended state, and after becoming straight line in two sections pair, centering main reinforcement position is simultaneously utilized Pendant by all around controlling verticality, hang it is whole after the completion of welded with first segment steel reinforcement cage, welding quality is checked after the completion of welding, Above-mentioned steps are repeated after qualification and carry out lower section reinforcing bar cage hoisting, and whole connectors can be lowered into hole, steel reinforcement cage after connecting It after sinking to design position, fixes immediately, prevents from moving, steel reinforcement cage enters position error behind hole: plan-position deviation is not more than 10cm, bottom surface height variation are not more than ± 10cm；

(7) casting concrete obtains bored concrete pile, detects to pile foundation.

Step (3) control stake setting-out comprises the concrete steps that: the position of drill hole of drilling machine being marked in bottom hole, then steel pile casting is hung Into in hole, find out the center location of steel pile casting, with cross hairs at the top of steel pile casting or bottom hang up, then move steel pile casting, make Steel pile casting center is overlapped with drill hole of drilling machine center, keeps steel pile casting hard straight, steel pile casting is pressed into predetermined position with drilling bucket, Dregs is backfilled around steel pile casting, compaction in layers backfills steel pile casting outer periphery with coarse-grained soil, backfills closely knit.

16 reinforcement fabrication of Φ is used to be welded in steel reinforcement cage at ship shape bracket or ear muscle point outside the reinforcing bar of step (6) steel reinforcement cage Protective layer is used as in main reinforcement, ship shape bracket or ear muscle are symmetrical arranged four on steel reinforcement cage section, in steel reinforcement cage vertical position It is upper to be arranged by 2m spacing.

Step (6) steel reinforcement cage fixation is to pass through steel reinforcement cage at aperture with two steel pipes to be tied up in parallel with 12# iron wire in main reinforcement On, the steel pipe both ends every side of length is no less than 1000mm, before casting concrete each counterweight in every steel pipe both ends 200 × 300 × 500mm or more the rectangular slab of stone pushes down steel pipe.

Step (7) casting concrete includes dry hole pouring construction process, underwater concrete construction process,

Steps are as follows for the specific steps of dry hole pouring construction process:

1. installing conduit, conduit uses the steel pipe of diameter 250mm, with the standard pipe of 2.5~3m with the long 1~1.5m of 1~2 section Long short tube, intrusion pipe is fixed with ring flange connecting screw or the connection of silk tooth, and ring flange connection or silk tooth junction are respectively mounted O shape Conduit is slowly sunk to the depth apart from bottom hole 300mm~500mm by rubber seal；

2. continuous concrete above mentions conduit；

3. concreting finishes, conduit and steel pile casting are extracted；

Steps are as follows for the specific steps of underwater concrete construction process:

2. water proof plug is placed on the water surface in conduit；Because pile foundation depth is deeper, using underwater gliders technique Pile foundation concrete is more closely knit to be unlikely to concrete disintegration；

3. configuring 0.1~0.3m³Cement mortar pours into the conduit and funnel of water proof plug or more, then pours into again first batch of mixed Solidifying soil, cuts iron wire, cement mortar is made to stay in bottom hole, water proof plug emersion；

4. continuous concrete above mentions conduit；

5. concreting finishes, conduit and steel pile casting are extracted.

The calculation formula of the first batch of concrete amount of pouring into (beginning quantity) of step (7) are as follows:

V=D²π/4(H₁+H₂)K+d²π/4h₁=D²π/4(H₁+H₂)K+d²π/4[H-(H₁+H₂)]r₁/r₂

In formula:

V-- beginning quantity (m³)

D-- bore diameter (m)

D-- catheter diameter (m)

H₁-- conduit bottom end is away from hole bottom distance (m)

H₂-- conduit Transducers Embedded in Concrete depth (m)

H-- drilling depth (m)

K-- fullness coefficient, takes 1.10

r₁-- mud balance takes 1200kg/m³

r₂-- concrete specific gravity takes 2400kg/m³。

The pile measurement method is detected using single pile bearing capacity, the detection of low strain dynamic method and Large strain method The method combined carries out pile measurement, and the detection of low strain dynamic method and Large strain method are carried out after single pile bearing capacity is qualified The pile foundation quantity of detection, low strain dynamic method and the detection of Large strain method is 3~5 times of single pile bearing capacity amount detection.

Specific step is as follows for the single pile bearing capacity:

(1) the sampling observation quantity of single pile bearing capacity is determined according to code requirement；

(2) test pile pile cover top need to be lower than nature ground 800mm, measure capacity value using pressure gauge；It is flat using preloading ballast Platform Force Method is tested, and the parallel connection of 320t jack provides counter-force with mound as loading equipemtn, and sedimentation observation passes through installation Range at stake top diagonal line both ends is 50mm, the dial gauge that accuracy is 0.01mm measures, and diameter or hem width are greater than The pile foundation of 500mm, 4 dial gauges of symmetrical placement, diameter or hem width are less than or equal to the pile foundation of 500mm, 2 percentages of symmetrical placement Table；

(3) multistage loadings load, every grade of load are loaded as estimating the 1/10 of ultimate load, press 2 times of classification lotuses every time later Carry load, every grade load after the 5th, 15,30,45,60min survey read dial gauge in pile head settlement amount, later every 30min survey read Once, when pile head settlement rate reaches opposite stability criterion, then apply next stage load, stability criterion: stake top hourly Settling amount is less than 0.1mm, and continuously occurs twice；Every grade of load should keep load constant in its maintenance process；

(4) after reaching design load, load shedding pressure, every grade of unloading value takes 2 times of loaded value, and equivalent unloads step by step, When unloading, every grade of load maintains 1h, 15,30,60min surveys the pile head settlement amount in reading dial gauge in three times, unload next stage；Unloading To after zero, stake top residual settlement amount of reading is surveyed, dial gauge surveys read time 15,30min, and it is later primary every 30min survey reading dial gauge, It surveys and reads stake top residual settlement amount, survey and read that total time 3h must not be less than.

Specific step is as follows for the low strain dynamic method detection:

(1) according to stake diameter size, pile body top is arranged symmetrically 2~4 test points at away from 2/3 radius of pile center；Each At test point be arranged velocity sensor, acceleration transducer, velocity sensor, acceleration transducer respectively with RSM-PRT (T) base The connection of low strain detection of the pile instrument；

(2) using pile center as impacting point, apply external force, velocity sensor, acceleration transducer will acquire under external force Signal transmitting RSM-PRT (T) the Low Strain Dynamic Testing of Piles instrument arrived carries out data processing.

