首页|循环荷载下珊瑚礁灰岩孔隙结构演化分析

循环荷载下珊瑚礁灰岩孔隙结构演化分析

扫码查看
珊瑚礁灰岩力学行为的复杂性为"一带一路"和"海上丝绸之路"的建设带来挑战.利用基于原位CT扫描的三轴试验设备,定量评估了珊瑚礁灰岩在变幅循环荷载下的损伤演化特征.采用CT扫描和数字图像分析技术从细观上研究了珊瑚礁灰岩在不同应力状态下的结构变化.结果表明:珊瑚砾屑灰岩的割线模量随着压密和损伤的演化呈现先增大后减小的趋势,而弹性模量在压密阶段呈现减小的趋势;珊瑚礁灰岩内部孔隙的尖端在外荷载下会发生应力集中,裂纹最先在孔隙率最大且孔隙结构最复杂的区域扩展;根据裂纹在3维空间中的分布特征和切片分析可知,试样在围压为6 MPa的循环荷载下发生以剪切为主的张-剪破坏.研究结果为岛礁工程建设中围岩的安全稳定性评价提供了参考.
Evolution Analysis of Pore Structure of Coral Reef Limestone Under Cyclic Loading
The complexity of the mechanical behavior of the coral reef limestone induces challenges to the construction of the projects for the Belt and Road Initiative and the Maritime Silk Road.In this paper,the damage evolution characteristics of the coral reef limestone under the variable amplitude cyclic loading are quantitatively evaluated based on the in-situ CT scanning tri-axial test equipment.The structural changes of the coral reef limestone under different stress conditions are studied by the CT scanning and the digital image analysis technique.The results show that the secant modulus of the coral gravel limestone in-creases first and then decreases with the pressurization and evolution of the damage,while the elastic modulus decreases in the pressurization stage.The stress concentration occurs at the tip of inner pores of the coral reef limestone under the external load,and cracks expand first in the area with the largest porosity and the most complex pore structure.According to the distri-bution characteristics of cracks in the three-dimensional space and the slice analysis,the specimen under the cyclic load of 6 MPa occurs the tension-shear failure mainly with the shear.The research results provide a reference for the security and stabili-ty evaluation of surrounding rock in island and reef engineering construction.

CT ScanningCyclic Loading and UnloadingCoral Reef LimestonePore Network ModelLayer-by-Layer Porosity

贾西贝、孟庆山、吴凯、宋小龙

展开 >

武汉理工大学土木工程与建筑学院,武汉 430070

中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉 430071

中国科学院大学,北京 100049

CT扫描 循环加卸载 珊瑚礁灰岩 孔隙网络模型 逐层面孔隙率

2024

土工基础
湖北省土木建筑学会,中国科学院武汉岩土力学研究所,武汉市土木建筑学会

土工基础

影响因子:0.238
ISSN:1004-3152
年,卷(期):2024.38(6)