What has gepc developed?
gepc has developed a wide range of specialized measurement techniques for geotechnical engineering to reduce execution risks through monitoring.
Especially when individual elements are assembled into waterproof structural components, the positional accuracy of each element in its final position plays a crucial role.
Another focus lies on standard structures that are prone to requiring repairs, which can be executed with lower risk using customized measurement technology.
To achieve this, interdisciplinary techniques from mechanical engineering, electrical engineering, computer science, and applied physics have been combined to create new solution concepts.
How can gepc support project execution?
Project-related engineering support provided by gepc, with backup support from a senior engineer
A measurement engineer from gepc will carry out the measurement tasks during the project, in close consultation with a gepc managing director.
Training of site personnel
Training via pre-recorded training videos. Video tutorials can be provided and training sessions arranged for the application of measurement technology and the interpretation of measurement data.
Gepc provides engineering services to contractors.
Sale of supporting measurement technology
The required measurement system is designed, manufactured and handed over to the contractor.
Hire of supporting measurement technology
If required, the measurement system can also be hired for use on the project.
Who are the contact persons at gepc?
The managing directors Mr. Dipl.-Ing. Univ. Nikolaus Schneider, Mr. M.Sc. Eng. Jens Scheffler, and Dr.-Ing. Jens Mittag are available for further contact.
Email: scheffler@gepconsult.de
Email: mittag@gepconsult.de
Pioneering special measurement technologies
A chain inclinometer inside the jet grouting rod continuously records the borehole path in real-time. This allows deviations to be documented during execution.
The drill rods are equipped with dual-channel rods and contact couplings, transforming them into a chain inclinometer. This enables one-time measurement of borehole deviations at full depth.
The alignement of vibrated lances for grouted base layers can be measured using a self-propelled inclination reader.The actual inclination of the lance is measured at defined depth intervals, and the results are transmitted via Bluetooth to the project engineer’s laptop.
Upgrading drill rods with contact couplings enables the extension of drill strings into chain inclinometers, allowing for guided drilling. Asymmetric drill bits guide the drilling direction based on the known position of the drill head.
Deep-lying test columns can be measured geometrically with high precision using structure-borne sound, without excavation. Jetting against hardened columns, the overlap angle is determined via frequency analysis and allows to conclude for the exact column geometry.
Construction joints are the weakest points in waterproof retaining structures. Concrete that flows around lost joint elements is problematic due to unknown bonding quality. The Joint Inspector allows the detection of such flow-arounds during construction, enabling timely countermeasures during construction.
Deep diaphragm walls with grab depths beyond 40 m present unique challenges, as retrievable joint elements can hardly be removed by service cranes. The "Fire- brigade" joint was developed to address this: using a dual-shell design and pneumatic inflation of fire hoses, the joint is split. One part remains verifiably free of surrounding concrete, while the lightweight retrievable part can be detached.
Wall integrity testing of pile walls from unlined or slurry-supported bored piles is possible with the Pile Inspector, which can be inserted into the borehole via a service crane or Kelly bar. Mechanically guided measuring arms assess the wall geometry by depth, enabling evaluation. Pile base enlargements can also be measured and documented, supporting the analysis of concreting logs.
Compressed air is integrated into the jet grouting system to enhance the erosion effect of the high-pressure jet. A switching monitor redirects the air to power a down-the-hole hammer. To protect the directional system’s electronics from recoil, a shock absorber is installed between the monitor and steering assembly.
Jet grouting base layers are constructed in primary and secondary rows. When vibration sensors are placed in primary rows, vibration profiles induced by the jet grouted columns of the secondary rows can be used to assess connection criteria with primary elements. This enables real-time evaluation of secondary-to-primary column connections during execution.
The flushing head, exposed to high pressures from air and cement slurry, experiences heavy wear on its seals. By tracking the actual number of completed jet grouting columns via a control box, lubrication intervals can be scheduled separately for the high- and low-pressure sections of the flushing head.
Directional rods are assembled using regular screw joints, which must align precisely to capture total inclination. Through auto-calibration of the jet grouting rods on the inclined mast, the actual coupling positions can be correlated so that measured inclinations are synchronized in both directions.
