Wiertsema & Partners services

We offer various geotechnical consultancy. In this section you can find a selection of the most frequently occurring types of consultancy.Our consultants are specialised in the interpretation of test data, such as cone penetration test graphs. Will a steel-reinforced foundation suffice, or will piles need to be used? And which type of pile lends itself best to the location-specific situation? As well as calculating the bearing capacities of a foundation based on steel or piles, those are the questions specifically discussed in our consultancy reports. We always set out to provide complete advice that is characterised by a strong ability to put ourselves in the shoes of all the parties involved. Both technically and economically.

The future lies in sustainable energy combined with sustainable building. Clients are setting increasingly strict comfort requirements for new homes and commercial premises. The attractive indoor climate provided by sustainable energy adds quality and is being used more and more for the extra comfort it provides.

The shear test can be used to determine the undrained shear strength of undisturbed soil samples. This test can also be performed in-situ. The test involves placing a four-finned probe in undisturbed soil and rotating it. The amount of friction torque needed to turn the probe in such a way that the soil on the outside yields is measured. That friction torque can then be calculated into a yield force of the soil on the outside of the cylindrical lump of soil that is equal to the undrained shear strength of the soil.

When a top load is applied, such as a slope or a piece of raised ground, the underlying soil strata are compressed. The top load creates an increase in the effective load, which compresses the grain skeleton. To calculate this behaviour we need to know the behaviour of the ground. That information is obtained by carrying out compression tests on undisturbed soil samples in the laboratory. For this test an undisturbed soil sample is obliquely confined and vertically loaded. That prevents deformation from taking place horizontally. The deformation and load approximately correspond to the raising of land over a large surface. Raising the load on the sample in a number of steps and continuously registering the course of settlement makes it possible to derive the compression constant (C-value) from the sample.

An important activity in our geotechnical laboratory is the classification of soil samples. Our laboratory employees have many years of experience with this expertise. Our laboratory receives disturbed and undisturbed samples.  Most soil samples in our laboratory are described according the Dutch standard NEN 5104. A part of the samples that we classify are from abroad. For these samples other classification standards are used. For projects in Germany the standard is the DIN. Samples from offshore projects outside Europe are mostly classified according the British Standard or the ASTM.