CN108716225A - A kind of novel club-footed pile test device for multifunctional and method - Google Patents
A kind of novel club-footed pile test device for multifunctional and method Download PDFInfo
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- CN108716225A CN108716225A CN201810409727.3A CN201810409727A CN108716225A CN 108716225 A CN108716225 A CN 108716225A CN 201810409727 A CN201810409727 A CN 201810409727A CN 108716225 A CN108716225 A CN 108716225A
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- 238000012360 testing method Methods 0.000 title claims abstract description 129
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000006073 displacement reaction Methods 0.000 claims abstract description 110
- 238000005259 measurement Methods 0.000 claims abstract description 32
- 230000002787 reinforcement Effects 0.000 claims abstract description 17
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 11
- 239000010959 steel Substances 0.000 claims abstract description 11
- 239000002689 soil Substances 0.000 claims description 13
- 238000002474 experimental method Methods 0.000 claims description 9
- 238000009434 installation Methods 0.000 claims description 9
- 238000005266 casting Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 4
- 238000004458 analytical method Methods 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 3
- 238000011065 in-situ storage Methods 0.000 claims description 3
- 238000007689 inspection Methods 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 abstract description 4
- 238000004891 communication Methods 0.000 abstract description 4
- 238000010998 test method Methods 0.000 description 5
- 238000004873 anchoring Methods 0.000 description 4
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- 230000003068 static effect Effects 0.000 description 4
- 230000000903 blocking effect Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 238000007405 data analysis Methods 0.000 description 2
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- 238000009825 accumulation Methods 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
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- 230000007812 deficiency Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012417 linear regression Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- -1 silt take 0.8 Substances 0.000 description 1
- 238000007569 slipcasting Methods 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
- E02D5/38—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds
- E02D5/44—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds with enlarged footing or enlargements at the bottom of the pile
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- Mining & Mineral Resources (AREA)
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- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention discloses a kind of novel club-footed pile test device for multifunctional, including：Stake holes；Steel reinforcement cage stretches in stake holes；Load box is located at the bottom of stake holes；Pressure oil pump；Slide attack testing element, the slide attack testing element stretch to the top in the stake holes and positioned at load box, and the slide attack testing element includes test tube and the survey ring being installed in the test tube；Upper displacement measuring staff and bottom offset measuring staff stretch into be fixedly connected in stake holes and respectively with the upper plate of load box and lower plate；Displacement measurement equipment is installed on the top of displacement measuring staff and bottom offset measuring staff；Data acquisition equipment, the data information for receiving slide attack testing element and the acquisition of displacement measurement equipment.The invention also discloses a kind of novel club-footed pile bearingtest methods.The present invention can successfully solve the test problems of other a variety of base expanding and base expanding pile bearing capacitys such as mountain area, other complex site power transmission line columns and communication tower basis.
Description
Technical field
The present invention relates to bearingtest technical field, specially a kind of novel club-footed pile test device for multifunctional and side
Method.
Background technology
The static load test (such as accumulation load method, anchored pile-testing method) for the stake that China uses at this stage is that detection pile bearing capacity is the most reliable
A kind of method, both of which is to withstand on stake top using oil jack to be further applied load, and the counter-force of jack, the former passes through anti-
Heap weight on power frame balances therewith, and counter-force is transmitted to anchoring pile by the latter by reaction frame, the resistance to plucking dynamic balance with anchoring pile.Existing for it
Main problem is：The former must solve load source, stacking and the transportation problem of hundreds of tons of even upper kilotons, and the latter must be provided with
More anchoring piles and counter-force crossbeam, not only needed for somewhat expensive, the time is longer, and is easily limited by tonnage and site condition, with
The bearing capacity of many large-tonnage stakes and the stake in special place (such as mountainous region, bridge pier) is caused often to cannot get accurate data, foundation pile is dived
Power cannot be played rationally, this is a great problem of pile foundation field face.
To solve above problem, American scholar Osterberg first proposed self-balancing approach method of testing the eighties, and in
The mid-80 has carried out the research of pile bearing capacity test method, is applied successfully in bridge piling bar first, gradually promotes later
To various pile-type.Self-balancing approach provides counter-force to determine the side frictional resistance of bearing capacity of single pile and pile soil horizon using pile-soil system itself
Power, end resistance are close to the test method that vertical compression (pulls out) stake actual working state.Its principle is shown referring to Fig.1, is
In pile body or stake end buried loads case 31, compression test, preloading is replaced using epimere stake dead weight, epimere stake pile side friction
The anchoring pile in weight or anchored pile-testing method in method is to provide counter-force.When experiment, load box cavity is applied from stake top by petroleum pipeline
Pressure, case lid are open with bottom, while applying power equal in magnitude, that direction is opposite to epimere stake 30 and hypomere stake 32, promote
The frictional resistance of epimere stake 30 and hypomere stake 32 and the end resistance of supporting course 33 play a role, when pile-soil system destroys or meet engineering
Actual requirement when stop experiment.Working condition and the state of stake in actual work when self-balanced test is different, is
Close to a kind of approximation method of actual working state.
