CN101532930A - Pile model power-cycle test system - Google Patents

Abstract

The invention relates to a pile foundation research test system, in particular to an indoor pile model power-cycle test system. The test system comprises a model groove, a pressure frame, a loading device, a signal generating system and a data collecting device. The model groove adopts a bigger-scale steel groove provided with a waterproof bottom structure and a water-injection pipe arranged at the center of bottom; a plurality of round bolt holes used for lifting the model groove and fixing a counterforce frame are equally arranged on the notch; the loading device is connected and fixed with the model groove by the pressure frame to apply load to a pile body; and the data collecting device is connected with the loaded pile body by the signal generating system to obtain test data. The invention adopts the bigger-scale test groove to eliminate the 'model casing effect' generally existing in model test to the maximum extent; and the invention simultaneously integrates the loading device with high precision and long-term stability with measurement devices so as to actually and precisely reflect the change of each actually measured parameter in the model test process.

Description

Pile model power-cycle test system

Technical field

The present invention relates to a kind of pile foundation scientific research and testing system, relate in particular to indoor model stake power-cycle test system.

Background technology

At present, in the research of carrying out underground pile foundation, model test is the research means of widely using.Along with in recent years contour, big, dark such as offshore oil drilling platform, large-scale hoisting machinery factory building, high-speed railway and high voltage power transmission tower, rebuild a large amount of constructions that (structure) builds thing, building (structure) builds the load that foundation pile bears and no longer only is confined to static load, also bear the effect of dynamic loads such as huge storm load, wave load, mechanical load, vehicular load and wind load, it is stressed often to have following characteristics: (1) cyclic load frequency is lower; (2) time of Jia Zaiing is shorter relatively; (3) foundation pile cyclic shift amplitude is big.Therefore, in the aforementioned great advanced buildings or structures of introducing are built, when carrying out the pile bearing capacity design, in answering compliant, the relevant requirement of static load, be necessary to consider the cyclic load effect.

In pile foundation engineering, need cost great amount of manpower and material resources and time owing to carry out the test of a clump of piles or single pile, or can't carry out in-situ test because of the restriction of factors such as site condition.In this case, model test a kind of effective ways of becoming research, explore and dealing with problems.The model test of stake is the actual working state according to pile foundation, carry out comprehensively design rationally, set up the model that has the similarity rule with original shape, by scientific instrument and equipment, artificial control test condition, the test of the stress deformation characteristic of research pile foundation when a certain or some situation.It all occupied an important position in theoretical research application, design and the construction stage on dress basis.It not only provides test figure and testing and verification for the theoretical research of pile foundation, and for engineering design provide according to so that instruct engineering practice.

The model test of similarity criterion is satisfied in research, exploitation, and is significant to academic research and engineering construction.The cardinal rule of model test is to make model and original shape have comprehensive similarity, i.e. the law of similitude of model test.It is with each physical quantity of model test by certain relationship together, with the actual original shape of comprehensive representative.The law of similitude commonly used has mechanical similitude and geometric similarity.Usually dimensional method is used for the experimental study of scale model, can be used to determine similar judgement, carry out modelling.

There is following limitation in the equipment that former studies is used: the first, the size of model groove is less, and the steel tank of general size is difficult to simulate actual infinitely-great strata condition and mechanical characteristic thereof, thereby can not reflect truly that actual Pile Soil interacts.If carry out prototype stake or on-the-spot model test, expense costliness and test condition are often unstable, are difficult to obtain satisfied test findings; The second, static(al) research can accurately load by counterweight, yet the loading equipemtn that power research institute uses is inadequate slightly on control accuracy and long-time stability.

Summary of the invention

The objective of the invention is to develop a kind of pile model power-cycle test system that supplies scientific research to use, it not only can accurately control the loading environment of test, obtain high-precision measurement result, in reducing to greatest extent to test in the past because too for a short time " the model casing effect " brought of model casing size, and have reliable long-time stability, can be used in the experimental study of longer cycle.

For reaching above purpose, solution of the present invention is:

Pile model power-cycle test system, comprise model groove, pressure frame, charger, signal generating system and data collector, charger is connected and fixed by pressure frame and model groove, to the pile body load application, data collector links to each other with stressed pile body by signal generating system, records test figure.

Further, the bottom of this model groove is a waterproof construction, and is provided with filling pipe at bottom centre position, and notch evenly is furnished with a plurality of lifting of model groove and fixing circular bolt holes of reaction frame of being used for.

