NP.045 00 Normative.as.Regards.in.Situ.test Piles.et.Fondation.piles

7/27/2019 NP.045 00 Normative.as.Regards.in.Situ.test Piles.et.Fondation.piles

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R.I&C.B September 30th 2004

NORMATIVE AS REGARDS IN SITU TEST-PILES AND FOUNDATION

PILES

INDICATIVE NP 045-2000

1. Scope and application field

This normative assigns the specifications concerning the static “in situ” test of single(isolated) piles in order to set their bearing capacity and the relations between loadingsand deformations as in the dynamic in situ pre cast piles for evaluation through calculus of vertical bearing capacity.

Data obtaining as a result of in situ tests piles are used for:Piles foundation design; Auditing of the piles execution technologies according to geo-technical requirements site;QA of the execution;NOTE: The present Normative replaces the STAS 2561/2-81

The stipulations of this normative are applied also for in situ static test of bars for theconstruction foundation (defined in Technical Instruction P106-85).The preparation requirements and instrumentation of in situ piles can be also used in thescientific research works, representing a minimum level of strictness.

1.2. The stipulations of the present normative are in compliance with the principlescomprised in the chapter “ Piles Foundations” form European pre-norm ENV 1997-1:1994“Eurocod 7. Geo-technical Design. General Rules.” and recommendations form“Compression with vertical loadings for test-piles Methodology – Part 1: Static test.”(Elaborated under aegis of International Society of Soil Mechanics and Foundation andpublished in “ASTM Geo-technical Test Journal” – June 1985), to which this Europeanpre-norm refers.1.3. The data utilization obtained from in-situ test of the test-pile for the design foundationon piles is made according to the stipulations included into the design regulations to thiscategory of foundation. Likewise, on the base of these design settlements the number anddistribution in plan of the test-piles are established on construction site, as also type of

test, in correlation with another determination which could be useful to the determination of the bearing capacity form, the design structure foundations (tests for static penetration,dynamic penetration, barometers, etc.).In the case of moist sensitive soil, the program elaboration for in situ test of piles andinterpretations of the results will be made in compliance with P7-92 normative stipulations.1.4. The present normative stipulates the following types of vertical and isolated testspiles:Static tests with loading steps benches maintained in time: Axial, during compression; Axial, during strength;Transversal (with horizontal forces)

b) Tests on dynamic way (test foundation pilling)

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Notes:Some stipulations regarding the execution, preparation and test-piles can be also used for static test on piles groups, for which special test program will be elaborated.

When the axial static test is not possible (compression with vertical loadings test-piles)with the help of the hydraulic presses according to this normative, test with directballasting could be stipulated on the pile head, an elaboration of a special documentationbeing required.

3) Test of the test-piles with a required deformation speed can be used, on thebasis of some special working schedule, only when it’s demonstrated – for the type of pileand the foundation soil –equivalence of results with the one obtained through the statictests, with loadings steps maintained in time.4) Speed measurement of the waves propagation in beating piles, for determinations of bearing capacity or pile body integrity, on the base of the “wave equation”, it’s executedwith special equipments and does not make the object of this normative.

1.5. The test on piles will be executed according to the project and will be conducted bytechnical authorized personnel. The permanent presence of an experienced specialist willbe assured in this field during in situ test. An experienced engineer in this field will draw upa report that will include the test results interpretation.1.6. Depending on the goal wanted and the requirements required by the test andequipment program of piles, 4 levels of quality are established for in situ piles test, suchas:

Level N1: Tests for the science researchLevel N2: Tests performed near the designed construction site, for verification of theexecution technology of piles according to the soil properties and determination of thebearing capacity and dependency of loading movement, regarding piles foundationdesign;Level N3: Control test on foundation piles, for the bearing capacity confirmationLevel N4: Test for piles reception with possible flaws of execution.The designer, by the agreement of an engineer geo-technician (by mutual agreement) candecide the modification of the quality level comparing to the one indicated in the precedingalignment in accordance with the design structure type, by the geo-technical requirementcomplexity on the site and by the experience regarding similar piles behavior in the samesoil condition. Likewise, they can ask – for a certain level of quality – to respect adequate

requirements for a superior quality level regarding test program, preparation or instrumentation of the test-piles.1.7 Some STAS.

2. Related normative actsStandards:STAS 1242/1-89 Foundation ground. General principles of research.STAS 1243-88 Foundation ground. The classification and land identificationSTAS 2561/1-83 Foundation ground. Piles. Classification and terminology.STAS 2561/3-90 Foundation ground. Piles. General specifications for designingSTAS 2561/4-90 Foundation ground. Drilled piles of large diameter. General guidelines,

execution and reception.STAS 3950-81 Geo-technique. Terminology, symbols and measurement unitsSTAS 10101/0-75 pending actions. Classification of actions

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Technical regulations elaborated within MLPAT:-P. 106-85 technical instructions for bar designing and execution for constructionsfoundation-P.7-92 normative concerning the designing and execution of the constructions founded on

wet-sensible soils.-GE-029-97 Practical guidelines concerning the technology of foundation piles execution.