Therefore it buries in test load box to need to block filling pile cage of reinforcement, load box is respectively to upper during experiment
Section stake and hypomere stake are loaded, although can be tested with injecting treatment, for anti-horizontal force and resistance to plucking stress after experiment
Stake remains defect or security risk after having detected.
Invention content
For overcome the deficiencies in the prior art, one of the objects of the present invention is to provide a kind of novel base expanding and base expanding pile bearing capacitys
Experimental rig can successfully solve other a variety of base expanding and base expandings such as mountain area, other complex site power transmission line columns and communication tower basis
The test problems of pile bearing capacity can detect vertically pulling-resistant, vertical compression bearing capacity respectively, without blocking main reinforcement.
One of to achieve the above object, the present invention provides the following technical solutions：
A kind of novel club-footed pile test device for multifunctional, including：
Stake holes, the stake holes include the reaming part positioned at the non-reaming part of stake holes epimere and positioned at stake holes hypomere,
The non-reaming part and reaming part are respectively used to form the upper pile body of club-footed pile and lower pile body after casting concrete, it is described on
Pile body and lower pile body are using variable cross-section as interface；
Steel reinforcement cage, the steel reinforcement cage stretch in the stake holes；
Load box, the load box are located at the bottom of stake holes, the i.e. bottom of reaming part；
Pressure oil pump, the pressure oil pump are located at the outside of stake holes and are connected to load box by oil pipe；
Slide attack testing element, the slide attack testing element stretch in the stake holes and are located at load box
Top, the slide attack testing element includes test tube and the survey ring being installed in the test tube；
Upper displacement measuring staff, the upper displacement measuring staff are stretched into the stake holes and are fixedly connected with the upper plate of load box；
Bottom offset measuring staff, the bottom offset measuring staff are stretched into the stake holes and are fixedly connected with the lower plate of load box；
Displacement measurement equipment is installed on the top of upper the displacement measuring staff and bottom offset measuring staff；
Data acquisition equipment, the data letter for receiving the slide attack testing element and the acquisition of displacement measurement equipment
Breath.
The outside of the upper displacement measuring staff and bottom offset measuring staff is arranged with displacement bar protection pipe respectively and bottom offset bar is protected
Pillar.
The quantity of the test tube is four, and the quantity of the upper displacement measuring staff and bottom offset measuring staff is two.
First survey ring, the second survey ring and third are installed in the test tube and survey ring, the first survey ring is installed on change and cuts
Face position, the second survey ring and third are surveyed ring and are respectively arranged in pile body and lower pile body, and it is one that the third, which surveys ring, and described the
Two survey rings are multiple, and the multiple second survey ring is located in the installation region being arranged in upper pile body, the lower end of the installation region
Face is overlapped with variable cross-section, the upper surface to the upper top surface of pile body of the installation region, and two neighboring second surveys the distance between ring
For 1m, it is 1m to be located at the second of lower side to survey ring to survey the distance of ring to first, the survey number of rings amount in four test tubes it is equal and
Position corresponds to.
The second object of the present invention is to provide a kind of novel club-footed pile bearingtest method, can successfully solve
The test problems of other a variety of base expanding and base expanding pile bearing capacitys such as mountain area, other complex site iron tower of power transmission line and communication tower basis, can
To be detected respectively to vertically pulling-resistant, vertical compression bearing capacity, without blocking reinforcing bar.
To achieve the above object two, the present invention provides the following technical solutions：
A kind of novel club-footed pile bearingtest method, includes the following steps：
Test platform is built according to the club-footed pile test device for multifunctional described in one of above-mentioned purpose；
To age in casting concrete to stake holes；
Step stress test；
Unloading test step by step；
Test data is obtained according to the step stress test and step by step unloading test and test result is analyzed.
The step stress test includes：
Equivalent step by step is carried out to load box and loads capacity value, the capacity value of every grade of load is the 1/ of load box maximum load amount
10, the capacity value of every grade of load is classification capacity value；
To every grade load after displacement carry out survey reading, at every grade load after 5min, 15min, 30min, 45min with
And 60min surveys read bit and moves the displacement of measurement equipment and observe the reading of slide attack testing element, after 60min at interval of
30min surveys read bit and moves the displacement of measurement equipment and observe the reading of slide attack testing element；
Amplitude of variation of the capacity value of every grade of load in surveying read procedure must not exceed ± the 10% of classification capacity value；
When change in displacement rate when every grade of load reaches opposite stability criterion, then carry out the operation of next stage load.
