| Suction anchor has been widely used in marine engineering.The numerical simulation and theoretical research of its installation process are of great significance to guide engineering practice.However,due to its unique anchoring method,the installation process is often accompanied by the uplift of soil plug in the cylinder,which brings great troubles to the safe application of suction anchor.Therefore,it is of great guiding significance to the production practice of suction anchor in marine engineering by studying the influence law of pressure drop change rate on the height of plug uplift during the negative pressure generation process.This paper analyzes the working principle and installation process of suction foundation,studies the penetration resistance in Houlsby & Byrne theoretical calculation model,introduces the parameter of continuously changing permeability coefficient into Houlsby & Byrne theoretical calculation formula,obtains the improved theoretical formula of required suction,and establishes the theoretical formula of permeability coefficient changing with penetration depth.Based on the coupled Euler Lagrange method(CEL)of ABAQUS software,the soil plug phenomenon caused by the intermittent sinking process of suction anchor is numerically simulated,and the penetration resistance of the numerical simulation is compared with the improved theoretical formula,so as to verify the effectiveness and accuracy of the numerical simulation method.The effects of different load duration and interval on the sinking height and sinking speed of suction anchor are studied,and aiming at the effects of different length diameter ratio and thickness diameter ratio on the sinking height of suction anchor,when the length diameter ratio gradually increases,the uplift height of soil plug also increases;The greater the wall thickness of the suction anchor,the greater the uplift height of the soil plug inside the suction anchor.Using MATLAB,for the results of numerical simulation,the least square method is used to fit the surface,fit the height of soil plug,load duration and interval time,obtain the empirical formula of load duration and interval time for soil plug height,calculate the optimal load duration and interval time,and analyze the error.Therefore,when using intermittent penetration,proper selection of action time and interval time can effectively reduce the uplift height of the soil plug without increasing the installation time and achieve a more ideal final penetration depth. |
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