This model groove is the cylindrical shape steel tank, and its diameter is greater than the stake footpath of 5 times of Model Pile, and degree of depth stake above a times is long.

This charger is improved C.K.C circulation triaxial apparatus, and it has adopted long high-pressure air duct spare and range ability to be applicable to pressure transducer under the elevated pressures.

This charger adopts stingy cylinder control can reach high control precision by the cylinder control loaded, adopts big cylinder control then can reach maximum exciting force 10kN.

Signal generating system comprises strain amplifier, pressure transducer, displacement transducer, foil gauge, and pressure transducer, displacement transducer and foil gauge are located under the cylinder, and will record signal and amplify by strain amplifier.

Strain amplifier connects two compensating plates and two built-in testing sheets are formed full-bridge circuit, test figure is amplified and sends coupled data collector to.

This compensating plate is located on the alternate model pile body of non-stress, and is embedded in stressed pile body at a distance.

Owing to adopted such scheme, the present invention has following characteristics: the present invention has adopted bigger model test groove, can reduce ubiquitous in the model test " model casing effect " to greatest extent, and simultaneously integrated charger and measuring equipment with high precision and long-time stability, can accurately reflect the variation of respectively surveying parameter in the model test process really, have great importance carrying out rigorous scientific research.In addition, by the aqueous conditions of filling pipe control experiment, can select full water test or dry ground test flexibly.

Description of drawings

Fig. 1 is a reaction frame main backstop left side TV structure synoptic diagram.

Fig. 2 is for connecting the steel plate structure synoptic diagram of reaction frame and charger.

Fig. 3 is a reaction frame main backstop plan structure synoptic diagram.

Fig. 4 is the main TV structure synoptic diagram of the reaction frame behind the installation steel plate.

Fig. 5 is the plan structure synoptic diagram of the reaction frame behind the installation steel plate.

Fig. 6 is the left TV structure synoptic diagram of the reaction frame behind the installation steel plate.

Fig. 7 is the plan structure synoptic diagram of embodiment of the invention pilot system.

Fig. 8 is the main TV structure synoptic diagram of embodiment of the invention pilot system.

Fig. 9 is the left TV structure synoptic diagram of embodiment of the invention pilot system.

Figure 10 is full-bridge circuit figure of the present invention.

Figure 11 is a YEC DASP data acquisition system (DAS).

Figure 12 is a pilot system synoptic diagram of the present invention.

Figure 13 is sand (saturated) static load Q-S curve.

Figure 14 is sand (saturated) static load S-log (t) curve.

Figure 15 be sand (saturated, 50%Qus) loading-cyclic curve.

Figure 16 is load-cyclic curve (part).

Figure 17 be sand (saturated, 50%Qus) displacement-cyclic curve.

Figure 18 is sedimentation-cyclic curve (part).

Figure 19 be sand (saturated, 50%Qus) Q-S curve.

Figure 20 is that (saturated, 50%Qus) Q-S curve preceding 20 circulates sand.

Reference numeral: 1, steel tank 2, reaction frame main backstop 3, steel plate 4, bolt hole

Embodiment

The present invention is further illustrated below in conjunction with the accompanying drawing illustrated embodiment.

1, dimensional method principle

The kind that physical quantity belongs to becomes the dimension of this physical quantity.The basic dimension of using has seven at present, is respectively: length, quality, time, electric current, temperature, quantity, luminous intensity.Be separate between them.In the dynamics problem, use length L, these three basic dimensions of mass M and time T.Statics lacks a time T as basic dimension than it.The physical quantity of different dimensions can not be carried out plus and minus calculation, and its every dimension of adding and subtracting of any one correct physical equation is necessarily identical, the concordance of dimension that Here it is, and it is the basis of dimensional analysis.