The unloading test step by step includes：
Equivalent step by step is carried out to load box and unloads capacity value, the capacity value of every grade of unloading is 2 times that are classified capacity value；
Every grade of unloading maintains 1h, the displacement and observation slide attack testing element after being unloaded to every grade in the 1h
Reading carries out survey reading, and 15min, 30min and 60min after being unloaded at every grade survey displacement and the sight that read bit moves measurement equipment
Survey the reading of slide attack testing element；
When discharging quantity after unloading is zero, displacement and observation slide attack test member that read bit moves measurement equipment are surveyed
The displacement of the reading of part, displacement measurement equipment is denoted as residual displacement amount, and the survey read time of residual displacement amount is no less than 3h, is unloading
5min, 30min after discharging quantity after load is zero respectively survey reading once, are surveyed at interval of 30min after 30min and read a residual displacement
Amount；
Amplitude of variation of the capacity value of every grade of unloading in surveying read procedure must not exceed ± the 10% of classification capacity value.
During step stress test, occur under following either case, stops step stress test：
During certain grade of load test, displacement increment or bottom offset increment are not less than its previous stage load test mistake thereon
5 times of bottom offset increment in journey, and displacement or bottom offset amount are more than 40min thereon；
During certain grade of load test, displacement increment or bottom offset increment are more than its previous stage load test process thereon
5 times of middle bottom offset increment, and relatively stable mark has not yet been reached in the change in displacement rate during interior this grade of load test for 24 hours
It is accurate；
Reach maximum experiment loading capacity, and tests the change in displacement rate under loading capacity in the maximum and reach relatively stable mark
It is accurate；
Load box has reached load box maximum load amount or upper displacement and bottom offset amount has reached load box stroke.
It is described that test result is analyzed, including：
Draw the relation curve of the relation curve and displacement and load or unload time of capacity value and displacement；
Determine epimere stake limit loaded value and hypomere stake limit loaded value；
It calculates and obtains vertical allowable load capacity of single pile；
It calculates and obtains vertical ultimate uplift resistance of single pile；
Determine single pile vertical resistance pressure characteristic load bearing capacity and unit for single-pile vertical anti-pulling characteristic load bearing capacity.
It is described calculate obtain vertical allowable load capacity of single pile formula be：
Fud=Qud
Fuu=FAxle power
Wherein, QuFor vertical allowable load capacity of single pile, FuuAnd FudThe respectively single-pile vertical orientation of epimere stake and hypomere stake
Compressive ultimate bearing capacity, FAxle powerFor the pile shaft force value of the above position of variable cross-section, QudActual measurement for load box hypomere stake finally loads
Value；W is the sum of dead weight and impost of load box epimere stake, and the impost includes the weight of the superfilled height of stake top or more
Amount, empty pile cutoff mud or Cast-in-situ Piles in Sand-filling and soil dead weight；γ is load box epimere pile side resistance correction factor, according to load upper box part
The type of soil determines；
The pile shaft force value F of the above position of variable cross-sectionAxle powerIt is calculated according to following formula：
FAxle power iFor the axial force at arbitrary cross-section,For the mean strain of arbitrary cross-section, εiFor the strain value of a certain section,
It is obtained by slide attack testing element, EMixed iElasticity modulus when accordingly to strain, AMixed iFor the average pile body face of a certain section
Product, DMixed iFor the average stake diameter of a certain section, a and b are respectively regression coefficient and recurrence constant；
The vertical ultimate uplift resistance of single pile PuCalculation formula be：
=wherein, γ2For by the resistance to plucking frictional resistance conversion coefficient of inspection stake；
The single pile vertical resistance pressure characteristic load bearing capacity is the 50% of single pile vertical resistance pressure bearing capacity；
The unit for single-pile vertical anti-pulling characteristic load bearing capacity is the 50% of unit for single-pile vertical anti-pulling bearing capacity.
Compared with prior art, the present invention novel club-footed pile test device for multifunctional and method, advantage is：
The present invention can successfully solve other a variety of club-footed pile carryings such as mountain area, other complex site power transmission line columns and communication tower basis
The test problems of power are directed to and need to arrange place in the large-scale static load equipment of transport, lay road, expend a large amount of manpower and materials,
It is unfavorable for the case where traditional foundation pile static loading test is implemented, selection uses this scheme, can be carried to vertically pulling-resistant, vertical compression
Power is detected respectively, without blocking main reinforcement.