The specific steps of the Large strain method detection:

(1) the test pile foundation that selection concrete strength reaches design strength carries out Stake head handling and installs dolly；

(2) sensor is symmetrically mounted on to the stake side surface at 2D for stake diameter≤800mm, for stake diameter > 800mm The stake side surface being symmetrically mounted on sensor at D, sensor be acceleration transducer and strain force sensor, the same side The distances of two sensors be not more than 80mm, center sensor axis and pile center's axis keeping parallelism, acceleration transducer and answer Variant force snesor is connected with controller；

(3) it is dropped hammer hammering using cast iron, hammer weight >=1.0%Q_m, Q_mTo estimate ultimate bearing capacity of single pile, cast iron drops hammer Gao Jing Than >=1；

(4) sensor sends data to controller, and controller transfers data to computer and handled.

Beneficial effects of the present invention:

(1) ship shape bracket is arranged outside steel reinforcement cage in the present invention or ear tendon protective layer, steel reinforcement cage are firmer.

(2) present invention has beginning quantity when casting concrete, and the amount of first time casting concrete must not be lower than first watering Amount guarantees that pile foundation bottom is stablized, also achieves the Primary Location of steel reinforcement cage bottom while can also dilute, break up pile bottom sediment.

(3) dry hole pouring construction process of the present invention and underwater concrete construction process need in addition to underwater concrete construction process It sets except water proof plug, it is other same, it is adaptable when encountering different situations.

(4) construction method of the present invention has versatility, can cope with the construction of different geological environment cast-in-situ bored piles, practical Property it is strong, place occupy it is small can the operations simultaneously of more pile foundations.

(5) high degree of automation of the present invention, displacement are flexible and convenient；Low noise, low vibration, torque are big, speed of fulfiling hole is fast, effect Rate is high；Using diesel oil as fuel, it is not necessarily to water power, security performance is high；No mud circulation, environmental pollution are small；For " green construction Technique ", while the cost that compares is lower, economic benefit is more preferably.

(6) detection method of pile foundation of the present invention is convenient, novel, by single pile bearing capacity, low strain integrity testing method Combine with high strain monitoring method and detected, accuracy in detection is high.

Detailed description of the invention

Fig. 1 is the schematic diagram that the first batch of concrete amount of pouring into of the embodiment of the present invention 1 calculates；

Fig. 2 is 1 single pile vertical resistance pressure static load test detection schematic diagram of the embodiment of the present invention；

Fig. 3 is 1 low strain dynamic method pile integrity detection schematic diagram of the embodiment of the present invention.

Specific embodiment

The present invention will be further described in the following with reference to the drawings and specific embodiments.

Embodiment 1

A kind of construction method of mechanical hole perfusion post, specifically includes the following steps:

(1) it preparation: removes sundries and carries out place leveling again, smooth location size will be able to satisfy rotary drilling rig construction Position, earthwork levelling of the land are directly excavated to raft plate bed course bottom absolute altitude, carry out measurement review, and record data and put on record；

(2) stake position setting-out, by the position setting-out for carrying out pile foundation " from entirety to the principle of part ", the absolute altitude to drill is put When sample, the absolute altitude of setting-out should be checked in time, using the position of each stake point of total station accurate settingout, standardizing its error In it is required that, construction drill needs the construction direction of the pile foundation in every building from the inside to the outside, from top to bottom, that is to say, that the stake in every building It is played outward from innermost stake, the stake cooperation that left and right is jumped when innermost working face Zhan Bukai is played, principle construction direction, on → left and right → in → under (builder's road entrance)；When planning travelling line, maintain a certain distance sidewalk with bore position；With It is stable and easy for construction to exempt from influence hole wall；Borer chassis should not be placed directly on unsound banket, in order to avoid generate uneven sink It falls into；The placement of drilling machine is considered as the unearthed convenience cleared in aperture in drilling construction；

(3) steel pile casting is buried, before drilling machine is in place, whether the performance state of precheck drilling machine is good, guarantees drilling machine work Make normal；It is specifically embedded that steps are as follows:

A, the production of steel pile casting and inbuilt principle:

The height of steel pile casting is 3m at aperture, barrel thickness is 8mm, internal diameter 1m；Protecting tube embedding depth should meet design And related code requirement (protecting tube embedding height is above ground level to be not less than 700mm, meet concrete is superfilled to be poured), steel pile casting buries If middle guarantee steel pile casting gradient is not more than 1%；Before embedded steel pile casting, steel pile casting bottom is first drilled into using the drill bit of larger caliber in advance It after elevation location, proposes drilling bucket and steel pile casting is pressed into predetermined position with drilling bucket, with week on the outside of coarse-grained soil backfill steel pile casting It encloses, backfills closely knit；

B, protecting tube embedding work is the beginning of rotary drilling rig construction, and steel pile casting plan-position and verticality should be accurate, steel Around casing and steel pile casting footing should be close；

C, the position of drill hole of drilling machine is marked in bottom hole when burying steel pile casting；Steel pile casting is hung into hole again, finds out steel shield Then the center location of cylinder moves steel pile casting, makes steel pile casting center and drill hole of drilling machine with cross hairs at the top of steel pile casting or bottom Center is overlapped；Steel pile casting verticality is checked with horizontal ruler simultaneously；Hereafter it symmetrically, is equably backfilled around steel pile casting The dregs of optimum moisture content, compaction in layers, reaches best compactness, and rammer will prevent steel pile casting deflection when filling out；

(4) drilling construction:

Main working interface is directly entered by indicator knob when construction drill, then carries out bore operation, when drilling is first Drilling bucket is landed, operation is zeroed out by the reset button on display, records the home position of drill bit of drilling machine, at this point, aobvious Show the bar shaped column and number of the current location of device display drilling, operator can monitor the real work position of drilling by display It sets, each drilling depth position and hole depth position, to operate bore operation, in operation process, operator can pass through main interface Three virtual instruments display power head pressure, moulding pressure, master file pressure one by one, the work shape of real-time monitoring hydraulic system State when aperture, is self-possessed using drilling bucket and is pressurizeed as drilling power, a drilling depth billet shape column shows that the drilling of current drill bit is deep Degree, the movement position of strip column Dynamically Announce drill bit, the number of hole depth show the total depth in this hole, are full of when drilling bucket is extruded After boring mud, proposed that earth's surface, operation revolution operation handle make machine go to the position for unloading native position, boring mud transported with loading machine It walks, after, bore operation position is automatically returned to positive button machine by the self-return on operation display, or pass through hand Dynamic operation revolution operation handle makes machine return to bore operation position manually, this working condition can be by the main interface of display Return mark monitored, after aperture, be self-possessed using drill bit drilling rod and pressurize as drilling power, when drilling bucket be extruded full of brill After slag, earth's surface is proposed, boring mud is transported with loading machine, while observing monitoring and recording drill hole geologic situation；

The Special Geological Conditions such as solution cavity, boulder are encountered in boring procedure should take perfusion C20 concrete to drill again, have Body situation should formulate corresponding measure according to specific geological condition；