2. PRINCIPLES OF TEST METHODS

2.1. The static test is accomplished by the appliance of an isolated pile, identical with thatfrom work, of some controlled loadings, that maintain constant in certain period of time, bymeasuring the upper side of the pile.For qualitative upper level tests over some instrumented piles, the deformations aremeasured using special device in different points of the test-pile, above the level of theground as well as along the layout, in order to obtain some extra information, such as the

modification of the forces on the base and lateral surface of pile depending on the externalloading. Likewise, for the instrumented piles with pressure ratios, the normal forcees canbe measured on the base or lateral surface of the piles loadinged transversally.

In case of the replaced piles, with bigger diameter than (d≥60cm), having a high bearing

capacity, the execution of vertical static tests on model-piles is admitted which areexecuted with the same technology, having the same length, but with the diameter at leastequal with half of the piles from diameter value. In this situation, the tests are performed atthe same quality level N1 or N2 and the measuring of forces transmitted on base and onthe skin piles are mandatory during the test.Note: The replaced piles are executed by removing the soil volume equal with the pilevolume.

2.3 The test on dynamic way is applied only to the pre-cast piles and consist in followingthe residual axial movement of the pile brought to the final level, under a number of hitsexecuted with a breaking –machine on free falling or simple action, with a rare modulation(by applying to the pile an established mechanic thing)2.3 For a superior level quality test, the elastic movement is measured (elastic rejection)under each hit on the pile head.

The obtaining data through dynamic test are useful for the evaluation of bearing capacityto vertical compression of the pile.

3. PRELIMINARY ACTIVITIES FOR THE TEST EXECUTION

3.1. The test-piles meant for the determination of bearing capacity (quality level N2) will besought by the designer and the geo-technician near the site structure, so that thefoundation requirements may not be different too much (in a significant way).The piles from the foundation on which the control or reception test will be performed(levels N3 and N4) will be established by the designer and geo-technician, in accordance

with non-uniformities of the foundation field and by particularities mentioned during theexecution.

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3.2. Field geo-technical research

3.2.1. The field search where they are going to execute pile test shall specify thesuccession and geo-technical parameters of layers that will have to be more than 4d or minimum 5m.Note: In case the compacted hard rock should be under the test-piles level base, thesearch depth could be limited to 2d.3.2.2 The field search will be executed with geo-technical drills from which will be takenundisturbed and disturbed samples and also water sample for the chemical test. It isrecommended that it should be completed with in situ research methods of soil properties(static penetration, SPT, plate test in the BH, etc.)3.3 Test-piles execution3.3.1. The test-piles are performed with the same technologies and will have the same

dimensions with the final piles from the paper.3.3.2. During the test-piles execution, the general requirements will be respected as in“Practical guide for the execution technologies regarding piles foundation” indicative GE-0290-97 and specific requirement stipulated in the task book of the project.3.3.3 For each test-piles the next data will be specified:- Position in plan of the pile or group of piles;- equipment used in execution and its properties;- final dimensions of executed pile;- properties of the material from which the pile is executed (grade of concrete,reinforcement, etc.);- behavior during driving in of the pile, damages occurred (if any);- other Notess during execution;- presumed projected loading for the pile or group of piles (if known).3.3.4. The distance in the layout (plan) between axels of a 2 adjoined piles for test will bechosen as the soil volumes influenced by the intersection of the test loading in case eachpile may not be cut across.For the compression with vertical (loading) forces test-piles, the minimum distancebetween the axels of two adjoining test-piles shall be of at least 3 m for d ≤0.50 m and atleast 6d for d > 0.50 m(d being the side or cross section diameter of the pile). When two single test-piles aresimultaneously loading with vertical forces, the distance between them shall be at least

equal to the (l’).3.3.5. In case the piles execution should cause a strong stuffing effect of the adjacent soil,test-piles will be surrounded by other (dead) piles which are executed at distances fromthe project or at minimum 3 d .

3.3.6.Static tested test-piles will be protected, within the test period, against vibrations,shocks.3.3.7. The test-pile head (at the superior part where loadings will be applied and themovement are measured) will be protected against any degradation during the test. Anytransfer shall be eliminated of loading between the pile and the field, in this area.3.4 Testing of test-piles is performed in the following time during the interval since the end

of execution imposed by reaching of the designed strength (grade) of concrete or by theconsolidation in time of the adjoined soil (rest period). For the ramming piles( pre-castpiles the minimum rest period will be of:

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- 5 days, for piles driven in non-cohesive soils;- 2…4 weeks, for piles in cohesive soils (according to the ratio-smaller or greater-of clayous layers onto the depth performed by the pile).Note: 1. In case of sensitive loam soils, the rest of the period will be bigger than the oneindicated at 3.4. and it will be established based on special Notes.2. If cohesive layers have an insignificant contribution to the pile bearing capacity (under

5%), the relax time period will of minimum 5 days.3. A dynamic test-pile could be then static tested, after expiring the relax time period(stated according to the above specifications).

