【摘要】 生物成因的珊瑚礁灰岩明显有别于传统意义的地质岩体,通过对礁灰岩进行霍普金森压杆(SHPB)冲击试验,研究南海珊瑚礁灰岩的动力破碎形态和动态力学性能。研究表明:垂向沉积演化发育的强度高且致密的礁灰岩,具有较高的弹性波速和单轴抗压强度;单轴冲击荷载下礁灰岩主要发生沿轴向的张拉破坏,且主要发生在生物组分、珊瑚砾块与珊瑚藻的胶结面等薄弱部位;生物成因的礁灰岩的动态应力-应变模型与一般岩石不同,存在较明显的压密阶段,礁灰岩的动态抗压强度对应变率表现出更强的敏感性;礁灰岩的能耗密度、入射能和动态抗压强度呈线性关系,与应变率呈乘幂函数关系。珊瑚礁灰岩的动态力学性能对岛礁工程实践中的爆破开挖、冲击破碎和防震抗爆设计有重要的指导意义。更多还原

【Abstract】 Biogenic coral-reef limestone is distinct from the traditional geological rock. In this study, Hopkinson pressure bar tests on coral-reef limestone are conducted to investigate the dynamic fracture morphology and dynamic properties of coral-reef limestones of the South China Sea. Research results show that the high-strength and dense coral-reef limestone with vertical sedimentary evolution has high elastic wave velocity and uniaxial compressive strength; the tensile failure of coral-reef limestone mainly occurs along axis under uniaxial impact loading, and mainly in the weak parts such as the cementation surfaces between the bio-component, coral gravel and coral algae; the dynamic stress-strain model of reef limestone has obvious compaction stage, which is different from normal rock; the dynamic compressive strength of coral-reef limestone is more sensitive to the strain rate than that of normal rock;the energy density of the coral-reef limestone is linearly related to the incident energy and the dynamic compressive strength, and it shows a power function relationship with the strain rate. The dynamic mechanical properties of coral-reef limestone has an important guiding significance for the reef engineering practices such as blasting excavation, impact crushing, earthquake proof and antiknock design.更多还原