After pore-forming reaches designed elevation, hole depth, aperture, hole wall, verticality etc. are checked, taken measures when unqualified Processing；After pile foundation excavation meets embedding rock requirement to supporting course, answers and the related units of taking part in building such as Times management, owner check test together It receives；After the confirmation of the correlation side of taking part in building scene, timely descending reinforcing cage casting concrete is answered；

It reports with reference to geological mapping into rock depth, it is comprehensive descision backfill, sedendary soil, severely-weathered in conjunction with the long estimation table of stake Hierarchical position, and before accurate judgement pile foundation degree in weathering position, creep into middle decomposed rock, the rock slag that bit drill drills out can also Confirmed, it is also possible to which straight tube drills through out core confirmation, when rock strength reaches design requirement, then has been drilled through out with straight tube pick Whole core, until the socket length for meeting design；

Drill whole hole, and rotary digging stake pierces design socket length, need to report to management when being drilled into this stratum, be determined by management Whole hole drill is deep；It is required, to be reported when the close whole hole of drilling, inspection declaration is wanted in whole hole, carries out self-test before inspection declaration, such as according to engineering management Quality requirement is not achieved in self-test, then corrects the unqualified part of stake holes；

The verticality of stake holes is the major criterion for guaranteeing pile quality, so to check the vertical of pore-forming in drilling process Degree: encounter hard boulder, geological condition it is more complex when, answer 1~2m to check once；During remaining normal drilling construction, every 5 ~8m checks that once such as glancing off should stop creeping at once, and the anti-concrete that fills is crept into again, in rotary drilling rig work progress, It must not be to necromancer slag, other equipment and material within the scope of 6 meters near the aperture；

(5) borehole cleaning: borehole cleaning is the important ring that bored pile construction guarantees pile quality, ensures stake holes by borehole cleaning Quality index, bottom hole sediment thickness, amount containing boring mud and hole wall dirt etc. meet stake holes quality requirement；

Borehole cleaning is carried out using circulation drilling technology: behind stake holes end hole, drilling tool being replaced with dedicated scouring bit, passes through borehole cleaning Drill bit borehole cleaning 3 times repeatedly, then sediment thickness is detected by the method for sash weight measurement (lining rope) or is measured under drilling tool to below ground For length as bottom hole depth (note: the length of the bit generally takes its 2/3 to calculate), lining rope measures depth as sediment top surface depth, and two The difference of person is sediment thickness；Until clear complete sediment, it is ensured that sediment thickness meets design requirement (Chen slag Hou Du≤5cm)；

(6) steel reinforcement cage is lifted:

1. the making step of steel reinforcement cage is as follows: 9 meters of the every segment length of steel reinforcement cage sectional making, main reinforcement diameter is mainly 16mm three-level Steel, stirrup diameter 8mm, putting more energy into and binding round diameter is mainly 14mm, and steel reinforcement cage average length is 9 meters, then average weight is 1650kg, steel Muscle cage sectional making on hole forms, and 9 meters of every segment length, adjacent vertical muscle mutually staggers, and the length that is staggered is 35d, first segment steel reinforcement cage It is put into stake holes, is fixed using steel pipe support and there are 1~2 meter of high length and lower section steel reinforcement cage to weld；The upper layer of sleeve will have been twisted Reinforcing bar is screwed on connected reinforcing bar, is then rotatablely connected reinforcing bar or unscrewed sleeve to predetermined position, finally connector is tightened, lock Surely sleeve is connected, for the reinforcing bar not being able to rotate, lock nut and connection sleeve can be screwed into advance in the screw thread of lengthening, then instead It is screwed on another steel bar end screw thread, finally locks connection sleeve with lock nut；16 steel of Φ is used outside the reinforcing bar of steel reinforcement cage Muscle is fabricated to ship shape bracket point and is welded in as protective layer in the main reinforcement of steel reinforcement cage, and ship shape bracket is symmetrical arranged on steel reinforcement cage section Four, several C14 are set by 2m spacing on steel reinforcement cage vertical position and are put more energy into stirrup, are formed with the main reinforcement firm welding of steel reinforcement cage Skeleton is reinforced with triangular reinforced bar spot welding at hoop of putting more energy into；

Suspension centre is selected according to counter-force equal principle, and suspension centre is located at steel reinforcement cage and puts more energy into muscle and main reinforcement junction, and suspension centre is symmetrical 4 lifting points are arranged in arrangement, each steel reinforcement cage, and are the reinforcement measure reinforcing bar and main reinforcement welding that 20mm length is 10d with diameter, To guarantee that steel reinforcement cage is indeformable and fall off in lifting, suspension centre to weld it is real welds, guarantee not open in hanging hole whole process Weldering；

2. scene carries out the lifting of steel reinforcement cage using the crane of 25T, first segment reinforcing bar cage hoisting enters hole for framework of steel reinforcement It inserts in the hole after center and stake holes centering, to keep steel reinforcement cage vertical in decentralization process, the steel reinforcement cage being inserted into is stuck in aperture Place, is fixed using steel pipe support and there are 1~2 meter of high length, then temporarily hangs the second section steel reinforcement cage in suspention with crane State, after becoming straight line in two sections pair, centering main reinforcement position is simultaneously vertical by all around controlling using pendant Degree, hang it is whole after the completion of welded with first segment steel reinforcement cage, welding quality is checked after the completion of welding, repeated after qualified above-mentioned steps into Row is lower to save reinforcing bar cage hoisting, and whole connectors can be lowered into hole after connecting, solid immediately after steel reinforcement cage sinks to design position It is fixed, it prevents from moving, specific fixing means is topmost positioned in skeleton, it is necessary to calculate positioning bar by the aperture absolute altitude measured Length, and crosscheck it is errorless after weld positioning hanging ring again, with two steel pipes at aperture pass through steel reinforcement cage 12# iron wire it is parallel Tie up in main reinforcement, the steel pipe both ends every side of length is no less than 1000mm, before casting concrete each counterweight in every steel pipe both ends 200 × 300 × 500mm or more the rectangular slab of stone pushes down steel pipe, and cross hairs is pulled on steel reinforcement cage, finds out steel reinforcement cage center, finds out stake according to fender pile Position center, steel reinforcement cage are overlapped steel reinforcement cage center with stake position center when positioning, and steel reinforcement cage enters position error behind hole: plan-position is inclined Difference is not more than 10cm, and bottom surface height variation is not more than ± 10cm；

(7) casting concrete, the specific steps of underwater concrete construction process:

1. installing conduit, conduit uses the steel pipe of diameter 250mm, and the short tube of the long 1m long of 2 sections is matched with the standard pipe of 2.5m, fills Infuse effective ring flange connecting screw fix or silk tooth connection, ring flange connection or silk tooth junction be respectively mounted O shape rubber seal, Conduit is slowly sunk to the depth apart from bottom hole 400mm；

3. configuring 0.3m³Cement mortar pours into the conduit and funnel of water proof plug or more, then pours into first batch of concrete again, Iron wire is cut, cement mortar is made to stay in bottom hole, water proof plug emersion；In conjunction with Fig. 1, the calculation formula of the first batch of concrete amount of pouring into are as follows:

In formula:

V-- beginning quantity (m³)

D-- bore diameter (m)

D-- catheter diameter (m)

H₁-- conduit bottom end takes 0.4m away from hole bottom distance (m)

H₂-- conduit Transducers Embedded in Concrete depth (m) takes 1.5m

H-- drilling depth (m)

K-- fullness coefficient, takes 1.10

r₁-- mud balance takes 1200kg/m³

r₂-- concrete specific gravity takes 2400kg/m³；

4. continuous concrete above mentions conduit；

5. concreting finishes, conduit and steel pile casting are extracted.