4. Requirement for the equipments, devices and measuring devices used to test-piles

4.1. The device to take over the reaction to static test4.1.1. For the compression axial test, the device to take over the reaction could be:Ballast platform (annex A1);Pulling pile (anchor piles) and a beams system (annex A2);

Anchors (usually drilled) and beams system or a column head for transmitting the forcereaction; A structure (a construction) existing over the pile head (annex A4), possibly combined withbeams (annex A5);4.1.2. For the axial pulling test, the device for taking over the reaction could be composedof:Bearing plates or a concrete abutment and an interlocked metallic beam with the testedbeam (annex 6);Piles required at compression and a metallic beam (annex 7);In case of horizontal loadings (forces) test, the device to take over the reaction could be:a vertical plate or a concrete abutment( or masonry) located on the field( annex A8);a vertical pile, usually identical to the test-pile( annex A9);Vertical parameter of an existing structure (constructions), joined to the test-pile.

4.1.4. The efforts need to be simultaneously mobilized in elements take over the reaction(ballast platform, anchors, existing construction); it’s recommended that these elementsshould be symmetrically arranged in proportion to the force axial applied to test-pile4.1.5. The device for taking over the reaction will be dimensioned to at least 1,1 Q max (Qmax

– maximum loading that will applied to the test of the test-pile)4.1.6. The piles movement from work, used as anchor piles (according 4.1.1.) or as

bearing points to the pulling test (4.1.2.), will be pursued during the test, and maximumvalue of these movements shall not exceed 50% from the (settlement or rising) adequatemovement value, admitted for design structure.4.1.7. The minimum distance from the test-pile center till the nearest extremity for theballast (loading) rest (prop) or till the anchorage axial shall be of 2,5m or 3d (the largestdistance will be chosen).

4.2. The device for applying the force on the test-pile4.2.1. The applied force on the test-pile with the hydraulic press with a adequate capacity.4.2.2 The press or the press group shall be disposed in such a way so that the compositeforce may coincide with the pile axial. In order to avoid the admission of eccentricities

during the test, the penetration of a joint under spherical bell between the press and thetest-pile.

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4.2.3 The presses shall assure the progressive increasing and decreasing (without anyshocks) of pressure, and the race of the breaking machine shall be bigger than the sum of the pile head movement and deformation of bearing device of reaction, corresponding toforce Qmax.

NOTES: exception from this provision is made by the cyclic tests, to which the execution

of a loading cycle-discharge, clamps for the residual deformations compensation.

4.2.4 The utility of an automatic device of constant maintenance in time of the appliedforce is mandatory for the qualitative level tests N1 and it’ s recommendable for thequalitative level tests N2 independent of pile deformation and bearing device of reaction.

4.2.5 For the qualitative test N1 and N2, between press and bearing device of reaction, adevice of measuring the applied force is independent of pile deformation.The measuring device of force shall assure accuracy higher than ± 0.5% of the force valueor dynamo-metric ring).4.2.6 When any measurement force device is not stipulated according to 4.2.5(for the level

tests N3 and N4) the hydraulic presses will be aligned before every series of tests off alocation, by assuring an accuracy bigger than ±2% of the minimal force value that will beapplied for piles. The manometers will be aligned (calibrated) with the pump that will be setup during the tests.

4.3. DEVICES FOR INTERNAL FORCES DETERMINATION IN THE TEST-PILE

4.2.1 The reference devices (beam girder) for the movements measure.Devices for determining the efforts in sections of the test-pile are usually installed for leveltests N1 and for low level tests level (N2 and N3)- for the judicious designing of thefoundation- it’ s important that one should know about the distribution of the field reactionon lateral surface and on the basis of pile.The determination of internal force in instrumented test-piles are executed with the help of special devices by:Measuring the deformations in different points of the pile;Direct measuring of normal forces on the base or lateral surface of the pile;

4.3.2 The measuring of deformations into the pile body can be executed with devices of the following types:Electro- resistance transducer;

Acoustic transducers;Mechanic transducers (mechanical bench-marks)In order to determine the body pile efforts of reinforced concrete on the basis of deformation measurement, the determination of the deformation modulus is needed by:Determinations from the lab for samples collected at the pile concreteor Deformations measuring on the superior part of the pile, where a uniform distribution of efforts is assumed.The execution and interpretation of measuring the mechanic transducers (mechanicbench-marks) are described in the Technical Instructions P 106-85, annex 1.

4.3.3 The settlement, the installation and calibration of measuring devices of internalforces in the test-pile are detailed in the project drawn for each test of this type, dependingon the data obtained from the test and properties of the used devices.

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4.4 REFERENCE DEVICES (BEAMS) FOR MEASURING THE MOVEMENTS

4.4.1. The superior part movements of a test-pile will be measured with the devices andequipment (leaned) on the reference beam girders.Note: In case the utility of some reference beams is not possible, the measuring of pilemovements is allowed by top metrical methods that will assure an accuracy of ± 0.05 mmfor level tests N1 and N2, respectively of ± 0.1 mm for level tests N3 and N4. In this caseon the pile head, marks will be installed horizontally, in triangle or 2 perpendicular diameters.4.4.2 One of the reference beam edges shall be crippled across it, at temperaturevariations.

4.4.3 The bearing points on the field of reference beams shall be situated at distanceslarger than 2.5 or 3 d (the largest distance is chosen) towards the axial test-pile or anchorage, respectively towards the closest extremity of the bearing ballast.4.4.4 The quote of the reference beams (usually at their edges) shall be verified byaccuracy leveling (± 0.1mm):Before the beginning of each loading sequence;In the final level of appliance for each loading for level test N1;In the final level of maxim loading of each loading cycle – for level tests N1 and N2.The leveling of the points from the reference beams will be done in comparison with astable bench-mark (milestone or pile), situated at a distance of min. 10m towards the testsample.

