基于XFEM的土体水力劈裂模拟
Hydraulic fracturing simulation of soils based on XFEM
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摘要: 水力劈裂会对心墙堆石坝的安全造成严重的负面影响。宏观上,土体水力劈裂可看作是土体在水力楔劈作用下使局部裂缝(薄弱面)进一步发展的破坏过程。XFEM是一种可以有效描述裂缝的数值模拟方法。采用XFEM结合Biot固结理论,并对裂缝单元进行处理,从而以弥散式的裂缝状态和嵌入式的裂缝形态共同描述了土体的水力劈裂过程,并以一个模型算例和挪威Hyttejuvet坝的实际工程算例对方法进行了验证。该工作的成果有助于理解土体水力劈裂的成因和过程,可用于对土工结构物的流固耦合破坏分析。Abstract: Hydraulic fracture will have a serious negative impact on the safety of core rockfill dams. Macroscopically, the hydraulic fracture of soils can be regarded as the failure process of further development of local cracks (weak surfaces) under the action of hydraulic wedge splitting. XFEM is a numerical simulation method which can effectively describe cracks. In this study, XFEM combined with the Biot’s consolidation theory is used to deal with the crack element, so that the hydraulic fracturing process of soils is described by both the dispersive crack state and the embedded crack shape. The method is verified by a model example and a practical engineering example of Hyttejuvet dam in Norway. The results of this work are helpful to understand the cause and process of hydraulic fracture of soils, and can be used for fluid-solid coupling failure analysis of soil structures.