Analysis of resistance to uneven deformation of typical photovoltaic support in coal mining subsidence area

In this study, the impact of differential settlement in coal mining subsidence areas on the structural safety and operational performance of photovoltaic (PV) support structures was evaluated. Three-dimensional finite element models of fixed, horizontal single-axis tracking and flexible PV support structures were developed in ANSYS. Linear-gradient settlement was selected to represent ground inclination. The load-transfer paths, critical locations, and deformation adaptability of the three support types were compared. The results indicate that for fixed PV support structures, additional internal forces are mainly concentrated in the constrained columns. Mechanical response is strongly affected by both the support–settlement-gradient angle and the foundation constraint layout. The controlling critical inclination ranges from 17.5‰ to 19.2‰. Most load cases are governed by the column-top horizontal displacement limit. For horizontal single-axis tracking PV support structures, the strength-controlled and displacement-controlled critical inclinations are 31.8‰ and 17.5‰, respectively. However, the allowable height difference of the drive system limits the operation-controlled critical inclination to only 2.8‰. For flexible PV support structures, the prestressed steel strands are not the strength-controlled members within the analyzed range. In contrast, the Q235 end columns yield first. At this critical state, the controlling critical inclination is 18.3‰, and the column-top displacements remain within the code-specified limits. Fixed and flexible PV support structures exhibit comparable adaptability to the investigated inclination. In contrast, the horizontal single-axis tracking PV support structure is much more sensitive to foundation levelness and inter-column height differences. These findings provide a case-specific reference for comparing the deformation adaptability of the three investigated PV support systems under the prescribed linear-gradient settlement condition.