地震荷载下高拱坝坝体裂缝动态扩展研究

There exist a certain range of cracks on the surface and inside dam body of high arch dams, located in the Western China with strong ground motions, such as Xiaowan, Ertan, Jinping etc. during construction or operation period. These cracks, once encountering strong earthquake, will urge the development of dam damage, thus resulting in serious secondary disaster. On the foundation of seismic response analysis model of high arch dams and previous research on dynamic crack propagation of gravity dams, based on continuous–discontinuous medium mechanics theory, a new approach of two stage progressive prediction of crack propagation is put forward on the basis of Damage Mechanics Model (DMM) and Virtual Fracture Contact Mechanics Model (VFCMM). Consequently, nonlinear dynamic analysis model of crack propagation prediction of a high arch dam is established under the earthquake. In view of requirements of small element size and enormous calculation scale in the study of crack propagation of a high arch dam, the cloud computing platform is constructed according to domain decomposition parallel computation algorithm. Therefore, the dynamic test data of the concrete material is utilized to study the fracture and expansion mechanism of the concrete at the crevice of the high arch dam body under seismic load. The research is of certain value on promoting the development of seismic design and analysis of high arch dams, and provides reference for earthquake disaster prevention and reduction of high arch dams in strong earthquake area.

位于我国西部强震区的高拱坝，如小湾、二滩、锦屏一级等大坝施工期或运行期在坝体表面以及坝体内部出现了一定范围的裂缝。这些裂缝一旦遭遇强震，将促使坝体损害，由此可能引发严重的次生灾害。本项目拟在高拱坝地震响应动力分析模型和前期重力坝裂缝动态扩展研究的基础上，基于连续-不连续介质力学理论，提出损伤力学与虚拟裂缝接触力学模型两阶段递进预测裂缝扩展的思路，建立地震荷载下高拱坝坝体裂缝动态扩展预测的非线性动力分析模型。针对高拱坝裂缝扩展研究要求单元尺寸小、计算规模庞大的特点，构建基于区域分解并行算法的云计算平台，结合混凝土动态材料试验数据，研究地震荷载下高拱坝坝体裂缝缝端混凝土的破裂扩展机理。研究成果对推动高拱坝抗震设计分析理论具有一定价值，为指导强震区高拱坝抗震防灾减灾提供参考。

位于西部强震区的高拱坝，如小湾、二滩等大坝施工期或运行期在坝体表面以及坝体内部出现了一定范围的裂缝。一旦遭遇强震，这些裂缝将促使坝体损坏，由此可能引发严重的次生灾害。本项目建立了地震荷载下高拱坝坝体-裂缝-库水-地基体系非线性动力分析模型，考虑了坝体-库水相互作用、横缝开合变形、地震动不均匀输入、地基辐射阻尼效应、以及裂缝界面的复杂状态；基于连续介质的损伤力学模型与非连续介质的虚拟裂缝接触模型，建立了两阶段预测裂缝的动态扩展分析模型；自主研发了基于区域分解法的高性能并行计算程序，与国家超级计算中心合作，构建基于互联网的云计算平台。研究了地震荷载下高拱坝坝体裂缝扩展，研究成果对地震荷载下高拱坝安全状态评估具有参考意义。