CN111336931A - Special vehicle deck detonation point back dynamic displacement testing method - Google Patents

Special vehicle deck detonation point back dynamic displacement testing method Download PDF

Info

Publication number
CN111336931A
CN111336931A CN202010310539.2A CN202010310539A CN111336931A CN 111336931 A CN111336931 A CN 111336931A CN 202010310539 A CN202010310539 A CN 202010310539A CN 111336931 A CN111336931 A CN 111336931A
Authority
CN
China
Prior art keywords
displacement
deck
sensor
vehicle
impact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010310539.2A
Other languages
Chinese (zh)
Other versions
CN111336931B (en
Inventor
郭贵福
李振平
高振涛
李爱国
胡伟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China North Vehicle Research Institute
Original Assignee
China North Vehicle Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China North Vehicle Research Institute filed Critical China North Vehicle Research Institute
Priority to CN202010310539.2A priority Critical patent/CN111336931B/en
Publication of CN111336931A publication Critical patent/CN111336931A/en
Application granted granted Critical
Publication of CN111336931B publication Critical patent/CN111336931B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
    • G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

The invention discloses a method for testing dynamic displacement of the back of a detonation point of a special vehicle deck, which adopts a testing device comprising a laser displacement sensor, an impact vibration acceleration sensor, a sensor mounting auxiliary seat, a data acquisition system and a computer; the laser displacement sensor is arranged on the position of a top deck in the vehicle corresponding to the detonation point, the impact vibration acceleration sensor is arranged at the position close to the laser displacement sensor of the top deck, and the impact vibration acceleration sensor is arranged back to back at the same point inside and outside the top deck. The method adopts a mode of installing the laser displacement sensor on the top deck in the vehicle to realize the relative displacement parameter between the top deck installation point where the laser displacement sensor is located and the back of the detonation point of the tested deck, adopts a back-to-back mode to install the impact acceleration sensor to test the absolute displacement of the installation surface where the laser displacement sensor is located, obtains the actual absolute dynamic displacement parameter of the deck by a method of fusion calculation of the two, and solves the problem that the dynamic displacement cannot be measured under the explosion condition.

