In mountainous regions, the usability of roads and railway tracks strongly depends on the safety and the condition of retaining structures. Consequently, an early detection and identification of structural degradation, damages and potential failure mechanisms is of major interest. Currently, single point measurements using total stations or other sensors depict the state-of-the-art in deformation monitoring of retaining structures. Due to the large number of such structures in mountainous regions, e.g. the Alps, establishing a monitoring system for every object is unfeasible. This paper presents an approach for a large-scale deformation monitoring with a mobile mapping system (MMS). A MMS with two highquality laser scanners has been installed on the roof of a standard car. A newly developed algorithm processes the gathered data in a partially automated manner in order to perform deformation analysis on the one hand and to detect structural deficiencies (e.g. concrete spalling) on the other hand. Data of multiple (periodical) measurement campaigns of selected retaining structures have been used to evaluate the proposed approach. It is demonstrated, that mobile mapping in combination with targeted processing algorithms is a promising, efficient and comprehensive alternative to traditional static, single point monitoring solutions.
Soil nailing systems are a common way to stabilize slopes and construction pits. Their design is usually based on the mechanical equilibrium of a rigid body motion and therefore, only tensile stresses are considered and accompanying forces like bending (shear stresses) in the soil nails are neglected. Continuous strain measurements along nails could verify this assumption, but may not be performed using conventional sensing technologies. This paper reports about monitoring of a soil nailed slope stabilization using distributed fiber optic sensing. Soil nails in different anchoring horizons were instrumented and autonomously monitored over several weeks, in which the construction pit was excavated continuously. After the excavation, the final load bearing capacity of one selected nail was determined within a classical geotechnical load test. In addition to the field measurements, the bending behavior of the instrumented nail system was analyzed under laboratory conditions. The presented studies demonstrate the high potential of distributed fiber optic sensing systems and their capability to extend traditional measurement methods in foundation engineering applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.