The geosynthetic manufacturer Naue offers a new design software on its website. The Naue Platform Software provides a quick and simple design tool for geogrid stabilised and reinforced working platforms. The correct design of working platforms is decisive for the stability and the operational safety on the platform.
For the use of heavy construction equipment, such as crawler cranes or piling rigs, often temporary working platforms made of compacted granular fill are constructed. Considering all relevant load conditions, the in-situ subgrade strength is often insufficient to ensure the safe operation of the construction plant.
Against this background, geogrid stabilised and reinforced base courses are being used more frequently. The interaction between the geogrid and the granular platform material reduces lateral spreading of the fill, and loads from the construction equipment are distributed over a larger area. This reduces stresses transmitted to the soft subgrade and increases the overall stability of the working platform.
For numerous projects, e.g. the construction of wind turbines, heavy construction equipment is often used on soft subgrades with low bearing capacity. Therefore, the correct design of working platforms is of utmost importance for the stability and the operational safety on the working platform.
In this regard, there is a need for optimisation. Often the requirements of the construction equipment do not match with the prepared working platforms. Furthermore, there are no generally accepted technical regulations for the design of such temporary working platforms, made of unreinforced or geogrid stabilised and reinforced granular fill. Only simplified and, therefore, often conservative design models are available.
Naue has recognised the need for action and provides a design tool for stabilised and reinforced working platforms with the NAaue Platform software. On the basis of scientific research using large-scale model testing, a holistic design approach for Secugrid® and Combigrid® stabilised and reinforced working platforms has been developed.
The “Hybrid” model, as implemented in the software, allows the design of working platforms over soft to stiff cohesive subgrades against different potential failure modes. These could, for example, be punching shear failure or rotational and overall failure mechanisms using the so-called Kinematic-Element-Method (KEM). The adapted model can automatically identify the decisive failure mechanism and determine the granular platform thickness to withstand the most critical situation. In addition, immediate deformations, differential settlements as well as tilting of the equipment caused by the operational loads can be estimated by the Naue Platform software.
The calculation results allow a direct comparison between Secugrid & Combigrid stabilised and reinforced granular working platforms and the conventional construction method without geosynthetics. Secugrid & Combigrid stabilised and reinforced working platforms offer the following advantages:
- Increase of bearing capacity of the working platform
- Reduction of construction costs due to thinner granular platforms
- Reduction of construction time due to thinner granular platforms
- Reduction of soil excavation, imported fill material and carbon footprint
- Improved serviceability
Source: NAUE GmbH & Co. KG