4.4.5 DEVICES FOR MEASURING THE MOVEMENTS AND DEFORMATIONS

4.5 1 In order to measure the movements of superior part of test-pile the followings areused:

Micro-comparators;Electronic transducer for movement;Wire devices (flex meters) (flex meter = bending measuring device or deflect meter);The accuracy of the devices shall be of 0,05 mm;

Note : if the wire devices are used, the accuracy measuring can be 0.05 mm, on thecondition of permanent measuring of proper temperature and correction corresponding toreadings.

4.5.2 The deformations of test-piles transversally (axial spinning) can be measured withbatter level, with the superior accuracy of angle value of 5x 10-5 radians.4.5. 3 the devices for measuring the movements will have a measuring field large enoughin order to avoid their change during the test.

4.6. TEST DEVICES - CONTROL AND PROTECTION OF THE MEASURE EQUIPMENT

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4.6.1 Before running the test, a pre-loading of pile will be performed with a force that willnot exceed 0.05 Qmax for the control and adjustment of devices and equipment, followed bya complete discharge.4.6.2 During the test, the located devices will be protected against the isolation, wind or shocks and the measuring devices - against the rain or humidity from other sources. For the qualitative level tests N1 the setting of a temporary close-up where to maintain a

constant temperature during each testing.4.6.3 The electronic and electric compounds (transducers, tens metric brands, cables)incorporated into the test-piles or installed near them will be specially protected against themechanical actions, concrete cutting-in, clay mud, and water during the piles executionand preparing of their upper side.4.6.4 In order to prevent the sudden subsidence of undertaken device of reaction, it isrecommended that the marginal points of the ballast platform and anchorages should beincluded at the final loading steps in the measuring of optic leveling.

4.7 THE PILE BEATING EQUIPMENT AND THE REFUSE MEASURING DEVICE FOR

THE DYNAMIC WAY TEST

4.7.1 For the equipment that executes the test foundation piling the following will bementioned:The type of the used pile driver;The type and modulation piling of the breaking machine;The volume of the breaking machine and the head determined with an accuracy of ±1%;The mechanic thing efficiently transmitted by a hit( lowering the losses due to the wearing-in case of direct test;The mass of the protection head determined with an accuracy of ±1%; and the material of which the anti- vibration layers;4.7.2 the volume of the breaking machine will be at least equal with:-1.5M for piles with mass M< 2t;-M for piles with M> 2÷ 4t;0.75 M for piles with M> 4t; (M being the mass of pile).

4.7.3 The measuring device of axial movement of pile under 10 nits shall assure anaccuracy of ±1 mm.The measuring device of elastic movement (elastic refuse) under a hit will assure anaccuracy of 0.1 mm.

5. THE COMPRESSION VERTICAL (AXIAL) TEST

5.1 The recommended scheme for test execution of the pile vertical compression areshown in annexes A1….A5.The requirements regarding the properties and location of the devices and equipment,

which form this schemes are specified in the chapter 4.Note: other schemes can be used for the test-pile loading, on the condition of respectingthe requirements presented in ch. 4, for all the components of these schemes.

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5.2. The measuring of the pile vertical movements under loading will be performed at thesuperior part of the pile, in a horizontal plan, with at least 3 equipment arranged non-collinear around the pile.Note: In this case the quality level N1 is mandatory, and for the N2 level test is indicated tomeasure the horizontal movement of the pile head, with equipment arranged on 2horizontal axial, perpendiculars.

5.3. TEST EXECUTION

5.3.1. The test shall be done without interruption. It’s admitted, just for the nonce, thatduring the night, the Notess can be stopped, on the condition of keeping the loadingconstant on the pile, in the meanwhile.5.3.2. The pile’s loading is made in equal steps ΔQ with 1/8 at the most from the Q max

presumptive maximum loading value.The loading step size shall be chosen in order to allow a clear tracing (marking) of thesettlement diagram; in this way it is recommended the step sizes should be reducedbefore the fail test.

5.3.3. After the application of one step loading, which shall be quickly executed (maximuminterval 1 minute), the records are performed with equipment for measuring of movements(vertical and horizontal) at 0’, 2’, 5’, 10’, 15’, 20’, 25’, 30’, 40’, 50’, 60’ and so on – if necessary – at 10 min. interval, till the vertical movement is stabilized, according to 5.3.4.The difference between records on every settlement measure equipment shall not bemore then sm average value50%, for sm <1mm;30%, for sm=1…5mm;20%, for sm>5mm;Otherwise, the test is not valid.5.3.4. For each loading step, the records are performed for all measuring equipment till theconventional stabilization of the pile movement, that it’ s considered to be reached whenthe difference of average settlement measured at an interval of 20 min doesn’t exceed 0.1mm.

