立足国内水利水电工程对绿色高效筑坝技术的发展需求,以遵义地区多座堆石混凝土坝工程实例为依托,结合理论分析、试验监测数据及工程运行情况,研究堆石混凝土坝不分区、不分缝或少分缝的结构型式。结果表明:堆石混凝土具备强度高、抗渗性好、水泥用量少、绝热温升低等优良特性,当坝基地质条件良好、坝体不需要设置沉降缝时,中低坝可采用全断面堆石混凝土且不分缝的结构型式。该结构型式能够简化施工工艺,减少施工干扰,加快施工进度,有利于质量控制。研究成果优化了坝体结构,简化了施工流程,可为堆石混凝土坝应用创新提供借鉴。

[Objective] Conventional rock-filled concrete (RFC) dams face challenges including complicated construction procedures, frequent construction interference, prolonged construction periods, and difficult quality control caused by material zoning and structural jointing. To overcome these limitations, this study optimizes the structural forms of RFC dams to improve construction efficiency and long-term operational safety, thereby providing technical support for the development of green and efficient dam construction technologies for water conservancy and hydropower projects in China. [Methods] Based on multiple completed RFC dam projects in Zunyi, an integrated approach was adopted, combining theoretical analysis, experimental tests, on-site monitoring, and engineering verification. First, the design specifications for material zoning and dam jointing of conventional RFC dams were reviewed and their limitations were assessed according to current hydraulic dam codes. Second, based on on-site core drilling, compressive strength tests, borehole water pressure tests, impermeability tests, and actual operation performance, the mechanical properties and impermeability of RFC were evaluated. Finally, mix proportion optimization tests of high-performance self-compacting concrete were conducted to develop an optimal proportion scheme with low cement content and low hydration heat. Temperature monitoring devices were then installed at different pouring layers and positions of ongoing dam projects to collect full-scale temperature data during construction and operation. Combined with simulation analysis, the heat absorption characteristics of rock aggregates and the temperature variation patterns of dam bodies were investigated to verify the rationality of the joint-free structural design. [Results] The actual compressive strength of RFC was more than 50% higher than the design value, and the impermeability grade reached W6. Its mechanical and impermeability properties met the service requirements of medium and low dams, enabling RFC to replace the conventional dam foundation bedding course and upstream impermeable layer. After mix proportion optimization of high-performance self-compacting concrete, the cement consumption of RFC was maintained at 60-80 kg/m³, resulting in low cement consumption and low hydration heat. Due to the heat absorption capacity of rock aggregates, the maximum adiabatic temperature rise of RFC ranged from 13.5 ℃ to 15.1 ℃. This effectively reduced the thermal stress of dam bodies and prevented thermal cracking. Overall, RFC exhibited superior comprehensive performance, including high compressive strength, excellent impermeability, low cement consumption, low adiabatic temperature rise, and low thermal stress. For medium and low RFC dams built on foundations with uniform lithology, intact rock masses, and no adverse geological structures such as faults and fracture zones, the conventional concrete bedding course and upstream impermeable layer could be removed. Therefore, a full-section joint-free RFC structure could be adopted. [Conclusion] The optimized dam structure effectively simplifies construction processes, reduces construction interference, and shortens the construction cycle. It also enhances the structural integrity of dams and reduces seepage risks, thereby addressing the limitations of conventional dam construction technologies involving material zoning and jointing. Future research should focus on improving the durability of RFC, including its impermeability, frost resistance, and crack resistance, to promote the application of non-zoning and joint-free structural forms in high dams and water conservancy projects in cold regions.