Investigation Of The Scouring Effect On Lateral Load Capability Of Offshore Platform's Pile Foundation

Recently, marine petroleum exploration and exploitation has alreadily focused on satisfying the requirements of energy for the development of economy of our country and even the world. And it plays a key role in the progress of exploration and exploration about Offshore Jack-up Platform, which has many characters such as shallower driving depth and suitable for a variety of work environment and so on, comparing to ordinary work platform. And because of these characters, it is widely applied to drilling operations and workover operations in the depth of water less than a hundred meters. However, when it is being scour from ocean current to the soil around pile foundation of the platform, there may be some accidents for the declined horizontal bearing capacity of the pile foundation. Therefore, when this kind of platform is being scour from ocean current to the soil around pile foundation, there may be some accidents for the declining horizontal bearing capacity of the pile foundation. Therefore, it will produce a large influence to the security monitor platform to develop the pile foundation's research of the changing horizontal bearing capacity under scour. In this paper, the main researching works include:(1) It summaries research situation about horizontal bearing capacity of pile foundation on the basis of domestic and international scholars'studies and analyze research status on the pile foundation's scour. According to practical situation, it calculated the scour depth of pile foundation on these researches.(2) It analyzes the corresponding theory of p-y curve method based on the foundation beam theory of Winkler and gives a brief analysis of mathematical model on pile and interface element. According to these theories, it briefly scribes the computing progress of pile foundation's horizontal bearing capacity of FLAC3D and single pile's horizontal bearing capacity of group piles.(3) A sensitivity study is performed on deformation of single pile's model suffering horizontal loads from FLAC3D. And it includes various parameters: boundary effects, ratio of the pile's length to diameter, soil elastic modulus, mesh fineness, pile-soil adhesion and so on. And these parameters'analysis of sensitivity is made by comparing the results of model. According to the results of the sensitivity's analysis, it performs a numerical simulation analysis and selected calculating parameters based on the experimental research of Broms. Meantime, it makes a simulation analysis of the Brom's research. What's more, the good correspondence between the calculating results of models and field measurements indicates that the models of FLAC3D is suitable for simulating the deformation of laterally loaded pile in soft soil.(4) Combined with the data of the Jack-up platform, it selected some suitable scour depths and model parameters based on the sensitivity analysis. And the established models of FLAC3D are used to simulate and analyze the different deformation of laterally loaded pile in some kinds of condition such as without scour and maximum scour and so on. According to compare the model's results, it studies the influence for the different two scour depth to pile foundation's horizontal bearing capacity.