2 diagramsFig.1, Fig.2 – page 116

5.3.5. The loading will be increased, in steps, till the Qmax maximum value is reached, thatis defined at 5.3.6 and 5.3.7 depending on the test quality level.The loading variation can be executed in one of two ways shown below (established by

mutual agreement between the designer and the construction):Through monotone loading till Qmax; (fig.1);Through 2 cycles loading: first till approximate 0.5 Qmax, with discharge, followed bysecond cycle of loading till the Qmax (fig. 2).When maintaining time for Qmax loading ends up, it is recommended that the dischargeshould be done in double steps (2ΔQ) according to loading step size. At each dischargestep the movements are measured at two intervals of 5 minutes each. After the finaldischarge, at one-hour interval a last series of measurements are performed.5.3.6. For the loadings of N1 and N2 qualitative level, Qmax. value corresponds to Qr failingloading (in comparison with soil), which will reach the loading step for which one of therequirements will be carried out:

Average settlement sm is bigger than 1/10 from the pile diameter;Within 24 hours since the step has been applied the stabilization requirement from pct.5.3.4 is not obtained.

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As critical loading on pile Qcr the loading is considered to be accordingly to the previousloading step for which the Qr has been determined.

Note: In case of big capacity pile, when the lack of technique for the failure loading

reaching, the Qmax loading will be at least equal with 1,5 times, the maximum test value onthe working piles, calculated in the design for the ultimate limit state the adequate groupsof actions (according to STAS 10101/0-75). In this case, the pile critical loading will be of Qcr=Qmax;

5.3.7. At N3 and N4 level test (executed on foundation pile), the loading Qmax will be atleast with 1,5 times, maximum loading value for the working piles, established by designfor the fundamental grouping of actions according to the normal exploitation limit state(STAS 10101/0-75).For the N3 and N4 level tests, when the verifying of the test-piles will be needed (thesettlement determination under loading being unessential for designing), “fast test” could

be done. The force variation on pile is executed after schemes shown in fig. 1 or fig.2 withthe maintenance of every step loading till stabilization condition is reached from pct. 5.3.4,but no more than an hour, the readings have to be done at intervals shown at pct. 5.3.3.In this case the test stops when reaching the maximum loading Qmax according 5.3.7.The variation diagram of pile settlement “s” with loading Q can be constructed inapproximate way only if the variation diagram of measurement average settlement s m withtime t represented at logarithmic level, it’ s confirmed. In this case, the stabilizedsettlement will be considered the value obtained through extrapolation for t=3 hours (fig.3).

Note: It is recommended that the effectuation of “quick” test should be only in case of endbearing piles or floating piles that transmit the most of the loading into layers made of non-cohesive soil.

5.3.7 For the level tests N3 and N4 (executed on the foundation piles, loading Q max shallbe at least equal with 1.5 from the value of the max. loading on working piles, determinedby the project for the basic action grouping corresponding to the normal limit exploitationstate ( STAS 10101/0-75).

5.3.8 For the level tests N3 and N4, when the bearing capacity verification of test-piles isnecessary (foundation settling determination not being essential for designing), “ fast tests“ can be performed.

The force variation on pile are accomplished according to the schemes shown in fig.1 or fig. 2 by maintaining each loading step until reaching the stabilization requirement frompoint 5.3.4 , but no longer than an hour, the performance of readings being at 5.3.3

In this case the test stops when reaching the loading Qmax according to 5.3.7The variation diagbreaking machine of foundation pile s with loading Q can beapproximately built only if linearizarea of variation diagbreaking machine for the averagefoundation piling sm is confirmed with time t represented on a logarithmic level. In thiscase, as a foundation settlement stabilized s, the obtained value is considered byextrapolation for t= 3 hours.(

Diagram ( fig. 3).

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5.4.3 Relying on these pile test data, breaking machines diagram are drawn up on adiagram breaking machine( fig.4) that comprises:test variation Q with time t;Variation of pile head foundation depending on the time;Foundation pile variation of head pile with the loading.

Diagram breaking machine( fig. 4)

If other measurements were executed, breaking machines diagrams are drawn uprepresenting the following:Variations of transversal movements of pile head with loading Q;Variation of deformations along the pile for different values Q;Loading variation on the top of the surface and lateral pile surface depending on Q;Tangential force variation on the lateral pile surface along this for different values Q;

6. PULLING TEST AXIAL TEST

6.1 THE RECOMMENDED SCHEMES for the execution of pulling test axial tests of pilesin annexes A6 and A7 and the requirements concerning the properties and settlement of devices and instruments are mentioned in ch. 4.The appliance of pulling test strength Qsm is done, usually, with two pressessimultaneously actuated, and efforts transmission to the test-pile- by its reinforcement -that will be dimensioned for an equal force with at least 1.5 Qsm max. (Qsm max.- being the max.pulling test force presumed in test) Measures will be adopted so that all thesereinforcements can be uniformly requested during the test.

6.2 THE TEST EXECUTION WAY for pulling test and execution of measurements issimilar to the stipulated at 5.2, 5.3.1, 5.3.2, 5.3.3 and 5.3.4 for compression tests.

Slow increasing of the pulling test force is gradually preferred (point 5.3.5 fig. 1), value Q sm

max resulting from the requirements shown at 5.3.6 and 5.3.7.

As a critical value of pulling test force Qsm er is considered:The value of the force corresponding to the previous force of pulling test value Q sm for thelevel tests N2 and N3.

Note: After reaching the Qsm force the following step is the total pile unloading, afterwardsthe movements ∆ at an hour interval.

