Cross-Hole Sonic Logging Test for RRTS Project
Posted by: Stanlay India
Application requirement:

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.

Customer:
Aadco Testing & Research Laboratory (P) Ltd
Download Case study

 

Solution:

Aadco uses All In One KIT MCHA Ultrasonic Cross-hole Testing Equipment by Stanlay as per ASTM D6760-16 standard.

Aadco performs Pile Integrity Testing for APCO Infratech for their ongoing Delhi-Meerut RRTS project of NCRTC as per the NCRTC guideline to check the homogeneity of the concrete.

The Cross-hole Sonic Logging method is an ultrasonic test that involves measuring the propagation time of ultrasonic signals between two probes in vertical tube in a shaft. It is a NDT method which consists of ultrasonic signal transmission through the pile between two similar water filled tubes.

Probes Under Water Filled Tubes
Probes under water-filled tubes, total depth of one tube is 31m.

The difference in signal coming time permits one to calculate and identify areas of low compactness of concrete. For the case of good concrete, pulse velocity is on the order of 4000 m/sec, depending on its ingredients. Concrete consists of soil, gravel, betonies or honeycombing which causes lower propagation velocity so that the presence of these irregularities is immediately observable.

Inserting two probes ( 1 Tx & 1 Rx ) through the pile between two similar water-filled tubes
Inserting two probes ( 1 Tx & 1 Rx ) through the pile between two similar water-filled tubes


The total depth of the piles was 31 meters & they use All In One KIT MCHA Ultrasonic Cross-hole Testing equipment which has 60-meter cable along with 2 probes ( 1 transmitter & 1 receiver) for this test.

All In One KIT MCHA Ultrasonic Cross-hole Testing Equipment
All In One KIT MCHA Ultrasonic Cross-hole Testing Equipment

 

The output graph was displayed on the datalogger screen which had pre-installed software to measure the output signal & present it in formatted graphical way.

Velocity & Time Output Graph from cross-Hole Testing