The physical equation of any dimension harmony all can be expressed as one group of function between the dimensionless group, and the number that the number of the dimensionless group of composition equals to influence the physical quantity of this process deducts the number of the basic dimension that is used to represent these physical quantitys.Dimensional method is used for the experimental study of scale model, can be used to determine similar judgement, carries out modelling.Concrete method is called Buckingham theorem, thes contents are as follows:

If physical equation

f(q ₁，q ₂，…，q _n)＝0 (1)

Contain n physical quantity altogether, wherein have k to be fundamental quantity, and keep the concordance of dimension, then this irrational equation can be reduced to

F(1，1，…，1，π _k+1，π _k+2，…，π _n)＝0 (2)

π in the formula _K+1, π _K+2..., π _nBe long-pending by the dimensionless that physical quantity constituted in the equation, i.e. criterion of similarity.In the formula,

${\mathrm{\&pi;}}_m=\frac{q_m}{q_1^{x_{m1}}{q}_2^{x_{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="A200810034655E00121.png,A200810034655E00122.png"\; state="\{\{state\}\}">m</figure-callout>}2}}\&CenterDot;\&CenterDot;\&CenterDot;q_k^{x_{\mathrm{mk}}}},m=k+1,k+2,\&CenterDot;\&CenterDot;\&CenterDot;,n---\left(3\right)$

The general step of 2, dimensional analysis method:

Find out all independent factors that influence a certain physical phenomenon by test, write out the generic function relational expression;

Determine k fundamental physical quantity and basic dimension thereof;

Write out n-k the dimensionless group that other each physical quantity is formed with this k fundamental physical quantity respectively successively by formula (3);

List the harmonious system of equations of dimension according to the harmonious principle of dimension, simultaneous solution is determined undetermined parameter x _1m, x _2m..., x _Km, draw the concrete form of each dimensionless group;

According to The above results, write out accurate number correlation.

3, concrete calculation procedure

(1), list model test correlation parameter expression formula according to similarity criterion:

f(σ，ε，E，μ，l，ρ，a，P，T)＝0 (4)

Parameter is respectively in the following formula: σ stress; The ε strain; The E elastic modulus; The μ Poisson ratio; L length; ρ density; The a acceleration; P power; The T time.

(2) selecting length l, density p, acceleration a is fundamental quantity group's physical quantity, and its dimension is respectively: L, M/L ³, L/T ², satisfy separate and occur once condition at least.

${\mathrm{\&pi;}}_1=\frac{\mathrm{\&sigma;}}{l^{\mathrm{\&alpha;}}{\mathrm{\&rho;}}^{\mathrm{\&beta;}}{a}^{\mathrm{\&chi;}}}=\frac{{\mathrm{FL}}^{-2}}{L^{\mathrm{\&alpha;}}{(M/L^3)}^{\mathrm{\&beta;}}{(L/T^2)}^{\mathrm{\&chi;}}},$ If this formula of wanting becomes dimensionless group, α=1 must be arranged, β=1, x=1.So have ${\mathrm{\&pi;}}_1=\frac{\mathrm{\&sigma;}}{\mathrm{l\&rho;a}},$ Can get C _σ=C _lC _ρC _a

π ₂=ε has C _ε=1.

${\mathrm{\&pi;}}_3=\frac{E}{l^{\mathrm{\&alpha;}}{\mathrm{\&rho;}}^{\mathrm{\&beta;}}{a}^{\mathrm{\&chi;}}}=\frac{M/\left({\mathrm{LT}}^2\right)}{L^{\mathrm{\&alpha;}}{(M/L^3)}^{\mathrm{\&beta;}}{(L/T^2)}^{\mathrm{\&chi;}}},$ Obtain ${\mathrm{\&pi;}}_3=\frac{E}{\mathrm{l\&rho;a}},$ Can get C _E=C _lC _ρC _a

π ₄=μ has C _μ=1.

${\mathrm{\&pi;}}_5=\frac{P}{l^{\mathrm{\&alpha;}}{\mathrm{\&rho;}}^{\mathrm{\&beta;}}{a}^{\mathrm{\&chi;}}}=\frac{M{\mathrm{LT}}^{-2}}{L^{\mathrm{\&alpha;}}{(M/L^3)}^{\mathrm{\&beta;}}{(L/T^2)}^{\mathrm{\&chi;}}},$ Obtain ${\mathrm{\&pi;}}_5=\frac{\mathrm{<figure-callout\; id="3"\; label="P\; l"\; filenames="A200810034655E00121.png,A200810034655E00122.png"\; state="\{\{state\}\}">P</figure-callout>}}{l^{}},$ Can get $C_P=C_l^3{C}_{\mathrm{\&rho;}}{C}_a.$