6.3 TEST RESULTS PRESENTATION

6.3.1 The measurements executed during the test and the operator’s notes are recordedin the record sheet that shall comprise all the mentioned data from 5.4.1The record sheet is kept under the requirements from 5.4.2

6.3.2 The test data are useful to elaboration of an centralized table( fig 5) that comprise:

- pulling test force variation Qsm with time t;Movement variation of pile head ⌂, depending on the time;Vertical movements variation stabilized of the pile head with the pulling test force.

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If, during the pulling test test, other measurements were performed, diagram-breakingmachines should be drawn up, if necessary;

Transversal/cross movements variation of pile head with force Qsm ;

Deformation variation and efforts along the pile for different values Qsm.

Diagram ( fig. 5)

7. HORIZONTAL FORCES TEST

7.1 The horizontal forces test of the isolated pile aims at determination of critical horizontalforce Qor.er. or breaking machines of rigidity horizontally on the field in collaboration withthe pile, under the requirements of a simple static scheme of its request.

Note: the deformation way and the subsidence of the pile transversally requested dependon the rigidity of the foundation ground, and the resistance and pile rigidity, static schemeof request(influenced by the connection with the pile foundation raft) and the intensity of axial forces into the pile.

Horizontal forces test of the test-piles are usually executed, corresponding to the accuracyof levels N1, N2 or N3, if necessary.

7.2 Loading schemes7.2.1 the layout of devices and tools for the test execution according to the schemesshown in annexes A8 and A9.The requirements concerning the properties and arrangement of devices and measuringinstruments are shown in ch.4.7.2.2 Force is applied by arrangement of devices and measuring instruments at a level asclosed as possible to the size of pile foundation raft of the designed construction.The horizontal movements of the pile are measured on the horizontal level of theforce( movement ∆or 1) and at a superior size with 0.80…1.00m ( movement ⌂or 2 )The spinning of the superior part of the pile(above the action layout of force) semn iscalculated by reporting the differences of movements ∆or 2- ∆or1 at the distance between themeasuring layouts.

Within the superior qualitative level tests (mandatory- for N1, recommendable- for N2) themeasuring of the vertical axial spinning of the pile is assured with a mobile battle level for which a special vertical channel is provided within the test-pile.

7.3 THE TEST EXECUTION AS REGARDS THE DETERMINATION OF CRITICHORIZONTAL FORCE OF THE HEAD PILE

7.3.1 The test-pile is executed by increasing the horizontal, slow force, in levels with the

equation ∆ Qor = 5…50kN, corresponding to 1/15…1/10 of the equation of the critical forceassumed for the requested piles. Each level is maintained for 30 mi, by measuring thehorizontal movements at 0’, 5’, 10’, 30’ from the application moment.

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At the beginning and at the end of application of each level, the position of the press isverified, by recording its possible dips. The loading keeps going to some movements onhorizontal force level: ∆or≥0.1d ( d- being the diameter or side of the pile section ) or to thereduction of pile opposed resistance noticed by the obvious decreasing of the oil pressureinto the press.

Note: For a test couple of piles (according to scheme from annex A9), the test stops whenthe above requirement is carried out to one of the piles.

7.3.2 The critical horizontal force Qor cr corresponds to the max. loading level for which themovement on the horizontal level of force is ∆ or1 ≤ 25mm.

7.4 Test execution with horizontal forces for the determination of breakingmachines field rigidity breaking machine using pile

7.4.1 In order to determine the adjacent field rigidity breaking machines of the test-pile (for instance the lateral coefficient reaction Es defined in STAS 2561/3-90 annex C) the test isperformed by pursuing the movements and pile deformation in the previous subsidencestages.

7.4.2 the test-pile is executed by increasing the horizontal force, in steps ∆Q or ≤ 1/8 Qor max.

the max. force Qor max is determined out of the most restrictive requirement given by belowinequalities:for qualitative level tests N1 and N2,Mmax ≤ 0.8 Mcap or ∆or1 ≤ 0.1dfor level tests N3( foundation piles)Mmax ≤ 0.8 Mcap or ∆or1 ≤ 1.5 ∆or adm

Where:Mmax – max. bending moment calculated in pile cross sections under the action of force

Qmax ( on the basis of a calculation model of pile-ground collaboration):Mcap- max. Bending moment in the pile section corresponding to the elastic behavior of material;∆or adm – horizontal movement of pile head, admitted in the pile foundation project;d- diameter or pile section side.

7.4.3 Each step of horizontal force is maintained for 30 min., by measuring the horizontalmovements at 0’, 5’, 10’, 30’, from the application moment.

Measurements with batter level are performed between 20-30 min from the stageapplication, to intervals of 0.5…1.0 min. at the beginning or at the end of each stage thepress position, by recording its possible dips.

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7.4.4 After the maintenance of the corresponding stage Qor max., the downloading up to

0.5 Q or max , maintaining of this downloading for 15 mi with readings of movements at 0’, 5’,15’ and then total discharge with measurements movements and if necessary with batter level – at 30 min.

