土石坝工程领域的若干创新与发展

我国高土石坝数量居世界之首,保证高坝大库建设与长期运行安全是国家经济和公共安全保障的重大需求。系统总结了长江科学院近年来在土石坝工程领域的若干创新与发展。提出了基于“旁压模量当量密度法”的粗粒料级配相似理论试验方法;介绍了研发的系列CT三轴仪,实现了粗粒料组构要素的定量测量;提出了三轴试验中加载板与试样之间由滑动摩擦变为滚动摩擦、整体式接触变为分散式接触的减摩新方法,研发了相关减摩装置;研制了大尺寸、高压力、微摩擦、刚柔复合加载的土工真三轴仪;揭示了粗粒料真实三维应力条件下的强度与变形变化规律、湿化与蠕变变形特性;构建了粗粒料三参量非线性K-K-G剪胀模型、六参数湿化模型、九参数蠕变数学模型及相应的参数确定方法;基于当量密度法的原创思想,提出了利用旁压试验间接确定超百米级深厚覆盖层现场密度的试验方法。上述研究成果可为高土石坝工程建设提供重要科技支撑。

Some Innovations and Developments in the Field of Earth-Rock Dam Engineering

China ranks top in the world in the amount of high earth-rock dam. To ensure the construction and long-term operation safety of high earth and rockfill dams is a major demand posed by national economic and public security. We summarize the major research progresses in the field of earth-rock dam engineering made by the Yangtze River Scientific Research Institute in recent years. Such progresses include: the test method of gradation similarity theory of coarse-grained material based on equalling density with pressuremeter modulus, the series CT triaxial apparatus for quantitatively measuring fabric of coarse-grained material, a novel friction reduction method in which the contact between soil and loading plate is changed from holistic contact to distributed contact and sliding friction to rolling friction, as well as its corresponding friction reduction devices. Moreover, true triaxial apparatus with large scale, high pressure, micro-friction and rigid-flexible composite loading has been developed. The variation law of strength and deformation and the wetting and creep deformation mechanism of coarse-grained materials under real three-dimensional stress have been revealed. The K-K-G nonlinear dilatancy model with three parameters, the wetting model with six parameters, the creep model with nine parameters and the corresponding parameter determination method have been established. In addition, in line with the original idea of equivalent density method, a test method for indirectly determining the field density of deep overburden with over 100 meters by pressuremeter test has been proposed. The above research findings offer crucial scientific and technological supports for the construction of high earth-rock dams.