Study On Dynamic And Static Disasters Of Artificial Island

After the second world war of the last century, human society entered the explosive development phase. The pure land space already could not satisfy the human production and living needs, so the human turned to vast oceans to expand living space. Since the1960s, the coastal countries such as Europe and the United States were actively exploring the island type pier construction pattern. Through artificial island construction, the safety development and better coordination function of the port was realized. After that Japan actively learned from the advanced experience of Europe and the United States and became the world’s largest construction artificial island of the world. Artificial islands had contributed important role to human development, comprehensive development and utilization of Marine resources and protect the waters ownership. Since the beginning of the21st century, our country’s artificial island projects were at an unprecedented speed rapid development. Most foundations of artificial islands were soft soil foundation. The characteristics of soft soil were high natural water content, great natural void ratio, low shear strength, high compressibility and poor permeability. In load the soft soil foundation is low bearing capacity, great settlement, big uneven settlement also, and long lasting. Thus the soft soil foundation is most common encountered in engineering practice and most difficult to manually handle. Although the study of land structure and its foundation has made a lot of achievements, but for nearly sea seismic geology, engineering geology, ocean currents, waves, sea, and climate characteristics of the artificial island engineering has not been deeply and systematic research. In this paper, the studies are emphasized on numerical analysis on dynamic and static disasters of artificial island located in deep soft soil layer with the finite element method. The main research contents are as follows:1. Based on the layering summation method and the finite element method, the final settlement and the consolidation settlement process of the artificial island section located in the deep soft soil layer are provided in this paper. The calculation results indicate that for the artificial island located in the deep soft soil layers with a wide range of filling, the final settlement of the finite element method calculation results are much more safe and reliable than those of layering summation method calculation results. The finite element method can fully reflect whole process of consolidation of the foundation, while the layering summation method, though with simple parameters, due to the natural defects, is not suitable for being used in the artificial island structure located in deep soft soil layers with a wide range of filling.2. Based on the finite element analysis software, total island consolidation settlement process is obtained. It indicates the characteristics of the artificial island structure located in the deep soft soil layers with a a wide range of filling:long consolidation time, even for decades; huge final settlement amount, to several meters; Drainage conditions have had a huge impact on the accuracy of the whole simulation process, and so on3. Through finite element calculation and analysis software, the numerical simulation for solidification process of bank protection have been carried on. The results indicate that the artificial island revetment under static consolidation will produce uneven settlement. uneven settlement of the absolute value is larger, but due to huge size little gradient caused by the uneven settlement.4. Through the FE-FD coupling numerical analysis method which is based on two phase saturated porous media Biot dynamic coupling theory, the lateral of the gentle slope of the artificial island which is located in the the deep soft soil layers under submarine earthquake liquefaction is calculated and analyzed. The results indicate that for the gentle slope of the artificial island undersea earthquake struck, gentle slope earthquake liquefaction is the principal factor which caused lateral and vertical movement. With the ground motion input increasing, the soil deformation and displacement of the surface increase sharply. With the increase of slope, the lateral produced by the liquefied layer increases sharply, sliding trend obviously, but small variations in the vertical subsidence, soil slope impact for lateral is greater than the vertical settlement.