【摘要】 研制的多功能静动力大型三轴试验系统是中国首台能够测量堆石料动态体变过程的大型三轴试验设备,构建了国内外70多座重要高土石坝筑坝堆石料静动力学性质试验数据库,揭示了静动荷载作用下堆石料的颗粒破碎规律及其影响因素、强度与剪胀(缩)非线性变化规律、地震残余变形发展规律、流变规律和饱和砂砾石料地震液化规律等。创建了高土石坝离心机振动台模型试验技术与试验结果分析方法,成功应用于高面板堆石坝与心墙堆石坝地震破坏机理和抗震加固方案有效性验证,得出的高土石坝地震加速度反应和地震残余变形定性与定量分布规律、高土石坝地震破坏机理结果得到了汶川地震后紫坪铺面板堆石坝和碧口心墙坝震害资料的证实。较好解决了目前高土石坝地面振动台模型试验与原型应力水平相差过大,常规离心机振动台模型试验因模型箱尺寸和振动台功率限制无法进行与原型应力水平一致的模型试验的难题。创建了土石坝溃坝离心模型试验技术与试验结果分析方法;研发了离心机大流量水流控制系统,实现了水流在地面普通重力场和超重力场之间的平稳过渡;研发了将模型布置和模型测量两部分有机融合为一体的专用溃坝模型箱,有效解决了管道流量计在坝体溃口流量变幅大和泥石流下无法正常工作的难题,实现了土石坝溃坝全过程溃口洪水流量的测量。上述研究成果为进一步提升高土石坝灾害预测与防控水平提供了重要技术支撑。更多还原

【Abstract】 The multifunctional large-scale triaxial experimental system invented by the author and his research team in Nanjing Hydraulic Research Institute(NHRI) is the earliest one in China. It can dynamically capture the volumetric strain during cyclic loadings. Using this system, rockfill materials in more than 70 worldwide earth-rock dams are tested, and a fruitful database is established. On this basis, the particle breakage during static and dynamic loadings as well as the influencing factors, the nonlinear variation of the strength and dilatancy indexes, the evolution of residual strains during dynamic loadings, the creep behaviors of rockfill materials and the liquefaction properties of sand-gravel materials are extensively explored. For the investigation of dynamic responses of high earth-rock dams, experimental techniques for centrifugal shaking table tests and the corresponding method for result interpretation are proposed and successfully applied in studying the failure mechanism of earth-core rockfill dams(ECRD) and concrete face rockfill dams(CFRD), and in verifying the effectiveness of reinforcement measures. The acceleration response and the residual deformation as well as the earthquake failure mechanism of earth-rock dams obtained by centrifugal shaking table tests are found in good agreement with the in-situ observations from Zipingpu CFRD and Bikou ECRD after great Wenchuan Earthquake. The use of a centrifuge effectively solves the problem that the stress within a conventional(ground) shaking table differs too much from that within the prototype, and the proposed experimental and analytical method makes the conditions that the stresseswithin the model and the prototype are approximately the sameunnecessary. Therefore, the centrifugal shaking table can be used to investigate the behaviors of vast masses like high earth-rock dams in spite of the limitation of capacities of the involved equipments. For the breaching mechanism of earth-rock dams, experimental techniques and corresponding analysis method are established. A flow discharge control equipment is devised for the centrifugal model test system so as to maintain a stable transition between the normal and high gravity fields for water flows. Meanwhile, a specific model container for dam breaching experiments that integrates the measurement system with the model arrangement system organically is fabricated, and such an arrangement effectively eliminates the deficiency of using pipeline flowmeters outside the model container under large variation of debris flow discharge.Therefore, an accurate measurement of flood discharge in the whole breaching process is attained by utilizing this measurement system. The above achievements and their engineering applications provide a technological support for improving the level of both the disaster consequence assessment and the safety control of earth-rock dams.更多还原