Digital measurement technology in foundation works / In-process monitoring to ensure quality

In recent years, the topic of digitalisation in foundationengineering has been steadily driven forward. With innovative approaches and ideas - such as the b-project data management software - the collection, processing and evaluation of data at Bauer has been increasingly automated and the collaboration of all project participants more and more digitalised. In addition to the process data from the production of the foundation elements, which is recorded element-based by the drilling equipment (suspension quantities, verticality, GPS position, etc.), we also record anchor forces, temperature curves, suspension levels, etc. on our construction sites as required during or after the production of the respective elements. This data is transmitted directly, analysed and displayed in the dashboard we have developed. BAUER Spezialtiefbau GmbH has used and continues to use this successfully on projects, depending on the requirements. The following are some examples of the use of our digital tools to ensure product quality during the manufacturing process. In Feldolling, a cut-off wall was produced in 2022/2023 using the MIP (Mixed in Place) method in various construction phases with a scope of around 20,000 m². One section of this sealing wall was also constructed during the winter months of 2022/2023. The client required a temperature of +10°C to be guaranteed in the freshly constructed sealing wall during this period. This monitoring was carried out using suitable temperature sensors, whose data was transmitted to the BAUER Cloud at defined times via a data acquisition and transmission unit (IoT device) also installed there. The data itself was displayed in the dashboard developed by BAUER. This form of monitoring helped us to obtain the temperature development data efficiently and promptly and to provide evidence for the client. With regard to the monitoring of entire excavation pits, this is currently taking place on a construction project in Cologne. The excavation pit for the construction of a new Centre for Family Health (CEFAM) is being built on the grounds of Cologne University Hospital. This 8,000 m² excavation pit is up to 14 metres deep and consists partly of a bored pile wall, a mixed-in-place (MIP) wall and a soldier pile wall. The entire excavation wall is anchored back over the height with up to three anchor layers. Up to 32 digital load cells are installed to monitor the anchor forces. The monitoring itself is carried out automatically via the IoT device installed there, which can continue to supply data even in the event of a power failure thanks to solar power. The measurement data is sent to the BAUER Cloud and is displayed and specifically monitored via the dashboard. Another special monitoring task was realised on a project in Sweden in 2020. In the immediate vicinity of the Royal Opera House in Copenhagen, BST constructed a back-anchored excavation pit consisting of 6600 m² of diaphragm wall for the construction of the "Operaparken" underground car park. To ensure the high quality of a diaphragm wall, it is important, among other things, that the slurry level in the diaphragm is at the required level during construction. If an excavated slot remains open during the production of a diaphragm wall element, e.g. overnight, a slot watch is required to check the suspension level. This was also difficult to do with on-site personnel due to the coronavirus pandemic, so a sensor unit was developed to monitor the slurry level. The monitoring and data transfer were similar to the systems mentioned above. One special feature was that the person responsible was called via mobile phone if the level fell below a warning value so that appropriate measures could then be initiated. The three examples show how we can record and directly analyse parameters relevant to product quality during construction using our self-developed monitoring system consisting of the appropriate sensor technology, the IoT device for sending to the BAUER Cloud and the evaluation and display via our dashboard.