三峡高重力坝技术实践综述

Technology practice summary of the Three Gorges high gravity dam

三峡工程重力坝最大高度181 m,目前已蓄水至设计水位。大坝设计和施工过程中,通过特殊地质勘探、多种稳定计算方法对比分析、综合工程措施解决左岸坝段深层抗滑稳定问题;布置多层大孔口解决大流量、多任务的泄洪要求,运用钢筋混凝土有限元方法计算孔口配筋;运用二次风冷骨料、个性化动态通水、表面保温等技术进行温控防裂;采用富浆混凝土防渗、预埋冷却水管等技术进行碾压混凝土施工;采用封闭抽排方案、无盖重固结灌浆技术进行坝基处理。分析了大坝运行过程中纵缝开度变化、水位影响下坝踵应力变化的规律,提出了高重力坝在纵缝结构整体性、坝踵应力与应力控制标准、强震作用下大坝破坏机理及抗震措施等方面有待进一步研究的问题。

The Three Gorges Project,with maximum dam height of 181m,has been designed for water level storage.During the design and construction period of the dam： ① Distinctive geological exploration,a variety of stability calculation method of comparative analysis and comprehensive engineering measures have been applied to solve the left bank dam stability against deep sliding;② Arranging multilayer outlets to satisfy flood discharge of large flow with multiple tasks,orifice reinforcement is based on FEM;③ Aggregate secondary-cooling,individual water filling system and surface heat preservation are adopted for temperature control and crack prevention of the dam;④ Rich slurry concrete permeability control and embedded cooling pipe are used in the construction of roller compacted concrete;and,⑤ Closed pump drainage and no cover load consolidation grouting are used for foundation treatment.We put forward the relevant problems needed to be further studied on the aspects of longitudinal joint structural integrity of the high gravity dam,dam heel stress and stress control criterion of dam,seismic damage mechanism by intensive earthquake and anti-seismic measures,etc.by analysis of longitudinal joint opening variation and the change rule of the dam heel stress due to the water level variation.