Description of the drawings
Fig. 1 is the schematic diagram of existing Self-balanced Testing Method；
Fig. 2 is the structural schematic diagram of novel club-footed pile test device for multifunctional of the invention.
In figure：1, load box；2, upper displacement bar protection pipe；3, slide attack testing element；4, steel reinforcement cage main reinforcement；5, number
According to collecting device；6, data acquire cable；7, upper displacement measuring staff；8, displacement measurement equipment；9, bottom offset measuring staff；10, bottom offset
Bar protection pipe；11, reference stake；12, oil pipe；13, datum line beam；14, pressure oil pump；15, stirrup；16, upper pile body；17, lower pile body；
18, stake week rock-soil layer；19, grouting behind shaft or drift lining pipe；30, epimere stake；31, load box；32, hypomere stake；33, supporting course.
Specific implementation mode
In the following, in conjunction with attached drawing and specific implementation mode, the present invention is described further, it should be noted that not
Under the premise of conflicting, new implementation can be formed between various embodiments described below or between each technical characteristic in any combination
Example.
A kind of novel club-footed pile test device for multifunctional, please refers to shown in Fig. 2 comprising stake holes, steel reinforcement cage, sliding are surveyed
Micro- meter testing element 3, load box 1, pressure oil pump 14, upper displacement measuring staff 7, bottom offset measuring staff 9, displacement measurement equipment 8 and number
According to collecting device 5.
Wherein, the stake holes, periphery are stake week rock-soil layer 18, and stake holes includes non-reaming part and is located at the non-expansion
The reaming part of bore portion lower part, the non-reaming part and reaming part form club-footed pile after being respectively used to casting concrete
Upper pile body 16 and lower pile body 17, upper pile body 16 and lower pile body 17 are using variable cross-section as interface；It is provided on the outside of stake holes
Reference stake 11 and datum line beam 13.
Steel reinforcement cage stretches in the stake holes, and steel reinforcement cage includes steel reinforcement cage main reinforcement 4 and stirrup 15.The slide attack is surveyed
Examination element 3 stretches in the stake holes, and positioned at the top of load box, and slide attack testing element includes test tube and is installed on
Survey ring in the test tube, test tube are four, are bundled in steel reinforcement cage main reinforcement 4, and the survey number of rings amount in each test tube is equal, and
Position corresponds to, i.e. on the same cross section of survey ring in four test tubes on corresponding position.It is equipped with first in the every test tube
It surveys ring, the second survey ring and third and surveys ring, the first survey ring is installed on variable cross-section position, and the second survey ring and third are surveyed ring and distinguished
Be installed in pile body 16 and lower pile body 17, it is described first survey ring, third survey ring be one, it is described second survey ring be it is multiple,
The multiple second survey ring is located in the installation region being arranged in upper pile body 16, lower face and the variable cross-section weight of the installation region
It closes, the upper surface to the upper top surface of pile body of the installation region, two neighboring second surveys the distance between ring as 1m, is located at most lower
It is 1m that the second of side, which surveys ring and survey the distance of ring to first, remaining position is not provided with surveying ring.
The load box 1 is located at the bottom of stake holes, the i.e. bottom of reaming part, and therefore, such device need not pour
Club-footed pile is cut into two parts after concrete to test, i.e. the epimere stake of load box 1 is entire club-footed pile, and hypomere is not present
Stake；The pressure oil pump 14 is located at the outside of stake holes and is connected to load box 1 by oil pipe 12；The upper displacement measuring staff 7 stretches into
It is fixedly connected in the stake holes and with the upper plate of load box 1；The bottom offset measuring staff 9 stretches into the stake holes and and load box
1 lower plate is fixedly connected；Displacement measurement equipment 8 is installed on the top of upper the displacement measuring staff 7 and bottom offset measuring staff 9.
Upper displacement measuring staff 7, load box 1 upper plate and upper displacement measuring staff 7 on displacement measurement equipment 8 between coordinate, use
In the upper displacement for measuring 1 epimere stake of load box, displacement on abbreviation, bottom offset measuring staff 9, load box 1 lower plate and bottom offset
The cooperation between displacement measurement equipment 8 on measuring staff 9, the bottom offset for measuring 1 hypomere stake of load box, simultaneously due to load box 1
There is no hypomere stakes, and therefore, the bottom offset of hypomere stake here in fact refers to pile bottom settlements.
Data acquisition equipment 5 acquires cable 6 by data and is electrically connected with displacement measurement equipment 8, for receiving
Rheme moves the data information that measurement equipment 8 acquires.The data information received is also sent to processing equipment by data acquisition equipment 5
Such as computer etc. carries out data analysis.The data information of slide attack testing element 3 is acquired using slide attack.
