Physical Simulation And Relevant Studies Of The Alluvial System And Deltas

On the Basing of efforts derived particularly from the works of the predecessors, the theory and methodology for simulating alluvial system-delta sedimentation are set forth systematically in this thesis. The basic and the applied simulating experiments of the forming process of the alluvial fan, river, delta, and fan delta are made. The basic rules and the working systems of the physical simulating experiment of the clastic sedimentation are established. Three sections including six chapters are involved in the thesis. In chapterl , the developing course of sedimentation simulating technology is systematically reviewed. It states that the developing course can be divided into three stages, The important researches of each stage and the creative achievement of distinguished experts arc summarized. It also expatiates the present developing situation of the sedimentation simulate in our country. The features of the experimental instruments of the sedimentation simulation Lab of CNPC are particularly introduced. The five developing tendencies of sedimentation simulation are analyzed. The model of the sedimentation simulating experiment, archetype geometric similarity, moving similarity, dynamical similarity, and the three comparative rules which include suspending similarity, grain movement similarity and transformational similarity of river course ,derived from of the three above similar theories, are basic theories of physical simulation of clastic sedimentation process. the major method of clastic sedimentation simulation research, that is natural model method and compare ruler model method, is stated. Combining with working experiences in many years, the thesis puts forward the main steps of the physical simulation of clastic sedimentation process. This is the important content of the second chapter in the thesis. Alluvium fan is an important kind of coarse grain sedimentation. Through simulating experimentation of the alluvial fan forming process, It sets forth the important function of flow and grain size in the formation of alluvial fan and the effect of the slope of alluvial fan. The depending relation between the slope of alluvial fan and the flow direction is analyzed. And then the evolutional process of the river course on the alluvial fan can be processed as Markov process. All of the above indicates the major work of the third chapter in this thesis. The simulation experiment of river sedimentation course is a keystone of the thesis. In chapter 4, through the experiment of developing process of sand dune in channel the evolutional disciplinarian of widening-reach channel bar, the evolutional tendency of Bai lizhou in Yangtse River, the simulation experiment of point bar in meandering river, the transport process of the sedimenton in the convergence of river course as well as the research in band river while the bed is fixed, the common rule of forming course and controlling factor are discussed. Some new worthwhile perceptions are put forward. In chapter 5, the simulated experiment of the Chang 6 delta forming procession in Erdos basin Jing-an oil field is carried through. Growth procession of the delta is detailed. The main controlling factors of evolution of delta in Chang 6 are put forward. The vertical section ,horizontal section and plane distribution of experimental results in diverse time units and different locations are seriously analyzed. These results are compared with the characters of the archetype sand body in distribution of grain, change of thickness and distribution of facies. It emphasizes some new perception that u...