Description

Special vehicle deck detonation point back dynamic displacement testing method
Technical Field
The invention belongs to the field of blasting tests, and relates to a method for testing dynamic displacement of the back of a detonation point of a special vehicle deck.
Background
In the test process of the special vehicle protection capability examination, the problem that the dynamic displacement process of the deck under the explosion condition cannot be obtained is often faced, and the parameter is an important parameter for correctly simulating and guiding the design and the system protection capability evaluation and can only be replaced by an assumed displacement curve. At present, a dynamic displacement process curve can only be obtained in a simulation mode, and the reliability is not high.
In the traditional method, static displacement data is generally used for replacing dynamic displacement process data, but the static measurement is difficult to replace dynamic displacement parameters due to a certain difference in the static and dynamic displacement processes caused by the dynamic contraction process of a mechanical mechanism, and the support effect on the design is relatively limited to a certain extent.
Disclosure of Invention
The invention provides a method for testing dynamic displacement of the back of a detonation point of a special vehicle deck, which aims at the reason that a real vehicle cannot obtain a dynamic displacement process of the deck under an explosion condition.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the invention provides a special vehicle deck detonation point back dynamic displacement testing device, which comprises a laser displacement sensor, an impact vibration acceleration sensor, a sensor mounting auxiliary seat, a data acquisition system and a computer, wherein the laser displacement sensor is arranged on the back of a special vehicle deck detonation point;
welding corresponding sensor mounting auxiliary seats at positions in the vehicle corresponding to the explosion measuring points on the deck on the back surface, wherein the sensor mounting auxiliary seats are used for mounting a laser displacement sensor and an impact vibration acceleration sensor;
a data acquisition system is arranged at a position which is in a vehicle or outside the vehicle and is a safe distance away from an explosion point, and the data acquisition system is connected with the impact vibration acceleration sensor and the laser displacement sensor through cables;
and starting the data acquisition system, automatically acquiring and recording dynamic signals of the three sensors in the whole process of the data acquisition system, and copying the data to a computer for analysis and processing.
Further, the impact vibration acceleration sensor selects a charge type or ICP type acceleration sensor according to the magnitude of the impact.
Furthermore, when the data acquisition system is arranged in the vehicle, cables in the vehicle are fixed one by one along the signal transmission direction; when the data acquisition system is arranged outside the vehicle, the cable penetrates through a steel pipe firmly welded with the vehicle body and is guided into the underground outside the vehicle, and the cable is dug and buried to the data acquisition system.
The invention also provides a special vehicle deck detonation point back dynamic displacement testing method, which comprises the following steps:
the method comprises the following steps that firstly, an impact vibration acceleration sensor is reversely arranged at the same position inside and outside a vehicle top deck, and a laser displacement sensor is arranged close to the impact vibration acceleration sensor;
and step two, carrying out an explosion impact test, acquiring and recording real-time signals of the three sensors, carrying out difference processing on impact acceleration signals of the impact vibration acceleration sensors arranged back to back, carrying out zero drift removal, band-pass filtering and secondary integration on the difference signals, obtaining reference absolute displacement signals, and then fusing the reference absolute displacement signals with test data of the laser displacement test sensors to obtain the absolute displacement of the bottom deck.
Further, the second step further includes:
2.1, if the acceleration measured by the impact vibration acceleration sensor is a (t), the acceleration is integrated for one time to obtain a velocity v (t):
Figure BDA0002457437970000031
wherein, aiAcceleration sample value at the moment i, △ t is the time difference between two side samples and is the reciprocal of set sampling frequency, a0＝0；
2.2 integrating the velocity once can obtain the displacement S1:
Figure BDA0002457437970000032
wherein, a (t) is a continuous time domain impact acceleration test waveform; v (t) is a continuous time domain rate waveform; s (t) is a continuous displacement waveform; v. ofiThe rate value at time i; v. of0＝0；
2.3 calculating the actual absolute dynamic displacement of the bottom deck;
the displacement motion direction of the left bottom deck and the right bottom deck is upward due to explosion impact, and the displacement direction of the top deck is uncertain, so that when the displacement directions of the left bottom deck and the right bottom deck are the same, the left bottom deck and the top deck are in the same direction
S2+S＝S0+S1
Then, S-S0 + S1-S2
