Pile load testing

Load tests

We conduct all kinds of static (vertical/horizontal) load tests. Usually, at the request of the client, these are based on the guidelines issued by the German Geotechnical Society (DGGT) working group (AK) 2.1. and on the DIN 1054 standard, or on applicable national requirements.

As an option, we can conduct the test under path or force control. In cohesive soil especially, a great deal of time can be saved by path-controlled testing (likewise in accordance with DGGT AK 2.1).

We conduct load tests on

  • piles
     
  • pile groups
     
  • CSV columns 
     
  • sheet piles 
     
  • MIP bodies 
     
  • diaphragm wall panels
     
  • jet-grouted bodies 
     
  • anchors 
     
  • soil (load plate) 
     
  • ground nails and 
     
  • micro piles
schlitzwandppb



Force-controlled testing

At the start of the test a loading programme is specified. Usually, the desired maximum test load is applied in eight stages. A minimum time is waited after each load stage and the creepage criterion is checked. If the criterion is met, the next load stage up is applied. This is continued up to the maximum test load.
In relation to cohesive soils, attaining the specified creepage criterion can considerably prolong the test.

 
Path-controlled testing

In path-controlled testing, the rate of displacement of the pile head is preset rather than the load. When the working load is reached, the pile is pressed into the ground at a constant rate and the applied load is recorded. This considerably speeds up testing in cohesive soil.
 

Tensile testing 
 
Tensile tests are usually conducted on anchors and micro piles with preset thread bar anchors/profile steels or strands.

Tensile testing can only be carried out up to 0.9 times the yield stress of the tendon.
 

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  Compression testing 
 
  Compression tests are classified as dead-load tests or tests with tension elements
  depending on the type of reaction system.
  In the case of reaction systems with tension elements, there are different loading
  structures depending on the test load and the site conditions. The different structures
  are beam and cruciform construction and load crowns.

  Dead load 

  In tests with dead load, there are one or more hydraulic cylinders between the pile
  head and the thrust block by which the individual load stages can be applied. 
 

Beam construction                                                     

with tension piles
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  Cruciform beam construction 

  Under higher test loads a cruciform structure comprising multiple beams is
  deployed.                                
Load crown

Higher loads can be applied by arranging multiple load crowns one on top of the other.
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 horizontalversuch   Horizontal testing

  Piles are subjected to load transverse to the pile axis in order to verify the bearing
  capacity in the horizontal direction.