The outside of the upper displacement measuring staff 7 and bottom offset measuring staff 9 is arranged with displacement bar protection pipe 2 and bottom offset bar respectively
Protection pipe 10.Upper displacement bar protection pipe 2 and bottom offset bar protection pipe 10 are used for that mud and concrete is isolated, it is ensured that upper displacement measuring staff
7 and bottom offset measuring staff 9 can freely up and down move.
As a preferred embodiment, based on the considerations of cost and measurement accuracy, upper displacement measuring staff 7 and bottom offset measuring staff 9
Quantity be two, other quantity can also be arranged to certainly, be evenly arranged.
After the test, it is contemplated that stake upper and lower displacement causes load box upper and lower bottom plate displacement, produced between load box upper and lower plates
Raw gap, can be by stretching into the slip casting into gap position of grouting behind shaft or drift lining pipe 20 in stake holes.Using above-mentioned novel base expanding and base expanding pile
Carry the method that power experimental rig carries out club-footed pile self-balanced static-load testing, including the following contents：
After the concrete poured in stake holes reaches age, start the bearingtest test to live pile body.
Field test test execution《Architecture foundation pile self-balanced static-load testing technical regulation (JGJ/T403-2017)》Want
It asks.Experiment is using maintained load test (ML-test) hierarchical loading at a slow speed.
(1), experiment Load-unload mode should meet following provisions：
1. load should be classified progress, load box load operation is realized to load box oiling through oil pipe by pressure oil pump, it should
In the process, it should be loaded using equivalent step by step, the capacity value of every grade of load is the 1/10 of load box maximum load amount, and described every grade adds
The capacity value of load is denoted as classification capacity value, wherein 2 times of the desirable classification capacity value of first order load；
2. progress should be also classified by unloading, every grade of unloading measures 2 times of classification capacity value, and equivalent unloading should be classified lotus step by step
2 times of carrying capacity；
3. when Load-unload, should make load transmit uniformly, it is continuous, without impact, and variation of the every grade of load in maintenance process
Amplitude must not exceed ± the 10% of classification capacity value.
(2) it is met the following requirements using maintained load test (ML-test) test procedure at a slow speed：
1. displacement, which is surveyed, reads interval time：To every grade load after displacement carry out survey reading, at every grade load after 5min,
15min, 30min, 45min and 60min survey read bit and move the displacement of measurement equipment and observe slide attack testing element
It reads, the reading that read bit moves the displacement and observation slide attack testing element of measurement equipment is surveyed at interval of 30min after 60min
Number.
2. displacement is with respect to stability criterion：Since the 30min after classification load applies, by continuous 3 times every 30min of 1.5h
Displacement observation value calculate, displacement increment is no more than 0.1mm per hour, and continuously occurs twice.
3. loading standard：When change in displacement rate reaches opposite stability criterion, then apply next stage load；
4. unloading standard：When unloading, every grade of load maintains 1h, presses 15min, 30min, 60min respectively and surveys reading displacement
And after the reading of observation slide attack testing element, you can unload next stage load；After being offloaded to zero, it should survey and read residual displacement amount
And observation slide attack testing element reading, must not hold time less than be 3h, survey read interval time be 5min,
30min respectively surveys reading once, is surveyed later every 30min and reads a residual displacement amount.
(3), there are following situations for the moment in the displacement of the stake of load box epimere or hypomere stake, you can terminates load.
1. under certain grade of load action, the displacement increment of the stake of load box epimere or hypomere stake is greater than or equal to previous stage load
When acting on 5 times of bottom offset increment, and total displacement amount is more than 40mm.
2. under certain grade of load action, the displacement increment of epimere stake or hypomere stake increases more than previous stage load action bottom offset
2 times of amount, and opposite stability criterion has not yet been reached for 24 hours；
3. the maximum experiment loading capacity and load box epimere and hypomere displacement that have reached design requirement reach relatively stable
(convergence) standard.
4. when load~displacement curve of epimere stake or hypomere stake is slow change type, 40mm can be loaded onto by shifting up total amount
~60mm；It can be loaded onto 60~80mm to bottom offset total amount；When end resistance not yet gives full play to, total displacement amount can be loaded onto
More than 80mm.
5. it has been more than load box stroke that load box, which has reached the load limit of load box or the upper and lower section shifting of load box, i.e.,
Load can be terminated.
Test result analysis
Detection data analysis executes specification《Architecture foundation pile self-balanced static-load testing technical regulation (JGJ/T403-2017)》.