S is the actual absolute dynamic displacement of the bottom deck, S0 is a distance parameter measured by the laser displacement sensor under the static condition, and S1 and S2 are the dynamic absolute displacement of the top deck obtained by integrating the impact vibration acceleration sensor and a relative displacement signal between the top deck and the bottom deck tested by the laser displacement sensor.
When the two moving directions are opposite, then there are:
S0＝S1+S2+S
then S is S0-S1-S2.
The invention has the advantages that:
the method adopts a mode of installing the laser displacement sensor on the top deck in the vehicle to realize the relative displacement parameter between the top deck installation point where the laser displacement sensor is located and the back of the detonation point of the tested deck, adopts a back-to-back mode to install the impact acceleration sensor to test the absolute displacement of the installation surface where the laser displacement sensor is located, obtains the actual absolute dynamic displacement parameter of the deck by a method of fusion calculation of the two, and solves the problem that the dynamic displacement cannot be measured under the explosion condition.
Drawings
FIG. 1 is a schematic view of a special vehicle deck detonation point back dynamic displacement test mounting structure of the invention, and the structure comprises (a) a front view and (b) a side view.
FIG. 2 is a schematic diagram of the absolute displacement synthesis calculation of the present invention, a) the displacement directions of the top deck and the bottom deck are the same, and b) the displacement directions of the top deck and the bottom deck are opposite.
In the figure: 1 is two impact vibration acceleration sensors, 2 is an installation auxiliary seat of the impact vibration acceleration sensors, 3 is a top deck and a bottom deck, 4 is a laser displacement sensor, 5 is a sensing point of the laser displacement sensor (namely the back position of a blasting point)
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings in which:
fig. 1(a) and (b) are installation diagrams of a test sensor for testing the dynamic displacement of a deck under an explosion condition, and the test sensor comprises a dynamic laser displacement sensor and two parts of dynamic impact vibration acceleration sensors which are arranged back to back. Before testing, the laser displacement sensor is selected according to the height of the vehicle body and a possible displacement range, and the dynamic laser displacement sensor is required to have good impact resistance, high testing precision and high dynamic characteristic, so that the requirement of the dynamic displacement testing of a real vehicle can be met; according to the actual measurement result or experience, selecting an impact vibration acceleration sensor with a proper range, selecting a charge type or ICP type acceleration sensor according to the impact size, and completing the calibration of the sensor according to the requirement. The positions corresponding to the detonation points vertically are marked inside and outside the top deck and the bottom deck of the vehicle or the simulated tested box body, the laser displacement sensor is arranged on the position of the top deck in the vehicle corresponding to the detonation points, and the impact vibration acceleration sensor is arranged on the same position inside and outside the top deck of the vehicle and on a point as close as possible to the laser displacement sensor (as shown in figure 1, a sensor mounting auxiliary seat adopts novel welding arrangement, so that the sensor mounting auxiliary seat has enough strength).
Completing the preparation of an acquisition system, connecting a cable of the impact vibration acceleration sensor and a cable of the laser displacement sensor to a test system, and checking; after the signal is confirmed to be correct, welding the cable auxiliary seat along the cable routing direction, finishing cable bundling, after the signal is confirmed to be correct, starting the test system according to on-site command, and collecting and recording three real-time signals in real time when explosion is carried out
And analyzing the acquired data, carrying out difference processing on the back-to-back impact acceleration signals, carrying out zero drift removal, band-pass filtering and secondary integration on the difference signals, obtaining reference absolute displacement signals, and then carrying out fusion calculation with the test data of the laser displacement test sensor to obtain dynamic displacement parameters.
When the laser displacement sensor and the impact acceleration sensor with proper measuring range and good environmental adaptability are used for testing, the sensors are ensured to finish calibration and laboratory test before the test.
And welding corresponding sensor mounting auxiliary seats at positions corresponding to the inner positions of the deck on the back of the explosion measuring points for mounting the laser displacement sensors, arranging impact vibration acceleration sensors at positions as close as possible to the laser displacement sensors on the top deck, wherein the impact vibration acceleration sensors are required to be mounted back to back at the same point inside and outside the top deck (as shown in figure 1) and connected with cables as required.