${\mathrm{\&pi;}}_6=\frac{T}{l^{\mathrm{\&alpha;}}{\mathrm{\&rho;}}^{\mathrm{\&beta;}}{a}^{\mathrm{\&chi;}}}=\frac{T}{L^{\mathrm{\&alpha;}}{(M/L^3)}^{\mathrm{\&beta;}}{(L/T^2)}^{\mathrm{\&chi;}}},$ Obtain ${\mathrm{\&pi;}}_6=\frac{T}{l^{0.5}{a}^{-0.5}},$ Can get $C_T=\sqrt{C_l/C_a}.$

(geometric similarity compares C according to intending selected parameter _l, density ratio of similitude C _ρ, modulus ratio of similitude C _E), can determine other ratio of similitude C _a, C _σ, C _P, C _T, can obtain each ratio of similitude of model test like this.According to these ratio of similitude, the just tentatively loading environment of confirmed test, cast material etc.

4, test model groove and reaction frame

In model test, can only in the container of finite size, simulate unlimited stratum.Because the effect of piling soil compaction, the soil body are subjected to the pile body extruding and produce side direction and vertical distortion, make the mechanical characteristic of stake soil can be subjected to the influence of smaller container wall restriction.Therefore, must select bigger container to simulate unlimited stratum as far as possible, to reduce the adverse effect that boundary effect is brought, its diameter will surpass the stake footpath of 5 times of Model Pile at least.In addition, according to the pile foundation engineering experience, select for use the degree of depth of steel tank should stake long above one times.

What this test was adopted is cylindrical shape steel tank 1, and this steel tank 1 usefulness 30mm steel plate is made.Internal diameter is 1.6m, and the degree of depth is 1400mm in the groove, and groove highly is 1600mm outward.This cylindrical shape steel tank 1 can overcome " model casing effect " adverse effect to greatest extent.The notch of cylindrical shape steel tank has evenly been arranged 40 circular bolt holes 4, is used for the lifting of steel tank and fixing reaction frame.

Reaction frame is the equipment that is used for connecting the charger of steel tank and C.K.C circulation triaxial apparatus, is a most key link in the total system exploitation, the foundation of design reaction frame mainly contain following some:

(1) can provide enough counter-forces, guarantee the basic demand of charger operate as normal.

(2) the test accuracy requirement is satisfied in the distortion of self.Because this test has higher requirement to the measurement of distortion, therefore the reaction frame as benchmark must be able to guarantee from the distortion that is produced when loading much smaller than the displacement of stake top.

(3) be easy to the position of installing and can guarantee to install.

(4) testing requirements under satisfied different loading and the varying environment.Because the load test elapsed-time standards may be more of a specified duration, particularly in summer, daytime and night the temperature difference bigger, so himself distortion under temperature effect will be taken into account especially.

In conjunction with testing experience in the past, and after using finite element software to carry out computational analysis, determine the design drawing of reaction frame such as Fig. 1-shown in Figure 6.And choose model be 20 standard channel-section steel as reaction frame main backstop 2 (as Fig. 3), what connect main backstop and C.K.C charger is that steel plate 3 (as Fig. 2) and 2 500mm of 2 410mm * 246mm * 28mm grow the screw mandrel of diameter 36mm.Calculate this reaction frame and under the effect of 2000N pressure, be out of shape, can satisfy the accuracy requirement of test fully less than 0.01mm.

Water-proofing treatment is carried out in the steel tank bottom, and preset filling pipe in the trench bottom center.Make it slowly inject steel tank by the control rate of water injection, can make the soil body evenly saturated, can be used to carry out the experimental study of saturated soil from the bottom filling pipe.Also can arrange that highly sensitive hole presses meter in stake week, the variation of analysis cycle loading procedure mesoporosity hydraulic pressure and to the influence of Pile Soil interphase interaction.

