All-in One system MCHA Cross-Hole Tester is an Ultrasonic Cross-Hole testing kit , also referred to Ultrasonic Crosshole Sonic Logging system . MCHA is used for a common test for concrete foundations , where tubes are cast into the concrete during construction so that a series of tests can be carried out between pairs of tubes. The transmitter and receiver Probes are lowered and transit time and energy is measured for high resolution , accurate and reliable assessment for integrity of deep foundation elements.
Uniform and good quality concrete will allow propagation of ultrasonic waves. Should the ultrasonic wave travel time be longer and energy measured be of a lower amplitude correspond to poor quality or concrete or concrete with voids. A complete loss in signal means a substantial void is hindering the transfer of the signal between the hydrophones.
The All-in-One MCHA is accordingly utilised for Quality Assurance testing of newly constructed critical drilled shaft foundations , auger cast piles and slurry walls. Ultrasonic cross-hole testing is designed for checking posts and diaphragm, cavities / faults and seepages detection. The CSL test procedure using MCHA All-In-One ultrasonic crosshole testing kit can detect anomalies inside concrete within just minutes. All-in-One MCHA s a rugged and reliable equipment with various dedicated piezoelectric sensors and probe that is characterized by an A/D board multichannel and selectable sampling rates from 1OOHz – 10 MHz. All acquired signals are displayed, computed and memorized directly on tablet pre-installed MCH-sonic software. Connection between All-in One system and tablet is via WiFi.
MCHA Cross-Hole Tester is available as KIT MCHA Ultrasonic Cross-Hole Testing option in the following Kit versions.
Item Code
KV-ALL1.M2
KV-ALL1.M2.100
KV-ALL1.M3
KV-ALL1.M3.100
Kit ver
CH 2
MCHA 2
MCHA 3
MCHA 3
No of Transmitter (Tx) and Receiver (Rx) probes
2 probes: 1 x Tx, 1 x Rx
2 probes: 1 x Tx, 1 x Rx
3 probes: 1 x Tx, 1 x Rx, 1 x Tx/Rx probe
3 probes: 1 x Tx, 1 x Rx, 1 x Tx/Rx probe
Cable rollers (nos) and length
2 nos, 60m
2nos, 100m
3nos, 60m
3nos, 100m
Link cable probe wheel/control unit and pulleys
2 nos
2nos
3 nos
3 nos
Other accessories included
1 x encoder, 1 x link cable Encoder/Control Unit, 1x Cable driver, 1x tripod, 1 x transport case, 1 x ruggedized tablet windows
The ultrasonic and sonic tests are based on the analysis of the velocity of the wave that crosses the object and thus allows the determination of the intrinsic parameters of the material (concrete, rock, etc.) such as the degree of homogeneity, the presence of fractures, the presence of cavity, the module (Young's Module) and the strength of the material. The Solgeo All-in-ONE ultrasonic instrumentation performs travel time measurements of the compressive waves (P waves) in the materials and, through the graphic interface, allows the visualization of the real wave form generated by the acquired signal with which it is possible to monitor the quality of the transmitted signal. The All-in-One MCHA Cross hole analyzer , performs According to the Norm: ASTM D676O-16, with 1 trnsmission channel and 2 recevier channels . The Allinone controller for the MCHA system itself is fully encased in a water – dust proof Pelicase with military grade connectors to allow use in any site condition. The system can be configured, per requirement with cable length options of 60 m x 2nos, 60m x 3 nos100m x 2nos or 100m x 3nos.
Schematic as below shows the encoder setup :
The software setup allows easy connectivity and configuration of parameters that can be updated on the encoder:
•- Step: distance between two measures (default: 2cm)
•- Start and End Depth
The software allows to configure and define new projects, in particular the name, depth and number of paths of each element that needs to be measured:
The number of paths represents depends on the number of transmitters and receivers:
One transmitter and one receiver measures one path
One transmitter and two receivers measure two paths
One transmitter, one hybrid receiver-transmitter and one receiver measure three paths.
The Start-Stop-pause operation can be controlled directly from the encoder controller or the Software, which in turn initiate triggers with new measurements at regular intervals (default setting of 2cms)
During the measure a representation of the different measures is shown in real time on a grey level scale as seen in the screenshot below:
The controller will continue to guide the operator to pull UP or shut down the function in case of OVERSPEED with indications to lower the probes until the last valid measurement.
Simultaneous Cross Hole measurements along three paths in pile foundation
Synchronization impulse using an encoder
Result can be printed promptly
Cavities / faults detection
Seepages detection
High power transmitter and highly sensitive active-type piezoelectric receivers (50 or 80 kHz)
Ruggedized Tablet with Window preinstalled software included
Specification
Channels
2 Receivers Channels
1 Transmission Channel
1 Transmission/receiver Channel
Converter type
2 Channels analogic/digital at 12 bit
Input
Type:
Differential / Single ended / IEPE
Range:
+/- 5 Volt
Amplification
Type:
Selectable gain by software
Range:
1 - 40.000
Pre trigger
Type:
Selectable by software: 0 -2000 samples
Sample frequency
10 kHz - 12,5 MHz (up to 5 MHz for 2 channel input)
Number of samples
16384 samples (up to 8192 for 2 channel input)
Resolution
12 bit@10MHz to >16bit@ 50kHz (with oversampling)
Filters
Antialias, digital selectable gains (DSP)
Transmitter command
Range:
100V -1200V
Impulse
Length:
1 - 65000 𝜇s
N of meas/s:
> 20 meas/s
Connectivity
WiFi 802.11 (distance: 100m)
Transducer: Transmitters
Models:
TSG-55 piezoelectric transmitter
TSG-20 piezoelectric transmitter
CHT-28 borehole transmitter probe
Tx-hammer Sonic hammer
Nominal frequency:
50 kHz for model TSG-55
20 kHz for model TSG-20
80 kHz for model CHT-28
Transducer: Receiver
Geometry:
Diameter: 26 mm
Length: 150 mm
Models:
RSG - 55 piezoelectric receiver
CHR-28 borehole transmitter probe
Accelerometric receiver with BNC connection
Nominal frequency:
50 kHz for model RSG-55
Power supply
Internal battery:
LiFePO4 (6 Ah) or (4,5 Ah)
External recharger:
recharging time 4h
Consumption
Standby:
0.8 W
working:
1.6 W
Autonomy
> 35h
Temperature range
0-60°C
Experience
Cross-Hole Sonic Logging Test for RRTS Project
To check the homogeneity of the concrete for the deep foundation of piles as per ASTM D6760-16 standard.
Aadco requires to perform Pile Integrity Testing for APCO Infratech for their ongoing Delhi-Meerut RRTS project of NCRTC as per the NCRTC guideline ( 25 % piles- Cross-hole ultrasonic test & 75% piles- Pile Integrity Test ) to check the homogeneity of the concrete that is going to be used in pile foundation. ...