Interpretation and prevention plan for active faults in diversion line of Dadu River to Minjiang River Water Diversion Project

The Dadu River to Minjiang River Water Diversion Project is located in the core area of the Y-shaped intersection zone along the southeastern boundary of the Bayankara Block, where the regional terrain features significant elevation differences and active neotectonics.To address the seismic and faulting challenges of the project, this study based on geological surveys and seismic safety assessments, interprets active faults intersecting with the project, such as the Wulong, Shuangshi-Dachuan, Dayi, and Pujiang-Xinjin faults, using topographic and geomorphological features, geophysical exploration data, drilling and trenching data, and historical seismic events.By combining the relationship between seismic rupture length and magnitude with quantitative analogies and sliding rates, the potential magnitudes and maximum sudden displacements of these four active faults were estimated.The results indicated a maximum potential earthquake magnitude of 7.68, with a 100-year maximum horizontal displacement of 3.27 m.Mitigation measures included increasing tunnel lining thickness and reinforcement, reducing structural joint spacing, and installing expansion joints for pipelines across active faults.The research results can provide a reference for similar projects.