7.5 RESULTS PRESENTATION

7.5.1 Measurements performed during the test and the operator’ s notes are recorded inthe record sheet that will include all the specific data at 5.4.1the record sheet is kept under the requirements shown at 5.4.2

7.5.2 The test data are useful for the centralized breaking machines diagram (those shownin fig. 6) that include:Horizontal force variation Qor with time t;Pile horizontal movement variation on the horizontal level of force ∆ or 1 at the superior leveldepending on time;Horizontal movements variation at those 2 levels, recorded at the end of application toeach level, with the loading.

The variation diagram of pile head spinning..Calculated on the basis of the values ∆ or 1and∆or 2.

If, other measurements are performed within the test, breaking machines diagrams aredrawn up representing, if necessary.Pile vertical axis deformation at different horizontal forces;Contact normal pressure variation on vertical sides of the pile, for different values of horizontal force.Diagram fig. 6

8. SPECIAL REQUIREMENTS FOR STATIC TEST EXECUTION IN FLOODED FIELD

8.1 The static test of the piles in flooded filed are performed if any humidity – sensitive soilwhose classification into group A or B is mentioned in the geo-technical study, accordingto the stipulations of the norm P7-92.Under these conditions the tests are usually performed according to the qualitative N1 andN2, on the base of a special breaking machine program, elaborated in collaboration by thedesigner of the work and the expert- geo-technician following the properties of thedesigned structure, as well as the evolution way of loadings on the construction piles andthe variation way of humidity on the foundation ground.

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8.2 For the static pile test identical piles are used with those from the work. The test-pileswill be located outside the designed construction precincts at a safety distance towards itand the over terrestrial or buried constructions and tools that already exist.

8.3 The devices and measuring tools used in the test will meet the requirements shown inch.4.8.4 The location of the adjacent soil as regards the flooding is made according to thoseshown at 8.6- for MSS of group A, respectively 8.7- for MSS of group B.

The water discharge installation in the flooded area will be forecast with a measuringdevice of quantities on the field with an accuracy of 0.1m3.

8.5 The determination of humidity soil test adjacent to test-pile is done:- Before the flooding, by drill wells ( usually of a diameter below 10 cm), of which

tests are collected at depth intervals of max. 1m;- During the flooding, by control drill wells executed as nearer the test-pile ( by

collecting the tests at depth intervals of max. 1m) by humidity ratios , or by radio-metric measurements in drill wells.

8.6 In P.S.U of group A, the measuring is not usually needed for settlement foundationground adjacent to the pile during the flooding and test loading. As a consequence, thesettlements of ground and loading device according to the scheme of annex A10 andstipulations from 8.6.1 and 8.6.2.

8.6.1 Around the test-pile 4 drill wells are executed crossed located at a distance of 1…1.5m against its axis, with the depth equal to the thickness abutment MSS. soil tests arecollected from these drill wells, at intervals of max. 1 m, where the initial humidity isdetermined and then they are filled in with drainage material (gravel with grains of 2…20mm). Likewise, around the piles a digging of min. 50 cm depth and dimensions on alevel of min. 3x3, on whose bottom a gravel layer of 30 cm thickness is spread.Maintaining into the dug precincts of a superior water level with 20...30 cm to the graveldrainage layer by measuring the low water quantities performs flooding.

8.6.2 After the saturation of soil adjacent to the test-pile resulted from measurementsperformed according to 8.5 the next step is its loading on the basis of theestablished test breaking machine.

If by the test breaking machine there wasn’t any other solution, the pile loading can beexecuted: by compression- according to stipulations from points 5./3, by pulling testaccording to stipulations from 6.2

8.6.3 During the test, the position of the reference beam girders shall be verified byaccuracy leveling ( ± 0.1 mm) at least:

- Before the beginning of each loading sequence;

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- One hour distance since the application of each loading step;- In the final application field of each loading or unloading step.

The leveling of the points off the reference beam girders will be done in comparison with astable bench-mark (preferably a depth one) located at a distance bigger than 10 m or thanH against the edge of the flooded digging (H being the thickness of the humidity sensitive

layer).

The measured values of pile head movements are corrected depending on the referencebeam girder movements, admitting a linear variation in time of beam girder settlementsduring the intervals between the leveled measurements.

8.7 For MSS of group B, due to the settlement by humidity under own weight of adjacentland, negative friction will develop on the lateral side of the test-pile. Under thesecircumstances, the flooded precincts will have the dimensions at least equal with thetotal thickness H of humidity sensitive layers, but not lower than 20 x 20m.

The scheme recommended for land facility and charge device is shown in annex A11.

Notes: 1 in order to accelerate the saturation process of MSS the execution of draineddrillings (filled with small gravel) on the entire surface of flooded precincts. These drillingsare useful to the initial humidity determination in the adjacent land of the test-piles.

2. The execution of some very closed drillings can be taken into account, even tangent, onthe perimeter of flooded precincts, in view of volume separation from humid sensitive soils,of adjacent abutment.

8.7.1 When the precincts start to be flooded (by maintaining a superior water level with20…..30 cm of a gravel embankment and the measuring of the water quantities slippedin), the next step is the settlement measuring of the bottom precincts on enacted marks inpoints that are established by test breaking machine.For the quality level tests N1, depth marks will be provided for measuring the variation withthe settlements depth of MSS under own weight, and the pile test will be equipped withdevices for efforts measuring in different sections, during the precincts flooding and itscharge.

