Study on deformation–time law of airport runway during horizontal directional drilling

The study focuses on the lack of basis for surface deformation in airport navigational lighting aid projects using horizontal directional drilling (HDD) technology. Taking Guanghan airport as an example, a runway test section was constructed to explore the time-series law of cement surface deformation during HDD installation of navigational lighting. Small-calibre (10 cm) HDD technology was used to simulate the actual process and verify its feasibility in the airport. Micro-deformation monitoring radar, ground-penetrating radar and a heavy weight deflectometer were employed for displacement monitoring and detecting the reaction characteristics of the base layer to reveal the intrinsic driving force of the runway surface deformation. The results showed that the intrinsic cause of surface deformation was structural changes in the runway structural layer during construction. The settlement, observed as a manifestation of surface deformation during HDD, could be divided into three stages – sharp settlement, slow rebound and stable settlement. After completion of construction activities, the cumulative displacement remained stable within −1.4 mm while the maximum change rate of the impact stiffness modulus did not exceed 1%, thereby meeting the requirements of airport flight operation management.