Geo Dynamics has extensively conducted High Strain Dynamic Pile Tests (HSDPT) at various metro projects in the country after conducting reliability studies at each project. The method has been used as a replacement to static load testing for generally for working piles and in few cases also for some of the initial piles to ascertain capacity / integrity. For DMRC, the tests were accepted by the relevant authority based on such successful reliability studies. Generally diameters from 800mm to 1500mm were tested in all types of soils including rock. Test load varied from 300 tons to 1800 tons. Two such studies are shown below.
The entire project consisted of installing approximately 18000 pre-cast piles 350mm x 350mm square and 50m (16m+16m+18m) length at one of the major oil and gas installations in the country.45 piles were initially driven along the entire stretch and were monitored with High Strain testing both for EOID and re-strike. Few initial piles were co-related with static load tests with encouraging results. Based on the findings, the pile depths were eventually reduced by 2m for almost 15000 piles resulting in direct cost saving of millions to the client. It also reduced the problems in handling the last 18m segment as with reduced length, all the segments were now 16m length each resulting in major savings in time and cost to the client. Numerous piles were monitored during the entire duration of piling and it was a norm to immediately conduct PDA on questionable piles or those that showed unusual penetration record.
Geo Dynamics was engaged to monitor steel piles during End of Drive and Restrike for Cruise Berth Terminal constructed at Mauritius. Geo Dynamics was approved as a testing company by the Port Authority and consultants in UK based on their specific experience in these types of marine jobs. The project consisted of 813mm spirally welded steel pipes to be driven by a Junttan HHK 18A hammer. The first few piles were tested for End of Drive and also restrike tests conducted at the project site. Correlations conducted both for tension and compression piles showed excellent match between the test results. There was major variation in soil stratum and the pile depths varied from 6.5m to 43.6m. Geo Dynamics engineers monitored the piles on regular basis and the test results and analysis provided good confidence to everybody to install piles in such varying depth of soil stratum.
For a project site located in Vallarpadam, it was proposed to construct a Container Terminal. R.C.bored piles having diameter of 800mm, and 1200mm were installed at the site. The lengths of the piles were ranging from 48m to 75m. The design loads were ranging from 500tons to 1100tons. LSIT was performed on around 500 piles. HSDPT was also performed on 15 piles having 1200mm diameter after establishing the correlation with static load test. This was the first time in India that such long piles were cast and it was required to quickly evaluate the integrity and capacity of these piles to remove any doubts about the applicability of such long piles. The methods and the expertise of the analysts was useful in evaluating so many piles in quick time and also helped the project execution time.
National Highways Authority of India (NHAI) located 128 piles of 500mm that were abandoned by the previous contractor more than 10 years back. No technical data like pile depth or capacity was available. A combination of dynamic and pile integrity tests was used on the project site. Initially PIT conducted on the piles reported pile lengths about 20m. Borehole taken adjacent to two such typical piles confirmed the findings. Dynamic testing on the pile helped establish its design load. Static test was also conducted by the client on the pile dynamically tested for further confirmation. The static and dynamic test results matched well helping the client save lot of time and money, since most of the piles could be used in further construction at no additional cost.
Geo Dynamics performed several PITs, HSDPTs, and Lateral load tests for DFCC Rail Project. More than 50 HSDPTs were performed on initial and routine piles and several correlation studies also submitted for client’s approval. Pile diameter was typically 1000mm and 1200mm and pile depths were typically around 25m to 30m. Test loads were ranging from 600tons for routine piles to around 1200 tons for test piles. The entire testing program were successfully executed.
Geo Dynamics was engaged to perform PITs and HSDPTs for Gabon Special Economic Zone(GSEZ). Conventional Static load testing was performed on initial piles (TP-1 & TP-2) by the contractor and High strain dynamic test was performed on same piles for reliability study purposes. Total 7 routine piles were tested at the Project site after Geo Dynamics demonstrated that HSDPT can be adopted for routine piles based on acceptance of reliability studies.Pile diameter was 1400mm and pile depths were typically from 10m to 35m. Test loads were ranging from 1400tons for routine piles and 2400tons for test piles. However, with the help of 25ton hammer Geo Dynamics was able to mobilize pile capacities more than 3000tons for these rock socketed piles.