Stress Deformation of Construction Structures in Double-Tube Deep Shafts under Complex Conditions

[Objective] As a common form of underground structure in hydraulic geotechnical engineering, deep shafts have attracted widespread attention regarding their stress deformation and safety issues. This study takes a double-tube deep shaft near a reservoir in a water diversion project as the research subject, aiming to investigate its stress deformation characteristics and key influencing factors. [Methods] An integrated numerical modeling approach was employed, using multi-software platform interactive modeling to establish a 3D numerical model that accounted for complex geological conditions and reservoir proximity effects. Then, the influence patterns of key parameters, such as diaphragm wall segmentation, embedment depth, construction sequence, and segmented excavation height, were systematically analyzed. [Results] Diaphragm wall segmentation was identified as the most sensitive factor affecting the stress deformation of structures, with its segmentation scheme directly determining the distribution patterns of wall stress deformation. Embedment depth of the diaphragm wall ranked second in significance, while the construction sequence and segmented excavation height exhibited relatively minor effects on construction. [Conclusions] This study innovatively reveals the stress deformation mechanisms of double-tube shafts, providing crucial theoretical foundations and practical guidance for the safe construction of similar underground hydraulic engineering projects.