CN2031522U - Nondestructive shift survey for concrete pile bed - Google Patents
Nondestructive shift survey for concrete pile bed Download PDFInfo
- Publication number
- CN2031522U CN2031522U CN88212156U CN88212156U CN2031522U CN 2031522 U CN2031522 U CN 2031522U CN 88212156 U CN88212156 U CN 88212156U CN 88212156 U CN88212156 U CN 88212156U CN 2031522 U CN2031522 U CN 2031522U
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- signal
- sampling
- transducer
- stake
- dynamic
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Abstract
The utility model discloses a nondestructive shift survey for concrete pile bed, which comprises an exciter, a sensor, a controller, a sampler and a pocket computer. The mixed programmed of the machine language and the BASIC language is adopted by the pocket computer to make the sampling and the treatment integrative and continuous. The utility model has the advantages of light weight, high speed and low measurement fees.
Description
Concrete pipe base nondestructive dynamic test instrument belongs to solid material stress test field.
Along with increasing of skyscraper, bridge and large-scale civil engineering, concrete pipe base is widely used.Owing to be subjected to the influence of geologic condition and construction technology, fracture or defective such as inhomogeneous take place in concrete pipe base sometimes, thereby reduce the load force of stake.For guaranteeing construction quality, must detect pile foundation.
The pile foundation checkout equipment that uses has quiet survey and moves and survey two kinds at present.Quiet measurement equipment is by instruments such as pressure gauge, dial gauges, determines the ultimate load (being bearing capacity) of stake with the variation characteristic of load according to settling amount.Use this testing of equipment, the time is long, the testing expense height, and after tested, pile foundation sustains damage.Comparatively influential in the moving measurement equipment is hydroelectric effect method equipment, and it is made up of a plurality of instruments such as nautical receiving set, magnetic recording instrument, storer, spectrum analyzer and processor systems.It carries out the in-site modeling record by nautical receiving set, magnetic recording instrument, again through information processings such as indoor playback, sampled digitalization, deductions.Just can obtain a result in minimum like this 1-2 of taking days.And during playback, will produce error unavoidably, and make result inaccurate, equipment set expense height needs high pressure (volt up to ten thousand) during exciting, dangerous.
In order to improve peg speed, instrument is easy to carry, can accomplish site disposal, the ad hoc the utility model of having counted.
The utility model--concrete pipe base nondestructive dynamic test instrument is formed (figure one) by exciting device 3, signal transducer 4, controller 5, sampling thief 6, pocket computer 7.2 is pile foundation to be measured among the figure one, and 1 is stake limit soil.(exciting mode is mechanical exciting by exciting device stake to be applied an acting force, acting force can be transient state and like transient state), signal transducer is in order to receive the response of stake under the effect of power, mechanical vibration wave is changed into electric signal be input to controller, power according to input signal, select the different sensitivity of controller for use, signal is input to sampling thief with suitable amplitude.By pocket computer control sampling thief that continuous electric is signal digitalized, store, handle, infer by pocket computer then, the parallel machine print result.Among the figure one, signal transducer can be selected speed pickup for use as 65 type electromagnetic type seismic pendulums, 64 type seismic pendulums, JJS-10A(CD-2, CDJ-Z27 by the size of exciting force) wave detector, also usable acceleration sensor, displacement transducer.When sensor is output as electric charge, should after sensor, add a charge amplifier.Controller is by signal setting on-off circuit (R
1, R
2, switch AB) and signal control circuit (R
3～R
8) composition (figure two).According to the power of input signal CD, regulate R
6, R
7Can regulate the output amplitude of electric signal, regulate R
3, R
4, R
5The level of may command signal, the control of the break-make of switch AB is preset the sampling time, presets sampling number, thereby before forces are applied, makes pocket computer enter sample states in stake, and generally presetting the sampling time is 0.3ms～3ms, is advisable to adopt 1～10 of ignore.As long as pocket computer has the storage area that can use for the user as more than the 10K byte, and have drawing function all can, as PC-1500, PC-1500A, PC-1501PC-1600, PB-700 pocket computer.The pocket computer program adopts the method design of machine language and BASIC hybrid programming, to satisfy the needs that data acquisition faster and FFT calculate, draw, program design block scheme such as figure three respectively.Sampling period is designed in 100us～10s, is best with 300～500us.The serial port of pocket computer also is connected to printer, and result is printed.Whole process just can be finished in 30 minutes.
Characteristics of the present utility model are:
1. can observe and write down pile foundation vibration time-domain curve, and be converted into frequency curve;
2. when calculating frequency curve, spectral amplitude, power spectrum, phase spectrum, simple crosscorrelation can be selected to calculate as required, and different spectral windows can be added according to the difference interference;
3. judge pile foundation damaged degree, the damaged face degree of depth and bearing capacity;
4. the instrument cost is low, compares with the instrument combination of identical function and precision, and cost is hanged down 1/3-1/10;
5. instrument is light, people's portability, and testing expense is low, and speed is fast;
6. this dynamic tester also can be used for measuring the frequency of other mechanical vibration.
Embodiment:
In certain building site to No. 1 stake, place sensor on the smooth pile crown and make it fixing, with weight as exciting device, sensor uses 65 type electromagnetic type seismic pendulums, and the sampling preset time is 3ms, and switch AB makes with carbon rod, place the top of stake, when weight hammering stake, strike off carbon rod earlier, before being put, pocket computer is in sample states.Regulate carbon rod to distance just scalable preset the sampling time; Sampling period is 300us; Pocket computer prints sampling curve after beginning half a minute from hammering stake face--and time-domain curve (figure four), then calculate frequency spectrum, and print frequency curve (figure five).After input stake, the native parameter about one minute, it was 25.6 tons that pocket computer prints bearing capacity of pile foundation F.By formula
J=T/2 * V(T is the time that reflection wave occurs, and V is the velocity of wave at this place)
Get L=4.8 rice (table one).
