Low Strain Integrity Test, also known as Pile Integrity Test (PIT) is a non-destructive testing method for integrity assessments of concrete piles (augured cast-in-place piles, drilled shafts or driven piles). If major defects exist, test results may be interpreted to estimate the magnitude and location of defect.
Because of the simplicity, speed of execution and relatively low cost, PIT may be performed on 100% of the piles on a given job site.
The methodology involves a small impact by hand-held hammer on the pile top that generates a compressive stress wave in the pile. The stress wave propagates down the pile shaft and is reflected when it encounters either the toe or a non-uniformity of the shaft. These reflections cause a change in the acceleration signal measured on the pile top, which is picked up and processed by the Pile Integrity Tester (PIT) equipment and interpreted using PIT-Software.
CIMEC is equipped with pile integrity testers from Pile Dynamics, USA to perform low strain pile integrity test on pile.
Cross Hole Sonic Logging Test (CHSL) is a non-destructive test method whichinvolves measuring of propagation time of ultrasonic signals between two probes in vertical tube /ducts casted in pile shaft. Shafts are prepared for testing during their construction by installation of access tubes. The total number of access tubes typically depends on the diameter of the shaft. These tubes are usually attached to the reinforcement cage along the full length of the shafts.
The test can be used to collect precise information on the quality and integrity of concrete at different depths. Combination of profilescan be assessed for evaluation of the location.
The CHSL Analyzer System lowers the probes to the bottom of the shaft and moves the transceivers upward in unison, until the entire shaft length is scanned. As probes are pulled up, the first arrival time (FAT) of signal is measured and recorded versus the elevation. This provides a vertical profile scan of signal transit time. The scan is repeated for each pair of tubes. The data is interpreted for delayed pulse arrivals (or low signal strength) which indicate potential defects, and later reprocessed using CHSL-software. Poor concrete between the tubes also delays or disrupt the signal.
CIMEC is equipped with Cross Hole Analyzer Systems (CHAMP-Q) from Pile Dynamics, USA to perform Cross Hole Sonic Logging Test on piles.
Dynamic Load Testing is a fast, reliable, and cost-effective method of evaluating foundation load bearing capacity. CIMEC can perform Dynamic Load Testing on driven piles, drilled shafts, auger-cast piles, micro piles, and other cast in place foundations. Due to less execution time, several dynamic load tests can be conducted in a single day. In addition to bearing capacity, Dynamic Load Testing provides information on resistance distribution (shaft resistance and end bearing) and evaluates the shape and integrity of the foundation element.
A Pile Driving Analyzer (PDA) with pile top force and velocity transducers are used to conduct the pile test. Two strain transducers and two accelerometers are attached to the pile head, on opposite sides of the pile to cancel bending effects during hammer impact. The signals of strain and acceleration are conditioned and processed by the PDA. Signals of pile top force and velocity are measured and analysed during each hammerimpact. At the time of testing, PDA compute static pile capacity from pile top force and velocity data. This is subsequently checked with the more rigorous signal matching technique by a computer program ‘CAPWAP’ (Case Pile Wave Analysis Program) to estimate the static load capacity of pile and distribution of soil resistance along pile length.
CIMEC is equipped withPile Driving Analyzers (PDA-8G) from Pile Dynamics, USA to perform dynamic load test on piles.
Static load tests are used to measure the way in which a pile behaves under an applied load. The load is applied at a low strain and pile displacement is measured. Due to the slower and more precise process, the static load tests are considered to provide the most accurate results when measuring pile load carrying capacities and settlement/uplift of the pile.
Static load tests can be performed to validate foundation design assumptions regarding the axial compression or axial tension resistance provided by a pile, or its deflected shape under a lateral load. Another benefit of a static load test is that it can be carried out in all soil conditions and on all pile types.
Readings of the applied load determined from the jack pressure gage or load cell, and pile head movement determined by LVDTs, digital dial gages, or mechanical dial gages, are used to determine the safe load capacity of pile under axial loads or under lateral loads.
After processing the collected load test data, the results are analysed for load-movement results and pile movement analysis.
CIMEC is equipped with multiple jack system with total load capacity of 8000MT.