We prepared a number of GRLWEAP studies to help select the correct equipment and verify driveability on steel sheet piles and tubular piles of different sizes at the Uig dock redevelopment. We then carried out Dynamic Load Testing with a BSP CX110. We were able to mobilise with only one day’s notice and carry out testing over a weekend. The report was delivered within two hours’ of testing.

We can test all types of piles. Here we’re testing bottom driven steel cased piles with a D500 drop hammer at a residential development near Reading. We carried out the CAPWAP analysis concurrently to speed up delivery of the report and keep the project moving.

With only a day’s notice we mobilised to carry out Pile Integrity Testing using the PET (Pile Echo Tester). We arrived first thing, used our battery powered grinder to carry out final preparation of the pile top, and collected high quality data quickly and efficiently.

We prepared GRLWEAP studies to help predict pile performance at a project in London. We have also carried out Dynamic Load Testing and CAPWAP analysis. We were asked to compare the results of a Static Load Test to the CAPWAP Simulated Static Load Test Curve. The results compare favourably, with less than 1mm difference between the predicted deflections at Working Load and 1.5x Working Load on the test pile and another pile, giving our client confidence in both test methods.

We tested all 114 CFA piles on a project in the Midlands at cast level. Testing at cast level means that the piling contractor can be confident that adverse integrity test results have not been caused by cracking from poor quality cropping. The piles still need to be cleared and with good quality concrete exposed. The test also requires a flat spot for the accelerometer and hammer to strike the pile top. Preparation like in the photo above is adequate, and allows for many piles to be tested in one visit.

Here we are testing some precast piles on a grain silo in Northumberland. We regularly test on precast piles for commercial and housing projects alike. The test is quick, the results are provided almost straight away and we can test tens of piles in a day.

We are often engaged to test on housing projects. The piles tested are usually smaller section steel tubular piles or precast concrete piles. Here near Westhoughton we tested steel tubular piles. We tested one pile on each plot and the CAPWAP analyses had Match Qualities of 1.43, 1.35 and 1.49, which is excellent, and we issued the report by 11am on the same day as testing.

Here we are testing precast concrete piles near Cardigan. We test all over the UK. Precast concrete piles are well suited to dynamic load testing and CAPWAP analysis. With a good rig (Junttan PM16 here) and rig driver, it is possible to test tens of piles in one visit.

We carried out Pile Integrity Testing under an existing building in Essex. There was movement in the foundation and our client needed to know the length of the existing piles. The results were conclusive - showing a clear toe signal at 7.2m. This was a quick, affordable, and relatively non-intrusive way to find out information on existing piled foundations. We have also had good results testing through a concrete pile cap over a pile. Pile Integrity Testing is quite affordable and is often worth trying before using more invasive methods of testing.

We have been testing quite a few steel sheet piles lately. Most recently in Grimsby and in Sussex. We can test sheet piles individually or as part of a wall. This gives information about bearing capacity in compression and tension, as well as pile integrity and driving stresses. The data from steel sheet piles can be more difficult to analyse in CAPWAP, but our experts didn't have any problems achieving Match Qualities as low as 1.21.

Our client was tasked with replacing a pile on the Thames that had been struck by a boat. But they needed to know how long the pile was. We tested the piles either side using Dynamic Load Testing, and analysed the data in CAPWAP. The results will allow our client to design the replacement.

These piles were only around 2m deep. The data collected showed clear toe signals, and we used the FFT (Fast Fourier Transform) method to assess pile integrity because of the shallow depth of the piles.

We had to test at low tide, so it required an early start. The piles were driven into chalk and testing was required to check for set up. The piles had been installed on Thursday and tested the following Monday. The piles barely moved showing good set up in the chalk, and the CAPWAP Match Qualities were around 1.2. The report was issued by 9.45 on the morning of testing.

Although less common in the UK, it is possible to carry out Dynamic Load Testing on timber piles. We tested these piles in London. We compared the Dynamic Load Test data to Pile Integrity Test data to double check the wave speed, and the CAPWAP results were good.

Pile Dynamics Inc States: "While match quality (MQ) is not the only parameter, it is perhaps the most important one to guide the engineer in finding the best solution."

They also advise that: "For good data, you should always get below 5, usually below 4, often below 3, sometimes below 2, and rarely below 1.  With experience, these numbers will be easier to achieve, so that maybe you get below 2 often (for example), except for concrete piles that have cracks or piles with very low blow counts (large set per blow), which are more difficult to analyze."

Here, on a precast concrete pile tested near Birmingham, we achieved a Match Quality of 0.62. We are experienced and knowledgeable about CAPWAP and pile testing, and we supply the highest quality analysis.

Match Quality should always be included in a CAPWAP report.