Development in Pile Testing
Fitri Jones & Stephen Buttling
Australia probably qualifies as one of the countries which carry out the lowest number of static pile load tests each year. When a contractor was asked in 2007 “How many pile load tests have failed to reach their design capacity?” he replied, “I don’t know, we don’t do any”. The Osterberg Cell, or O-cell test was developed as a method for testing piles with high load capacity, negating the requirement for large reaction systems. It has now been around for more than 20 years, in which time nearly 4,000 tests have been carried out world-wide. It was not until 2007 that Australia first used this technology and still only 14 tests have been carried out to date with a further 6 tests under way.
To complement the O-cell test for preliminary sacrificial piles, Fugro Loadtest has developed the RIM-cell, a low cost, cast in-situ test for the purposes of serviceability load verification of drilled shaft production piles.In a further pile testing related development, a test for assessing the pile base bearing capacity or stiffness of rock is being planned and both will be described in detail, with potential applications discussed.
Fitri Jones, also known to some as Peter Jones, has been involved in the foundation industry for 25 years since graduating from Cardiff University in 1988. After 5 years of foundation contracting with Cementation Piling & Foundations in the UK and a further 6 years in Hong Kong, Malaysia, Singapore, Qatar and Bahrain, the majority of the following 13 years has been spent in the field of pile testing, most of it with Loadtest (Fugro Loadtest since January 2009). In this time he has performed O-cell tests all across Asia, and managed the Middle East operations of Loadtest for 5 years. After a 2 year period of marketing in the Asia Pacific region, he currently heads up the new Fugro Loadtest operation for pile testing services in Australia, and is based in Perth.
Stephen Buttling is now well-known to many members of AGS. He started testing bored piles with embedded vibrating wire strain gauges 40 years ago, while he was also with Cementation Piling & Foundations and it was still novel, and has tested piles in the UK, Hong Kong, Singapore and Thailand. He has been closely involved in the testing of at least 20 piles on each of two projects in Thailand, and Singapore must be the opposite of Australia in having the most static pile load tests per year per head of population. On average two tests are carried out every weekday, with one instrumented test to failure for every project, and one test for every 100 piles cast. In more than 6 years in Australia he has still not been involved in a single static load test, although he did carry out analysis of the Gateway O-Cell tests after the event. He has recently been working with Fugro to develop a simple test to verify end-bearing in rock sockets.
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