棉花滩碾压混凝土重力坝设计

Design of RCC gravity dam of Mianhuatan Hydropower Station

棉花滩碾压混凝土重力坝最大坝高 111m ,坝顶长 30 8 5m ,共分为 7个坝段 ,其中 1、2坝段为左岸非溢流坝 ,3、4坝段为溢流坝 ,5、6、7坝段为右岸非溢流坝。设计中 ,坝基面及层面抗剪断值、各坝段基础抗滑稳定、非溢流坝体层面抗滑稳定安全系数符合规范要求 ;各坝段在各种基本荷载组合条件下 ,其应力分布是安全的 ;根据国内外工程实践 ,棉花滩大坝不设纵缝只设横缝 ,间距为 33～ 6 4m ;在防渗方面 ,采用二级配RCC防渗 ;同时 ,在施工中还采取了比较严格的温控措施 ,以保证RCCD的质量。

The Mianhuatan RCC gravity dam has its maximum dam height of 111 m and the crest length of 308.5 m. It is divided into seven dam sections, among which No.1 and No.2 sections are the left bank non overflow dam, No.5, No.6 and No.7 sections the right bank non overflow dam, and No.3 and No.4 sections the overflow dam. In the design, the shear strength of dam foundation surface and bedding surface, the stability against sliding of the foundation of different dam sections, and the safe coefficient of stability against sliding of non overflow dam all meet the requirements of the specifications. Under the combination conditions of various basic loads, the stress distribution of different dam sections is safe. By reference to the project practices at home and abroad, the Mianhuatan gravity dam only adopts transverse joints with the distance of 33 64 m but no longitudinal joint. In the seepage control, the second grade RCC seepage control measures have been taken. Meanwhile the strict temperature control measures have been adopted in the construction to guarantee the quality of the RCC dam.