3. continuous concrete above mentions conduit；

4. concreting finishes, conduit and steel pile casting are extracted；

The instillation process of concrete:

(1) check after hole quality is qualified should casting concrete as early as possible, pouring the time should control within an hour, in order to avoid Hole wall collapses, and mudstone is fallen into hole, influences bottom hole quality, and concrete uses commerical ready-mixed concrete, slump control 180~ 220mm, concrete should be pumped to aperture using vehicle-mounted concrete day with prestissimo, be perfused as early as possible, concrete beginning quantity dress When full hopper, the sealing cover of feed hopper bottom is opened, is made in concrete inflow hole, continuous placing pours coagulation until stake top absolute altitude When native, vibrate within the scope of 5m below stake top, after concreting, before concrete final set, check main reinforcement position and Stake top absolute altitude is simultaneously protected in time, and pile concrete stays test specimen, every one group of random witness sampling, and standard curing reaches age Afterwards, unit pressure testing is surveyed in inspection；The concreting pile foundation degree of falling that inclines must not exceed 2m, and using perfusion pipe construction, concrete is necessary Primary concreting pile is wanted in placement layer by layer, stake, when due in technical and construction organization must interval when, the intermittent time Should be short as far as possible, and should finish concreting before previous concrete initial set, reinforcing bar is paid attention in concreting process at any time Cage situation should take timely measure processing when there is deformation, displacement；

(2) foundation pile concrete is poured, and reaches the 80% of design requirement to concrete strength, can carry out next step work Sequence,

According to on-site actual situations, superfilled 60cm concrete is rejected using artificial, until exposing stone, must not damage steel Muscle, this picks chisel part concrete and pours in place together with cushion cap concrete.

The present embodiment also detects pile foundation, is answered using single pile bearing capacity, the detection of low strain dynamic method and height The method that combines of political reform detection carries out pile measurement, carried out after single pile bearing capacity is qualified the detection of low strain dynamic method and The pile foundation quantity of the detection of Large strain method, low strain dynamic method and the detection of Large strain method is single pile bearing capacity amount detection 3 times.

Single pile bearing capacity, the purpose is to engineering pile detections, and detecting vertical allowable load capacity of single pile is It is no to meet design requirement, and provide examining report and for the acceptance of work provide acceptance basis specific step is as follows:

A, detection foundation and quantity:

It is required to carry out test pile single pile bearing capacity according to design drawing, specification and consigner；

B, the preparation before detection:

Before single pile dead-load detection, following items should be carried out:

1) consigner should contact design side, management side and construction party etc. and determine test pile position；

2) test load preferably uses hydraulic jack, when loading using two and the above jack, answers synchronous work in parallel Make, and should meet the following requirements:

1. the jack model, the specification that use are answered identical；It the resultant force center of jack should be with the cross-section centroid weight by inspection stake It closes；The administrative staff of profession are arranged to be reduced to error generated when the construction teams and groups labor service personnel installation of floor manager installing handle It is minimum；To guarantee to make jack resultant force center to be overlapped with pile center line, jack, pressure gauge etc. should be sent to again before test The measurement unit of authorized by state qualification is examined and determine；

2. load measurement is using the pressure gauge measurement oil pressure for being parallel to jack oil circuit, test pressure gauge, oil pump, oil pipe The 80% of regulation operating pressure is not to be exceeded in pressure in maximum load；

3) settling amount measurement is measured using long range dial gage, and should be met the following requirements:

1. measurement error is not more than 0.1%FS, resolving power is superior or equal to 0.01mm；

2. diameter or hem width are greater than the pile foundation of 500mm, should be in 4 displacement measurement instrument (hundred of two direction symmetrical placement Divide table), the stake of diameter or hem width less than or equal to 500mm can 2 displacement measurement instrument (dial gauge) of symmetrical placement；

3. preferably in stake top 200mm, once position, measuring point should be firmly fixed at pile body to sedimentation measurement plane；

4. datum line beam should have certain rigidity, one end of beam should be fixed on reference stake, and the other end answers freely-supported in benchmark In stake；

5. temperature, vibration and other extraneous factors should be avoided in the fixture and datum line beam that fix and support displacement meter (dial gauge) Influence；

4) vertical static load test on single pile selects ballasting platform counterforce device, and the counter-force that counterforce device provides is not answered small In estimating 1.2 times of maximum finder charge, the centre distance between test pile and reference stake answers >=(3) 4D and > 2.0m；

5) test pile completes that the time specified in following table should not be less than the time interval between dead-load detection；Or according to Design requirement, according to this area reality, it is proposed that interval time was no less than 25 days, if cast-in-place concrete pile, no less than 28 days；Tool Body see the table below 1.

Table 1

C, single pile vertical resistance pressure static load test:

1) test pile pile cover top need to be lower than nature ground 800mm；

2) displacement measurement: the axial displacement of test pile uses the dial gauge that range is 0.01mm for 0.00~50.00mm, precision Measurement；

3) it capacity value: is measured using pressure gauge；

4) preloading mode:

Using preloading weighted ballast counterforce method, proposed adoption 320t jack parallel connection is provided as loading equipemtn with mound Counter-force；Sedimentation observation by be mounted on stake top diagonal line both ends 2 ranges be 50mm, accuracy be 0.01mm dial gauge into Row measurement；National standard: " Code for design of building " (GB50007-2011) and " architecture foundation pile detection technique is pressed in test Specification " (JGJ106-2014) requirement carry out, by specification, regulation read；Detection schematic diagram such as Fig. 2:

D, add unloading manner, at a slow speed maintained load test (ML-test):

According to engineering practice this single pile bearing capacity using maintained load test (ML-test) at a slow speed:

1) loading method: the detection for providing foundation for design should be carried out using maintained load test (ML-test) at a slow speed, i.e. multistage loadings, often Grade load reaches after opposite stability criterion again plus junior's load, until design load value, after be unloaded to zero step by step；