This stake is measured with hydroelectric effect method, and bearing capacity is 28 tons, and the damaged face degree of depth is 5.4 meters, and getting bearing capacity with quiet survey method is 26 tons.
Table one:
| Stake long (m) | Stake diameter (m) | Bearing capacity (T) | The time (ms) that reflection wave occurs | Velocity of wave (m/s) | The damaged degree of depth (m) |
| 8.1 | 0.35 | 25.6 | 3.7 | 2575 | 4.8 |
2. above-mentioned condition is constant, in certain building site different three stake A, B, C and quiet survey method is compared test, result such as table two.
Table two:
| Pile No. | Stake long (m) | Stake diameter (m) | Static pressure bearing capacity (T) | Dynamic tester bearing capacity (T) | Design bearing capacity (T) |
| A | 9.2 | 0.35 | 15 | 15.1 | 15 |
| B | 5.8 | 0.35 | 14 | 14.6 | 20 |
| C | 9.0 | 0.35 | ＞20 | 28 | 20 |
3. the utility model also can be used to try to achieve the transport function of pile foundation, and reportedly delivery function is inferred pile foundation damaged degree, the damaged face degree of depth and bearing capacity again.As figure seven, additional force transducer on exciting device, pocket computer can be for the storage area of user's use more than the 18K byte.Under the effect of controller, the response in pile body when vibration and exciting force signal enter sampling thief by people having a common goal not.Through signal digitalized, fft analysis, calculating and analysis transport function, can obtain damaged degree, the damaged face degree of depth and bearing capacity.In this test, replace force transducer with acceleration transducer, as figure six, also can obtain same result.
Description of drawings:
Figure one: the utility model block scheme
Figure two: the circuit diagram of controller, sampling thief
Figure three: the pocket computer flow chart
Figure four: pile foundation vibration time-domain curve
Figure five: pile foundation vibration frequency curve
Figure six: when adopting transport function, and connection layout of the present utility model.9 is acceleration transducer among the figure, and 8 is charge amplifier
Figure seven: when adopting transport function, and connection layout of the present utility model.10 is force transducer among the figure
Claims (6)
1, concrete pipe base nondestructive dynamic test instrument, it is characterized in that, the utility model comprises makes the vibrative exciting device of pile foundation, make the signal transducer of pile foundation vibration stress response becoming electric signal, the signal controller of selective sensitivity, control sampling preset time and stabilization signal level, make the signal digitalized sampling thief of continuous electric, and the control complete machine makes it carry out the pocket computer of data acquisition, storage, processing.
2, dynamic tester according to claim 1 is characterized in that, signal transducer can be speed pickup, acceleration transducer, displacement transducer.
3, dynamic tester according to claim 1 and 2 is characterized in that, exciting device is the mechanical hook-up that stake is applied an acting force, or with force transducer stake is applied the mechanical hook-up of an acting force.
4, dynamic tester according to claim 1 is characterized in that, controller is by R
1, R
2Signal setting on-off circuit, R with initialize switch AB composition
3～R
8The signal control circuit of forming is formed.
According to claim 1 or 4 described dynamic testers, it is characterized in that 5, the preset time of signal setting switch is 300us～3000us.
6, dynamic tester according to claim 1 is characterized in that, the sampling period of sampling thief is 100us～10s, and sampling resolution is not less than 1/256.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88212156U CN2031522U (en) | 1988-02-06 | 1988-02-06 | Nondestructive shift survey for concrete pile bed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88212156U CN2031522U (en) | 1988-02-06 | 1988-02-06 | Nondestructive shift survey for concrete pile bed |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2031522U true CN2031522U (en) | 1989-01-25 |
Family
ID=4845495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN88212156U Expired - Lifetime CN2031522U (en) | 1988-02-06 | 1988-02-06 | Nondestructive shift survey for concrete pile bed |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2031522U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102877490A (en) * | 2012-09-18 | 2013-01-16 | 河海大学 | Method for detecting quality of large-diameter tubular pile at low strain |
| CN103088849A (en) * | 2013-01-09 | 2013-05-08 | 山东正元地理信息工程有限责任公司 | Method of in-service bridge foundation pile stress wave back wave nondestructive testing |
| CN111272586A (en) * | 2020-02-22 | 2020-06-12 | 江苏东南特种技术工程有限公司 | Method for detecting vertical load of existing building structure by exciting vibration force |
-
1988
- 1988-02-06 CN CN88212156U patent/CN2031522U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102877490A (en) * | 2012-09-18 | 2013-01-16 | 河海大学 | Method for detecting quality of large-diameter tubular pile at low strain |
| CN102877490B (en) * | 2012-09-18 | 2014-06-11 | 河海大学 | Method for detecting quality of large-diameter tubular pile at low strain |
| CN103088849A (en) * | 2013-01-09 | 2013-05-08 | 山东正元地理信息工程有限责任公司 | Method of in-service bridge foundation pile stress wave back wave nondestructive testing |
| CN103088849B (en) * | 2013-01-09 | 2016-04-06 | 山东正元地理信息工程有限责任公司 | A kind of servicing bridges foundation pile stress wave echo lossless detection method |
| CN111272586A (en) * | 2020-02-22 | 2020-06-12 | 江苏东南特种技术工程有限公司 | Method for detecting vertical load of existing building structure by exciting vibration force |
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| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CX01 | Expiry of patent term |