(1) processing of detection data should be met the following requirements：
1. the single pair number curve of the relation curve and displacement and loading times of load and displacement should be drawn, can also draw
Other assistant analysis curves；
(2) epimere stake limit loaded value QuuWith hypomere stake limit loaded value QudDetermination should be integrated as follows：
1. determined with the variation characteristic of load according to displacement, for abrupt change type curve, it should take curve that apparent abrupt change occurs
The corresponding payload values of starting point；2. ultimate bearing capacity is determined according to the displacement feature that changes with time, should take displacement with plus
There are the previous stage payload values being obviously bent in the single pair number curve tail portion for carrying the time；3. when there is this regulation the 4.3.4 articles the 1st, 2
When money situation, previous stage payload values are preferably taken；4. can be determined according to displacement to slow change type curve, epimere stake limit loaded value takes pair
Answer displacement be 40mm when load, when epimere stake it is long be more than 40m when, preferably consider the Elastic penetration of pile body；The hypomere stake limit adds
It is the corresponding payload values of 40mm that load value fetch bit, which moves, and the stake of 800mm is greater than or equal to diameter, and the desirable downward displacement of load box is
The corresponding payload values of 0.05D (D is stake end diameter)；5. when not can determine that by the 1st~4 section of this article, preferably it is respectively oriented, downwards
The maximum finder charge of both direction is as epimere stake limit loaded value and hypomere stake limit loaded value.
(3) the suitable equivalency transform of load-displacement curve that self-balanced static-load testing measures is load-position of traditional static test
Move curve (reference《Architecture foundation pile self-balanced static-load testing technical regulation (JGJ/T403-2017)).
(4) single pile vertical resistance pressure (pulls out) ultimate bearing capacity, should be calculated according to the following formula：
1. vertical allowable load capacity of single pile is：
Fud=Qud
Fuu=FAxle power
QuFor vertical allowable load capacity of single pile (kN), FuuFor the vertical allowable load capacity of single pile of epimere stake
(kN)；FufFor the vertical allowable load capacity of single pile (kN) of hypomere stake, FAxle powerFor the pile shaft force value of the above position of variable cross-section
(kN)；W is the sum of dead weight and the impost of load box epimere stake (kN), and impost should include the superfilled height of design stake top or more
The weight of degree, empty pile cutoff mud or Cast-in-situ Piles in Sand-filling, soil are conducted oneself with dignity, and buoyant weight degree should be taken to calculate below level of ground water.γ is load box epimere
Pile side resistance correction factor is determined according to the type of load upper box part soil：Cohesive soil, silt take 0.8, and sand takes 0.7, and rock takes
1.0, weighted average is taken when there is different soil.
The measurement method of the utility model proposes the test method of the final loaded value of actual measurement of load box epimere stake, according to load
The final loaded value of actual measurement of case epimere stake is practical to be equal to above base expanding and base expanding stake body variable cross-section position axle power suffered by pile body, utilizes sliding
Micro-measuring technique measures the final loaded value of actual measurement of load box epimere stake.It is calculated in the following manner：
It is used from top to bottom and from bottom to top before load initial in slide attack testing element every test tube of 2 measurement
Reading, to ensure to measure corresponding readings after measuring accuracy, every grade of load are stablized, difference is each test tube institute under loads at different levels
In the strain value ε i for surveying section.
Elasticity modulus can be calculated with the changing rule of strain magnitude according to the stake bottom strain under loads at different levels, can generally be used
Linear equation with one unknown is expressed, such asAccording to recurrence strain curves at different levels, the strain of stake bottom can calculate differently strained amount
The lower pile body average elastic modulus of grade obtains the linear equation of Ei=f (ε i) by linear regression, when calculating axle power under loads at different levels
Using different bullet modulus value.
Pile body axial force：
Mean strain:
Average stake area：
Elasticity modulus：
F in formulaAxle power iFor the axial force (kN) at arbitrary cross-section,For the mean strain of arbitrary cross-section, EMixed iAccordingly to strain
When elasticity modulus (GPa), AMixed iFor the average pile body area (m of a certain section2), DMixed iFor the average stake diameter (m) of a certain section, a
It is respectively regression coefficient and recurrence constant with b.
The pile shaft force value F of the above position of variable cross-section is calculated by above methodAxle power(kN)。
2. vertical ultimate uplift resistance of single pile should be calculated as follows：
In=formula：γ2For by the resistance to plucking frictional resistance conversion coefficient of inspection stake；Pressure-bearing type uplift pile should take 1.0, for bearing type
Uplift pile should be determined by the Comparability test and regional experience of similar conditions according to actual conditions, but cannot be less than 1.1.
(5) single pile vertical resistance pressure (resistance to plucking) characteristic load bearing capacity should be by single pile vertical resistance pressure (resistance to plucking) ultimate bearing capacity
50% value.