2) load is classified: every grade of load of test pile is loaded as estimating the 1/10 of ultimate load, and the first order can be by 2 times of classification lotuses Load is carried, every grade of load should keep load constant in its maintenance process；

3) settle discharge observation: after every grade of load by the 5th, 15,30,45,60min survey and read pile head settlement amount, later every 30min, which is surveyed, to be read once, when pile head settlement rate reaches opposite stability criterion, then applies next stage load；

4) stability criterion: pile head settlement amount hourly is less than 0.1mm, and continuously occurs (applying from classification load twice 30min afterwards starts, and calculates by the settlement observation value of 1.5 hours continuous every 30min)；

5) when pile head settlement rate reaches opposite stability criterion, next stage load can be applied；

6) unloading is with unloading settlement observation: unloading should be classified progress, and every grade of unloading value takes 2 times of loaded value, unloads step by step, Amplitude of variation of the every grade of load in maintenance process must not exceed ± the 10% of this grade of increment；When unloading, every grade of load maintains 1h, It is surveyed in three times by 15,30,60min after reading pile head settlement amount, next stage can be unloaded；After being offloaded to zero, it is heavy that reading stake top remnants should be surveyed Drop amount, hold time 3h, and surveying read time is respectively 15,30min, surveys to read once to survey every 30min later and reads stake top residual settlement Amount；

Engineering pile acceptance test preferably uses maintained load test (ML-test) at a slow speed, when there is mature regional experience, can also be used quickly Maintained load test (ML-test), every grade of fast load-keeping method is held time should not be less than 1h, and it is heavy to work as the stake top under the same level load action When reduction of speed rate restrains, next stage load can be applied；

E, detection process:

This test uses weighted ballast counterforce method, and for the parallel connection of proposed adoption jack as loading equipemtn, test pile sedimentation observation is logical Crossing and being mounted on 4 ranges at stake top diagonal line both ends is 50mm, and accuracy is that the dial gauge of 0.01mm measures；Test is by mark Quasi- corresponding code requirement carries out, and is read by specification, regulation；

When there are following situations for the moment, load can be terminated:

1) the maximum load amount of load counterforce device has been reached；

2) the maximum load amount of design requirement is had reached；

3) under certain grade of load action, pile head settlement amount is greater than 5 times of settling amount under previous stage load action；

Note: when pile head settlement can be stablized and total settlement is less than 40mm, being preferably loaded onto stake top total settlement is more than 40mm；

4) when load-subsidence curve is in slow change type, 60~80mm of stake top total settlement can be loaded onto；In special circumstances Under, it is more than 80mm that stake top can be loaded onto according to specific requirement to add up settling amount；

5) under certain grade of load action, pile head settlement amount is greater than under previous stage load action 2 times of settling amount, and through for 24 hours still Not up to stability criterion；

F, detection data arranges:

According to code requirement, test measured data is inputted into computer disposal, and draw each test pile Q-S, S-LgQ and S-Lgt curve obtains the ultimate vertical bearing capacity measured value Qui and ultimate vertical bearing capacity standard value of test pile after comprehensive analysis Quk and corresponding vertical bearing capacity of single pile characteristic value Ra is obtained according to relevant criterion；

The determination of bearing capacity value:

Vertical ultimate bearing capacity of single pile comprehensive analysis can determine as follows:

1) it is determined according to sedimentation with the feature of loads change: for drop type Q-S curve suddenly, taking it that obvious dropped suddenly occurs Payload values corresponding to initial point；

2) under certain grade of load action, pile head settlement amount is greater than under previous stage load action 2 times of settling amount, and through for 24 hours still Not up to stability criterion；Take previous stage load；

3) feature changed over time according to sedimentation determines: taking S-Lgt curve tail to occur obvious reclinate previous Grade payload values；4) for slow change type Q-S curve, preferably according to stake top total settlement, the corresponding payload values of S=40mm are taken；To D, (D is Stake end diameter) stake, can use S and be equal to the corresponding payload values of 0.05 times of D；When stake is long is greater than 40m, pile body elastic compression is preferably considered Amount；

5) when being unsatisfactory for the 1st~4 section of situation of this article, the vertical pole resistance to compression limit carrying Etech of stake takes maximum load value；

The determination and calculating of single pile vertical resistance pressure characteristic load bearing capacity Ra provides the single pile vertical resistance pressure pole of foundation for design The statistical value for limiting bearing capacity, should meet the following requirements:

1) when being not more than 3 less than the stake number under 3 or foundation platform to test pile quantity, low value should be taken；

2) to participate in arithmetic average test pile testing result, when it is very poor be no more than average value 30% when, can use its put down Mean value is single-pile vertical orientation ultimate compressive bearing capacity；

3) when it is very poor more than average value 30% when, reason should be analyzed, in conjunction with pile-type, construction technology, foundation condition, basis The engineerings concrete condition such as form is comprehensive to determine ultimate bearing capacity；When cannot specify very poor excessive reason, preferably increase test pile quantity；

4) the single pile vertical resistance pressure characteristic load bearing capacity Ra under construction unit identical conditions should be by the single pile vertical resistance pressure limit 50% value of bearing capacity.

The specific steps of low strain dynamic method detection pile body integrity:

(1) should be met the following requirements by inspection stake: pile strength concrete strength is at least up to the 70% of design strength, and not Less than 15MPa；The stake of low-strain dynamic measure should remove the laitance of pile crown, polish, clean up；

(2) signal acquisition and screening should be met the following requirements:

According to stake diameter size, the stake heart is arranged symmetrically 2 test points；The useful signal number of each test point record should not be less than 3；

(3) test process:

1. this detection device is the inspection of Chinese Academy of Sciences Wuhan rock-soil mechanics research RSM-PRT produced (T) foundation pile low strain dynamic Instrument and ancillary equipment are debugged before surveying instrument, mating velocity sensor, acceleration transducer detection, basic mechanical design feature Index should meet the pertinent regulations of existing professional standard；

2. after single pile bearing capacity meets design requirement, carrying out the pumping of low strain dynamic method detection pile body integrity Inspection, sampling observation quantity are 3 times that single pile bearing capacity inspects quantity by random samples；

3. being arranged symmetrically 2 test points at away from 2/3 radius of pile center at the top of pile body according to stake diameter size；Each detection Velocity sensor, acceleration transducer are set at point, and velocity sensor, acceleration transducer are low with RSM-PRT (T) foundation pile respectively Strain detector connection, velocity sensor, acceleration transducer are bonded at the top of pile body；

4. impacting point should avoid the influence of reinforcing bar using pile center as impacting point, apply external force, velocity sensor, acceleration Signal collected under external force is passed to RSM-PRT (T) Low Strain Dynamic Testing of Piles instrument, the analysis of detection data by sensor It is carried out according to analysis software by related Regulations with judgement, four classes of low-strain dynamic measure pile quality rating point are shown in Table 2:

Table 2

The specific steps of Large strain method detection:

(3) it is dropped hammer hammering using cast iron, hammer weight=1.5%Q_m, Q_mTo estimate ultimate bearing capacity of single pile, cast iron drops hammer Gao Jing Than=1.5；

After completing pile measurement, judges according to standard, provide examining report.

