天然气水合物在海底沉积物中广泛存在，在作为未来能源的同时，其大量分解也会造成严重的地质灾害。论文借助离心模型试验技术，通过试验模拟水合物分解过程中产生高孔隙压力对海底沉积物稳定性的影响。论文中采用在土体中直接通过管道加载高孔隙水压的方法来模拟实际情况下的孔隙压力。试验采用高岭土进行试验，在制样过程使用盐水来配制高岭土膏，并且在试验中高岭土膏全部浸没在盐水环境中，以此来更加真实的模拟海洋沉积物的性质。模型采用25°、20°和15°三种角度的斜坡，并且每种角度下对不同厚度的土层进行试验。离心实验采用50g加速度，分级加载稳定后想模型向内通入超静孔隙压力。从离心试验结果中得到以下成果：1.天然气水合物分解会影响海底沉积物的稳定性，破坏形式可以分为海底滑坡以及气火山两种。 其中，诱发海底滑坡在时间上可以明显分为裂隙开展和滑坡发生两个阶段。海底滑坡的空间尺寸，如陡壁高度、滑移距离等，与斜坡的角度以及土层的厚度具有较好的相关性。2.水合物分解对沉积物层强度的主要影响之一是使得沉积物层中产生裂隙。裂隙一般由于高孔隙压力扩散而产生。裂隙不仅对沉积物内部的强度有削弱的作用，其通过使沉积物层断裂的方式对坡体的整体稳定性也有削弱作用。3.天然气水合物对海底结构物的作用在过程上可以分为两类，一种是初期产生的膨胀压力，一种是发展到一定程度后诱发滑坡所产生的土压力。前者在一般产生于水合物分解初期，并伴随有小规模的沉积物位移；后者由于滑坡体作用于结构物产生。滑坡对结构物的作用按照可否消散可以分为两部分，其一是长时间作用的有沉积物自重应力引起的土压力，其二是滑动过程中沉积物对结构物的冲击产生的作用力。

Natural gas hydrate is widespread in submarine sediments. As an important energy source in the future, gas hydrate can cause terrible geo-hazard because of its dissociation as well. This paper analysed the effect of high pore pressure, which is caused by the dissociation of hydrate, on the stability of submarine slope, by the means of geotechnical centrifuge test. The high pore pressure in real situation, is simulated by the way of pressing water into the soil model through the pipeline buried before. In the experiment, the geo-models are made of the kaolin mixed with salt water(salinity of the South China Sea), and the whole model is submerged by the salt water as well. The models are set on the slopes at 15°,20°, 25°. At each degree level, tests of different soil thickness are conducted. Water pressure loaded after the models have been at a 50-g centrifugal acceleration. From the centrifugal test results we can get the following achievements:1. The dissociation can affect the instability of submarine sediments, by the following two means: gas-volcanic and submarine slide. In terms of time, the process of slide can be divided into 2 parts, which are fissure development and landslide. There is a good relativity between the space sizes of slide( height of steep wall, length of slide, etc.) and the gradient of slope, as well as the thickness of the soil. 2. One of the most important effect caused by the dissociation is the fissure development. The fissure often developed with the expansion of high pore pressure. The fissure make effect on the slope not only by reducing the strength of sediments, but also by snapping the whole sediment layer. 3. The effect of gas hydrate on submarine structure, in terms of process, can be divided into 2 types. One is the inflation pressure, the other is landslide pressure. The former effect often is produced with a tiny displacement at the first of the dissociation progress, the latter effect is produced because of landslide. The force acted on the structure also can be divided into 2 parts. The first is the pressure of gravity stress of sediments, which can press on the structure for a long time. The second is the impact force of the landslide.