中文摘要：

随着海上丝绸之路战略的推进,中国在多个钙质岛礁上开展了工程建设。沉降变形是岛礁建设所面临的主要问题之一。由于钙质砂工程性质的特殊性,钙质岛礁的沉降变形过程和机理具有一定的独特性。然而,由于岛礁位置通常远离内陆,使用常规监测方法不易于开展岛礁沉降研究,有关钙质岛礁沉降变形的研究仍较少。本研究选取我国典型钙质岛礁,利用永久散射体干涉测量技术（Permanent Scatterer Interferometry,PSI）,准确反演了其沉降变形过程,并进行数值模拟分析。初步结果表明：钙质岛礁的沉降变形存在明显的时空分异特征,总体上,岛礁边缘沉降速率略大于其内部沉降速率,工程扰动区大于非扰动区;与其他吹填材料的区域相比,钙质岛礁沉降速率偏小,总体上稳定。但是沉降过程在时间上表现出明显的非线性波动特征,受工程建设和海洋水动力影响明显。考虑到钙质砂特殊的结构特征和复杂的颗粒破碎机理,钙质岛礁未来的沉降变形仍然存在一定的不确定性,需要进一步的过程监测和机理分析,以期为我国岛礁的安全建设提供科学支撑。

英文摘要：

A large number of constructions have been carried out on calcareous islands and reefs in China with the advancing of national policy of Maritime Silk Road.Due to the special engineering properties of calcareous sands,the calcareous islands and reefs exhibit distinct characteristics of subsidence and deformation processes compared with other regions with different materials.Traditional techniques are difficult employed in the remote maritime islands and reefs.A remote sensing approach,Permanent Scatter Interferometry（PSI）,is used to measure the subsidence processes of typical calcareous island-reefs.Further numerical analysis is carried out to analyze the characteristics of their settlement and deformation.Spatiotemporal variation of subsidence has been observed.In general,the subsidence rate along the boundary of island-reef is larger than that in the center.The disturbance of engineering construction plays an important role on the accelerating the ground deformation of island-reef.The coral calcareous island within the monitoring period is stable as shown from the smaller subsidence rate compared with other regions with different materials.The non-linear fluctuated subsidence processes are observed showing the close effects of engineering construction and marine hydrodynamics.The large of uncertainty of calcareous island deformation process is still a concern due to the special engineering properties of calcareous sands,such as the skeleton grain breakage behavior.Further monitoring and analyzing are necessary to facilitate the safety of engineering construction on the coral calcareous islands and reefs.