Embodiment 2

A, the production of steel pile casting and inbuilt principle:

The height of steel pile casting is 3m at aperture, barrel thickness is 8mm, internal diameter 1m；Protecting tube embedding depth should meet design And related code requirement (protecting tube embedding height is above ground level to be not less than 700mm, meet concrete is superfilled to be poured), steel pile casting buries If preceding, first accurate surveying and locating guarantees that steel pile casting top side location deviation is not more than 5cm, and it is little to bury middle guarantee steel pile casting gradient In 1%；Before embedded steel pile casting, after being first drilled into the elevation location at steel pile casting bottom in advance using the drill bit of larger caliber, propose drilling bucket and Steel pile casting is pressed into predetermined position with drilling bucket, steel pile casting outer periphery is backfilled with coarse-grained soil, backfills closely knit；

C, the position of drill hole of drilling machine should be marked in bottom hole by the control stake setting-out of positioning when burying steel pile casting；Again steel Casing is hung into hole, finds out the center location of steel pile casting, and with cross hairs at the top of steel pile casting or bottom, then Mobile steel is protected Cylinder, is overlapped steel pile casting center with drill hole of drilling machine center；Steel pile casting verticality is checked with horizontal ruler simultaneously；Hereafter i.e. in steel The dregs that optimum moisture content symmetrically, is equably backfilled around casing, compaction in layers, reaches best compactness, and rammer is wanted when filling out Prevent steel pile casting deflection；

(4) drilling construction:

Borehole cleaning is carried out using circulation drilling technology: behind stake holes end hole, drilling tool being replaced with dedicated scouring bit, passes through borehole cleaning Drill bit borehole cleaning 4 times repeatedly, then sediment thickness is detected by the method for sash weight measurement (lining rope) or is measured under drilling tool to below ground For length as bottom hole depth (note: the length of the bit generally takes its 2/3 to calculate), lining rope measures depth as sediment top surface depth, and two The difference of person is sediment thickness；Until clear complete sediment, it is ensured that sediment thickness meets design requirement (Chen slag Hou Du≤5cm)；

(6) steel reinforcement cage is lifted:

1. the making step of steel reinforcement cage is as follows: 9 meters of the every segment length of steel reinforcement cage sectional making, main reinforcement diameter is mainly 16mm three-level Steel, stirrup diameter 8mm, putting more energy into and binding round diameter is mainly 14mm, and steel reinforcement cage average length is 9 meters, then average weight is 1650kg, steel Muscle cage sectional making on hole forms, and 9 meters of every segment length, adjacent vertical muscle mutually staggers, and the length that is staggered is 500mm, first segment reinforcing bar Cage is put into stake holes, is fixed using steel pipe support and there are 1~2 meter of high length and lower section steel reinforcement cage to weld；The upper of sleeve will have been twisted Layer reinforcing bar is screwed on connected reinforcing bar, is then rotatablely connected reinforcing bar or unscrewed sleeve to predetermined position, finally connector is tightened, Lock nut and connection sleeve can be screwed into advance in the screw thread of lengthening the reinforcing bar not being able to rotate by locking connection sleeve, then Unscrewed enters on another steel bar end screw thread, finally locks connection sleeve with lock nut；Φ 16 is used outside the reinforcing bar of steel reinforcement cage Reinforcement fabrication is welded in the main reinforcement of steel reinforcement cage at ear muscle point as protective layer, and ear muscle is symmetrical arranged four on steel reinforcement cage section, Several C14 are arranged by 2m spacing on steel reinforcement cage vertical position to put more energy into stirrup, form skeleton with the main reinforcement firm welding of steel reinforcement cage, It puts more energy into and is reinforced with triangular reinforced bar spot welding at hoop；

2. scene carries out the lifting of steel reinforcement cage using the crane of 25T, first segment reinforcing bar cage hoisting enters hole for framework of steel reinforcement It inserts in the hole after center and stake holes centering, to keep steel reinforcement cage vertical in decentralization process, the steel reinforcement cage being inserted into is stuck in aperture Place, is fixed using steel pipe support and there are 1~2 meter of high length, then temporarily hangs the second section steel reinforcement cage in suspention with crane State, after becoming straight line in two sections pair, centering main reinforcement position is simultaneously vertical by all around controlling using pendant Degree, hang it is whole after the completion of welded with first segment steel reinforcement cage, welding quality is checked after the completion of welding, repeated after qualified above-mentioned steps into Row is lower to save reinforcing bar cage hoisting, and whole connectors can be lowered into hole after connecting, solid immediately after steel reinforcement cage sinks to design position It is fixed, it prevents from moving, specific fixing means is topmost positioned in skeleton, it is necessary to calculate positioning bar by the aperture absolute altitude measured Length, and crosscheck it is errorless after weld positioning fixed link again, it is flat that steel reinforcement cage 12# iron wire is passed through at aperture with two steel pipes Row is tied up in main reinforcement, and the steel pipe both ends every side of length is no less than 1000mm, in each counterweight 200 in every steel pipe both ends before casting concrete × 300 × 500mm or more the rectangular slab of stone pushes down steel pipe, and cross hairs is pulled on steel reinforcement cage, finds out steel reinforcement cage center, is found out according to fender pile Stake position center, steel reinforcement cage are overlapped steel reinforcement cage center with stake position center when positioning, and steel reinforcement cage enters position error behind hole: plan-position Deviation is not more than 10cm, and bottom surface height variation is not more than ± 10cm；

(7) casting concrete, steps are as follows for the specific steps of dry hole pouring construction process:

1. installing conduit, conduit uses the steel pipe of diameter 250mm, and the short tube of the long 1.5m long of 1 section is matched with the standard pipe of 3m, fills Infuse effective ring flange connecting screw fix or silk tooth connection, ring flange connection or silk tooth junction be respectively mounted O shape rubber seal, Conduit is slowly sunk to the depth apart from bottom hole 500mm；

2. continuous concrete above mentions conduit；

3. concreting finishes, conduit and steel pile casting are extracted；

The instillation process of concrete:

The present embodiment detects pile foundation in the way of embodiment 1, using single pile bearing capacity, low answers The method that political reform detection and the detection of Large strain method combine carries out pile measurement, carries out after single pile bearing capacity is qualified The detection of low strain dynamic method and the detection of Large strain method, the difference is that the sampling observation quantity of the detection of low strain dynamic method and the detection of Large strain method is Single pile bearing capacity inspects 4 times of quantity by random samples, and the test point that low strain dynamic method detects the sampling observation of pile body integrity is 3, After being offloaded to zero when unloading is with unloading settlement observation, hold time 4h, the hammer weight=1%Q of Large strain method detection_m, cast iron drops hammer Ratio of height to diameter=1.2 judge result to according to standard, provide examining report after completing pile measurement.

