A Peridynamic Approach to Investigate Ground Fissures Triggered by Groundwater Withdrawal: A Case Study of Longyao (Hebei), China

Ground fissures induced by groundwater withdrawal are an important geological hazard in many plains and sedimentary basins. In Longyao, China, long-term groundwater exploitation has caused continuous groundwater level decline, land subsidence, and stronger ground-fissure activity. This process includes both continuous deformation and crack propagation, which are difficult to describe with traditional local continuum methods. In this study, peridynamics is used to simulate the formation and evolution of ground fissures induced by groundwater withdrawal in Longyao. First, the theoretical basis of peridynamics is reviewed, including governing equations, boundary conditions, and damage modeling. Then, a numerical model is established to describe aquifer system compaction, differential settlement, and fissure propagation under groundwater withdrawal. groundwater level decline is introduced through pore-pressure change, and a combined tension-shear damage criterion is used to describe crack initiation and propagation. A two-dimensional simplified model is used to analyze the effects of porosity, density, Young’s modulus, cohesion, and internal friction angle. The results show that Young’s modulus mainly controls settlement, while cohesion and internal friction angle mainly control fissure development and stability. Among these parameters, the internal friction angle has the strongest effect on fissure extent and model response. Based on the simplified analysis, a three-dimensional model is further built for Longyao, and both calibration and validation are carried out using field data and InSAR records. The results show that the model can reasonably reproduce differential settlement and fissure development under continuous groundwater level decline. The simulated results agree with the observed deformation in both magnitude and trend, indicating that the model is applicable to this case. Overall, this study shows that peridynamics provides an effective method for analyzing the coupled process of compaction, settlement, damage, and fissure evolution under groundwater withdrawal, and the results provide a basis for understanding ground-fissure development in Longyao.