This study systematically investigates the resistivity characteristics of unsaturated compacted loess with artificial slotting by the alternating current measurement method. The LCR digital bridge was employed to determine the resistivity of slotted samples different length, width, depth and quantity, so as to analyze the intrinsic correlation between fracture parameters and resistivity. The results indicate that the resistivity ratio (ρ/ρr) increases significantly with the growth of fracture length, width, depth, and quantity. Notably, when the fracture depth exceeds half the sample thickness, the resistivity exhibits an obvious nonlinear increase. This study confirms that resistivity can effectively characterize the structural damage and fracture development of compacted loess, providing theoretical support for monitoring the stability of loess subgrades and ground using the resistivity method in engineering practice.
Stability of support structures is critical to the overall safety of hydropower stations when hydraulic tunnels cross active fault zones. A representative engineering case of hydraulic tunnel that cross the active fault zone was investigated. A 3D numerical calculation model incorporating the fault-affected zone and the tunnel support system was established. The stress and displacement responses of the support structure were evaluated in four typical conditions, including normal operation, temperature decrease, fault creep, and fault dislocation. And the results indicate that when the fault displacement reaches 600 mm, the maximum compressive stress is generated on the left side of the steel pipe and significant stress concentration develops. The radial compressive stress of the surrounding concrete reaches 11.21 MPa. All calculated stresses remain below the corresponding strength limits, and a safety margin of 7.3
As an important water conservancy infrastructure, the seismic safety of small reservoirs is related to people’s lives and property, as well as the stability of regional water resources. A large number of small reservoirs in China generally have problems such as low design standards and insufficient maintenance, which are prone to damage under earthquake action. This article systematically reviews typical earthquake damage cases of reservoirs both domestically and internationally, summarizing the main types and mechanisms of damage such as dam cracks, leakage, settlement, dam foundation liquefaction, reservoir bank landslides, and damage to ancillary facilities. On this basis, a comprehensive strategy was proposed to enhance the seismic resilience of small reservoirs. Provide reference for seismic safety and sustainable management of small reservoirs.
Extreme rainfall is a core driver of mudslides. Debris flows pose a serious threat to residents’ lives, infrastructure and ecological environment. Source distribution assessment is a key support for disaster prevention planning in the region, while accurate source traceability and motion trajectory simulation are core technical requirements. Based on the data of the digital elevation model (DEM), the Flow-R model is used to integrate parameters such as slope and confluence convergence, and the energy conservation and propagation algorithms are used to identify debris flow sources and predict the movement distance. Finally, three directions are proposed to improve the accuracy of the model: optimizing DEM data, integrating multi-source information and parameter rate determination, so as to provide stronger technical support for regional disaster prevention and mitigation.
Through a case study, the effects of a deep foundation pit nearby the Metro Line 4 were analyzed. A three-dimensional finite element model was developed considering the excavation stages and local soil properties. The model predictions for tunnel horizontal movement and vertical settlement were validated against long-term monitoring data from the field. The findings indicate that lateral ground movement and vertical deformation increase with excavation depth but remain within allowable limits. Despite minor discrepancies between numerical and measured results, the overall trends agree well, confirming the reliability of the proposed model. This study provides practical guidance for tunnel safety assessment in urban areas affected by nearby deep excavation projects.