Embodiment 3

A, the production of steel pile casting and inbuilt principle:

(4) drilling construction:

Main working interface is directly entered by indicator knob when construction drill, then carries out bore operation, when drilling is first Drilling bucket is landed, operation is zeroed out by the reset button on display, records the home position of drill bit of drilling machine, at this point, aobvious Show the bar shaped column and number of the current location of device display drilling, operator can monitor the real work position of drilling by display It sets, each drilling depth position and hole depth position, to operate bore operation.In operation process, operator can pass through main interface Three virtual instruments display power head pressure, moulding pressure, master file pressure one by one, the work shape of real-time monitoring hydraulic system State when aperture, is self-possessed using drilling bucket and is pressurizeed as drilling power, a drilling depth billet shape column shows that the drilling of current drill bit is deep Degree, the movement position of strip column Dynamically Announce drill bit, the number of hole depth show the total depth in this hole, are full of when drilling bucket is extruded After boring mud, proposed that earth's surface, operation revolution operation handle make machine go to the position for unloading native position, boring mud transported with loading machine It walks, after, bore operation position is automatically returned to positive button machine by the self-return on operation display, or pass through hand Dynamic operation revolution operation handle makes machine return to bore operation position manually, this working condition can be by the main interface of display Return mark monitored, after aperture, be self-possessed using drill bit drilling rod and pressurize as drilling power, when drilling bucket be extruded full of brill After slag, earth's surface is proposed, boring mud is transported with loading machine, while observing monitoring and recording drill hole geologic situation；

Borehole cleaning is carried out using circulation drilling technology: behind stake holes end hole, drilling tool being replaced with dedicated scouring bit, passes through borehole cleaning Drill bit borehole cleaning 5 times repeatedly, then sediment thickness is detected by the method for sash weight measurement (lining rope) or is measured under drilling tool to below ground For length as bottom hole depth (note: the length of the bit generally takes its 2/3 to calculate), lining rope measures depth as sediment top surface depth, and two The difference of person is sediment thickness；Until clear complete sediment, it is ensured that sediment thickness meets design requirement (Chen slag Hou Du≤5cm)；

(6) steel reinforcement cage is lifted:

1. the making step of steel reinforcement cage is as follows: 9 meters of the every segment length of steel reinforcement cage sectional making, main reinforcement diameter is mainly 16mm three-level Steel, stirrup diameter 8mm, putting more energy into and binding round diameter is mainly 14mm, and steel reinforcement cage average length is 9 meters, then average weight is 1650kg, steel Muscle cage sectional making on hole forms, and 9 meters of every segment length, adjacent vertical muscle mutually staggers, and the length that is staggered is 35d, will twist sleeve Top bars are screwed on connected reinforcing bar, are then rotatablely connected reinforcing bar or unscrewed sleeve to predetermined position, finally connector is twisted Tightly, lock nut and connection sleeve can be screwed into advance the screw thread of lengthening for the reinforcing bar not being able to rotate by locking connection sleeve It is interior, then unscrewed enters on another steel bar end screw thread, finally locks connection sleeve with lock nut；It is used outside the reinforcing bar of steel reinforcement cage 16 reinforcement fabrication of Φ is welded in the main reinforcement of steel reinforcement cage at ship shape bracket point as protective layer, and ship shape bracket is right on steel reinforcement cage section Claim setting four, several C14 are set by 2m spacing on steel reinforcement cage vertical position and are put more energy into stirrup, weld jail with the main reinforcement of steel reinforcement cage Admittedly forming skeleton, reinforced at hoop of putting more energy into triangular reinforced bar spot welding；

(7) casting concrete is underwater concrete construction with embodiment 1.

The present embodiment detects pile foundation in the way of embodiment 1, using single pile bearing capacity, low answers The method that political reform detection and the detection of Large strain method combine carries out pile measurement, carries out after single pile bearing capacity is qualified The detection of low strain dynamic method and the detection of Large strain method, the difference is that the sampling observation quantity of the detection of low strain dynamic method and the detection of Large strain method is Single pile bearing capacity inspects 5 times of quantity by random samples, and the test point that low strain dynamic method detects the sampling observation of pile body integrity is 4, After being offloaded to zero when unloading is with unloading settlement observation, hold time 4h, the hammer weight=2.5%Q of Large strain method detection_m, cast iron falls It hammers ratio of height to diameter=1 into shape, after completing pile measurement, result is judged to according to standard, provides examining report.

Claims

1. a kind of construction method of mechanical hole perfusion post, which is characterized in that specifically includes the following steps:

(1) smooth location, removing sundries carry out place leveling according to the position of rotary drilling rig construction, are excavated to after levelling of the land Raft plate bed course bottom absolute altitude, the stake position for being intended to drilling release, and fix cross protection stake；

(2) stake position setting-out: by the position setting-out for carrying out pile foundation " from entirety to the principle of part ", to putting when the absolute altitude setting-out of drilling The absolute altitude of sample is checked, and places construction drill by the pile foundation construction direction from the inside to the outside, from top to bottom in every building；

(3) bury steel pile casting: by the control stake setting-out of positioning, steel pile casting gradient is not more than 1% when burying steel pile casting；

(4) drilling construction: first landing drilling bucket, when aperture, is self-possessed using drilling bucket and is pressurizeed as drilling power, when drilling bucket is extruded After boring mud, earth's surface is proposed, transports boring mud, return to bore operation position, the verticality of pore-forming is checked in drilling process, Until bore operation to the socket length for meeting design；After pore-forming reaches designed elevation, to hole depth, aperture, hole wall, verticality into Row checks；

(5) it borehole cleaning: behind stake holes end hole, is no less than 3 times using dedicated scouring bit cleaning stake holes, sediment is detected by lining rope method Thickness Chen slag Hou Du≤5cm；

(6) steel reinforcement cage is lifted:

By first segment hang load hole steel reinforcement cage framework of steel reinforcement center and stake holes centering after insert in the hole, using slotting thick stick method by reinforcing bar Cage is stuck at aperture, and the second section steel reinforcement cage is then hung perpendicular suspended state, is welded with first segment steel reinforcement cage, and welding is completed After check welding quality, repeat above-mentioned steps after qualified and carry out lower section reinforcing bar cage hoisting, whole connectors are lowered into after connecting Hole after steel reinforcement cage sinks to design position, is fixed, and steel reinforcement cage enters position error behind hole: plan-position deviation is not more than 10cm, bottom surface height variation are not more than ± 10cm；

(7) casting concrete obtains bored concrete pile, detects to pile foundation.