5, test loads and opertaing device

C.K.C circulation triaxial apparatus is indoor geotechnological triaxial test instrument, is used for surveying the parameters such as modulus at rapid deformation, damping ratio and liquefaction strength of soil.Now the Pneumatic loading of the C.K.C circulation triaxial apparatus that California, USA geotechnique instrument company is made is reequiped, as the loading equipemtn of this system.C.K.C circulation triaxial apparatus has adopted long high-pressure air duct spare among the present invention, make C.K.C circulation triaxial apparatus under the air pressure of the highest 1MPa, to work, and the gases at high pressure transmission range also increases to 50m by original 2m, has expanded its working range and safety coefficient greatly.Because first wife's pressure transducer limit of range is not suitable for the model test under the elevated pressures effect, so used following JHBS6010 type pressure transducer to replace first wife's pressure transducer, range extends to 200kg by 25kg.C.K.C circulation triaxial apparatus uses little cylinder can reach high control precision by the cylinder control loaded, and its maximum exciting force is 0.25 times of big cylinder, and the maximum exciting force that uses big cylinder to reach is 10kN (these two cylinders are standard fitting); Can apply static load and dynamic load, dynamic load can be various ways such as square wave, harmonic wave, triangular wave, and frequency is 0-2Hz; Precision can be controlled in 0.1% of instrument load, displacement maximum range, and the maximum range of load and displacement is respectively 2000N, 25mm.No matter be waveform, frequency and the size that loads, all can satisfy the loading needs of test preferably.Therefore choose the loading equipemtn of its subelement, structural drawing such as Fig. 7-Fig. 9 after by reaction frame charger and model test groove being fixed as test.

6, test figure collecting device

Size, the displacement of Model Pile top and the model pile body strain curve of loading can be measured and write down to pilot system in real time.Mainly form by signal generating system and data acquisition system (DAS).Signal generating system comprises strain amplifier, sensor (pressure transducer, displacement transducer, foil gauge).Data acquisition system (DAS) comprises data acquisition unit, computer and data acquisition software.The pressure transducer that adopts is that the range of JHBS6010 type is the pressure transducer of 200kg, has disposed transmitter to improve the sensitivity of signal.The input bridge is pressed and is 12V, and output signal is 5V.Synthesis precision is 0.1% (FS).

Displacement transducer adopts the high precision inductance type dynamic displacement sensor of C.K.C itself.Sensitivity is 600mV/mm, and maximum range is 50mm.

The strain amplifier that adopts is the YE-3817C type strain amplifier that Jiangsu Lianneng Electronic Technology Co., Ltd. (former Yangzhou Er Chang) makes, data collector is the Ua302 collector, connect stressed stake by YE-20093 bridge box, connect two compensating plates and two built-in testing sheets and form full-bridge circuit, as Figure 10.Insert data collector by strain amplifier by special-purpose seven core terminals.Do like this and both eliminated the influence of temperature variation the model strain, again can amplifying signal.Wherein, A, D are test pieces, and B, C are compensating plate, and compensating plate is attached on another root Model Pile, and are embedded in distance loading stake at a distance.The amplification voltage signal that obtains is:

$U_o=\frac{{\mathrm{<figure-callout\; id="2"\; label="KU\; i"\; filenames="A200810034655E00121.png,A200810034655E00122.png"\; state="\{\{state\}\}">KU</figure-callout>}}_i}{2}\mathrm{\&epsiv;}$

Wherein, K is the sensitivity coefficient of foil gauge.The foil gauge that can select different sensitivity according to demand is to reach best test effect.

Each physical quantity gathers 11 by YEC DASP data acquisition system (DAS) in the test.This system is made up of computer, Ua302 data acquisition box, YE3817C dynamic strain amplifier and data acquisition software.

In system when operation,, the signal after amplifying through the YE3817C dynamic strain amplifier imports computer into by the Ua302 data acquisition box, then can show, write down, preserve by acquisition software and analyze the test figure that collects.

7, test apparatus using method

The model test system architecture as shown in figure 12.Air compressor provides power for pneumatic cylinder, the size of automatically controlled pressure regulator valve control loaded and cycle.Be positioned at pressure transducer under the pneumatic cylinder, measure electric signal that the foil gauge of the displacement transducer of stake top sedimentation and pile body produces, by signal picker signal is sent into computer again by behind the strain amplifier amplifying signal.Needed to carry out the demarcation of each sensor before on-test.

According to the test needs, in model test groove, put into test in advance with soil, treat after its fixed finishing the Model Pile of making to be buried to the precalculated position.

According to similar law and in conjunction with the test experience, determine the loading environment of model test, comprise cycle, the size of loading, and definite CYCLIC LOADING number of times.

Open air compressor, will load size by automatically controlled pressure regulator valve and be adjusted to the test plan size, the loading waveform that selection needs is set loading frequency.

Open data acquisition software, setting recording file, opening entry data.The operation loading equipemtn loads behind the data opening entry.

Embodiment:

1, saturated sand slow test

By the sand in the main water pipeline saturation testing groove, and by leaving standstill its excess pore water pressure dissipation of 15 angels, sand is fixed.