The above embodiment is only the preferred embodiment of the present invention, and the scope of protection of the present invention is not limited thereto,
The variation and replacement for any unsubstantiality that those skilled in the art is done on the basis of the present invention belong to institute of the present invention
Claimed range.
Claims (10)
1. a kind of novel club-footed pile test device for multifunctional, it is characterised in that including：
Stake holes, the stake holes includes the reaming part positioned at the non-reaming part of stake holes epimere and positioned at stake holes hypomere, described
Non- reaming part and non-reaming part form the upper pile body of club-footed pile and lower pile body, upper pile after being respectively used to casting concrete
Body and lower pile body are using variable cross-section as interface；
Steel reinforcement cage, the steel reinforcement cage stretch in the stake holes；
Load box, the load box are located at the bottom of stake holes, the i.e. bottom of reaming part；
Pressure oil pump, the pressure oil pump are located at the outside of stake holes and are connected to load box by oil pipe；
Slide attack testing element, the slide attack testing element stretch in the stake holes and positioned at the upper of load box
Side, the slide attack testing element includes test tube and the survey ring being installed in the test tube；
Upper displacement measuring staff, the upper displacement measuring staff are stretched into the stake holes and are fixedly connected with the upper plate of load box；
Bottom offset measuring staff, the bottom offset measuring staff are stretched into the stake holes and are fixedly connected with the lower plate of load box；
Displacement measurement equipment is installed on the top of upper the displacement measuring staff and bottom offset measuring staff；
Data acquisition equipment, the data information for receiving the slide attack testing element and the acquisition of displacement measurement equipment.
2. club-footed pile test device for multifunctional according to claim 1, it is characterised in that：The upper displacement measuring staff and bottom
The outside for moving measuring staff is arranged with displacement bar protection pipe and bottom offset bar protection pipe respectively.
3. club-footed pile test device for multifunctional according to claim 1, it is characterised in that：The quantity of the test tube is four
A, the quantity of the upper displacement measuring staff and bottom offset measuring staff is two, is evenly arranged.
4. club-footed pile test device for multifunctional according to claim 3, it is characterised in that：It is equipped with first in the test tube
It surveys ring, the second survey ring and third and surveys ring, the first survey ring is installed on variable cross-section position, and the second survey ring and third are surveyed ring and distinguished
It is installed in pile body and lower pile body, it is one that the third, which surveys ring, and the second survey ring is multiple, and the multiple second surveys ring
In the installation region being arranged in upper pile body, the lower face of the installation region is overlapped with variable cross-section, the installation region
Top surface on upper surface to pile body, two neighboring second surveys the distance between ring as 1m, is located at the second of lower side and surveys ring to first
The distance for surveying ring is 1m, and the survey number of rings amount in four test tubes is equal and position corresponds to.
5. a kind of novel club-footed pile bearingtest method, it is characterised in that include the following steps：
Test platform is built according to claim 1-4 any one of them club-footed pile test device for multifunctional；
To age in casting concrete to stake holes；
Step stress test；
Unloading test step by step；
Test data is obtained according to the step stress test and step by step unloading test and test result is analyzed.
6. club-footed pile bearingtest method according to claim 5, it is characterised in that：The step stress test packet
It includes：
Equivalent step by step is carried out to load box and loads capacity value, the capacity value of every grade of load is the 1/10 of load box maximum load amount,
The capacity value of every grade of load is classification capacity value；
To every grade load after displacement carry out survey reading, at every grade load after 5min, 15min, 30min, 45min and
60min surveys read bit and moves the displacement of measurement equipment and observe the reading of slide attack testing element, after 60min at interval of
30min surveys read bit and moves the displacement of measurement equipment and observe the reading of slide attack testing element；
Amplitude of variation of the capacity value of every grade of load in surveying read procedure must not exceed ± the 10% of classification capacity value；
When change in displacement rate when every grade of load reaches opposite stability criterion, then carry out the operation of next stage load.
7. club-footed pile bearingtest method according to claim 6, it is characterised in that：The unloading test packet step by step
It includes：
Equivalent step by step is carried out to load box and unloads capacity value, the capacity value of every grade of unloading is 2 times that are classified capacity value；
Every grade of unloading maintains 1h, to the reading of displacement and observation slide attack testing element after every grade of unloading in the 1h
Survey reading is carried out, 15min, 30min and 60min after being unloaded at every grade survey the displacement and observation cunning that read bit moves measurement equipment
The reading of dynamic micrometer testing element；
When discharging quantity after unloading is zero, surveys read bit and move the displacement of measurement equipment and observe slide attack testing element
Reading, the displacement of displacement measurement equipment are denoted as residual displacement amount, and the survey read time of residual displacement amount is no less than 3h, after unloading
Discharging quantity be zero after 5min, 30min respectively to survey reading primary, surveyed at interval of 30min after 30min and read a residual displacement amount；
Amplitude of variation of the capacity value of every grade of unloading in surveying read procedure must not exceed ± the 10% of classification capacity value.
