The invention discloses a device for monitoring a state of a ballastless track structure through fibber bragg
grating sensing, which comprises M fibber bragg
grating steel rail temperature and stress combined sensors, N fibber bragg
grating steel rail horizontal displacement, longitudinal displacement and
vertical displacement combined sensors, P fibber bragg grating steel rail horizontal acceleration, longitudinal acceleration and
vertical acceleration combined sensors, Q fibber bragg grating plate type
ballast horizontal displacement, longitudinal displacement and
vertical displacement combined sensors, R fibber bragg grating plate type
ballast horizontal acceleration, longitudinal acceleration and
vertical acceleration combined sensors, a multi-channel fibber bragg grating
wavelength demodulator, a
data processing terminal and an
alarm device. The combined sensors are arranged at state monitoring points of the ballastless track structure of a
rapid transit railway, and are directly contacted with the steel rail, the
ballast and a base or are fixed by a supporting layer,
wavelength output signals of various sensors are respectively transmitted to the demodulator through a
transmission fiber and then are transmitted to the real-
time data processing terminal and the
alarm device, and if an abnormal state is monitored, the
alarm device is started for early warning.