Fibre optic monitoring of slope stability

katedra geotechnik

Laboratory and In-Situ Testing of Integrated FBG Sensors for SHM for Concrete and Timber Structures

Long-term structural health monitoring (SHM) plays an important role in the safety of public transport infrastructure such as bridges or tunnels and warns in the event of any emerging problem. This article describes development and testing of system based on fiber Bragg grating (FBG) sensors that can detect changes in strain and temperature. The first phase of the research has been focused on the development of new fiber optic sensors for the monitoring of concrete structures and their investigation in laboratory conditions. The work also shows novel applicability of the same FBG technology for glulam structures. Mechanical loading tests of the concrete beam as well as glulam beam with embedded sensors were carried out. Data measured by developed fiber optic sensors were compared with the readings from reference sensors as well as with the analytically calculated values. The achieved results proved good agreement between the measured data, analytical data and reference methods. In second phase of the research, the pilot installation of the sensors was carried out on the newly constructed prestressed-concrete bridge. The bridge was monitored throughout pre-stressing phase and monitoring continued after the completion of the construction works. Problems with the fragility of the sensors occurred during the measurements, but the obtained results provide a good basis for further improvement of the system

Nanofibrous material from hyaluronan derivatives preserving fibrous structure in aqueous environment

Nanofibrous materials produced from natural polymers have wide range of potential uses in regenerative medicine. This paper focuses on preparation of nanofibrous layers produced from intentionally hydrophobized derivatives of hyaluronan, which is known for its ability to promote wound healing. This structural modification of hyaluronan expands the range of potential uses of this promising material, which is otherwise limited due to the hydrophilic nature of hyaluronic acid. The aim of this research was preparation of nanofibrous material that would retain its fibrous structure and dimensional stability even after getting into contact with an aqueous medium, which is impossible to achieve with layers composed solely of native hyaluronan. As a result, such material would be able to retain its breathability and good mechanical properties when both dry and wet. Furthermore, all prepared materials were proved non-toxic for cells. This self-supporting nanofibrous matrix can be used as a scaffold, or porous wound dressing. © 2021 Elsevier Lt