A high precision and small size Fiber Bragg Grating (FBG) inclination sensor which is used for slope monitoring is proposed in this paper. The FBG inclination sensor has a pendulum structure for high precision and a circular body for easy installation in the common inclinometer pipe. The sensitivity of the FBG inclination sensor can reach 400 pm/deg by optimizing its parameters. The test results show the superior performance of this FBG inclination sensor in terms of static characteristics, and its sensitivity is 406.6 pm/deg. The comparison experiment shows the static characteristics of the FBG inclination sensor are better than the traditional electrical inclination sensor.

A highly integrated sensing technology, combining a stimulated Brillouin scattering-based distributed sensor with XFG (fiber Bragg grating (FBG) and long-period fiber grating (LPFG)) sensors on a single fiber, is proposed for the simultaneous measurement of fully distributed and multiple discrete dynamic strains/temperatures. A multiparameter monitoring scheme for slope safety is developed using this integrated sensing technology. An indoor simulation test is carried out to verify its ability to simultaneously monitor a slope’s surface displacement, an anchor reinforcement’s axial force, and rockfall vibration. The experimental results show that distributed static strain and discrete dynamic strain can be well-measured simultaneously with little interference. The results also demonstrate the XFG sensors’ capability for multi-type and multipoint multiplexing. In addition, the proposed hybrid sensor system has potential for the monitoring of multiple slope parameters simultaneously.

The dynamic response of an Euler–Bernoulli beam under moving distributed force is studied. By decomposing the distributed force into Fourier series and extending them to semi‐infinite sine waves, the complex procedure for solving this problem is simplified to three base models, which are calculated by the modal superposition method further. The method is proved to be highly accurate and computational efficient by comparing with the finite element method. For verifying the theory and exploring the relationship between dynamic pressure due to train gust and vibration of the structure, a site test was conducted on a platform canopy located on the Beijing‐Shanghai high‐speed railway in China. The results show the theory can be used to evaluate the dynamic response of the beam structure along the trackside due to the train gust. The dynamic behavior of a 4‐span continuous steel purlin is studied when the structure is subjected to the moving pressure due to different high‐speed train passing.

Partially assembled structures were used to replace earth-retaining struts during construction of a prefabricated subway station on the Shenzhen Metro in China. A three-dimensional numerical model was developed to investigate the interaction between the Pingxi station structure and the earth-retaining system for different assembly sequences. The results showed that the prefabricated structure performed satisfactorily during construction, and the sequence of assembly had a significant influence on the distribution of internal forces and stresses, especially in the substructure. The analytical approach applied here can be extended to assess other prefabricated underground structures.

The trade-off between sensitivity and frequency band is problematic for FBG accelerometer, synchronous enhancement is an urgent technical problem. We report a novel fiber-optic accelerometer with high figure of merit based on double short gratings, which are inscribed by a femtosecond laser and symmetrically fixed to a M-shaped hinge to increase the sensitivity and reduce the temperature interference. Experiments show that the sensor possesses a resonant frequency of 400 Hz, a high acceleration sensitivity of 729.24 pm/g (1.5 dB), and a high figure of merit of 116678400 pm·g ^-1 ·Hz ² , which is higher than the level (5000000 pm·g ^-1 ·Hz ² ) of conventional FBG sensors. The sensor has great potential in low-frequency (as low as 0.1Hz) micro-vibration measurement.