胶东白垩系泥岩干湿循环抗剪强度试验研究

Study on Shear Strength of Cretaceous Mudstone under Dry-wet Cycles in Eastern Shandong

为研究胶东白垩系泥岩在干湿循环作用下的抗剪强度特征,选用胶东某铁路项目泥岩设计了一种干湿循环直剪试验对其干湿循环过程中的吸水率、凝聚力、内摩擦角以及岩样的破坏特征进行了研究。研究结果表明,随着干湿循环次数的增加,岩样的裂缝条数、裂缝宽度、裂缝深度不断增加,岩样中的裂缝开展具有不可逆性;干湿循环次数对岩样的吸水率影响较小,随干湿循环次数增加岩样的吸水率略有增加;干湿循环作用下,岩样的凝聚力、内摩擦角均有所降低,凝聚力降幅大于内摩擦角降幅。研究结论可为该地区的工程设计与施工提供指导和参考。

In order to study the shear strength of the Cretaceous mudstone under dry-wet cycles in Eastern Shandong,the water absorption,cohesion force,internal friction angle and failure characteristics were researched by direct shear test under dry-wet cycles.The test results show that with the increase of drywet cycles,the number of cracks,crack width and crack depth increase continuously.The crack development in rock samples is irreversible.The wet-dry cycles have little effect on the water absorption,and the water absorption increases slightly with the increase of wet-dry cycles.The cohesive force and internal friction angle of the rock sample decreased under the dry-wet cycles,and the cohesive force decreased more than the internal friction angle.The conclusions can provide guidance and reference for the design and construction of the project in this area.