Data acquisition system is laid apart from explosion point safe distance position in the car or outside the car, the cable begins to arrange, if adopt the car in arrange the collection system mode, collector vibration isolation measure will target in place, prevent to strike and destroy the system or make the integrated circuit board contact abnormal, if adopt the data acquisition system car to arrange the test system mode, it leaves sufficient safe distance to require the test system apart from between the explosion point, the cable should pass with the leading-in underground outside the car of automobile body welded firm steel pipe, and the ditching buries and covers cable to collector department, prevent the impact damage of explosion shock wave to the cable outside the car.
After accomplishing preliminary antithetical couplet of cable after preliminary connection and confirming that the signal is normal, begin to arrange the interior cable of car, the interior cable of car will be fixed one by one along the signal transmission direction, requires fixed firm, and the fixed clearance is preferably about with 20cm, ensures that the cable ties up firmly as far as possible, can not cause signal interference because of cable relative motion.
After the cables are arranged, the acquisition system is started again, the real vehicle verifies whether the shock vibration acceleration sensor works normally or not in a deck mode near the hammering shock vibration acceleration sensor, the amplitudes of output signals of the two sensors are the same, the signs of the output signals of the two sensors are opposite, and a mode of moving a standby sensing point is adopted to test whether the laser displacement sensor works normally or not.
The test is implemented according to a preset test scheme and steps, the acquisition system automatically acquires and records dynamic signals in the whole process, and the data is copied to a computer for analysis and processing in a later downloading mode.
The working principle of the invention is realized as follows:
under the action of explosion impact force, the body of the special vehicle starts to deform under the action of shock wave, the laser displacement sensor tests a deformation signal, but the position where the laser displacement sensor is installed also deforms under the action of the shock wave, and the reference of an installation deck of the laser displacement sensor is not the static position of an absolute zero position. The absolute displacement signal of the position can be directly tested by the secondary integration of the signals output by the back-to-back installation of the impact vibration acceleration sensors, and the dynamic displacement test is realized by testing the two signals and performing the fused post-processing.
Wherein, the acceleration measured by the impact vibration acceleration sensor is a (t) (unit m/s2), and the acceleration is integrated for one time to obtain the velocity (unit m/s):
Figure BDA0002457437970000061
the displacement (in m) can be obtained by once integrating the velocity signal:
Figure BDA0002457437970000071
wherein, a (t) is a continuous time domain impact acceleration test waveform;
v (t) is a continuous time domain rate waveform;
s (t) is a continuous displacement waveform;
aiacceleration sample value at time i, aiPerforming zero drift and band-pass filtering;
vithe rate value at time i;
a0＝0；v00 (an impact process starting with an acceleration of 0 in the explosion process)
△ t is the time difference between the two side samples, the inverse of the set sampling frequency.
In the actual calculation, the obtained acceleration is the difference between the signals of the two impact sensors arranged back to back, is a double relation of the impact signals, and is divided by 2 after the displacement is obtained.
After obtaining the test signal and the reference displacement signal of the laser displacement sensor, setting S1 and S2 as the dynamic absolute displacement of the top deck and the relative displacement signal between the top deck and the bottom deck tested by the laser displacement sensor, respectively, obtained by integrating the impact vibration acceleration sensor, the actual absolute dynamic displacement of the bottom deck is (as shown in fig. 2a) and b)):
the displacement motion direction of the left bottom deck and the right bottom deck is upward due to explosion impact, and the displacement direction of the top deck is uncertain, so that when the displacement directions of the top deck and the bottom deck are the same, the top deck and the bottom deck are always in the same state
S2+S＝S0+S1
Then, S-S0 + S1-S2
Where S is the actual absolute displacement of the bottom deck, and S0 is the distance parameter measured by the laser displacement sensor under static conditions (i.e., the distance between the top deck and the bottom deck).
When the displacement directions of the top deck and the bottom deck are opposite, the following steps are provided:
S0＝S1+S2+S
then S0-S1-S2
In actual analysis, data from 0 to the first trough in the first impact process is correctly selected as analysis data, and whether a calculation formula is adopted is judged according to the positive and negative of a displacement signal obtained by signal integration of an acceleration sensor, so that correct impact dynamic displacement is obtained (secondary displacement and impact signals exist in other data segments, and the data segments can be selected according to actual analysis requirements).