By counterweight Model Pile is loaded then, obtain the saturated sand static(al) and load settling time statistics of features table (table 1), and load time Q-S curve (Figure 13) and settling time logarithm S-log (t) curve (Figure 14).The ultimate bearing capacity that can determine saturated sand is 500N.

Table 1 sand (saturated) static(al) loads the settling time statistics of features

2, saturated sand dynamic test

The ultimate bearing capacity of single pile of determining according to the static(al) load test, and dynamic test load applying method, can obtain estimating constant dead load Qm is 125N, and the size of cyclic load Qc in each group experiment.Can determine the loading scheme such as the following table of this test.

Table 2 sand (saturated) power cycle test loading scheme

Cyclic load is than (Q c/Q us)	Actual dynamic load size (N)	Loads change scope (N)	Cycle index (inferior)
				0.500	250	125—375	>2000

Loading dead load part size is 125N, and cyclic load is 250N, and cycle period is 120s.Cycle index is about 1600 times, and the global cycle load time is about 54 hours.The loaded cycle curve uses triangular wave for loading waveform as shown in figure 15.Because it is more to load number of times, curve is closeer.Choose the local amplification of loading curve and can see the actual loaded waveform as shown in figure 16.

As seen from Figure 17, through about 1600 CYCLIC LOADING, stake top maximum settlement reaches 20.178mm.Choose the local amplification of subsidence curve and can obtain actual subsidence curve waveform as shown in figure 18.In the process of the test, along with the increase of cycle index, the speed of sedimentation reduces gradually, because the test cyclic load is bigger, subsidence curve does not finally tend towards stability, but keeps the slope of an approximately constant.Actual subsidence curve is in conjunction with Figure 15 and 16, and what obtain is exactly the Q-S curve of Figure 19, and Figure 20 is preceding 20 circulations of Q-S curve, and the hysteresis circle of this figure loads one, it is more obvious to load two hysteresis circle, and lines are rule more.The hysteresis circle that circulation several times produces before same is bigger, and along with the further densification of the soil body, the stake top displacement that circulation each time can produce has the trend that reduces, but the accumulative total displacement still can produce continuous increase.

The above-mentioned description to embodiment is can understand and apply the invention for ease of those skilled in the art.The person skilled in the art obviously can easily make various modifications to these embodiment, and needn't pass through performing creative labour being applied in the General Principle of this explanation among other embodiment.Therefore, the invention is not restricted to the embodiment here, those skilled in the art should be within protection scope of the present invention for improvement and modification that the present invention makes according to announcement of the present invention.

Claims (8)

1, a kind of pile model power-cycle test system, it is characterized in that: comprise model groove, pressure frame, charger, signal generating system and data collector, charger is connected and fixed by pressure frame and model groove, to the pile body load application, data collector links to each other with stressed pile body by signal generating system, records test figure.

2, pile model power-cycle test system as claimed in claim 1, it is characterized in that: the bottom of this model groove is a waterproof construction, and be provided with filling pipe at bottom centre position, notch evenly is furnished with a plurality of lifting of model groove and fixing circular bolt holes of reaction frame of being used for.

3, pile model power-cycle test system as claimed in claim 1 is characterized in that: this model groove is the cylindrical shape steel tank, and its diameter is greater than the stake footpath of 5 times of Model Pile, and degree of depth stake above a times is long.

4, pile model power-cycle test system as claimed in claim 1 is characterized in that: this charger is improved C.K.C circulation triaxial apparatus, and it has adopted long high-pressure air duct spare and range ability to be applicable to pressure transducer under the elevated pressures.

5, pile model power-cycle test system as claimed in claim 1 is characterized in that: this charger adopts stingy cylinder control can reach high control precision by the cylinder control loaded, adopts big cylinder control then can reach maximum exciting force 10kN.

6, pile model power-cycle test system as claimed in claim 1, it is characterized in that: signal generating system comprises strain amplifier, pressure transducer, displacement transducer, foil gauge, pressure transducer, displacement transducer and foil gauge are located under the cylinder, and will record signal and amplify by strain amplifier.

7, pile model power-cycle test system as claimed in claim 6 is characterized in that: strain amplifier connects two compensating plates and two built-in testing sheets are formed full-bridge circuit, test figure is amplified and sends coupled data collector to.

8, pile model power-cycle test system as claimed in claim 7 is characterized in that: this compensating plate is located on the alternate model pile body of non-stress, and is embedded in stressed pile body at a distance.

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