Seismic Wave Velocity Seismograph Shear Wave Surface Wave Seismic Survey Instrument Foundation Inspection Ground Microtremor Survey Seismic Imaging Seismograph
Seismic Wave Velocity Seismograph: Used to measure the velocity of seismic waves in different subsurface materials, helping to assess the soil and rock properties for engineering and geotechnical purposes, as well as for identifying potential hazards such as liquefaction-prone areas.
Shear Wave Seismograph: Utilized to determine the shear wave velocity profiles of soil and rock formations, important for assessing the material's strength, deformation characteristics, and seismic response.
Surface Wave Seismic Survey Instrument: Enables the measurement of surface wave velocities to evaluate shallow soil layers and to provide data for site response analysis.
Foundation Inspection Ground: Supports the assessment of the integrity and load-bearing capacity of foundations by evaluating the subsurface conditions, identifying potential weak zones, and assessing the likelihood of settlement.
Microtremor Survey: Conducted using microtremor measurements to characterize site-specific soil amplification effects and assess the soil's dynamic characteristics, which is crucial for seismic hazard assessments.
Seismic Imaging Seismograph: Employed to obtain detailed subsurface images, allowing for the identification of geological structures, fault lines, and potential hazards, and supporting the planning of construction projects and infrastructure development.
• Wave speed (sheared wave) survey
• Transient multifold Rayleigh wave prospecting
• Multi-wave high density seismic imaging
• Shallow refraction survey
• Foundation pile inspection
• Civil engineering quality detection
• Site constant shake survey
• Shake-to-blasting survey
| Channel number |
24 |
| Sample stations |
1024, 2048, 4096, 8192, 16384 |
| Sample frequency |
a, Generally, 10μs, 25μs, 50μs, 100μs, 200μs, 500μs, 1ms, 2ms, 5ms, 10ms, 20ms |
| b, For micro-tremor survey, 1ms ~ 200ms selectable |
| A/D converter |
24 bit |
| Signal stack and amplification |
32 bit |
| Dynamic range |
140dB |
| Frequency bandwidth |
0.1Hz ~ 4000Hz |
| Noises |
1μV(full-frequency state) |
| Amplitude consistency |
±0.2% |
| Phase consistency |
±0.01ms |
| Time lapse |
0~9999ms |
| Date format |
SEG-2 |
| Working temperature |
0ºC~50ºC, 90%RH |
| Storage temperature |
-20ºC ~ +60ºC |
The system is composed by two parts: the tablet PC and the collecting unit. The data of collecing unit is transferred to PC by USB port. Each parts is powered separtely, and the power of the collecitng unit is available to switch freely.
System software, under WINDOWS, is object-oriented, with friendly interface and easy operation. System software has powerful display function. Signals can be clearly displayed in forms of curve and in variable density style, with wave vertical or horizontal. Dynamic and static cursor can not only read absolute time of a sample but read amplitude as well; background noises are monitored at real time; what's more, it supports digital filtration and spectrum analysis.
Shear wave velocity tester is, the instrument uses hammer, electric spark or explosion as an excitation source, the exploration depth from a few meters to more than 100 meters, the use of delay function, can ensure the testing accuracy of deep formation vibration signal.
There are many vibration sources used in single-hole wave velocity test, such as blasting, air compression gun, spring-type S-wave excitation device, rocket launcher and so on
But the percussion plate excitation source is most commonly used in the field shear wave velocity test.
Percussion plate excitation source: Shear wave testing equipment - knock plate vibration source will be a piece of resilient board (board about 2 meters long, about 0.4-0.5 meters wide, 0.1 m thick) by the hammer the iron plate on the two ends of the bag, on flat ground, heavy pressure on above, the board to close contact with the ground, and then tap on both sides of the board, this board will give a horizontal force on the ground, Excite shear vibration of soil layer. The excited vibration is mainly SH wave.
Percussion plate excitation source:
Under the condition of a certain percussion impulse, the amplitude of SH wave increases with the increase of the weight on the board, but the influence decreases when it exceeds a certain value. The effect of long board is better than short board; The contact condition between the board and the ground has obvious influence on the excitation effect, and the effect can be improved if the nail teeth are nailed at the bottom of the board and water or cement slurry is poured on the ground to increase the closeness of the contact between the board and the ground.
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