2. the construction method of mechanical hole perfusion post according to claim 1, which is characterized in that step (3) controls stake setting-out Comprise the concrete steps that: the position of drill hole of drilling machine is marked in bottom hole, then steel pile casting is hung into hole, find out steel pile casting the center of circle position Set, with cross hairs at the top of steel pile casting or bottom hang up, then move steel pile casting, make steel pile casting center and drill hole of drilling machine centre bit Coincidence is set, keeps steel pile casting hard straight, steel pile casting is pressed into predetermined position with drilling bucket, dregs is backfilled around steel pile casting, layering is rammed It is real, steel pile casting outer periphery is backfilled with coarse-grained soil, is backfilled closely knit.

3. the construction method of mechanical hole perfusion post according to claim 1, which is characterized in that outside step (6) steel reinforcement cage Portion is welded in the main reinforcement of steel reinforcement cage at ship shape bracket or ear muscle point as protective layer using 16 reinforcement fabrication of Φ, ship shape bracket or Person's ear muscle is symmetrical arranged four on steel reinforcement cage section, is arranged on steel reinforcement cage vertical position by 2m spacing.

4. the construction method of mechanical hole perfusion post according to claim 1, which is characterized in that step (6) steel reinforcement cage is fixed It is to pass through steel reinforcement cage at aperture with two steel pipes to be tied up in main reinforcement in parallel with 12# iron wire, the steel reinforcement cage both ends every side of length of steel pipe No less than 1000mm pushes down steel pipe in each 200 × 300 × 500mm or more of the counterweight rectangular slab of stone in every steel pipe both ends before casting concrete.

5. the construction method of mechanical hole perfusion post according to claim 1, which is characterized in that step (7) casting concrete Including dry hole pouring construction process, underwater concrete construction process,

1. installing conduit, conduit uses the steel pipe of diameter 250mm, with the standard pipe of 2.5~3m with the long 1~1.5m's long of 1~2 section Short tube, intrusion pipe is fixed with ring flange connecting screw or the connection of silk tooth, and ring flange connection or silk tooth junction are respectively mounted O shape rubber Conduit is slowly sunk to the depth apart from bottom hole 300mm~500mm by sealing ring；

2. continuous concrete above mentions conduit；

3. concreting finishes, conduit and steel pile casting are extracted；

2. water proof plug is placed on the water surface in conduit；

3. configuring 0.1~0.3m³Cement mortar pours into the conduit and funnel of water proof plug or more, then pours into first batch of concrete again, Iron wire is cut, cement mortar is made to stay in bottom hole, water proof plug emersion；

4. continuous concrete above mentions conduit；

5. concreting finishes, conduit and steel pile casting are extracted.

6. the construction method of mechanical hole perfusion post according to claim 5, which is characterized in that step (7) first batch of concrete The calculation formula for the amount of pouring into are as follows:

In formula:

The first batch of concrete amount of the pouring into (m of V--³)

D-- bore diameter (m)

D-- catheter diameter (m)

H₁-- conduit bottom end is away from hole bottom distance (m)

H₂-- conduit Transducers Embedded in Concrete depth (m)

H-- drilling depth (m)

K-- fullness coefficient, takes 1.10

r₁-- mud balance takes 1200kg/m³

r₂-- concrete specific gravity takes 2400kg/m³。

7. the construction method of mechanical hole perfusion post according to claim 1, which is characterized in that quiet using single pile vertical resistance pressure It carries the method that test, the detection of low strain dynamic method and the detection of Large strain method combine and carries out pile measurement, the examination of single pile vertical resistance pressure static load The detection of low strain dynamic method and the detection of Large strain method are carried out after testing qualification, the pile foundation quantity that low strain dynamic method and Large strain method detect is single pile 3~5 times of static-loading test amount detection.

8. the construction method of mechanical hole perfusion post according to claim 7, which is characterized in that the examination of single pile vertical resistance pressure static load Test that specific step is as follows:

(2) test pile pile cover top need to be lower than nature ground 800mm, measure capacity value using pressure gauge；It is anti-using preloading ballast platform Force method is tested, and jack parallel connection provides counter-force with mound, sedimentation observation is by being mounted on stake top pair as loading equipemtn The dial gauge at linea angulata both ends measures, the pile foundation of diameter or hem width greater than 500mm, 4 dial gauges of symmetrical placement, diameter or side Width is less than or equal to the pile foundation of 500mm, 2 dial gauges of symmetrical placement；

(3) multistage loadings load, classification load are loaded as estimating the 1/10 of ultimate load, and the first order is loaded by 2 times of classification loads, Later every grade by classification load load, every grade load after the 5th, 15,30,45,60min survey read dial gauge in pile head settlement amount, It is surveyed later every 30min and reads once, when pile head settlement rate reaches stability criterion, then to apply next stage load, stability criterion: Pile head settlement amount hourly is less than 0.1mm, and continuously occurs twice；Every grade of load should keep load permanent in its maintenance process It is fixed；

(4) after reaching design load, load shedding pressure, unloads step by step by 2 times of every grade of unloading value loaded value, when unloading, every grade Load maintain 1h, 15,30,60min surveys in three times reading dial gauge in pile head settlement amount, unload next stage；After being offloaded to zero, surveys and read Stake top residual settlement amount, dial gauge survey read time 15,30min, later primary every 30min survey reading dial gauge, and it is residual to survey reading stake top Remaining settling amount is surveyed and reads that total time 3h must not be less than.

9. the construction method of mechanical hole perfusion post according to claim 7, which is characterized in that low strain dynamic method detects specific Step:

(1) according to stake diameter size, pile body top is arranged symmetrically 2~4 test points at away from 2/3 radius of pile center；Each detection Point place setting velocity sensor, acceleration transducer, velocity sensor, acceleration transducer respectively with Low Strain Dynamic Testing of Piles instrument Connection；

(2) using pile center as impacting point, apply external force, velocity sensor, acceleration transducer will be collected under external force Signal transmits Low Strain Dynamic Testing of Piles instrument and carries out data processing.

10. the construction method of mechanical hole perfusion post according to claim 7, which is characterized in that the tool of Large strain method detection Body step:

(2) sensor is symmetrically mounted on to the stake side surface at 2D for stake diameter≤800mm, for inciting somebody to action for stake diameter > 800mm Sensor is symmetrically mounted on the stake side surface at D, and sensor is acceleration transducer and strain force sensor, and the two of the same side The distance of a sensor is not more than 80mm, center sensor axis and pile center's axis keeping parallelism, acceleration transducer and strain-type Force snesor is connected with controller；

(3) it is dropped hammer hammering using cast iron, hammer weight >=1.0%Q_m, Q_mTo estimate ultimate bearing capacity of single pile, cast iron drop hammer ratio of height to diameter >= 1；