Abstract: A model of airport clearance with a variable-slope runway is proposed, and its analytical formula is studied to improve the efficiency and accuracy of building super elevation evaluation in the airport clearance area. First, an airport clearance 3D model is established according to the airport runway parameters. The plane limitation range of each limit surface is calculated by considering the influence of runway slope and airport grade on the obstacle limit surface. Then, the clearance elevation model is constructed, and an algorithm is designed to determine the type of limit surface where the point is on, and calculate the limit height. The constructed airport clearance 3D model and elevation model are applied to the actual study, which verifies the validity of the model, and the accuracy and speed of the clearance limit height calculation are improved. Furthermore, the visualization of the clearance model is realized based on Cesium, which is convenient for the staff to quickly judge whether the building exceeds the clearance limit.

Key words: simulation modeling, airport clearance model, variable-slope runway, mathematical model of clearance surface, clearance height model