Claims (5)

1. A method for testing dynamic displacement of the back of a detonation point of a special vehicle deck is characterized by comprising the following steps: the method comprises the following steps:
the method comprises the following steps that firstly, an impact vibration acceleration sensor is reversely arranged at the same position inside and outside a vehicle top deck, and a laser displacement sensor is arranged close to the impact vibration acceleration sensor;
and step two, carrying out an explosion impact test, acquiring and recording real-time signals of the three sensors, carrying out difference processing on impact acceleration signals of the impact vibration acceleration sensors arranged back to back, carrying out zero drift removal, band-pass filtering and secondary integration on the difference signals, obtaining reference absolute displacement signals, and then fusing the reference absolute displacement signals with test data of the laser displacement test sensors to obtain the absolute displacement of the bottom deck.
2. The special vehicle deck detonation point back dynamic displacement testing method of claim 1, characterized in that: the second step further comprises:
2.1, if the acceleration measured by the impact vibration acceleration sensor is a (t), the acceleration is integrated for one time to obtain a velocity v (t):
Figure FDA0002457437960000011
wherein, aiAcceleration sample value at the moment i, △ t is the time difference between two side samples and is the reciprocal of set sampling frequency, a0＝0；
2.2 integrating the velocity once can obtain the displacement S1:
Figure FDA0002457437960000012
wherein, a (t) is a continuous time domain impact acceleration test waveform; v (t) is a continuous time domain rate waveform; s (t) is a sequential bitShifting the waveform; v. ofiThe rate value at time i; v. of0＝0；
2.3 calculating the actual absolute dynamic displacement of the bottom deck;
the displacement motion direction of the left bottom deck and the right bottom deck is upward due to explosion impact, and the displacement direction of the top deck is uncertain, so that when the displacement directions of the left bottom deck and the right bottom deck are the same, the left bottom deck and the top deck are in the same direction
S2+S＝S0+S1
Then, S-S0 + S1-S2
S is the actual absolute dynamic displacement of the bottom deck, S0 is a distance parameter measured by the laser displacement sensor under the static condition, and S1 and S2 are the dynamic absolute displacement of the top deck obtained by integrating the impact vibration acceleration sensor and a relative displacement signal between the top deck and the bottom deck tested by the laser displacement sensor.
When the two moving directions are opposite, then there are:
S0＝S1+S2+S
then S is S0-S1-S2.
3. The method for realizing the special vehicle deck detonation point back dynamic displacement test of claim 1 or 2 is characterized by comprising the following steps of: the device comprises a laser displacement sensor, an impact vibration acceleration sensor, a sensor mounting auxiliary seat, a data acquisition system and a computer;
welding corresponding sensor mounting auxiliary seats at positions in the vehicle corresponding to the explosion measuring points on the deck on the back surface, wherein the sensor mounting auxiliary seats are used for mounting a laser displacement sensor and an impact vibration acceleration sensor;
a data acquisition system is arranged at a position which is in a vehicle or outside the vehicle and is a safe distance away from an explosion point, and the data acquisition system is connected with the impact vibration acceleration sensor and the laser displacement sensor through cables;
and starting the data acquisition system, automatically acquiring and recording dynamic signals of the three sensors in the whole process of the data acquisition system, and copying the data to a computer for analysis and processing.
4. The special vehicle deck detonation point back dynamic displacement testing method of claim 3, characterized in that: the impact vibration acceleration sensor selects a charge type or ICP type acceleration sensor according to the impact size.
5. The special vehicle deck detonation point back dynamic displacement testing method of claim 3 or 4, characterized by comprising the following steps: when a data acquisition system is arranged in the vehicle, cables in the vehicle are fixed one by one along the signal transmission direction; when the data acquisition system is arranged outside the vehicle, the cable penetrates through a steel pipe firmly welded with the vehicle body and is guided into the underground outside the vehicle, and the cable is dug and buried to the data acquisition system.
CN202010310539.2A 2020-04-20 2020-04-20 Special vehicle deck detonation point back dynamic displacement testing method Active CN111336931B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010310539.2A CN111336931B (en) 2020-04-20 2020-04-20 Special vehicle deck detonation point back dynamic displacement testing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010310539.2A CN111336931B (en) 2020-04-20 2020-04-20 Special vehicle deck detonation point back dynamic displacement testing method

Publications (2)

Publication Number Publication Date
CN111336931A true CN111336931A (en) 2020-06-26
CN111336931B CN111336931B (en) 2021-12-07

Family

ID=71186716

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010310539.2A Active CN111336931B (en) 2020-04-20 2020-04-20 Special vehicle deck detonation point back dynamic displacement testing method

Country Status (1)

