Main Participants: WANG Haibo, GUO Shengshan, LI Shiping, ZHANG Cuiran, LI Chunlei, LI Haifeng, YOU Ling, LIANG Hui, ZHAO Lijun, HE Junrong, CHEN Houqun, TU Jin
The seismic safety of large elevated aqueducts in areas with high seismic intensity presents a significant challenge in the construction and operation of long-distance water transfer projects in southwest China. The seismic safety analysis and assessment of aqueducts in such areas involve multi-disciplinary theories and innovative technologies related to seismic ground motion input, dynamic interaction between aqueduct structure and internal water bodies, nonlinear dynamic responses of structures, foundation-structure interactions, seismic isolation techniques for aqueducts, etc. The research, based on China’s “13th Five-Year” National Key R&D Program and the seismic safety review of the Minghe Aqueduct in the middle route of the South-to-North Water Diversion Project, has conducted in-depth studies in relevant fields, achieving significant results which have been applied in the Water Diversion Project for Central Yunnan Province and the middle route of the South-to-North Water Diversion Project.
· Having established a statistical model for the nonstationary response spectra of seismic ground motion, developed a method for synthesizing seismic ground motion time by matching target nonstationary response spectra, and generated artificial seismic waves with nonstationary amplitude and frequency.
· Having delved into the dynamic interaction between large thin-walled aqueducts and water through large-scale shaking table dynamic model tests and with theoretical analysis methods, exploring practical methods for simulating the dynamic response of water in large aqueducts in seismic analysis.
· Having examined the elevated large aqueduct structure of the Water Diversion Project for Central Yunnan Province, developed numerical simulations for the dynamic interaction between the foundation, aqueduct structure and water, developed numerical models and large-scale parallel computational methods and software for efficient dynamic nonlinear integral analysis of large-scale elevated aqueducts, which have been applied to the seismic safety review of the Minghe Aqueduct in the middle route of the South-to-North Water Diversion Project.
· Having developed self-resetting support with seismic isolation effects for large elevated aqueducts.
· Having conducted research on the impact of pre-stress arrangement of the aqueduct structure on its seismic resistance.
· Having proposed an enhanced method for selecting and synthesizing seismic ground motion input time histories, accurately reflecting the actual nonstationary characteristics of ground motion, which could be applied to nonlinear seismic response analysis of aqueduct structures.
· Having quantitatively determined fluid impact and convection effect within aqueducts through model testing, validating the effectiveness of the aqueduct-water interaction model and the feasibility of its application to the anti-seismic design of aqueduct engineering projects.
· Having developed a large-scale parallel computing software for nonlinear wave analysis based on relevant theories, taking into account the interaction among pile foundations, aqueduct piers, aqueduct structures and water.
· Having launched a self-resetting support system with a sloped guide with good seismic isolation and self-resetting function to effectively prevent aqueduct displacement during earthquakes.
· Having established a model for evaluating prestress loss of aqueduct structure during operation to enhance seismic safety assessment.
The research findings have been applied in the preliminary design and technical implementation of the Jifu Village aqueduct in the Water Diversion Project for Central Yunnan. The innovative seismic analysis methods and safety assessment techniques for large elevated aqueducts in areas with high seismic intensity, having been applied in the seismic review of the Minghe Aqueduct in the middle route of the South-to-North Water Diversion Project and primed for widely application in other aqueducts seismic design in large scale water transfer projects in China, has significantly advanced seismic design for large aqueducts in areas with high seismic intensity and promoted superior construction standards for water transfer projects, yielding substantial socio-economic benefits.
Figure 1 Large-scale Shaking Table Dynamic Model Tests
Figure 2 Three-dimensional Finite Element Integral Model of Aqueduct and Foundation
Figure 3 Self-resetting Seismic Isolation Support for Large Elevated Aqueducts
