Northeast Frontier Railway Tender

DISPLACEMENT SENSORS: Installation of displacement sensors as per RDSO-BS 106 for measuring defections in the superstructure for various load case like (1) Test train at static state (2) Test train at traction effort case (3) Braking force (4) Acceleration at full speed/ maximum speed (5) Dynamic Augment.

WIRELESS ACCELEROMETER SENSORS: Installation of Tri-axial wireless accelerometer 2 sensors on bridge critical locations (ie. superstructure and substructure) as per RDSO-BS: 106 guidelines to identify and to record vibration data, frequencies, damping values using test train for various load cases like (1) Test Train at Static state. (2) Test train at Traction effort case. (3) Braking forces. (4) Acceleration at full speed/ maximum speed.

PROFESSIONAL FEE: Preparation and submission of final report from the Instrumentation data (Sensor) and Modal Analysis. A) DATA ANALYSIS: Sensor data from accelerometers, strain sensors and displacement sensors is acquired, Fast Fourier Transformation (FFT) plots using data acquisition. Software (Sensor Connect). Also, maximum displacement, strains at critical locations of bridge is required, tabulated from instrumentation data for dynamic load cases and in static condition for both test train with current axle load and higher axle load (Say 25T) for health monitoring of each span and finding impact on the bridges operating at different speed limits. B) OPERATIONAL MODAL ANALYSIS (OMA): Used to identify modal parameter (natural frequencies, 6 damping and mode shapes) of structures, model parameters will be calculated from the first set of measurement for model callibration. (C) NUMERICAL MODELING AND CALIBRATION: 3D numerical model is developed for each span with the existing geometry, material property, boundary conditions and loading to derive the theoretical/ actual deflection, stress and other parameters using ANSYS or any other FEM software. The model calibration is based on the OMA and other test results ie. static and dynamic strain, displacement and acceleration. (D) CONDITION ASSESSMENT AND PERFORMANCE EVALUATION: Using calibrated numerical model, develop bridge-vehicle interaction model to identify the impact of in-situ axle loads and speed limits on the super and sub structure. Use 3D Non-linear soil-structure interaction, if necessary, and investigate the safety and serviceability of the well foundation. (E) FINAL REPORT & RECOMMENDATION: Prepare final report including recommendations for the allowable axle load and speed limit.