Country Link
CN (1) CN111336931B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102519675A (en) * 2011-12-16 2012-06-27 重庆长安汽车股份有限公司 Automobile closure member dynamic displacement test method
CN104296663A (en) * 2013-07-17 2015-01-21 英华达（上海）科技有限公司 Object size measuring system and method
KR20150068209A (en) * 2013-12-11 2015-06-19 주식회사 케이티 Apparatus and method for measuring length
CN105923015A (en) * 2016-05-04 2016-09-07 江西日月明测控科技股份有限公司 Steel rail undulatory wear mobile measurement method with vibration reduction platform as inertia displacement standard
CN107843195A (en) * 2017-11-02 2018-03-27 中铁西南科学研究院有限公司 A kind of active breaking belt tunnel structure DEFORMATION MONITORING SYSTEM and method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102519675A (en) * 2011-12-16 2012-06-27 重庆长安汽车股份有限公司 Automobile closure member dynamic displacement test method
CN104296663A (en) * 2013-07-17 2015-01-21 英华达（上海）科技有限公司 Object size measuring system and method
KR20150068209A (en) * 2013-12-11 2015-06-19 주식회사 케이티 Apparatus and method for measuring length
CN105923015A (en) * 2016-05-04 2016-09-07 江西日月明测控科技股份有限公司 Steel rail undulatory wear mobile measurement method with vibration reduction platform as inertia displacement standard
CN107843195A (en) * 2017-11-02 2018-03-27 中铁西南科学研究院有限公司 A kind of active breaking belt tunnel structure DEFORMATION MONITORING SYSTEM and method

Also Published As

Publication number Publication date
CN111336931B (en) 2021-12-07

Similar Documents

Publication Publication Date Title
CN102422154B (en) System, device for structural damage detection and method for structural damage detection
CN102011389B (en) Soil body in situ test device and test method applying same
US9903972B2 (en) Seismic cable, system and method for acquiring information about seismic, microseismic and mechanical vibration incidents in a well
CN103669428B (en) With the integrity detection system of cushion cap foundation pile
US9010176B2 (en) Scour sensor and method of using same
CN112162034B (en) Steel-concrete combined beam damage identification method applying structural noise
CN102296644B (en) Internal support of foundation pit demolition blasting vibration safety monitoring system and monitoring method
JPH10206390A (en) Method for detecting damage of covering of buried steel pipe
CN108226288B (en) Subway tunnel ballast bed void monitoring method
CN102812381A (en) Using seismic sensor transfer functions for high fidelity seismic imaging
CN106959248A (en) A kind of concrete sample damage Crack Detection experimental rig and test method
CN112663689B (en) Multi-measuring-point low-strain detection method for high-bearing-platform pile foundation
CN104019952A (en) Vibration detecting method for reactor fault diagnosis
WO2021033503A1 (en) Seismic observation device, seismic observation method, and recording medium in which seismic observation program is recorded
CN111336931B (en) Special vehicle deck detonation point back dynamic displacement testing method
CN102830165B (en) Structural-dynamic-response jacket platform damage diagnosis method
CN103774701A (en) Method for detecting completeness of high bearing platform pile under existing structure object by virtual isolation single pile method
CN109469114A (en) A kind of method for the existing foundation pile integrity of low strain integrity testing that can eliminate superstructure influence
CN106226177B (en) Extra-high voltage direct current composite wall bushing internal and external anti-seismic testing device and testing method
KR101821652B1 (en) The measurement system and method of underground conduit line
CN108240003B (en) Foundation pile detection method for existing building
CN106049567A (en) Detecting device for determining length of foundation pile by parallel earthquake method and detecting method thereof
CN103969295A (en) Method for in situ detection of corrosion degree of metal material
CN205875237U (en) Detection apparatus for foundation pile length is confirmed to parallel seismic wave method
Vitali et al. Developing a system for down-hole seismic testing together with the CPTU

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant