巨厚覆盖层上高闸坝沉降控制关键技术研究与实践

Study on Key Technology of Settlement Control for High Sluice Dam on Gaint-thick Overburden

多布水电站是我国复杂巨厚覆盖层上最高闸坝,覆盖层厚度为360m,最大坝高54.3m,针对复杂巨厚覆盖层高闸坝的沉降控制关键问题,研究提出了能够保证机组稳定运行和结构安全的不均匀沉降和沉降标准,不同水工建筑物差异化地基处理技术、混凝土分区限高差浇筑沉降控制技术和随层浇筑连续不间断变形监测等系列关键技术.提出了考虑应力路径的广义塑性本构模型,反映覆盖层土体的强度非线性、剪胀非线性特征,适应复杂的应力加载路径,客观反映土体的超固结特性,结合数值模型计算结果与现场监测数据验证,所采用的本构模型和计算方法是有效和合理的.

Duobu Hydropower Project(HPP)is built with the highest sluice dam on the complex giant-thick overburden in China.The thickness of the overburden is 360 m and the maximum dam height is 54.3 m.With regard to the key problems of settlement control of dams built on complex giant-thick overburden,the Paper proposes the nonuniform settlement and settlement standard capable of ensuring the stable operation and structural safety of the Units,different foundation treatment technologies for different types of hydraulic structures,settlement control technologies for partition concrete placement by confining level difference as well as key technologies for continuous deformation monitoring series with layered con-crete placement.The Paper also proposes generalized plastic constitutive model considering the stress path,which can reflect the nonlinearity of the strength of the overburden soil mass,the non-linear characteristics of the dilatancy and loading path adaptable to the complex stress,and reflect the over consolidation charac-teristics of the soil mass in an objective manner.In combination with validation study on the results of numerical model calculation and site monitoring data,the constitutive model and calculation method applied are effective and reasonable.