Low Stain Pile Integrity Testing   (PIT - Testing)


Low Strain Pile Integrity Testing is a quick and cost effective method to evaluate the shaft integrity of
cast-in-situ piles. The testing is able to provide information on:

                                a) physical dimension

                                b) pile continuity

                                c) consistency of material      

Low Strain Pile Integrity Testing is normally carried out on cast in-situ piles. Driven piles are also

able to be tested the right condition. The effectiveness of the system is limited to a pile length

not exceeding 30 to 60 pile diameters depending on soil condition and concrete quality.



Sonic Integrity Logging (Sonic Logging)

The Sonic Integrity Logging is used to detect defects in cast in-situ bored piles caissons, barrettes

and diaphragm walls.


When cast in-situ piles are constructed, the following defects may occur, hence the main objectives

in the testing is to provide the client/consultants information about :-

          a) honeycombing due to inadequate vibration.

          b) segregation due to over vibration and improper concrete placement methods.

          c) washouts of cement due to groundwater flow.

          d) cracks in pile shaft due to shrinkage.

          e) inclusion of foreign material causing contamination of the concrete.

          f) necking of the pile due to collapse of side walls during withdrawal  of the temporary

              casings.


This method of integrity testing requires prior preparation in that G.I pipes needs to be

installed together with the steel reinforcement bars. There is no limit in the depth where

the pile profile is able to be logged.



High Strain Dynamic Pile Testing  (PDA-Testing)

High Strain Pile Testing is used to provide data on strain or force and acceleration of a pile under an

impact force. The data is used to evaluate the bearing capacity and the structural integrity of the pile

as well as hammer performance, pile stresses and soil characteristics, such as soil damping

coefficients and quake values. Pile integrity, which is accurately evaluated on site, would allow the

engineer to accept/reject the pile immediately.



Actually driving stresses and hammer performance data obtained during pile monitoring can be used

to reduce the risk of pile damage. Piles no longer have to be overdriven, resulting in higher cost.



Random testing of installed piles would also provide the design engineers/contractor/client a measure

of confidence in the foundation as he would probably not be at the site all the time to witness the pile

installation. It is also to ensure that the installed piles can function as designed.




CAPWAP Analysis


The force and velocity data obtained in the field by the PDA is processed and a representative blow

will be used for further analysis using the CAPWAP suite of computer software. A typical output

of the CAPWAP results will be :-

             a) Total computed soil capacity
              - sum of Skin Friction and Toe Bearing

             b) Computed load against settlement curve

             c) Resistance distribution along pile shaft









Vibration and Sound Monitoring

Vibration monitoring is used to provide ground/structures vibration emission levels. The results

obtained are in the form of Peak Particle Velocity (PPV). The PPV obtained is compared to the

allowable emission levels for the particular structures evaluated.



Sound monitoring is also similar to vibration measurements. It measures the maximum noise level at

the transducer location. This results are then compared to the recommended levels by the local

authority or the environmental noise and vibration emission limits.




Settlement Monitoring

Precision leveling is used to monitor the settlement of a building or ground over a period of time.

The frequency of readings varies from one week to a month. To accomplish this goal, protective

settlement markers and high precision survey equipment are used.



The company has a Leica digital level NA 3003 complete with the invar bar code staff where the

accuracy is up to 0.01mm.




Static Axial Tensile Load Test

Axial tensile load test is used to determine response of the pile to a static tensile load applied

axially to the pile. Dynamic Pile Testing Ltd shall provide the reaction set-up for the system.



The test shall be carried out to the required test load in accordance to the ASTM specifications.

The results provided are factual results and interpretation of the pile performance and capacity should

be done by the Consultant Engineers.

Dynamic Load Test   (PDA) vs. Maintain Load Test   (MLT)