8.7.2 If by the test breaking machine there wasn’t any provision the pile charge can beexecuted, after the saturation abutment of P.S.U, according to clues from 5.3( tocompression), respectively 6.2 ( to pulling test).

The position of reference beam girders will be verified by accuracy leveling ( ±0.1m):- Before the beginning of each charge step;- During the loading and unloading the pile, at 10 min. intervals, by applying

adjustments to the measurements of pile head movement depending on themeasured settlement of the reference beam girder.

The leveling of the reference beam girders will be done in comparison with a (depth)

stable bench-mark situated at a distance larger than 20 m or than H against the edge of the flooded precincts ( H being the total thickness of MSS abutment).

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9. THE DYNAMIC TEST

9.1 The dynamic test of the test-piles (test beating) is performed on pre-cast piles, put in atthe final bench-mark from the project, after a time has elapsed since the end of the driftingat least equal with the rest time indicated in 3.4.

The requirements concerning the equipment for the test beating and the measurement

devices are mentioned in 4.7.2 and 4.7.3.

9.2 On the test beating, 10 hits are applied with the same hitting height of the breakingmachine and the total remnant penetration of the pile on the field.The refusal (remnant average penetration under a hit) is calculated with the equation:E= e1/10

The classic refusal (reversing of the pile head under a hit) is recorded, separately, for eachhit from the 10 hits- series. As an expanding refusal to test beating, the arithmetic average of the expanding refusalvalues recorded within the 10 hits series.

9.3 the results of the dynamic test are recorded in the test record sheet that will include thefollowing data:

- Unity that performs the test;- Work ( building site, objective);- Identification number of the test-pile;

- Type of the pile and its dimensions;- End data of pile drifting;- Data of dynamic test;- Type of pile driver used for the test beating;- Type and beating stroke of the breaking machine;- Bulk of the breaking machine and fall head- Mechanic efficient thing transmitted by a hit (lowering of losses due to the

frictions)- if it has been directly measured;- Mass of the protection helmet and material of which the amortized layers are made;- Measuring device of refusal;Measuring device of expanding refusal;

- Measurements of pile penetration during the dynamic test and expanding refusal *)- Notes during the preparation and test performing (pile body behavior, bending

striking hammer);

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- Operator’ s full name

*) The automatic records are usually attached of the expanding refusal measuring

device.

The beating test record is kept in the executioner’ s archive, and its copies aredelivered to the beneficiary within the test rapport.

10. THE TEST RAPPORT

10.1 The field test results of the piles are presented as a rapport that shall encompass:

a) Labeling and address of the unit that performed the pile test in the field;b) Labeling, address and authorization no. of test labs ( if within the pile test breaking

machine geo-technical determinations were executed or on the material of the pilebody);

c) Labeling and client’ s address;d) Topic for the pile test;e) Indication of the technical guidelines on whose bases the tests have been

performed;f) Comments on obtained results;g) Indications of the measuring incertitude caused by the location requirements, by

mentioning the respective causes;h) Goal definition and field for which the test results can be used;i) Conclusions and design recommendations; j) Declaration concerning the fact that the performed tests have not been performed

under any kind of pressures;k) Table of the parts attached to the rapport(records, test diagbreaking machines,

drawings);l) Name, job title and signature of the people who are technically responsible for

respecting the technical norms and who certify from technically point of view theresults of the performed tests and recorded in the rapport.

10.2 At the test rapport the following parts are attached:a) Layout with the position of the test-piles and trial pit executed around;b) Drawings with a planned arrangement and vertical sections of pile arrangement –

test and measuring devices, for each static test, by mentioning the field level aheadof the piles, or application forces level and by representing the field arrangement inlayers on the basis of the most closed trial pit;

c) The trial pits records closed to the test-piles position, by comprising the results of the lab tests and in-situ tests (penetrations, compression gauge);

d) Trial pits records – concreting or drifting (according to 3.3.2) for each test-pile;e) Dynamic pile test records

f) The record sheets of static test results on piles (only at beneficiary’ s request)g) Centralized breaking machines diagram of static tests (according to 5.4.3, 6.3.2 or

7.4.2)

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h) Test results on collected material samples of the pile body (if necessary);i) Other breaking machines diagram representing the results of the extra

measurements (of deformations, internal forces) executed during the pile tests; j) Breaking machines diagram representing the infiltrated water quantities and

humidity variation in time, in case of field flooding adjacent to the pile tests.

10.3 The test rapport and attachments are kept by the tests’ executioner, construction’ sdesigner and beneficiary’ s, by making part and parcel of the design documentationincluding the construction book for the respective construction.

11. MEASURES SPECIFIC FOR WORK SAFETY TECHNIQUE

11.1 All the work safety measures stipulated in ch. 12 of the Practical guideline concerningthe execution technology of pile foundations GE-029-97.

11.2 The requirements shown in art. 4.1 will be respected for the dimensioning of thereaction overtaking devices.

11.3 The effects resulted from breaking by accident of the pressure ducts of loadinghydraulic devices will be overcome by their installing inside of protection tubes.

Notes:

1. PSU- MSS MEANS MOISTURE SENSITIVE SOILS2. THE ANNEXES OF THE NORM AS WELL AS THE DIAGRAMS

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NP.045 00 Normative.as.Regards.in.Situ.test Piles.et.Fondation.piles

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