8. club-footed pile bearingtest method according to claim 7, it is characterised in that：In step stress test process
In, occur under following either case, stops step stress test：
During certain grade of load test, displacement increment or bottom offset increment are not less than during its previous stage load test thereon
5 times of bottom offset increment, and displacement or bottom offset amount are more than 40min thereon；
During certain grade of load test, under displacement increment or bottom offset increment are more than during its previous stage load test thereon
5 times of displacement increment, and opposite stability criterion has not yet been reached in the change in displacement rate during interior this grade of load test for 24 hours；
Reach maximum experiment loading capacity, and tests the change in displacement rate under loading capacity in the maximum and reach opposite stability criterion；
Load box has reached load box maximum load amount or upper displacement and bottom offset amount has reached load box stroke.
9. club-footed pile bearingtest method according to claim 8, it is characterised in that：It is described that test result is divided
Analysis, including：
Draw the relation curve of the relation curve and displacement and load or unload time of capacity value and displacement；
Determine epimere stake limit loaded value and hypomere stake limit loaded value；
It calculates and obtains vertical allowable load capacity of single pile；
It calculates and obtains vertical ultimate uplift resistance of single pile；
Determine single pile vertical resistance pressure characteristic load bearing capacity and unit for single-pile vertical anti-pulling characteristic load bearing capacity.
10. club-footed pile bearingtest method according to claim 9, it is characterised in that：
It is described calculate obtain vertical allowable load capacity of single pile formula be：
Fud=Qud
Fuu=FAxle power
Wherein, QuFor vertical allowable load capacity of single pile, FuuAnd FudThe respectively single pile vertical resistance pressure of epimere stake and hypomere stake
Ultimate bearing capacity, FAxle powerFor the pile shaft force value of the above position of variable cross-section, QudFor the final loaded value of actual measurement of load box hypomere stake；W
For the sum of the dead weight of load box epimere stake and impost, the impost includes the weight of the superfilled height of stake top or more, sky
Pile cutoff mud or Cast-in-situ Piles in Sand-filling and soil dead weight；γ is load box epimere pile side resistance correction factor, according to load upper box part soil
Type determines；
The pile shaft force value F of the above position of variable cross-sectionAxle powerIt is calculated according to following formula：
FAxle power iFor the axial force at arbitrary cross-section,For the mean strain of arbitrary cross-section, εiFor the strain value of a certain section, pass through
Slide attack testing element obtains, EMixed iElasticity modulus when accordingly to strain, AMixed iFor the average pile body area of a certain section,
DMixed iFor the average stake diameter of a certain section, a and b are respectively regression coefficient and recurrence constant；
The vertical ultimate uplift resistance of single pile PuCalculation formula be：
=wherein, γ2For by the resistance to plucking frictional resistance conversion coefficient of inspection stake；
The single pile vertical resistance pressure characteristic load bearing capacity is the 50% of single pile vertical resistance pressure bearing capacity；
The unit for single-pile vertical anti-pulling characteristic load bearing capacity is the 50% of unit for single-pile vertical anti-pulling bearing capacity.
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| CN111609952A (en) * | 2020-05-28 | 2020-09-01 | 机械工业勘察设计研究院有限公司 | Calibration device and method for testing pile foundation internal force by line measurement method |
| CN114397199A (en) * | 2022-01-08 | 2022-04-26 | 中国电力工程顾问集团西北电力设计院有限公司 | Method for testing torsion resistance of pile body |
| CN114397199B (en) * | 2022-01-08 | 2023-09-01 | 中国电力工程顾问集团西北电力设计院有限公司 | Pile torsion resistance testing method |
| CN115839109A (en) * | 2022-05-05 | 2023-03-24 | 青岛理工大学 | Device for testing settlement of pile end of rock-socketed PHC pipe pile and installation method |
| CN115075309A (en) * | 2022-07-27 | 2022-09-20 | 河海大学 | System and method for testing axial force and side friction resistance of pile body |
| CN115075309B (en) * | 2022-07-27 | 2023-08-18 | 河海大学 | Pile shaft axial force and side friction resistance testing system and method |
| CN115595962A (en) * | 2022-09-08 | 2023-01-13 | 中山大学（Cn） | Pile bottom expanding and reinforcing device and reinforcing method |
| CN115595962B (en) * | 2022-09-08 | 2024-02-02 | 中山大学 | Pile bottom expansion reinforcing device and reinforcing method |
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