A method for calculating a temperature-dependent mid-span vertical displacement of a girder bridge includes: setting a joint rotation of a main girder at each support as an unknown quantity, and establishing an equation according to a bending moment equilibrium condition at the joint; then introducing a sequence to establish a quantitative relationship between each unknown quantity; substituting the relationship into the equation, to obtain an analytical formula for a rotation at each joint; establishing an analytical formula for a bending moment at each joint through a principle of superposition; and finally, establishing an analytical formula for a mid-span vertical displacement of each span girder through a principle of virtual work. This method provides an analytical formula with exact solutions for prismatic girder bridges which have equal side spans yet have any number of spans.

A damage diagnosis device is provided with: a detection unit for detecting that, immediately after a vehicle crossing a bridge has exited from the bridge, another vehicle is not crossing the bridge; a determination unit for determining whether the weight of the vehicle satisfies a criterion; and a diagnosis unit that, when the detection unit has detected that no other vehicle is crossing the bridge and the determination unit has determined that the weight of the vehicle satisfies the criterion, diagnoses damage to the bridge on the basis of information representing free vibration generated in the bridge due to the crossing of the vehicle, thereby improving the precision of diagnosis when damage to a bridge is diagnosed on the basis of information representing free vibration generated in the bridge due to the crossing of a vehicle.

An automatic wall climbing type radar photoelectric robot system for damages of a bridge and tunnel structure, mainly including a control terminal, a wall climbing robot and a server. The wall climbing robot generates a reverse thrust by rotor systems, moves flexibly against the surface of a rough bridge and tunnel structure by adopting an omnidirectional wheel technology, and during inspection by the wall climbing robot, bridges and tunnels do not need to be closed, and the traffic is not affected. Bridges and tunnels can divide into different working regions only by arranging a plurality of UWB base stations, charging and data receiving devices on the bridge and tunnel structure by means of UWB localization, laser SLAM and IMU navigation technologies, a plurality of wall climbing robots supported to work at the same time, automatic path planning and automatic obstacle avoidance realized, and unattended regular automatic patrolling can be realized.

A system for monitoring a building structure is described. The system comprises a laser source which emits an infrared radiation and an interferometric arrangement which divides the radiation into an object beam and a reference beam. The object beam irradiates the building structure and is scattered by it, while the reference beam interferes with the scattered object beam so as to create a hologram of the building. The system also comprises a sensor which detects a sequence of holograms and a processing unit which reconstructs the evolution in time of deformations or displacements of the building by numerically processing the sequence of holograms. The system—being based on digital holography—offers various advantages compared to known monitoring techniques, for example techniques which make use of seismometers (possibility of remote monitoring, substantial space-time continuity of the monitoring, capacity for detecting a wider range of deformations and displacements).

Based on a defective state of a structure, a degree of soundness that indicates how much the structure is sound is determined. Information about a defective state of the structure that provides grounds for this determination is outputted.

The present invention proposes a method for identifying the spatial-temporal distribution of the vehicle loads on a bridge based on the DenseNet. The method includes five steps: firstly, mounting a plurality of cameras in different positions of a bridge, acquiring images of the bridge from different directions, and outputting video images with time tags; secondly, acquiring multichannel characteristics of vehicles on the bridge by using DenseNet, including color characteristics, shape characteristics and position characteristics; thirdly, analyzing the data and characteristics of the vehicles from different cameras at a same moment to obtain vehicle distribution on the bridge at any time; fourthly, continuously monitoring the vehicle distribution in a time period to obtain a vehicle load situation on any section of the bridge; and finally, integrating the time and space distribution of the vehicles to obtain spatial-temporal distribution of the bridge.

A derivation method includes: an acquisition step of acquiring time-series data including a physical quantity generated at a predetermined observation point in a structure as a response caused by a movement of a formation moving object formed with one or more moving objects on the structure; an environment information acquisition step of acquiring, as environment information, information on a structure length that is a length of the structure, a moving object length that is a length of the moving object, and an installation position of a contact portion of the moving object with the structure; a fundamental frequency derivation step of deriving a fundamental frequency of the time-series data based on the time-series data; a passing period derivation step of deriving a passing period during which the formation moving object passes through the structure based on the time-series data; and a number derivation step of deriving the number of the moving objects included in the formation moving object based on the environment information, the fundamental frequency, and the passing period.

A dynamic response at a designated position is derived based on a deflection amount normalized by a vibration component of the dynamic response, an amplitude ratio, which is a ratio of a first deflection amount that is the normalized deflection amount indicating a distribution of a vibration amplitude of the observation point to a second deflection amount that is the normalized deflection amount indicating a distribution of a vibration amplitude of a designated position, the vibration component of the designated position derived based on the vibration component and the amplitude ratio, and the static response of the designated position derived based on the time-series data and the estimated value.

A time point is acquired by steps including a data acquisition step of acquiring time-series data indicating a time change of a displacement of a structure based on a physical quantity generated at a predetermined observation point in the structure as a response caused by a movement of a formation moving object formed with one or more moving objects on the structure; a removing step of removing a vibration component included in the time-series data; and a time point acquisition step of acquiring an entry time point at which the formation moving object enters the structure and an exit time point at which the formation moving object exits from the structure, based on the time-series data after the vibration component is removed.

A first index value, which is an index value of a deflection amount of a structure generated at an observation point, and a second index value, which is an index value of a deflection amount at a designated position in the structure, are acquired based on the number of moving objects formed in a formation moving object, an entry time point, an exit time point, and environment information. An estimated value of the deflection amount of the structure at the designated position is derived based on time-series data measured at the observation point, the first index value, and the second index value.