高聚物胶凝堆石料静动力学特性及抗震加固机理研究

This project is based on the requirement of the earthquake resistance and hazard mitigation of high earth rockfill dam in the high earthquake intensity area in the western China after "5.12" Wenchuan earthquake. In view of the shortage of the current aseismic measures on high earth rockfill dam, the mechanical characteristics and seismic effect of aseismic measures of high earth rockfill dam reinforced by polyurethane foam adhesive (PFA) will be studied. Combined with PFA characteristics, the method of sample preparation of PFA-reinforced rockfill materials will be put forward and the sample preparation equipment is designed. Static and dynamic triaxial tests will be conducted to study the static characteristics and the dynamic residual deformation characteristics of PFA-reinforced rockfill materials, and the static constitutive model taking into consideration of the influences of PFA on rockfill materials will be built. Combined with microscopic observation, the reinforcement principle of PFA on rockfill materials will be researched and revealed. The static constitutive model and the dynamic model of residual deformation will then be introduced to the geotechnical numerical analysis software so as to calculate the dynamic response of earth rockfill dam and evaluate the aseismic mechanism of high earth rockfill dam reinforced with PFA. The results can enrich the research on aseismic measures of high earth rockfill dams and the strengthening of rockfill materials, which has important social significance and practical value for the seismic prevention and disaster mitigation work on high earth rock dams in high earthquake intensity area of China.

本项目以“5.12”汶川地震后我国西部地震高烈度区高土石坝抗震减灾需求为背景，鉴于当前高土石坝抗震措施存在的不足，研究高聚物加固高土石坝抗震措施的力学特性与抗震效果。结合高聚物材料特性，提出高聚物胶凝堆石料制样方法并设计制样装置。开展静、动力三轴试验，研究高聚物胶凝堆石料的静力特性、动残余变形特性，建立考虑高聚物对堆石料影响的高聚物胶凝堆石料静力本构模型、动残余变形模型。结合细观观测与对比分析，探讨和揭示高聚物胶凝堆石料加固的细观机制。将高聚物胶凝堆石料静力本构模型、动残余变形模型开发到岩土数值分析软件中，开展高土石坝动力响应分析，评价高聚物加固高土石坝抗震措施的抗震效果，研究其抗震加固机理。研究成果将丰富高土石坝抗震措施和堆石料加固方面的研究，对我国地震高烈度区高土石坝的抗震减灾工作有重要的社会意义和实用价值。

我国已建、在建和拟建的高土石坝大多位于西部地震高烈度区，迫切需要开展高土石坝抗震加固措施的研究。进行了高聚物胶凝堆石料的静、动力学特性研究及高聚物加固高土石坝抗震措施的抗震效果评价，取得的研究成果：（1）开展了静力三轴剪切试验，研究了高聚物胶凝堆石料的强度特性和变形特性，分析了高聚物对准黏聚力、切线弹性模量和切线体积模量的影响，建立了修正的静力本构模型；（2）开展了动三轴试验，研究了高聚物胶凝堆石料的动模量和阻尼比特性，分析了围压、高聚物质量比、固结比和加载频率等对动模量和阻尼比的影响，提出了一个考虑高聚物质量比对最大剪切模量影响的修正双曲线模型，预测了归一化后的动剪切模量和剪应变之间的关系，给出了高聚物胶凝堆石料阻尼比的上、下界限；（3）研究了高聚物胶凝堆石料的残余变形特性，分析了循环荷载条件、围压、高聚物质量比和先期振动等对残余变形的影响，建立了考虑高聚物质量比对残余变形影响的修正沈珠江模型；（4）探讨了高聚物加固堆石料的加固机理；进行了加固前、后高土石坝三维动力响应分析，研究了高聚物加固高土石坝抗震措施对坝体应力分布、加速度响应和地震永久变形的影响，对该抗震措施进行了效果评价。通过本项目，揭示了高聚物胶凝堆石料静、动力学特性，验证了高聚物加固高土石坝抗震措施的抗震效果，研究成果为该抗震措施在高土石坝工程中的应用提供理论依据，具有重要的工程应用价值。